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Fruits and vegetables (FV) are important components of a healthy diet. They usually have low energy density and are sources of many vitamins, minerals and other bioactive components that bring health benefits( 1 – 3 ). According to WHO, low consumption of FV is one of the top ten risk factors for global mortality. Their adequate intake reduces the risk of non-communicable chronic diseases and also prevents and corrects multiple micronutrient deficiencies, especially in low- and middle-income countries( 1 , 2 , 4 ). Despite existing strategies and campaigns such as the ‘global strategy of food, physical activity and health’ and ‘5 a day’ which aim to increase the consumption of FV( 5 , 6 ), FV intake is still low among individuals of all ages in comparison with the current recommendation (400 g/d)( 6 – 8 ). Furthermore, several studies have found that this scenario of low consumption is especially common among children and adolescents from low-, middle- and high-income countries( 9 – 11 ). For instance, the literature shows that many Brazilian adolescents do not eat enough FV( 12 – 14 ). There is growing evidence that major behavioural and biological risk factors arise early in life and continue to have a negative impact over the subsequent years( 1 ). In addition, studies assessing eating habits suggest there are critical aspects during adolescence that have an impact on chronic diseases, such as the development of risk factors during this period and their potential stability throughout life( 1 , 15 – 17 ). The latter could be measured through tracking analyses, which assess the stability of a certain outcome variable over a period of time. These analyses involve the maintenance of a relative position within a distribution of values over time( 18 – 20 ). Also, the study of the dynamics of consumption towards a less or more healthy direction may be important in predicting the development of a disease. In high-income countries, there are several studies reporting longitudinal trends of consumption of FV( 15 , 21 – 28 ). However, we could not find studies assessing this item among low- and middle-income countries, where this information has become relevant for the nutrition transition phase that is taking place in those settings( 1 ). Therefore, the purpose of the present study was to examine the stability and changes in FV intake of urban Brazilians adolescents over a 3-year period. A greater knowledge of these issues will be useful for the development of actions to promote healthful eating habits during this life stage.

PurposeTo evaluate the associations between family socioeconomic trajectories from 0 to 11 years of age and risk factors for noncommunicable disease at 15 years.MethodsIndividuals born in the city of Pelotas, Brazil, in 1993 are part of a birth cohort study. Socioeconomic position, collected at birth and at 11 years of age, was our main exposure. Risk factors for chronic disease were collected at 15 years. Body mass index was transformed into Z score using the World Health Organization standard. Transport and leisure-time physical activity, smoking, and alcohol consumption were assessed by self-report. Blood pressure was measured using a digital sphygmomanometer.ResultsOf 5,249 cohort members, 85.7% were located at the 15-year follow-up visit. Rich adolescents were more likely to be overweight, be obese, and not use active modes of transport to school. Poor adolescents were more likely to smoke. In relation to socioeconomic trajectories, the odds of obesity were 46% higher among those who were “always rich” compared with those who were “always poor”; the odds of use of an inactive mode of transportation were 326% greater among the “always rich” than the “always poor,” whereas the reverse was observed for smoking (odds of 200%). The “always rich” had one-half the odds of walking or cycling to school compared with those who became wealthy in the studied period.ConclusionsAdolescent socioeconomic position is a stronger determinant of risk factors for noncommunicable diseases than socioeconomic trajectories. However, trajectories do matter, particularly in terms of use of active transportation to school.

PurposeWe explored predictors of nutritional status change from 11 to 15 years of age by analyzing prospective data.MethodsWe collected data at 11 and 15 years of age from individuals born in 1993 in Pelotas, Brazil. We assessed nutritional status using body mass index (BMI) for age in z-score according to the World Health Organization 2007 standards. Independent variables collected at 11 years of age were socioeconomic position, adolescent's perception of own weight, body dissatisfaction, and weight loss dieting.ResultsOf the 4,032 adolescents whose nutritional status could be evaluated in the two follow-ups, 93% maintained their nutritional status classification from 11 to 15 years. A total of 102 (2.8%) became obese and 181 (4.5%) ceased to be obese in the 4-year period. The prevalence of obesity decreased from 11 to 15 years of age in both boys and girls. Low-income girls were more likely to become obese from 11 to 15 years of age compared with high-income ones. Among boys, those with high income were more likely to cease being obese compared those with low income. Those who perceived themselves to be obese, who wished to have a smaller silhouette, and who were on diets to lose weight were more likely to become obese or to achieve a normal BMI category at 15 years of age.ConclusionsBMI tracks strongly in early adolescence. This finding suggests that interventions to more effectively change nutritional status should be implemented in childhood and should consider emotional aspects as well as social and biological ones.

Purpose To evaluate the prospective association between leisure-time physical activity practice at 11 years of age and incidence of school failure from 11 to 15 years of age. Methods The sample comprised >4,300 adolescents followed up from birth to 15 years of age participating in a birth cohort study in Pelotas, Brazil. The incidence of school failure from age 11 to 15 years was calculated by first excluding from the analyses all subjects who experienced a school failure before 11 years of age, and then categorizing as "positive" all those who reported repeating a grade at school from 11 to 15 years of age. Leisure-time physical activity was measured using a validated questionnaire. Results The incidence of school failure was 47.9% among boys and 38.2% among girls. Adolescents in the top quartile of leisure-time physical activity practice at 11 years of age had a higher likelihood of school failure (OR: 1.36; 95% CI: 1.06, 1.75) compared with the least active adolescents. In adjusted analyses stratified by sex, boys in the top quartile of leisure-time physical activity practice at 11 years of age were also more likely to have failed at school from age 11 to 15 years (OR: 1.60; 95% CI: 1.09, 2.33). Conclusions Adolescents allocating >1,000 min/wk to leisure-time physical activity were more likely to experience a school failure from 11 to 15 years of age. Although this finding does not advocate against physical activity promotion, it indicates that excess time allocated to physical activity may jeopardize school performance among adolescents.

Background Although there is longstanding evidence of the short-term benefits of promoting rapid growth for young children in low-income settings, more recent studies suggest that early weight gain can also increase the risk of chronic diseases in adults. This paper attempts to separate the effects of early life weight and length/height gains on blood pressure, body mass index (BMI), sum of skin folds and subscapular/triceps skin fold ratio at 14–15 years of age. Methods The sample comprised 833 members of a prospective population-based birth cohort from Brazil. Conditional size (weight or height) analyses were used to express the difference between observed size at a given age and expected size based on a regression, including all previous measures of the same anthropometric index. A positive conditional weight or height indicates growing faster than expected given prior size. Results Conditional weights at all age ranges were positively associated with most outcomes; each z-score of conditional weight at 4 years was associated with an increase of 6.1 mm in the sum of skin folds (95% CI 4.5 to 7.6) in adolescence after adjustment for conditional length/height. Associations of the outcomes with conditional length/height were mostly negative or non-significant—each z-score was associated with a reduction of 2.4 mm (95% CI −3.8 to −1.1) in the sum of skin folds after adjustment for conditional weight. No associations were found with the skin fold ratio. Conclusion The promotion of rapid length/height gain without excessive weight gain seems to be beneficial for long-term outcomes, but this requires confirmation from other studies.

The aim of this study is to describe the methodology of the 2004-2005 follow-up visit of the 1993 Pelotas (Brazil) birth cohort. All children born in Pelotas in 1993 and whose mothers lived in the city at that time were eligible to be enrolled in a longitudinal study. Between July 2004 and March 2005, all cohort participants were sought for a follow-up visit. Several strategies were used to help trace cohort members, including a census of the city's schools and a census of all households in the municipality. The Mortality Information System was monitored in order to identify deaths among cohort members. Of the 5,249 cohort members, 4,452 were interviewed in 2004-5. When added to the 141 deaths, these represent 87.5% of the original cohort. In spite of the logistic and financial difficulties, it is possible to carry out prospective studies with long-term follow-up in the Brazilian context.

Evidence has shown the negative effects of unsupervised diets and those with excessive calorie restriction. The aim of this study was to determine the proportion of adolescents engaging in weight loss dieting and associated factors. This was a cross-sectional study of 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil, in 1993. The outcome was defined as adolescents that reported having practiced some type of weight loss dieting in the previous 12 months. Prevalence of such dieting was 8.6% (95%CI: 7.7;9.4), and was higher in girls. Elevated maternal body mass index (BMI) was associated with dieting among girls. The adolescent's and parents' view of the adolescent's weight, excess weight, and consumption of diet or light soft drinks were associated with adolescent dieting. There was a positive association between dieting and socioeconomic status. The findings provide important backing for policies aimed at improving adolescents' diet, since they express a major concern over weight and thus a significant percentage of individuals with erroneous and unhealthy behaviors. Evidências mostram efeitos negativos de dietas sem orientação e de alta restrição calórica. O objetivo do estudo foi determinar o percentual de adolescentes que realizaram regime de emagrecimento e os fatores associados a este comportamento. Estudo transversal incluindo 4.452 nascidos em Pelotas, Rio Grande do Sul, Brasil, no ano de 1993. Os adolescentes que relataram ter feito algum tipo de regime com a finalidade de emagrecimento nos últimos 12 meses foram positivos ao desfecho. A freqüência de realização de regime foi de 8,6% (IC95%: 7,7;9,4), sendo maior entre as meninas. O índice de massa corporal (IMC) materno elevado associou-se à realização de regime entre meninas. O sentimento do adolescente e dos pais em relação ao peso do jovem, o excesso de peso e o consumo de refrigerantes diet/light mostraram-se associados ao desfecho. Encontrou-se associação positiva entre regime e nível econômico. Tais achados constituem-se um importante subsídio para formação de políticas a fim de melhorar a dieta de adolescentes, uma vez que expressa a grande preocupação com o peso, e assim, um porcentual significativo de indivíduos tendo comportamentos equivocados.

The aim of this study was to investigate medicine use and associated factors among adolescents. This was a prospective cohort study including 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil, in 1993. Information on medicine use in the 15 days prior to the interviews was collected from the mothers. Overall prevalence of medicine use was 30.9%, and 64.7% of the medicines had been prescribed by a physician. The most frequently used pharmacological groups were medicines for the nervous (35.9%) and respiratory systems (25.7%). Medicine use was directly associated with socioeconomic status, maternal schooling, complications during pregnancy or delivery, and neonatal problems resulting in the need for intensive care. Underweight and obese adolescents were more likely to use medicines as compared to those with normal body mass index. A direct association was observed between maternal use of hypnotic drugs and sedatives and adolescent medicine use. It is essential to implement educational policies aimed at promoting rational use of medicines by adolescents.

To investigate the main dental caries life course determinants and predictors of dental caries at age 12.This study was nested in a population-based birth cohort started in 1993 in Pelotas, Brazil. A sample of 359 children was followed-up. Dental examinations and interviews were performed at 6 and at 12 years old. Dental caries (DMFT) at 12 years old was the outcome. Exploratory variables included socioeconomic and demographic variables at birth, children's nutritional and development characteristics, primary dental caries, oral health related behaviors and dental service use at age 6 and 12. Poisson regression was used in order to provide relative risk ratio estimates. Attributable risk or etiology fraction and population attributable risk for both main early life variables were calculated. Dental caries prediction (DMFTor= 1) at 12 years old was tested using logistic regression analyses.Children who presented height-for-age deficit at 12 months (RR 1.50 CI: 95%=1.03-2.18), children who showed a DMFT of 1-3 and 4-19 at 6 years (RR=2.01; CI: 95%=1.33-3.03, and RR=2.66; CI: 95%=1.81-2.53, respectively) and those children aged 12 in the highest tertile of proportion of teeth experiencing gingival bleeding (RR=1.58; CI: 95%=1.11-2.24) presented a higher level of dental caries at age 12. Attributable risk for dental caries at age 12 were 79.1% and 74.2% for deficit in height for age at 12 months and for primary dental caries at age 6 years respectively; population attributable risk for dental caries at age 12 were 3.1% for deficit in height for age at 12 months and 64.9% for primary dental caries at age 6. The level of accuracy in predicting dental caries at age 12 by using life course socioeconomic, behavioral and clinical data was modest.The results of this study support the hypothesis linking social, biological and behavioral exposures and dental caries at 12 years old. In addition, the findings reinforce the lack of accuracy of dental caries predictors therefore limiting the individuals high-risk approach as a public health strategy.

To evaluate the association between breastfeeding duration, introduction of solid or semi-solid foods before four months of age and overweight/obesity at 11 years.Prospective population-based birth cohort study, including 1 204 adolescents aged 11 years who were born in Pelotas (Brazil), in 1993, and were previously interviewed at birth, six and 12 months of age. Five explanatory variables were used: duration of any breastfeeding, duration of exclusive or predominant breastfeeding, ever breastfeeding, introduction of solid or semi-solid foods before four months of age, and feeding pattern at four months of age. Risk of overweight was defined as body mass index (BMI)or = 85(th) percentile, and obesity was defined as BMIor = 85(th) percentile plus triceps and subscapular skinfoldsor = 90(th) percentile, using the National Center for Health Statistics curves.The prevalence of risk of overweight and obesity at 11 years were 23.2% and 11.6%, respectively. The lowest prevalence of both outcomes was found among subjects who were breastfed for one to three months. However, tests for linear trend or heterogeneity did not result in a significant association between breastfeeding indicators and anthropometry at 11 years. Adjustment for sex, skin color, birth weight, maternal schooling, smoking during pregnancy and maternal pre-pregnancy BMI did not alter the findings.Our results do not support the hypothesis that breastfeeding has a long-term lasting effect on anthropometry in this population.

Background:We aimed to describe levels of physical activity (PA) in adolescents living in southern Brazil and to explore associations between PA levels and demographic, socioeconomic, health-related, and parental variables. A further aim was to test the validity and reliability of the questionnaire used.Methods:We conducted a population-based, cross-sectional study including 857 adolescents selected randomly. Insufficient PA was defined as Results:Reliability of the questionnaire was good, and its validity in comparison with a longer questionnaire was also satisfactory. In comparison with pedometer data, the questionnaire presented moderate agreement. The prevalence of insufficient PA in the whole sample was 69.8% (95% CI = 66.7–72.9). Boys were more active than girls. The prevalence of insufficient PA increased with age in girls but not in boys. Among boys, those from low socioeconomic levels were more likely to be sedentary. Among girls, paternal PA was directly associated with adolescent activity levels.Conclusions:Urgent strategies aimed at increasing levels of activity of adolescents are necessary in Brazil given the high prevalence of insufficient PA detected in this study. The variables associated with insufficient PA varied between boys and girls.

Background: All previous longitudinal community studies assessing the continuity of child behavioral/emotional problems were conducted in developed countries. Method: Six hundred and one children randomly selected from a Brazilian birth cohort were evaluated for behavioral/emotional problems through mother interview at 4 and 12 years with the same standard procedure – Child Behavior Checklist (CBCL). Results: CBCL Total Problem score presented a medium stability (r = .42) with externalizing problems showing higher stability and more homotypic continuity than internalizing problems. Of the children presenting deviant scores at the age of 4, only 31% remained deviant at the age of 12 (p

Disruption of circadian rhythms has been associated with obesity in children and adolescents, and with hypertension in adults, in industrialized populations.We examined cross-sectional associations between sleep duration or television viewing and obesity and blood pressure in Brazilian adolescents.The sample consisted of 4452 adolescents aged 10-12 years participating in a prospective birth cohort study in Pelotas, Brazil. Sleep duration and television viewing were determined through questionnaires. Obesity was assessed using international cut-offs for body mass index (BMI), and body fatness by skinfold thicknesses. Blood pressure was measured using a validated monitor.Short sleep duration was associated with increased BMI, skinfolds, systolic blood pressure, activity levels and television viewing. Each hour of sleep reduced BMI by 0.16 kg/m(2) (s.e. 0.04), and was associated with odds ratio for obesity of 0.86 (s.e. 0.04), both P0.001. Television viewing was associated with increased BMI and skinfolds, and increased blood pressure. The effects of sleep duration and television viewing on obesity were independent of one another. Their associations with blood pressure were mediated by body fatness.Both short sleep duration and increased television viewing were associated with greater body fatness, obesity and higher blood pressure, independently of physical activity level. These associations were independent of maternal BMI, identified in other studies as the strongest predictor of childhood obesity. Our study shows that behavioural factors associated with metabolic risk in industrialized populations exert similar deleterious effects in a population undergoing nutritional transition and suggest options for public health interventions.

Objectives: To assess the effect of birth weight, length and ponderal index at birth on body mass index (BMI) and skinfold thickness in early adolescence. Subjects/Methods: Population-based, prospective birth cohort study in Pelotas, Brazil. Out of 5249 cohort members, 87.5% were traced at 11 years of age. Birth weight, length and ponderal index (birth weight/birth length3 × 100)—treated as continuous variable and divided into fourths—were the exposure variables. BMI at 11 years, triceps and subscapular skinfolds were the outcomes. Confounders included sex, gestational age, parity, maternal schooling, family income, maternal smoking during pregnancy and maternal BMI. Results: All three exposure variables were significantly associated with BMI in early adolescence, but the strongest effect was observed for birth weight. Each unit (Z-score) increase in birth weight was associated with 0.46 kg m−2 increase in BMI at 11 years. The equivalent coefficients for ponderal index and birth length were 0.22 and 0.21 kg m−2, respectively. High birth weight, length and ponderal index were also associated with increased values for triceps and subscapular skinfolds at 11 years, and with increased prevalence of obesity. Conclusions: Of the three birth exposures studied, birth weight presented the strongest effect on anthropometry in early adolescence. Ponderal index, a proportionality indicator associated with infant mortality, hospitalizations and anthropometry in infancy, was also associated with anthropometry in early adolescence, but its predictive value for the latter is lower than that of birthweight alone. All three birth size indicators studied presented poor predictability of the later risk of obesity.

The aim of this study was to compare the evolution of nutritional deficits and overweight in one-year-old children from three birth cohorts started in 1982, 1993 and 2004 in Pelotas, Southern Brazil. Samples from the 1982 and 1993 cohorts and all children from 2004 were weighed and measured, and their mothers interviewed. Anthropometric deficits and overweight were assessed using both NCHS and WHO growth standards. A comparison of the existence of nutritional deficits showed that, after a decline between 1982 and 1993, its prevalence stabilized between 1993 and 2004. Across the whole period, a decrease in all deficits was observed. Obesity, on the other hand, increased. A deficit in the ratio of body length to age was found to be strongly associated with family income. The group with income below one minimum wage was the only to present a significant reduction of stunting during the study period. The most significant improvements in the reduction of nutritional deficits occurred in the first half of the study period, while social differentials remained. Fighting malnutrition is still necessary among the 40% of the population considered poor, and must be accompanied by efforts to combat overweight which is being observed in all social strata. O estudo teve como objetivo comparar a evolução dos déficits nutricionais e sobrepeso em crianças de um ano, com base em três coortes de nascimentos iniciadas em 1982, 1993 e 2004 em Pelotas, Rio Grande do Sul, Brasil. Amostras das coortes de 1982 e 1993 e todos as crianças da coorte de 2004 foram pesadas e medidas, e suas mães foram entrevistadas. Déficits antropométricos e sobrepeso foram analisados utilizando os padrões de crescimento definidos pelo NCHS e OMS. A comparação dos déficits nutricionais mostrou que, depois de declinar entre 1982 e 1993, a prevalência se estabilizou entre 1993 e 2004. Durante o período inteiro, foi observada uma diminuição em todos os déficits. Inversamente, houve um aumento na obesidade. Baixa estatura para a idade esteve fortemente associada com renda familiar. O grupo de renda familiar abaixo de um salário mínimo foi o único que mostrou uma redução significativa em baixa estatura para idade durante o período estudado. Houve melhorias importantes na redução dos déficits nutricionais na primeira metade do período de estudo, embora ainda persistam desigualdades sociais. Combater a desnutrição ainda é necessário nos 40% mais pobres da população, em paralelo com a luta contra o sobrepeso, que vem sendo observado em todas as classes sociais.

Various cut-off points for body mass index have been proposed to assess nutritional status in adolescents. The aim of this study was to compare two methods for evaluating overweight and obesity. In 2004-5, 4,452 adolescents from the 1993 Pelotas (Brazil) birth cohort study were evaluated, representing 87.5% of the original cohort. Overweight and obesity were evaluated using the methods proposed by the World Health Organization (WHO) and International Obesity Task Force (IOTF). Prevalence of overweight was similar when comparing the two methods (WHO: 23.2%; IOTF: 21.6%). Prevalence of obesity was higher according to the WHO criterion (total sample: 11.6%; boys: 15.1%; girls: 8.2%) as compared to IOTF (total sample: 5.0%; boys: 5.6%; girls: 4.4%). The kappa statistic was around 0.9 for determining overweight and 0.4 for obesity. The IOTF classification showed high specificity in comparison to the WHO criterion for determining overweight and obesity. However, sensitivity was high for overweight but low for obesity. Our data show that the IOTF classification underestimates the prevalence of obesity in early adolescence. Vários pontos de corte para o índice de massa corporal têm sido propostos para avaliação nutricional de adolescentes. O objetivo deste estudo foi comparar dois métodos de avaliação de sobrepeso e obesidade. Em 2004-2005, foram avaliados 4.452 adolescentes pertencentes à coorte de nascimentos de 1993 de Pelotas, Rio Grande do Sul, Brasil, representando 87,5% da coorte original. Sobrepeso e obesidade foram avaliados segundo os métodos da Organização Mundial da Saúde (OMS) e do International Obesity Task Force (IOTF). As prevalências de sobrepeso foram semelhantes entre os métodos: OMS: 23,2%; IOTF: 21,6%. A obesidade foi maior com o método da OMS (amostra total: 11,6%; meninos: 15,1%; meninas: 8,2%) do que com a classificação IOTF (amostra total: 5%; meninos: 5,6%; meninas: 4,4%). Para determinação de sobrepeso, o índice kappa foi ao redor de 0,90, enquanto na obesidade foi ao redor de 0,40. A classificação da IOTF mostrou alta especificidade em comparação à classificação da OMS para determinação de sobrepeso e obesidade. A sensibilidade foi alta para determinação de sobrepeso, mas baixa para determinação de obesidade. Os dados mostraram que a classificação IOTF subestima a prevalência de obesidade nessa faixa etária.

In 1982 a birth cohort study was initiated in Pelotas a Southern Brazilian city with a current population of 323 000 inhabitants. It started as a perinatal survey and later became one of the largest and longest running birth cohorts in the developing world. With the success of this initial study our group decided to propose a second birth cohort to be launched 10 years later. Due to delayed funding the new cohort could only start in 1993. Funding for the new cohort was obtained from the European Economic Commission in a collaboration that included the London School of Hygiene and Tropical Medicine and the Escuela Andaluza de Salud Publica from Granada. In the late 80s and early 90s the hypothesis that intrauterine infant and child growth could affect long-term health outcomes gained widespread attention. The beneficial effects of breastfeeding were also becoming more evident. To better describe growth and feeding patterns we opted to examine infants on several occasions at the ages of 1 3 6 and 12 months differently from our 1982 cohort when the first home visit took place at the age of 9-15 months. (excerpt)

Summary. Objectives: To explore the association between gender and leisure-time physical activity in a population-based sample of adults living in Brazil. To study a variety of variables possibly associated with physical activity levels. Methods: A multistage sampling of households was undertaken in Pelotas, a medium-sized Southern Brazilian city. Leisure-time physical activity was measured using the long version of the International Physical Activity Questionnaire. Data on potential predictors of leisure-time physical activity behavior were collected using a standardized questionnaire. 1 344 men and 1 756 women were interviewed. Several definitions of moderate and vigorous-intensity physical activity were used. Results: Regardless of the guideline used, males were more active than women. Socioeconomic level was positively associated with leisure-time physical activity in both genders. A positive dose-response between age and inactivity was found in men, but not among women. Conclusions: Because men and women have different levels of physical activity, and the variables associated with activity levels are not consistent across the genders, interventions promoting physical activity should take these differences into account.

Previous studies have suggested that birth size may influence blood pressure in later life. Most of these reported inverse associations only became evident after weight or body mass index at some later age was included in the regression model. In a prospective birth cohort study in Brazil, the effect of birth size on blood pressure at age 11 years was explored. Of the 5,249 cohort members, 4,452 were interviewed. Mean systolic and diastolic blood pressures were 101.9 mmHg (standard deviation, 12.3) and 63.4 mmHg (standard deviation, 9.9), respectively. Birth weight was positively associated with blood pressure in the crude analysis, but this effect was no longer significant after adjustment for confounders. When current body mass index-a possible mediating variable-was added to the model, the association between birth weight and blood pressure tended to become negative, though not quite significant. Birth length showed a positive effect on later blood pressure regardless of the adjustments made. Head circumference, gestational age, and ponderal index were not associated with blood pressure. Children born small for gestational age had lower blood pressure values. The postulated inverse association between birth weight and later blood pressure was not confirmed in this cohort. Instead, a positive effect of birth length was detected.

Purpose To evaluate the prevalence of tobacco use, and factors associated with it, in early adolescent (aged 10–12 years) participants of the 1993 Pelotas (Brazil) Birth Cohort Study. Methods Children born in 1993 in Pelotas, Brazil were included in a prospective health study. In 2004–2005, all cohort members were sought. Adolescents and mothers were interviewed. A confidential questionnaire was applied to adolescents, including a section on smoking. Smoking experience was defined as having tried at least one cigarette in life. Results Follow-up rate was 87.5%; 4452 adolescents were interviewed. Mean age was 11.3 years. Only 58 adolescents did not answer the question on smoking experience. Out of the 4394 respondents, 162 (3.7%; 95% confidence interval [CI] 3.1–4.2) had tried smoking. Of these, approximately half smoked the first cigarette before 10 years of age. Seventy-three cohort members reported smoking daily. In multivariable analysis, variables positively associated with smoking experience were: male gender, maternal smoking during pregnancy, living without the biological father, poor relationship with the mother, being beaten by the parents, family conflict, maternal smoking in 2004–2005, bad influences on the adolescent, participation in fights, history of attempting to run away from home, and experience with alcoholic beverages. The association was negative for socioeconomic level. Conclusion Family-related variables and habits of the adolescent were strongly associated with smoking in early adolescence. Because experimentation with tobacco in adolescence is related to a marked increase in the risk of tobacco addiction in adulthood, early interventions are warranted.

To study the prevalence and current predictors of low body mass index (BMI) in a population undergoing a rapid nutritional transition. Population-based cross-sectional study. Individuals living in the urban area of Pelotas, a medium-sized southern Brazilian city, were interviewed at home. A multiple-stage sampling strategy was used. Out of 3372 eligible subjects, 3047 were interviewed. The study was restricted to adults (≥20 y). Low BMI was defined as

The scope of the study was to identify factors associated with excess weight in Brazilian children less than five years of age. Data from a cross-sectional home-based study entitled the National Demographic and Health Survey (NDHS) of 2006 were used. The diagnosis of excess weight was performed using the weight-for-height greater than 2 z scores above the median anthropometric standard recommended by the World Health Organization in 2006. The population under study consisted of 4,388 children. The prevalence of excess weight in children was described according to socio-economic, demographic, anthropometric, and behavioral variables. Crude and adjusted analyses were carried out to assess statistical significance stratified by gender using Poisson regression. The prevalence of excess weight was 6.6%. After adjusting for potential confounding factors, maternal body mass index and birth weight were associated with excess weight. Furthermore, being overweight was associated with exclusive breastfeeding for boys and with the socio-economic level and marital status of the mother for girls. The need to implement public policies that act on the major determinants of excess weight since childhood is emphasized.

Background Large epidemiological studies in DNA biobanks have increasingly used less invasive methods for obtaining DNA samples, such as saliva collection. Although lower amounts of DNA are obtained as compared with blood collection, this method has been widely used because of its more simple logistics and increased response rate. The present study aimed to verify whether a storage time of 8 months decreases the quality of DNA from collected samples. Methods Saliva samples were collected with an OrageneTM DNA Self-Collection Kit from 4,110 subjects aged 14–15 years. The samples were processed in two aliquots with an 8-month interval between them. Quantitative and qualitative evaluations were carried out in 20% of the samples by spectrophotometry and genotyping. Descriptive analyses and paired t-tests were performed. Results The mean volume of saliva collected was 2.2 mL per subject, yielding on average 184.8 μg DNA per kit. Most samples showed a Ratio of OD differences (RAT) between 1.6 and 1.8 in the qualitative evaluation. The evaluation of DNA quality by TaqMan®, High Resolution Melting (HRM), and restriction fragment length polymorphism-PCR (RFLP-PCR) showed a rate of success of up to 98% of the samples. The sample store time did not reduce either the quantity or quality of DNA extracted with the Oragene kit. Conclusion The study results showed that a storage period of 8 months at room temperature did not reduce the quality of the DNA obtained. In addition, the use of the Oragene kit during fieldwork in large population-based studies allows for DNA of high quantity and high quality.

PurposeTo investigate the effect of obesity at the start of adolescence on the prevalence, incidence and maintenance of chest wheezing among individuals aged 11–15 years in a birth cohort in a developing country.MethodsThe seventh follow-up of the 1993 Pelotas birth cohort occurred in 2004 (individuals aged 10–11 years). Between January and August 2008, the eighth follow-up of the cohort was conducted. All the individuals of the original cohort who were alive (who were then adolescents aged between 14 and 15 years) were targets for the study. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to define wheezing. In addition to the body mass index (BMI), used to define obesity by the World Health Organization (WHO) criteria, we assessed skinfold thickness.ResultsFrom the original cohort, 4,349 individuals were located (85.7% follow-up rate). The prevalence of chest wheezing at 11 and 15 years were 13.5% (95% CI: 12.5%–14.5%) and 12.1% (95% CI: 11.1%–13.1%), respectively. The prevalence of wheezing at both times was 4.5% (95% CI: 3.9%–5.1%) and the incidence of wheezing was 7.5% (95% CI: 6.7%–8.3%). Independent of the effect of various confounding variables, the prevalence of wheezing at 15 years was 50% greater among obese individuals than among eutrophic individuals at 11 years (RR 1.53; 95% CI: 1.14–2.05). The greater the skinfold tertile at 11 years, the higher the prevalence of wheezing at 15 years was (p = .011). Weight status and skinfolds did not present any association with incident wheezing. After controlling for confounding factors, the risk of persistent wheezing among obese individuals at 11 years was 1.82 (95% CI: 1.30–2.54).ConclusionsSince obesity at the start of adolescence is associated with asthma symptom persistence, prevention and treatment of obesity may reduce avoidable healthcare costs and disease burden.

Background Socioeconomic status (SES) has been shown to be an important contributor to lung function. The aim of this study was to evaluate the association between lung function in adolescence and (a) SES at birth; (b) SES in adolescence; (c) SES trajectory from birth to adolescence ('never poor', 'non poor-poor', 'poor-non poor' and 'always poor'). Additionally, we investigate the role of adolescent and parental variables at mediating these associations. Methods Prospective birth cohort study in Pelotas, Brazil, including 4,005 adolescents (mean age: 14.7 years) followed up from birth. Lung function was measured by spirometry. Outcome variables were forced expiratory volume in one second in liters (FEV1) and forced vital capacity also in liters (FVC). Results Mean FEV1 was 3.46 L (95%CI 3.43-3.49) among boys and 2.93 L (95%CI 2.91-2.95) among girls. Mean FVC was 4.00 L (95%CI 3.97; 4.04) among boys and 3.30 L (95%CI 3.27; 3.32) among girls. SES at birth, in adolescence and its trajectory from birth to adolescence were inversely associated with lung function in both adolescent boys and girls. After adjustment for mediating variables, coefficients were largely reduced, particularly among boys, and the main predictor of change in coefficients was the inclusion of height in the models. Conclusion Low income adolescents from Brazil present impaired lung function as compared to the better off, and this is largely explained by height.

To review the scientific literature on the tracking of dietary patterns from childhood to adolescence.A search of the MEDLINE/PubMed, Lilacs and SciELO databases was performed, using the following key words: "tracking", "dietary patterns" and "childhood/adolescence" and their respective synonyms. A total of 45 abstracts were found and, after the inclusion criteria were applied, 13 articles were included. The tracking of dietary patterns was assessed by three main statistical analyses: (Pearson or Spearman) correlation coefficients, kappa coefficient and probability analysis.The tracking of dietary patterns ranged from weak to moderate between the childhood-childhood and childhood-adolescence periods. During adolescence, there appears to be no tracking.Dietary patterns in childhood may continue until adolescence, although such patterns may be changed or discontinued throughout adolescence.

Objectives:To explore cross-sectional and longitudinal associations between self-reported and accelerometry-based physical activity (PA) and blood pressure (BP) between 11 and 14 years of age.Methods:Prospective birth cohort study in Pelotas, Brazil. Participants were 427 cohort members who were followed up with at 11, 12, and 14 years of age, and had questionnaire data on PA and BP at 11 and 14 years, as well as accelerometry and questionnaire data on PA at 12 years. Outcome measures were continuous systolic and diastolic BP at 14 years, and change in BP from 11 to 14 years.Results:PA was unrelated to systolic BP in any analyses. PA measured by accelerometry at 12 years, but not questionnaire-derived PA, was inversely associated with diastolic BP at 14 years of age in fully adjusted models. Those who exceeded the 300-minutes PA threshold at all 3 visits had a 2.6 mmHg lower mean increase in DBP from 11 to 14 years compared with those classified below the threshold in all visits.Conclusions:Accelerometry-based PA was longitudinally inversely associated with diastolic BP. This finding was not evident when analyzing self-reported PA at a given age, suggesting a possible underestimation of the association when using subjective data.

The scope of this article was to describe the urban work patterns among 14 to 15-year-old youths from Southern Brazil. Child labor was characterized as any activity that resulted in retribution in the form of goods, services or money. The analyses were stratified by sex and economic level. Of the 4325 adolescents interviewed, the proportion of labor in the last year was 22.2%, namely 27.7% for the male sex, and 17% for the female sex. This proportion was also higher among the poorer strata of the population (30.0%) than the more affluent (14.3%). The majority of adolescents worked away from home and approximately half of them began working before 14 years of age, and around 80.0% reported that they worked by choice. Only 1.0% had a labor contract or work booklet, 30.0% worked more than six hours per day, and the average income was less than US$85/month. Domestic work predominated among the poorest teenagers. There is a need for greater surveillance of child labor and of interventions seeking to enforce prevailing legislation.

Este fasciculo tematico pretende contar-lhes uma historia de um periodo de 11 anos. Em 1993, na cidade de Pelotas, nasceram 4.452 bebes que passaram a constituir a coorte dos nascidos vivos de Pelotas daquele ano. Era um grupo de recem-nascidos e de suas maes que foram avaliados, entrevistados, pesados, medidos, dentre outros procedimentos. A partir da-quele momento, estabeleceu-se um elo entre nos – pesquisadores – e esta legiao de familias.Passamos, entao, a acompanha-los visitando alguns deles, escolhidos ao acaso, em dife-rentes idades. A cada acompanhamento, perguntavam-nos como tinham sido localizados; por que eles; o que fariamos com todas aquelas informacoes. Explicavamos a importância das visitas, o quanto aquelas informacoes poderiam ajudar-nos a entender o que se passa-va na infância e de que forma aquilo poderia refletir-se em idades posteriores.Como em toda historia, houve diferentes momentos e, quase “de repente”, nossas “criancas” tornaram-se adolescentes; estavam entao com 11 anos de idade. Sempre tive-mos vontade de acompanhar todos eles e naquele momento tinhamos recursos para isto; mas, como ja nao eram mais criancas, nossa abordagem tinha de ser diferente. Sabiamos que os questionamentos partiriam muitas vezes deles e nao mais das maes, e a equipe ti-nha de estar preparada para essa nova realidade.Sabiamos tambem que uma fase havia terminado e tinhamos grande curiosidade sobre o que iriamos enfrentar naquela idade de transicao. Elaboramos questionarios confiden-ciais para o adolescente (era claro para nos que nem tudo poderia ser contado na frente das maes) e, ao mesmo tempo, questionarios para as maes, pois adolescentes nao sabe-riam responder algumas questoes que so os adultos conheciam.E assim seguiu nossa historia... Como “detetives”, mediante mil estrategias e malaba-rismos contados no artigo de metodos deste fasciculo tematico, conseguimos encontrar 87,5% daqueles nascidos ha 11 anos, o que nos deixou muito satisfeitos, dada a grande mobilidade das familias.Frente a realidade do perfil do adolescente no cenario nacional, investigamos nao ape-nas o estado nutricional e seus habitos alimentares, mas tambem o consumo de gorduras e de fibras, regime para emagrecer e tambem a atividade fisica, ja que o padrao estetico vi-gente dos adolescentes, sobretudo do sexo feminino, parecia caracterizar-se pela magreza. Dentro desse contexto da idade das experiencias e das transformacoes, perguntamos sobre o uso de alcool, consumo de medicamentos, bem-estar e problemas de atencao e hipera-tividade. Na tentativa de identificarmos possiveis marcadores de risco para doencas croni-cas no futuro, investigamos a pressao arterial, pulso e hospitalizacoes. Tambem avaliamos, em uma subamostra, a saude bucal desses adolescentes.Os resultados da historia estao relatados nos diferentes artigos deste fasciculo tematico e nao vamos revela-los aqui no Editorial.Como dissemos previamente, esta e uma das etapas da historia da nossa coorte de nasci-dos em 1993 na cidade de Pelotas; outras historias poderao ser contadas sobre os proximos acompanhamentos desta “grande familia”, que vem sendo seguida desde o nascimento!

The aim of this study was to evaluate concurrent risk factors for high blood pressure in adolescents. This is a prospective cohort study including 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil, in 1993. Blood pressure was measured before and after the interview, and the mean value was used in the analyses. Mean systolic blood pressure was 101.9mmHg (SD = 12.3) and mean diastolic pressure was 63.4mmHg (SD = 9.9). Adolescents with black skin had higher blood pressure than those with white skin. Mean systolic pressure among subjects in the top quartile of body mass index (BMI) was 11.6mmHg higher than among those in the lowest quartile. Mean systolic pressure among postmenarcheal girls was 5.4mmHg higher than among premenarcheal girls. Similar trends were found for diastolic arterial pressure. Our findings suggest that blood pressure control must begin already in childhood and adolescence. O objetivo do presente artigo foi avaliar fatores associados com a pressão arterial de adolescentes. Trata-se de estudo de coorte prospectivo, incluindo 4.452 adolescentes nascidos em Pelotas, Rio Grande do Sul, Brasil, em 1993. A pressão arterial foi medida no início e final da entrevista com aparelho digital, sendo o valor médio utilizado nas análises. A pressão arterial sistólica média foi de 101,9mmHg (DP = 12,3) e a diastólica foi de 63,4mmHg (DP = 9,9). Adolescentes com pele preta apresentaram valores mais elevados de pressão arterial sistólica do que os de pele branca. Adolescentes no quartil superior do índice de massa corporal (IMC) apresentaram uma pressão sistólica média 11,6mmHg maior do que aqueles no quartil inferior. Meninas que já menstruaram apresentaram uma pressão sistólica média 5,4mmHg maior em comparação às demais. Os resultados foram similares para a pressão arterial diastólica. O controle da pressão arterial elevada deve ser iniciado desde a infância e adolescência.

We evaluate the influence of demographic, socioeconomic, and maternal variables on the nutritional status of adolescents aged 11 years. We conducted a prospective cohort study including 4,452 adolescents born in Pelotas, Southern Brazil, in 1993, accounting for 87.5% of the original cohort. Nutritional status was evaluated based on World Health Organization criteria. Subjects were classified according to nutritional status into thin, normal, overweight and obese. Independent variables analyzed included skin color, socioeconomic status, maternal schooling, and maternal body mass index (BMI). Analyses were stratified by sex, and multivariable regression was performed using the multinomial logistic approach. Overall, 7% of adolescents were classified as thin, 11.6% as overweight, and 11.6% as obese. Among boys, thinness was inversely associated with maternal schooling and maternal BMI. Among girls, thinness was directly associated with maternal BMI. Overweight and obesity were directly associated with socioeconomic status and maternal BMI, the former showing the strongest association with nutritional status among adolescents. O objetivo deste estudo foi avaliar a influência de fatores demográficos, sócioeconômicos e maternos sobre o estado nutricional de adolescentes, nascidos em 1993, em Pelotas, Rio Grande do Sul, Brasil. A amostra estudada (n = 4.452) representa 87,5% da coorte original. O estado nutricional foi avaliado conforme as recomendações da Organização Mundial da Saúde, categorizado em magro, eutrófico, sobrepeso e obeso. As variáveis independentes foram cor da pele, índice de bens, escolaridade e índice de massa corporal (IMC) maternos. As análises foram estratificadas por sexo, e a regressão logística multinomial foi usada. Ao todo, 7% dos adolescentes eram magros, 11,6% tinham sobrepeso e 11,6% eram obesos. Entre os meninos, a prevalência de adolescentes magros apresentou associação inversa com escolaridade e IMC maternos. Entre as meninas, ser magra se associou inversamente com o IMC materno. Sobrepeso e obesidade mostraram-se associados diretamente com índice de bens e IMC maternos, sendo esta última, a principal variável associada com o estado nutricional dos adolescentes.

This study describes the food intake of adolescents participating in the 1993 birth cohort from Pelotas, Southern Brazil, according to socioeconomic position. We carried out a cross-sectional analysis of data collected in the 2004-2005 follow-up visit. Food intake in the previous year was evaluated using the Block questionnaire. Socioeconomic status was evaluated based on an assets index, divided into quintiles. Foods with the highest frequency of daily intake were white bread (83%), butter or margarine (74.6%), beans (66.4%) and milk (48.5%). Intake of butter or margarine, bread, and beans was more frequent among poorer adolescents, and the inverse was true for milk. Intake of fruits and vegetables was low in all socioeconomic strata, but particularly low among the poor. In early adolescence, all socioeconomic groups showed high consumption of foods rich in fat and low consumption of foods rich in fiber. O estudo descreve alimentos consumidos por adolescentes pertencentes à coorte de nascimentos de 1993 de Pelotas, Rio Grande do Sul, Brasil, conforme o nível socioeconômico. Foi feita uma análise transversal com dados coletados no acompanhamento de 2004-2005. A freqüência alimentar no último ano foi avaliada pelo questionário Block. A posição socioeconômica foi verificada com base no índice de bens, dividido em quintis. Os alimentos mais consumidos diariamente foram: pão branco (83%), manteiga ou margarina (74,6%), feijão (66,4%) e leite (48,5%). O consumo de manteiga ou margarina, pão e feijão foram mais freqüentes entre adolescentes pertencentes ao primeiro (menor) quintil do índice de bens, e o consumo de leite foi maior no último quintil. Frutas, vegetais e salada verde tiveram baixo consumo principalmente entre os mais pobres. Todos os grupos socioeconômicos apresentaram consumo elevado de alimentos ricos em gordura e baixo consumo de alimentos ricos em fibra.

The aim of this study was to describe oral health follow-up studies nested in a birth cohort. A population-based birth cohort was launched in 1993 in Pelotas, Rio Grande do Sul State, Brazil. Two oral health follow-up studies were conducted at six (n = 359) and 12 (n = 339) years of age. A high response rate was observed at 12 years of age; 94.4% of the children examined at six years of age were restudied in 2005. The mean DMF-T index at age 12 was 1.2 (SD = 1.6) for the entire sample, ranging from 0.6 (SD = 1.1) for children that were caries-free at age six, 1.3 (SD = 1.5) for those with 1-3 carious teeth at six years, and 1.8 (SD = 1.8) for those with 4-19 carious teeth at six years (p < 0.01). The number of individuals with severe malocclusions at 12 years was proportional to the number of malocclusions at six years. Oral health problems in early adolescence were more prevalent in individuals with dental problems at six years of age. O objetivo deste trabalho foi descrever estudos de saúde bucal em uma coorte de nascimentos. Em 1993, teve início uma coorte de nascimentos de base populacional em Pelotas, Rio Grande do Sul, Brasil. Dois estudos de saúde bucal aos 6 (n = 359) e 12 anos de idade (n = 339) foram realizados. Foi observada uma alta taxa de resposta no período entre 6 e 12 anos de idade; 94,4% das crianças pesquisadas em 1999 foram examinadas em 2005. A média do índice CPO-D aos 12 anos foi de 1,2 (DP = 1,6) para a população como um todo, variando de 0,6 (DP = 1,1) para o grupo livre de cáries aos 6 anos, 1,3 (DP = 1,5) para os que apresentaram 1-3 dentes atacados pela cárie e 1,8 (DP = 1,8) para aqueles com 4-19 dentes atacados pela cárie (p < 0,01). Observou-se um aumento da proporção de indivíduos com oclusopatias muito severas aos 12 anos, conforme o número de oclusopatias presentes aos 6 anos de idade. Problemas bucais no início da adolescência foram mais prevalentes nos indivíduos que apresentaram agravos à saúde bucal na infância.

The aim of this study was to verify the agreement between different approaches for estimating levels of physical activity in adolescents. One questionnaire was administered to parents and two were administered to the adolescents. This was a cross-sectional analysis of data collected in the 2004-2005 follow-up of the 1993 Pelotas (Brazil) birth cohort study. Parents or guardians answered the following question: "Compared to most children the same age, would you say that your child exercises more, less, or the same amount?" A similar question was addressed to adolescents, as was a detailed questionnaire on physical activity. Agreement between the questionnaires was measured by the weighted kappa statistic. A total of 4,254 adolescents and parents/guardians answered the questionnaires. Kappa values indicated low agreement for all comparisons (kappa < 0.33 for all analyses). Measurement of physical activity in adolescents is complex, and available instruments should be validated prior to their use. O objetivo deste estudo foi verificar a concordância entre diferentes formas de se estimar o nível de atividade física de adolescentes. Um questionário foi aplicado aos pais e outros dois aos adolescentes. O estudo foi transversal aninhado ao acompanhamento de 2004-2005 da coorte de nascimentos de 1993 em Pelotas, Rio Grande do Sul, Brasil. Pais ou responsáveis responderam à questão: "Comparando com a maioria das crianças da mesma idade, o(a) Sr(a). diria que o seu filho faz mais exercícios que elas, menos exercícios que elas ou a mesma quantidade que elas?". Questão análoga foi aplicada aos adolescentes. Os adolescentes também responderam a um questionário mais detalhado sobre a prática de atividades físicas. A concordância entre os questionários foi avaliada pelo teste kappa ponderado. Um total de 4.254 adolescentes e responsáveis responderam aos questionários. Os valores de kappa indicaram concordância baixa para quaisquer das comparações (kappa < 0,33 para todas as análises). A mensuração de atividade física em adolescentes é complexa e os instrumentos disponíveis devem ser validados antes do uso.

Background There is evidence from two meta-analyses that children born through caesarean section (C-section) may have an increased risk of developing asthma compared with those born through vaginal delivery. Objective To evaluate the association between mode of delivery and wheezing (current and persistent) in childhood and adolescence, in two birth cohort studies in Brazil. Methods The outcome variable was based on the International Study of Allergy and Asthma questionnaire, which collects information about wheezing within the 12 months before the interview. Persistent wheezing was defined when it was present in more than one follow-up at different ages, in the 1993 cohort. The questions were asked to mothers when children were aged 4 years (1993 and 2004 cohorts) and directly to cohort participants at 11 and 15 years (1993 cohort). Mode of delivery was collected by the research team of each cohort when children were born. Results Response rates in the last follow-up visit of the 1993 and 2004 cohorts were 85% and 92%, respectively. The prevalence of current wheezing increased from 20% to 28% at 4 years from 1993 to 2004; at 11 and 15 years, the prevalence was around 14% and 12%, in the 1993 cohort. The proportion of C-sections increased from 30.5% to 45% between 1993 and 2004. In each cohort, the prevalence of current wheezing was similar among children born through vaginal and C-section. The risk for persistent wheezing in the 1993 cohort was higher among girls born through C-section than boys. Conclusion Despite the increase in the proportion of C-section in two cohorts in Southern Brazil, we found no evidence of an association between mode of delivery and the subsequent risk of wheezing. Among girls, although there was no statistical significance, the risk was higher for those born by C-section, especially regarding persistent wheezing.

Background We investigated the association between maternal anthropometric measurements in prepregnancy and at the end of pregnancy and their children's systolic (SBP) and diastolic (DBP) blood pressure at 11 years of age, in a prospective cohort study. Methods All hospital births which took place in 1993 in the city of Pelotas - Brazil, were identified (5,249 live births). In 2004, the overall proportion of follow-up was 85% and we obtained arterial blood pressure measurements of 4,452 adolescents. Results Independent variables analyzed included maternal prepregnancy weight and body mass index (BMI) and maternal weight, and height at the end of pregnancy. Multiple linear regression analysis controlling for the following confounders were carried out: adolescent's skin color, family income at birth, smoking, alcohol intake during pregnancy, and gestational arterial hypertension. Mean SBP and DBP were 101.9 mmHg (SD 12.3) and 63.4 mmHg (SD 9.9), respectively. Maternal prepregnancy weight and BMI, and weight at the end of pregnancy were positively associated with both SBP and DBP in adolescent subjects of both sexes; maternal height was positively associated with SBP only among males. Conclusions Adequate evaluation of maternal anthropometric characteristics during pregnancy may prevent high levels of blood pressure among adolescent children.

Background Socioeconomic inequalities in health outcomes are dynamic and vary over time. Differences between countries can provide useful insights into the causes of health inequalities. The study aims to compare the associations between two measures of socioeconomic position (SEP)—maternal education and family income—and maternal and infant health outcomes between ALSPAC and Pelotas cohorts. Methods Birth cohort studies were started in Avon, UK, in 1991 (ALSPAC) and in the city of Pelotas, Brazil, in 1982, 1993 and 2004. Maternal outcomes included smoking during pregnancy, caesarean section and delivery not attended by a doctor. Infant outcomes were preterm birth, intra-uterine growth restriction (IUGR) and breast feeding for

OBJECTIVE: To examine associations between certain aspects of self-reported Quality of Life (QoL) in early adolescence, and gender, skin color, maternal education at birth, and changes in socioeconomic position (SEP) occurring from 0-11 years of age. METHODS: A longitudinal study of a birth cohort composed of 5 249 individuals born in 1993 in Pelotas, Brazil, who were followed periodically from birth to age 11. Socioeconomic variables were collected at birth in 1993, and again, in 2004. The following eight variables were analyzed: relationship with mother, relationship with father, family conflicts, physical punishment by parents, family relationship problems, discrimination, academic failure, and fear of neighborhood of residence. Adjustments were made using a hierarchical model. RESULTS: Skin color was related to all the variables (more so for nonwhites than for whites), except in family conflicts. Physical punishment and academic failure were more frequent in males. Discrimination and fear of neighborhood were more prevalent in females. Maternal education at birth was inversely associated, especially with failing/repeating a grade in school(19.5 times more frequent in the lower maternal education group than in the highest). A similar pattern was found with the SEP change: worse QoL in the group that was always poor (at birth and at 11 years of age) than in the group that was never poor. Fear of neighborhood was not related to maternal education or SEP change. CONCLUSIONS: Gender, skin color, maternal education, and SEP change were related to various measured aspects of QoL. These results should be considered in policymaking that seeks to minimize inequities at birth, across the life-course, and for future generations.

The aim of this prospective analysis was to describe the cumulative incidence of hospital admissions in the first year of life and between 1 and 11 years of age and to explore associated factors. Hospital admissions were collected through regular monitoring in the first year of life, and through maternal report on admissions between 1 and 11 years. Analyses were stratified by sex and adjusted for confounding factors. 18.1% of children were hospitalized in the first year of life, and 30.7% between ages 1 and 11 years. Among boys, hospital admission in the first year was associated with low family income, paternal smoking during pregnancy, preterm delivery, and low birthweight. Among girls, in addition to the variables described for boys, black/mixed skin color was also a risk factor for hospital admission. For admissions between 1 and 11 years of age, low family income and gestational age ≥ 37 weeks were found to be significant risk factors. Com o objetivo de descrever a incidência cumulativa de hospitalizações no primeiro ano de vida e entre 1-11 anos de idade, e identificar fatores de risco precoces, foi realizado um estudo de coorte de nascimento de 1993 a 2004-2005. As hospitalizações foram coletadas por meio de monitoramento hospitalar até 1 ano de idade, e relato das mães sobre internações ocorridas de 1-11 anos. As análises foram estratificadas por sexo e ajustadas para fatores de confusão. Os percentuais de hospitalizações de 0-1 ano e de 1-11 anos foram 18,1% e 30,7%, respectivamente. As variáveis associadas com internações de 0-1 ano em meninos foram: baixa renda familiar, tabagismo paterno na gestação, prematuridade e baixo peso ao nascer. No sexo feminino, além dos fatores de risco descritos entre os meninos, observou-se associação com cor da pele preta/parda. Quanto às hospitalizações de 1-11 anos, no sexo masculino, encontrou-se associação com baixa renda familiar e idade gestacional ≥ 37 semanas.

Background Harmful social conditions in early life might predispose individuals to dental status which in turn may impact on adolescents' quality of life. Aims To estimate the prevalence of oral health impacts among 12 yr-old Brazilian adolescents (n = 359) and its association with life course socioeconomic variables, dental status and dental services utilization in a population-based birth cohort in Southern Brazil. Methods Exploratory variables were collected at birth, at 6 and 12 yr of age. The Oral Impacts on Daily Performances index (OIDP) was collected in adolescence and it was analyzed as a ranked outcome (OIDP from 0 to 9). Unadjusted and adjusted multivariable Poisson regression with robust variance was performed guided by a theoretical determination model. Results The response rate was of 94.4% (n = 339). The prevalence of OIDP = 1 was 30.1% (CI95%25.2;35.0) and OIDP ≥ 2 was 28.0% (CI95%23.2;32.8). The most common daily activity affected was eating (44.8%), follow by cleaning the mouth and smiling (15.6%, and 15.0%, respectively). In the final model mother schooling and mother employment status in early cohort participant's life were associated with OIDP in adolescence. As higher untreated dental caries at age 6 and 12 years, and the presence of dental pain, gingival bleeding and incisal crowing in adolescence as higher the OIDP score. On the other hand, dental fluorosis was associated with low OIDP score. Conclusion Our findings highlight the importance of adolescent's early life social environmental as mother schooling and mother employment status and the early and later dental status on the adolescent's quality of life regardless family income and use of dental services.

The objective of this study was to verify the frequency of fiber-rich food intake and evaluate its association with socioeconomic, demographic and behavioral characteristics. A city representative sample was selected and 3,993 subjects (> 10 years) were interviewed. The study used the Block Screening Questionnaire. A majority of subjects - 65.6% (95%CI: 64.2-67.1) - presented an inadequate intake frequency. Adjusted analysis for the overall sample showed an increased risk of inadequate frequency among men, adolescents, people of lower socioeconomic levels, current smokers, those insufficiently active and those having fewer than four daily meals. Age group-stratified analysis showed that among adolescents, living alone was a risk factor; for adults, risk factors were sex (male), current smoker, insufficiently active and fewer than four daily meals and; among the elderly they were male and being a current smoker. A lower socioeconomic level was associated to the outcome in all groups. Although the inadequate frequency of intake is very common in this population, teenagers are at a higher risk, pointing to a need for public health actions targeting this particular age group. Verificar a freqüência do consumo de alimentos fontes de fibras e avaliar sua associação com características sócio-econômicas, demográficas e comportamentais. Foi selecionada amostra representativa da cidade e 3.993 indivíduos (> 10 anos) foram entrevistados. Foi utilizado o instrumento Block Screening. A maioria da amostra, 65,6% (IC95%: 64,2-67,1), mostrou freqüência inadequada de consumo. A análise ajustada para amostra global mostrou risco aumentado de freqüência inadequada entre homens, adolescentes, de menor nível sócio-econômico, fumante atual, insuficientemente ativo e aqueles que faziam menos de 4 refeições/dia. A análise por faixa etária mostrou que entre adolescentes, morar sozinho foi um fator de risco; entre adultos, homens, fumantes, insuficientemente ativos e que realizavam menos de 4 refeições/dia; e, entre idosos, somente homens e fumantes. O menor nível sócio-econômico associou-se ao desfecho em todos os grupos. Ressalta-se que embora a população apresente alto porcentual do desfecho, chama atenção os adolescentes, sugerindo medidas prioritárias nesta faixa etária.

Background Developed and developing countries are facing rapid increases in overweight and obesity among children and adolescents. The patterns of overweight/obesity differ by age, sex, rural or urban residence and socioeconomic position (SEP) and vary between and within countries. Methods We investigated patterns of SEP – overweight status association among adolescents from the UK (ALSPAC) and Brazil (the 1982 and 1993 Pelotas birth cohort studies). All analyses were performed separately for males and females. Logistic regression analysis was used to examine the relationships between overweight status and two SEP indicators – family income and maternal education. Results A strong positive association was observed in 11-year-old boys from the 1993 Pelotas cohort, with higher prevalence of overweight among the least poor and among those whose mothers had more years of schooling (x2 for linear trend p < 0.001). In ALSPAC study higher prevalence of overweight was seen among boys whose mothers had lower educational achievement (x2 for linear trend p = 0.006). Among 11 year-old girls from 1993 Pelotas cohort study there was a positive association (higher prevalence of overweight in the higher socioeconomic and educational strata, x2 for linear trend p < 0.001 and p = 0.01, respectively) while an inverse association was found in the ALSPAC study (x2 for linear trend p < 0.001). Among males from the 1982 cohort study, overweight at 18 years of age showed a positive association with both SEP indicators while among females, the reverse association was found. Conclusion The results of this study demonstrate that the social patterning of overweight varies between and within populations over time. Specific approaches should be developed within populations in order to contain the obesity epidemic and reduce disparities.

The aim of this study was to describe resting pulse rate and associated factors among adolescents. This was a cross-sectional analysis nested in a prospective cohort study, including 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil in 1993, representing 87.5% of the original cohort. Pulse rate was measured with an electronic device at the beginning and end of the interview, and the mean value was used in the analyses. Mean pulse rate was 78.4bpm (SD = 11.0) in the total sample, 76.5bpm (SD = 10.7) in boys, and 80.2bpm (SD = 10.9; p < 0.001) in girls. Black adolescents showed lower mean pulse rates. There was a direct association between pulse rate and blood pressure. Physical activity was inversely associated with pulse rate in the crude analysis only. Elevated pulse rate is strongly associated with high blood pressure, and both variables are predictors of risk of chronic disease in adulthood. O objetivo do estudo foi descrever a freqüência do pulso de repouso em adolescentes e avaliar variáveis associadas. Trata-se de análise transversal aninhada a um estudo de coorte prospectivo, incluindo 4.452 adolescentes nascidos em Pelotas, Rio Grande do Sul, Brasil, em 1993, os quais representam 87,5% da coorte original. A freqüência do pulso foi mensurada no início e ao final da entrevista com aparelho digital, sendo o valor médio utilizado nas análises. O valor médio da freqüência do pulso foi de 78,4bpm (DP = 11,0), sendo de 76,5bpm (DP = 10,7) nos meninos e 80,2bpm (DP = 10,9; p < 0,001) nas meninas. Os adolescentes com pele preta apresentaram valores mais baixos da freqüência do pulso. Houve uma forte associação positiva entre pressão arterial e freqüência do pulso. O escore de atividade física associou-se inversamente com a freqüência do pulso somente na análise bruta. Valores elevados de freqüência do pulso estão fortemente relacionados com valores elevados de pressão arterial, sendo ambas variáveis preditoras do risco de doenças crônicas na vida adulta.

The aim of this study was to assess early determinants of attention and hyperactivity problems in adolescents. In 1993, all hospital births in the city of Pelotas, Rio Grande do Sul State, Brazil, were monitored and mothers were interviewed (N = 5,249). At 11 years of age, 4,423 mothers answered the Strengths and Difficulties Questionnaire (SDQ) in order to evaluate attention and hyperactivity problems in the adolescents. Crude and adjusted prevalence ratios were calculated using Poisson regression. Prevalence of attention and hyperactivity problems was 19.9%. Factors associated with the outcome in the adjusted analysis were: male gender, low family income, smoking during pregnancy, minor psychiatric disorders in the mother, and history of child's behavioral/emotional problems at four years of age. Early life events impacted attention and hyperactivity problems in adolescence. Risk factors for attention and hyperactivity problems found in this study were similar to those reported in other cultures.

The aim of this study was to estimate the prevalence of sedentary behavior and investigate associated factors in adolescents 11 years of age from the 1993 birth cohort in Pelotas, Rio Grande do Sul State, Brazil. Sedentary behavior was investigated with a questionnaire, and was defined as spending more than two hours per day watching television, playing videogames, or using the computer. Of the 4,452 adolescents interviewed, 98% reported watching television, 44% playing videogames, and 22% using the computer. The average time spent on each of these electronic media was 197, 36, and 17 minutes per day, respectively. Prevalence of sedentary behavior was 79.7% (95%CI: 78.6; 80.9) and showed a positive association with socioeconomic level and nutritional status and a negative association with well-being. These 11-year-olds spent extensive time at TV viewing, videogames, and the computer. Special attention should be given to the most exposed groups of adolescents, including the more affluent, overweight, and those with limited schooling. O objetivo deste estudo foi determinar a prevalência e investigar os fatores associados ao comportamento sedentário em adolescentes de 11 anos, pertencentes à coorte de nascimentos de 1993 de Pelotas, Rio Grande do Sul, Brasil. O comportamento sedentário foi coletado por meio de questionário, e definido como ficar mais de duas horas por dia assistindo à televisão, jogando videogame ou usando computador. Dos 4.452 adolescentes entrevistados, 98% assistiam à televisão, 44% jogavam videogame e 22% usavam computador. O tempo médio na frente de cada um desses meios eletrônicos foi, respectivamente, 197, 36 e 17 minutos por dia. A prevalência de comportamento sedentário foi de 79,7% (IC95%: 78,6; 80,9), e teve uma associação positiva com nível socioeconômico e com estado nutricional, e negativa com a escala de bem-estar. O tempo despendido em atividades como ver televisão, jogar videogame e usar computador foi elevado (média superior a 4 horas/dia). Maior atenção deve ser dada aos grupos mais expostos, tais como adolescentes de classe alta, acima do peso e com menor nível de bem-estar.

Objetivo: Avaliar a influência do apoio à amamentação sobre as taxas de aleitamento materno no município de Pelotas (RS). Métodos: Foram comparadas as prevalências de aleitamento materno de quatro coortes de crianças, nascidas em 1982, 1993, 1997-1998 e 2004. Participaramcrianças que preenchiam os critérios de inclusão do Estudo Multicêntrico de Curvas de Crescimento da Organização Mundial da Saúde, já que este originou a coorte de 1997-1998, na qual houve apoio sistematizado à amamentação. Resultados: Houve aumento nas taxas de aleitamento materno exclusivo: com 1 mês de vida, de 26% em 1993 para 77% em 2004, e, aos 3 meses, de 16 para 46%, respectivamente. As taxas de aleitamento materno mostraram ascendência, porém menos significativa: aos 12 meses de 15% em 1982 para 34% em 2004 e, aos 24 meses, de 6 para 14%, respectivamente. Conclusões: O apoio à amamentação contribuiu na tendência ascendente das taxas de aleitamento materno. Objective: To evaluate the influence of breastfeeding support on breastfeeding rates in the city of Pelotas (RS), Brazil. Methods: The prevalence rates of exclusive breastfeeding and of overall breastfeeding were compared in four cohorts of children, born in 1982, 1993, 1997-1998 and 2004. The children selected for this study fulfilled the inclusion criteria for the WHO Multicenter Growth Reference Study, in order to afford comparison with the 1997-1998 cohort, which was made up of children selected for that study. The 1997-1998 cohort received systematic breastfeeding support. Results: There was an increase in the rates of exclusive breastfeeding: from 26% at 1 month of age in 1993 to 77% at the same age in 2004, and from 16% at 3 months to 46% for the same dates, respectively. Breastfeeding rates at later ages exhibited a tendency to increase, although with less significance: from 15% in 1982 at 12 months to 34% in 2004 at the same age and from 6% at 24 months to 14% for the same dates, respectively. Conclusions: Breastfeeding support has contributed to a tendency for breastfeeding rates to increase.

This study estimated the lifetime prevalence of toothache at ages 6 and 12 yr, the prevalence of toothache during the last month, and their association with social, behavioural and clinical exposures in the course of life of 339 12-yr-old children from a birth cohort in Pelotas, Brazil. Exploratory variables were collected in the perinatal study and during several follow-up studies. Prevalence ratios were calculated using Poisson regression, following a hierarchical conceptual model. The lifetime prevalence of toothache at ages 6 and 12 yr were 39% [95% confidence interval (CI) = (34;45)] and 63% [95% CI = (58;69)], respectively. Toothache during the last month was reported by 11% [95% CI = (8;15)]. Children who did not live with their biological father at birth, and children with higher dmf-t counts, reported a higher lifetime prevalence of toothache at age 6 yr. Children experiencing poverty between ages 0 and 4 yr, with higher dmf-t and DMF-T indexes presented a greater lifetime prevalence of toothache at 12 yr. Toothache within the last month was more likely to be reported by girls and by children who did not live with their biological father at birth. Preventive strategies should be implemented in early stages of the life cycle, taking into account the socio-economic and family context in which pain mostly occurs.

To estimate the prevalence of psychiatric disorders in preadolescents aged 11-12 years from a birth cohort in a southern Brazilian city.This is a cross-sectional investigation nested in a cohort study with a two-phase design: screening and diagnosis. In the screening phase, 4,452 preadolescents and their mothers were interviewed with the Strengths and Difficulties Questionnaire (SDQ). In the diagnostic phase, all preadolescents with a positive SDQ (n = 122) and their mothers answered the Development and Well-Being Assessment for Children and Adolescents (DAWBA). A sample randomly selected among the cohort participants with a negative SDQ served as a control group (158 subjects and their mothers) and was also assessed using the DAWBA.After adjustment for the performance of the screening instrument, 10.8% (95% CI 7.1-14.5) of the preadolescents showed at least one psychiatric disorder according to either the DSM-IV or the ICD-10. The most prevalent disorders were disruptive behavior (prevalence rates were 8.5% according to the DSM-IV and 7.1% according to the ICD-10) and anxiety disorders (prevalence rates were 6.0% according to the DSM-IV and 6.2% according to the ICD-10).Both overall and individual prevalence rates of psychiatric disorders found in this study are in the same range of other international studies, although slightly higher than findings from developed countries. The results corroborate previous findings from other epidemiological studies in children and adolescents suggesting the universality of psychiatric disorders across cultures.

Birth weight has short and long-term effects on health. Some studies have used retrospective data on birth weight, reported by the subject or by the parents. This paper compares data on birth weight measured by the research team in 1993 with birth weight reported by the mother in 2004-2005, using data from the 1993 Pelotas Birth Cohort Study, Rio Grande do Sul State, Brazil. We also evaluate the role of misclassification when exploring the effect of birth weight on a given outcome. Mean difference between the two variables was 20g (SD = 288.3). Agreement for detecting low birth weight was 95.2% in the sample as a whole (kappa = 0.73), but was lower among low-schooling mothers. Mothers of children weighing less than 3,500g at birth tended to overestimate the child's birth weight. Inversely, mothers of heavier children tended to underestimate the values. One out of four mothers reported a difference of at least 200g in birth weight as compared to that measured in 1993. Use of reported birth weight diluted the magnitude of the association with body mass index at 11 years in comparison with measured birth weight. Reported birth weight should be used with great caution, if at all.

The objective was to evaluate the effect of adding a nutritional supplement "multimixture" to school meals on the nutritional status of children enrolled at municipal preschools. Longitudinal controlled intervention study of 24 preschools which were compared before and after an intervention. The control and intervention groups were defined by drawing lots to choose schools that had previously been paired for nutritional status. The intervention consisted of the addition of 10 g of multimixture to the meals provided to children attending the 12 schools in the intervention group. Outcome measures include changes in z scores for the three nutritional indices and hemoglobin values over the 6-month period during which the supplement was added. A multilevel model was used for analyses. Mean z scores for weight for age at the end of follow-up were 0.40 (plus or minus 1.34) and 0.31 (plus or minus 1.32) for the intervention and control groups respectively. The multilevel analysis demonstrated non-significant differences in favor of the intervention in mean z scores for weight for age (beta 0.05; 95%CI -0.03 to 0.12) and height for age (beta 0.02; 95%CI -0.06 to 0.09). Mean change in hemoglobin was against the intervention but this was also without significance (beta -0.01; 95%CI -0.36 to 0.34). Supplementation with 10 g of multimixture did not have a significant effect on any of the nutritional indices or measurements of the municipal preschool pupils studied here. (authors)