Search

Background: In the current Physical Activity Guidelines (PAG) for moderate- and vigorous-intensity physical activity (MVPA), abrupt transition from ≥ 60 min/day [youth PAG] to ≥ 150 min/week (≥ 22 min/day on average) [adult PAG] during emerging adulthood is poorly justified. The aim of this study was to examine body fat mass changes according to whether meeting the youth and adult PAGs in late adolescence (age 18 years) to early adulthood (age 22 years). Methods: The study sample included 2,099 participants (1,113 females) from the 1993 Pelotas (Brazil) Study. At ages 18 and 22 years, MVPA was measured using wrist-worn accelerometry and fat mass was measured using dual-energy X-ray absorptiometry. MVPA at age 18 was categorized into two groups: 0–59 or ≥ 60 min/day (no [N] or yes [Y] for meeting the youth recommendation, respectively). MVPA at age 22 was categorized into three groups: 0–21, 22–59, or ≥ 60 min/day (N, Y22, or Y60 for not meeting the adult recommendation, meeting the adult recommendation, or meeting the youth recommendation, respectively). The combination of these groups created six MVPA groups (N&N, N&Y22, N&Y60, Y&N, Y&Y22, and Y&Y60). Sex-specific multivariable linear regression analyses were conducted to estimate change in fat mass index (FMI) from age 18 to 22 years in the six MVPA groups. Results: Among males, compared to Y&Y60 (FMI increase = 1.2 kg/m2 [95% CI = 1.0, 1.4]), Y&Y22 and Y&N had larger FMI increases (1.9 [1.6, 2.1] and 1.9 [1.2, 2.5], respectively). Among females, Y&Y60 and Y&Y22 had an equal FMI increase (1.6 [1.4, 1.9] for both groups), while Y&N had a larger FMI increase (2.4 [1.8, 3.0]). Conclusions: These findings suggest that among those who were active in late adolescence, engaging in ≥ 22 min/day of MVPA in adulthood is associated with lower body fat gain for females, but not for males. [ABSTRACT FROM AUTHOR]

Purposes: The aims of this study were to investigate the cross-sectional and prospective associations between accelerometer-measured physical activity and cardiometabolic health in the transition to adulthood. Methods: Data from the 1993 Pelotas (Brazil) Birth Cohort were analyzed (n = 2280). Moderate-to-vigorous intensity physical activity (MVPA) (measured using a triaxial accelerometer) and cardiometabolic health (total fat mass, blood glucose, non-high-density lipoprotein cholesterol, triglycerides, and mean resting blood pressure) were examined at age 18 and 22 yr. Results: Overall, inverse dose-response associations between MVPA and cardiometabolic health at age 18 and 22 yr were observed in cross-sectional analyses of data from men and women. Prospective analyses showed that, in general, MVPA declined, and cardiometabolic health worsened in this 4-yr period in both men and women. Cardiometabolic health at age 22 yr reflected both MVPA at age 18 yr (β, -0.007; 95% confidence interval [CI], -0.014 to 0.000) and changes in MVPA from 18 to 22 yr (β, -0.030; 95% CI, -0.043 to -0.016) in men, but only changes in MVPA in women (β, -0.035; 95% CI, -0.058 to -0.011). In analyses of change overtime, men who improved MVPA by 20 to 30 min-d-1 showed significant improvements in cardiometabolic health over 4 yr. The magnitude of association was slightly stronger for MVPA in 10-min bouts than for MVPA accumulated in bouts of 1 min, especially in women. Conclusions: Moderate-to-vigorous intensity physical activity is an important predictor of cardiometabolic health in early adulthood. Strategies to prevent declines in MVPA at this life stage are required to prevent deteriorating cardiometabolic health profiles. [ABSTRACT FROM AUTHOR]

Since the beginning of the pandemic of COVID-19, there has been a widespread assumption that most infected persons are asymptomatic. Using data from the recent wave of the EPICOVID19 study, a nationwide household-based survey including 133 cities from all states of Brazil, we estimated the proportion of people with and without antibodies for SARS-CoV-2 who were asymptomatic, which symptoms were most frequently reported, number of symptoms and the association with socio-demographic characteristics. We tested 33,205 subjects using a rapid antibody test previously validated. Information was collected before participants received the test result. Out of 849 (2.7%) participants positive for SARS-CoV-2 antibodies, only 12.1% (95% CI 10.1–14.5) reported no symptoms, compared to 42.2% (95% CI 41.7–42.8) among those negative. The largest difference between the two groups was observed for changes in smell/taste (56.5% versus 9.1%, a 6.2-fold difference). Changes in smell/taste, fever and body aches were most likely to predict positive tests as suggested by recursive partitioning tree analysis. Among individuals without any of these three symptoms, only 0.8% tested positive, compared to 18.3% of those with both fever and changes in smell or taste. Most subjects with antibodies against SARS-CoV-2 are symptomatic, even though most present only mild symptoms. [ABSTRACT FROM AUTHOR]

Summary: Background: Gestational weight gain (GWG) has been associated with the accumulation of body fat in offspring, but little is known about the intergenerational relationship. Objective: To assess the effect of GWG in grandmothers and mothers on the child's body mass index (BMI). Methods: This is a sub‐study nested in the 1993 Pelotas (Brazil) Birth Cohort at 22 years follow‐up visit. We calculated the BMI‐for‐age z‐score (BAZ) and evaluated overweight (>2 SD in ≤5 years of age and >1 SD for >5 years of age for BAZ). Grandmothers' and mothers' GWG were calculated as the difference between weight in the beginning of pregnancy and the last recorded weight before delivery. We standardized the GWG by adjusting for pre‐gestational BMI. We also categorized GWG as adequate, excessive, or insufficient, in accordance with the Institute of Medicine (2009). Linear and logistic regressions stratified by child's age (≤2 years; 2.01‐5 years; >5 years) were used. Structural equations were modelled to calculate the total, indirect, and direct effects of grandmothers' and mothers' GWG on children's BAZ. Results: Nine hundred and forty‐six out of 1113 children evaluated were 5 years of age or under. There was an indirect effect (through maternal birthweight, maternal pre‐gestational BMI, maternal GWG, and child birthweight) of grandmother GWG on grandchild BAZ, from 2.01 to 5 years of age [β = 0.12 95%CI: 0.04‐0.20 (P < 0.01)]. Maternal GWG directly increased the child's BAZ at >5 years of age [β = 0.34 95%CI: 0.15‐0.53 (P < 0.001)]. Conclusions: GWG's effect on BMI does seem to be transmitted across three generations. Managing this will require health education during the gestational period for women and their families. [ABSTRACT FROM AUTHOR]

Introduction: Web-based epidemiologic surveys are being widely used, but still present lower response rates compared to traditional methods. Their design can influence survey response rates. Objective: Analyse the influence of questionnaire length, frequency of reminders, and the interaction between them, on the response rates of five web-based questionnaires. Methods: This is a 2×2 factorial study. Participants registered into the coortesnaweb platform (n=1,277) were randomly assigned to respond to short or long questionnaires, and to receive high or low frequency of reminders. We analysed the influence of these factors on the response rates of five web-based questionnaires applied in a longitudinal manner. The relative risk of responding to an additional questionnaire was also analysed. Results: The mean response rate was 54.3%. Sending reminders more frequently was positively associated with the response rates for the first questionnaires. Questionnaire length did not influence response rates. We found no interaction between questionnaire length and frequency of reminders. Women and highly educated participants had, respectively, 13.0% and 28.0% increased probability of responding an additional questionnaire. Conclusions: We obtained high response rates for the first questionnaires. Sending reminders more frequently and providing conditional incentives should be employed. Long questionnaires did not jeopardize response rates of web-based questionnaires. [ABSTRACT FROM AUTHOR]

Background: Infant-mortality rates have been declining in many low- and middle-income countries, including Brazil. Information on causes of death and on socio-economic inequalities is scarce.Methods: Four birth cohorts were carried out in the city of Pelotas in 1982, 1993, 2004 and 2015, each including all hospital births in the calendar year. Surveillance in hospitals and vital registries, accompanied by interviews with doctors and families, detected fetal and infant deaths and ascertained their causes. Late-fetal (stillbirth)-, neonatal- and post-neonatal-death rates were calculated.Results: All-cause and cause-specific death rates were reduced. During the study period, stillbirths fell by 47.8% (from 16.1 to 8.4 per 1000), neonatal mortality by 57.0% (from 20.1 to 8.7) and infant mortality by 62.0% (from 36.4 to 13.8). Perinatal causes were the leading causes of death in the four cohorts; deaths due to infectious diseases showed the largest reductions, with diarrhoea causing 25 deaths in 1982 and none in 2015. Late-fetal-, neonatal- and infant-mortality rates were higher for children born to Brown or Black women and to low-income women. Absolute socio-economic inequalities based on income-expressed in deaths per 1000 births-were reduced over time but relative inequalities-expressed as ratios of mortality rates-tended to remain stable.Conclusion: The observed improvements are likely due to progress in social determinants of health and expansion of health care. In spite of progress, current levels remain substantially greater than those observed in high-income countries, and social and ethnic inequalities persist. [ABSTRACT FROM AUTHOR]

Background: Adolescents spend many hours in sitting activities as television viewing, video game playing and computer use. The relationship between sedentary behavior and respiratory health remains poorly elucidated. To date there have been no studies evaluating the relationship between sedentary behavior and pulmonary function in young populations. The purpose of this study is to examine the association between the trajectory of screen-based sedentary behavior from 11 to 18 years and pulmonary function at 18 years in a Brazilian birth cohort. Methods: Data from a longitudinal prospective study conducted among the participants of the 1993 Pelotas (Brazil) Birth Cohort. Time spent on television, video games, and computers during a weekday was self-reported at ages 11, 15 and 18 years. For each age, sedentary behavior was defined as the sum of time spent on these screen-based activities. To evaluate the sedentary behavior trajectory during adolescence group-based trajectory modeling was used. Outcome variables were three pulmonary function parameters: forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF), evaluated by spirometry, at 18 years expressed as z-scores. Crude and adjusted linear regressions, stratified by sex, were performed. Results: The three-group trajectory of sedentary behavior was the best fitting model. The trajectory groups were: always high (representing 38.8% of the individuals), always moderate (54.1%), and always low (7.1%). In the adjusted analyses, boys in the always-low group for sedentary behavior had higher FVC at 18 years (β = 0.177; 95% CI:0.027;0. 327; p = 0.021) than boys in the always-high group. There were no differences for other pulmonary function parameters in boys. No significant association was found for girls. Conclusion: The trajectory of screen-based sedentary behavior throughout adolescence was not consistent associated with pulmonary function at 18 years. [ABSTRACT FROM AUTHOR]

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 nonsignificant--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. [ABSTRACT FROM AUTHOR]

Background: The prevalence of Chronic Obstructive Pulmonary Disease (COPD) in many developed countries appears to be increasing. There is some evidence from Latin America that COPD is a growing cause of death, but information on prevalence is scant. It is possible that, due to the high frequency of smoking in these countries, this disease may represent a major public health problem that has not yet been recognized as such. The PLATINO study is aimed at measuring COPD prevalence in major cities in Latin America. Methods/Design: A multi-country survey is being carried out in major cities in Latin America. In each metropolitan area, a population-based sample of approximately 1,000 individuals aged 40 years or older is being interviewed using standardized questionnaires. Eligible subjects are submitted to pre- and postbronchodilator spirometry, and classified according to several criteria for COPD. Anthropometric examinations are also performed. Several risk factors are being studied, including smoking, socioeconomic factors, exposure to domestic biomass pollution, occupational exposure to dust and hospital admissions due to respiratory conditions during childhood. Whether or not subjects affected by COPD are aware of their disease, and if so how it is being managed by health services, is also being investigated, as are the consequences of this condition on quality of life and work performance. Results: At the present time, the study is completed in São Paulo, Mexico City and Montevideo; Chile has started the study in March 2004 and it will be followed by Venezuela; two other metropolitan areas could still join the PLATINO project. Similar sampling procedures, with stratification for socio-economic status, are being used in all sites. Strict coordination, training and standardization procedures have been used to ensure comparability of results across sites. Overall 92% of the pre-bronchodilator spirometry tests fulfilled ATS criteria of quality in the three first sites (97% in Montevideo, 91% in Mexico and 89% in Sao Paulo). Conclusions: The PLATINO project will provide a detailed picture of the global distribution of COPD in Latin America. This project shows that studies from Latin America can be carried out with adequate quality and be of scientific value. [ABSTRACT FROM AUTHOR]

AbstractBackgroundMethodsFindingsConclusion\nHIGHLIGHTSThe objectives of this study were to investigate the relationship between perinatal risk factors and suicidal ideation and attempts in young adults in Pelotas, Brazil.The data were collected from the 1993 Pelotas Birth Cohort study. Every pregnant woman who gave birth in one of the hospitals in Pelotas Brazil in 1993 was invited to participate in the study. The current study uses perinatal data collected in 1993, and follow-ups at ages 18 and 22. The primary outcome was lifetime suicide attempts with past month suicide ideation a secondary outcome. The association between perinatal predictors and suicidal ideation or lifetime suicide attempts was investigated using hierarchical logistic regression.There was an analytic sample size of 3493. The perinatal factors association with lifetime suicide attempts were sex (OR = 2.25 CI: 1.76–2.89), paternal education at birth (OR = 0.60, 95%CI: 0.36–0.99), maternal education (9–11 years OR = 2.81, 95%CI: 1.41–5.59, & 0–8 years OR = 2.21, 95%CI: 1.07–4.58), support from friends or neighbors at birth (OR = 0.36 95%CI: 0.17–0.77), and maternal smoking during pregnancy (OR = 1.41, 95%CI: 1.10–1.79). Patterns of associations were broadly similar with suicidal ideation. Interactions between sex and the perinatal factors paternal education, maternal education, smoking and support from friends were assessed and found to be not significant.Several factors during the perinatal period are associated with risk of lifetime suicide attempts and ideation in young adults in Brazil. Early-life factors associated with suicide-related concerns in early adulthood were similar to those observed in studies from high-income settings.Perinatal factors associated with suicidal behaviour were determined using data from upper-middle income setting.Maternal education, and maternal smoking are associated with risk of lifetime suicide attempts.Perinatal factors associated with suicidal ideation were similar to those of suicide attempts, including sex, maternal education, and maternal smoking.Perinatal factors associated with suicidal behaviour were determined using data from upper-middle income setting.Maternal education, and maternal smoking are associated with risk of lifetime suicide attempts.Perinatal factors associated with suicidal ideation were similar to those of suicide attempts, including sex, maternal education, and maternal smoking. [ABSTRACT FROM AUTHOR]

Objectives. To evaluate the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) over 6 months in the Brazilian State of Rio Grande do Sul (population 11.3 million), based on 8 serological surveys. Methods. In each survey, 4151 participants in round 1 and 4460 participants in round 2 were randomly sampled from all state regions. We assessed presence of antibodies against SARS-CoV-2 using a validated lateral flow point-of-care test; we adjusted figures for the time-dependent decay of antibodies. Results. The SARS-CoV-2 antibody prevalence increased from 0.03% (95% confidence interval [CI] = 0.00%, 0.34%; 1 in every 3333 individuals) in mid-April to 1.89% (95% CI = 1.36%, 2.54%; 1 in every 53 individuals) in early September. Prevalence was similar across gender and skin color categories. Older adults were less likely to be infected than younger participants. The proportion of the population who reported leaving home daily increased from 21.4% (95% CI = 20.2%, 22.7%) to 33.2% (95% CI = 31.8%, 34.5%). Conclusions. SARS-CoV-2 infection increased slowly during the first 6 months in the state, differently from what was observed in other Brazilian regions. Future survey rounds will continue to document the spread of the pandemic. [ABSTRACT FROM AUTHOR]

The objective of this study is to examine the association between preterm infants' size at 1 year and attention-deficit/hyperactivity disorder (ADHD) assessed categorically and dimensionally in childhood and adolescence. We studied infants born < 37 weeks' gestation from two Brazilian birth cohorts (n = 653). ADHD was evaluated using the Development and Well-Being Assessment (DAWBA) interview at the age of 6 years in one cohort and by a structured interview according to DSM-5 criteria at 18 years in the other one. The presence of child attention difficulties was measured by the Strengths and Difficulties Questionnaire (SDQ) at 6 and 11 years in the 2004 and 1993 cohorts, respectively. We estimated associations of weight, length, head circumference, and BMI z-scores at 1-year chronological age with ADHD using Poisson Regression Model; and with attention difficulties using Linear Regression, adjusting for covariates. Mean birth weight was 2500 g and gestational age was 34.5 weeks. The aggregated ADHD prevalence in the two cohorts was 2.7%, and the median score for attention difficulties was 3.0. We found that increased head circumference at 1 year was associated with a lower risk of ADHD diagnosis (RR = 0.7, 95% CI 0.4, 0.9; p = 0.04 per standard deviation difference) and with fewer dimensional attention symptoms. In sensitivity analysis with other mental disorders, head circumference was associated with depression, but not with anxiety. Our findings emphasize poor head growth in the first year of life as a potential determinant of attentional difficulties in the preterm infant population. [ABSTRACT FROM AUTHOR]

Background Many low- and middle-income countries have high levels of violence. Research in high-income countries shows that risk factors in the perinatal period are significant precursors of conduct problems which can develop into violence. It is not known whether the same early influences are important in lower income settings with higher rates of violence. This study compared perinatal and sociodemographic risk factors between Brazil and Britain, and their role in explaining higher rates of conduct problems and violence in Brazil. Methods Prospective population-based birth cohort studies were conducted in Pelotas, Brazil ( N = 3,618) and Avon, Britain ( N = 4,103). Eleven perinatal and sociodemographic risk factors were measured in questionnaires completed by mothers during the perinatal period. Conduct problems were measured in questionnaires completed by mothers at age 11, and violence in self-report questionnaires completed by adolescents at age 18. Results Conduct problems were predicted by similar risk factors in Brazil and Britain. Female violence was predicted by several of the same risk factors in both countries. However, male violence in Brazil was associated with only one risk factor, and several risk factor associations were weaker in Brazil than in Britain for both females and males. Almost 20% of the higher risk for conduct problems in Brazil compared to Britain was explained by differential exposure to risk factors. The percentage of the cross-national difference in violence explained by early risk factors was 15% for females and 8% for males. Conclusions A nontrivial proportion of cross-national differences in antisocial behaviour are related to perinatal and sociodemographic conditions at the start of life. However, risk factor associations are weaker in Brazil than in Britain, and influences in other developmental periods are probably of particular importance for understanding male youth violence in Brazil. [ABSTRACT FROM AUTHOR]

Background: Trajectories of attention-deficit hyperactivity disorder (ADHD) traits spanning early childhood to mid-life have not been described in general populations across different geographical contexts. Population trajectories are crucial to better understanding typical developmental patterns.Methods: We combined repeated assessments of ADHD traits from five population-based cohorts, spanning ages 3 to 45 years. We used two measures: (i) the Strengths and Difficulties Questionnaire (SDQ) hyperactive-inattentive subscale (175 831 observations, 29 519 individuals); and (ii) scores from DSM-referenced scales (118 144 observations, 28 685 individuals). Multilevel linear spline models allowed for non-linear change over time and differences between cohorts and raters (parent/teacher/self).Results: Patterns of age-related change differed by measure, cohort and country: overall, SDQ scores decreased with age, most rapidly declining before age 8 years (-0.157, 95% CI: -0.170, -0.144 per year). The pattern was generally consistent using DSM scores, although with greater between-cohort variation. DSM scores decreased most rapidly between ages 14 and 17 years (-1.32%, 95% CI: -1.471, -1.170 per year). Average scores were consistently lower for females than males (SDQ: -0.818, 95% CI: -0.856, -0.780; DSM: -4.934%, 95% CI: -5.378, -4.489). This sex difference decreased over age for both measures, due to an overall steeper decrease for males.Conclusions: ADHD trait scores declined from childhood to mid-life, with marked variation between cohorts. Our results highlight the importance of taking a developmental perspective when considering typical population traits. When interpreting changes in clinical cohorts, it is important to consider the pattern of expected change within the general population, which is influenced by cultural context and measurement. [ABSTRACT FROM AUTHOR]

Background: Socioeconomic inequalities in child nutrition may change rapidly over time, particularly in populations undergoing the nutrition transition. Yet, the few available studies are repeated cross-sectional surveys. By studying three prospective birth cohorts in the same city over a period of more than two decades, we describe secular trends in overweight and stunting at different ages, according to socioeconomic position. Methods: Population-based birth cohort studies were launched in the city of Pelotas (Brazil) in 1982, 1993 and 2004, with follow-up visits at twelve, 24 and 48 months. Children were weighed and measured at every visit. Z-scores of length/height-for-age and body mass index-for-age were calculated using the WHO Child Growth Standards. The slope and relative indices of inequality, based on family income quintiles, were estimated for each follow-up visit. Results: Between the 1982 and 2004 cohorts, stunting among four-year-olds declined (from 10.9% to 3.6%), while overweight increased (from 7.6% to 12.3%). In every visit, stunting prevalence was inversely related to income. Both absolute and relative inequalities declined over time; among four-year-olds stunting dropped from 26.0% in the 1982 cohort to 6.7% in the 2004 cohort in the poorest group, while in the richest group stunting prevalence dropped from 2.7% in 1982 to 1.1% in the 2004 cohort study. The secular trend towards increased overweight was evident for four-year-olds, in almost all socioeconomic groups, but not among one and two-year-olds. Among four-year old children, overweight prevalence increased in all income quintiles, by 130% in the middle-income group, 64% in the poorest and 41% in the richest group. Conclusions: The decline in stunting is remarkable, but the increase in overweight among four-year olds -- particularly among the poorest and the middle-income groups- requires concerted efforts to prevent the long term consequences of child overweight. [ABSTRACT FROM AUTHOR]

Reduced physical activity (PA) is an independent risk factor for lung function decline, hospitalization and mortality in chronic obstructive pulmonary disease (COPD) and affects a large proportion of patients from Europe and the United States. However, little is known of the level of PA of COPD patients in Latin America. The aim of this study was to provide information of the level of PA and its determinants in COPD patients in Latin America. This is an observational, cross-sectional study on patients with COPD in seven Latin American countries. PA level was evaluated with the short version of the International Physical Activity Questionnaire (IPAQ) and the association between PA and other variables was investigated. Complete information of PA level was obtained in 734 COPD patients consecutively recruited from specialized outpatient clinics; 448 (61%) were men, with a mean age of 69.6 years (standard deviation [SD] = 8.7) and a mean FEV1 (% predicted) = 49.1% (17.5%). In 37.9% the level of PA was low, and the average sitting time was 36.1 h per week. Patients with low levels of PA were older, with higher levels of dyspnea and higher CAT scores. Additionally, we found that patients with low level of PA presented more symptoms during the day. Low levels of PA have been observed in a large proportion of COPD patients of Latin America, which is higher in women and older patients and it is related with worse functional and clinical characteristics. [ABSTRACT FROM AUTHOR]

Background: Growth faltering has been associated with poor intellectual performance. The relative strengths of associations between growth in early and in later childhood remain underexplored.Objectives: We examined the association between growth in childhood and adult human capital in 5 low- and middle-income countries (LMICs).Methods: We analyzed data from 9503 participants in 6 prospective birth cohorts from 5 LMICs (Brazil, Guatemala, India, the Philippines, and South Africa). We used linear and quasi-Poisson regression models to assess the associations between measures of height and relative weight at 4 age intervals [birth, age ∼2 y, midchildhood (MC), adulthood] and 2 dimensions of adult human capital [schooling attainment and Intelligence Quotient (IQ)].Results: Meta-analysis of site- and sex-specific estimates showed statistically significant associations between size at birth and height at ∼2 y and the 2 outcomes (P < 0.001). Weight and length at birth and linear growth from birth to ∼2 y of age (1 z-score difference) were positively associated with schooling attainment (β: 0.13; 95% CI: 0.08, 0.19, β: 0.17; 95% CI: 0.07, 0.32, and β: 0.25, 95% CI: 0.10, 0.40, respectively) and adult IQ (β: 0.74, 95% CI: 0.35, 1.14, β: 0.73, 95% CI: 0.35, 1.10, and β: 1.52, 95% CI: 0.96, 2.08, respectively). Linear growth from age 2 y to MC and from MC to adulthood was not associated with higher school attainment or IQ. Change in relative weight in early childhood, MC, and adulthood was not associated with either outcome.Conclusions: Linear growth in the first 1000 d is a predictor of schooling attainment and IQ in adulthood in LMICs. Linear growth in later periods was not associated with either of these outcomes. Changes in relative weight across the life course were not associated with schooling and IQ in adulthood. [ABSTRACT FROM AUTHOR]

Background: Brazil has made substantial improvements in the duration of breastfeeding. We use data from four population-based cohorts to examine how trends and inequalities in breastfeeding indicators changed over time in a Brazilian city.Methods: Data from four birth cohorts, each including all births in a calendar year (1982, 1993, 2004 and 2015) in the city of Pelotas were used. Information on breastfeeding was collected when children were aged between 3 and 20 months. The prevalences of continued breastfeeding at 1 year of age and of exclusive breastfeeding at 3 months were calculated according to family income, maternal skin colour and sex.Results: Prevalence of breastfeeding at 12 months increased from 16% to 41% in the 33-year period. The prevalence of exclusive breastfeeding at 3 months increased from 7% in 1993 to 45% in 2015. Increases in exclusive breastfeeding at 3 months were seen in all socioeconomic groups, but the 2015 rates remain highest (57.2%) among the women in the richest quintile, and lowest among those in the poorest quintile (34.6%). Black mothers were more likely to breastfeed at 12 months than Whites in the four cohorts. In the earlier cohorts, breastfeeding at 12 months was more common among the poor, but by 2015 these differences had disappeared.Conclusions: There were important positive changes in breastfeeding practices during this period, but less than half of the children in 2015 were receiving the full benefits of breast milk. Improved breastfeeding practices are being adopted by high-income women to a greater extent than by poor women. [ABSTRACT FROM AUTHOR]

Background: Hospital admissions in infancy are declining in several countries. We describe admissions to neonatal intensive care units (NICU) and other hospitalizations over a 33-year period in the Brazilian city of Pelotas.Methods: We analysed data from four population-based birth cohorts launched in 1982, 1993, 2004 and 2015, each including all hospital births in the calendar year. NICU and other hospital admissions during infancy were reported by the mothers in the perinatal interview and at the 12-month visit, respectively. We describe these outcomes by sex of the child, family income and maternal skin colour.Results: In 1982, NICUs did not exist in the city; admissions into NICUs increased from 2.7% of all newborns in 1993 to 6.7% in 2015, and admission rates were similar in all income groups. Hospitalizations during the first year of life fell by 29%, from 23.7% in 1982 to 16.8% in 2015, and diarrhoea admissions fell by 95.2%. Pneumonia admissions fell by 46.3% from 1993 to 2015 (no data available for 1982). Admissions due to perinatal causes increased during the period. In the poorest income quintile, total admissions fell by 33% (from 35.7% to 23.9%), but in the richest quintile these remained stable at around 10%, leading to a reduction in inequalities. Over the whole period, children born to women with black or brown skin were 30% more likely to be admitted than those of white-skinned mothers.Conclusions: Whereas NICU admissions increased, total admissions in the first year of life declined by nearly one-third. Socioeconomic disparities were reduced, but important gaps remain. [ABSTRACT FROM AUTHOR]

Background: Levels of child undernutrition have declined in many middle-income countries, whereas overweight and obesity have increased. We describe time trends in nutritional indicators at age 1 year in the 1982, 1993, 2004 and 2015 Pelotas (Brazil) Birth Cohorts.Methods: Each study included all children born in the urban area of the city, with over 4 200 births in each cohort. Children were measured at approximately 12 months of age. Anthropometric indicators were calculated according to World Health Organization Growth Standards. Stunting and wasting were defined as <-2 Z scores for length for age and weight for length, and overweight as >2 Z scores for weight for length. Prevalence was stratified by sex, maternal skin colour and family income.Results: The prevalence of stunting declined by 53% (from 8.3% to 3.9%) from 1982 to 2015. Wasting prevalence remained stable at low levels (1.8% in 1982 and 1.7% in 2015), whereas overweight increased by 88% (6.5% to 12.2%). Undernutrition was more common among boys, those born to mothers with brown or black skin colour and in the poorest quintile of families. Socioeconomic inequalities in undernutrition decreased markedly over time. Overweight was markedly more common among the rich in 1982, but fast increase among the poor eliminated socioeconomic differences by 2015, when all groups showed similar prevalence.Conclusions: Our results confirm the rapid nutrition transition in Brazil, with marked reduction in levels and inequalities in undernutrition in parallel with a rapid increase in overweight, which became the main nutritional problem for children. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the association between parental separation during childhood (up to 18 years of age) and cardiometabolic risk factors (body mass index, fat mass index, blood pressure, physical activity, smoking, and alcohol consumption) in late adolescence using a cross-cohort comparison and to explore whether associations differ according to the age at which the parental separation occurred and the presence or absence of parental conflict prior to separation. Data from the Avon Longitudinal Study of Parents and Children (ALSPAC, United Kingdom) (1991-2011) and the 1993 Pelotas Birth Cohort (Brazil) (1993-2011) were used. The associations of parental separation with children's cardiometabolic risk factors were largely null. Higher odds of daily smoking were observed in both cohorts for those adolescents whose parents separated (for ALSPAC, odds ratio = 1.46; for Pelotas Birth Cohort, odds ratio = 1.98). Some additional associations were observed in the Pelotas Birth Cohort but were generally in the opposite direction to our a priori hypothesis: Parental separation was associated with lower blood pressure and fat mass index, and with more physical activity. No consistent differences were observed when analyses were stratified by child's age at parental separation or parental conflict. [ABSTRACT FROM AUTHOR]

Background: Association between caesarian section (C-section) and obesity is controversial and mostly based on body mass index (BMI), which has inherent limitations. Using direct estimates of body fat mass, we aimed to assess the association between C-section and adiposity using fat mass index and BMI z-score in three birth cohort studies from Pelotas, Brazil.Methods: We measured weight, height and fat mass (using dual X-ray absorptiometry (DXA)) at ages 6, 18 and 30 years among participants in the 2004, 1993 and 1982 population-based Pelotas Birth Cohort Studies, respectively. We used multiple linear regression analysis to examine the crude and adjusted association between C-section and the body composition indicators. We also modelled height as an outcome to explore the presence of residual confounding.Results: We observed that fat mass index and BMI z-score were strongly and positively associated with C-section in the crude analysis. However, when we adjusted for socioeconomic characteristics, maternal BMI, parity, age and smoking during pregnancy, effect estimates were attenuated towards the null, except for 30-year-old women. In those women from the 1982 cohort, C-section remained associated with fat mass index (β = 0.82; CI95% 0.32;1.32) and BMI z-score (β = 0.15; CI95% 0.03;0.28), even after adjusting for all potential confounders, suggesting an increase in fat mass index and BMI at 30 years among those born by C-section.Conclusion: We found no consistent association of C-section with fat mass index measured by DXA and BMI z-score in individuals aged 6, 18 and 30 years, except for women in the latter group, which might be explained by residual confounding. Confounding by socioeconomic and maternal characteristics accounted for all the other associations. [ABSTRACT FROM AUTHOR]

Background: Attention-deficit/hyperactivity disorder (ADHD) symptoms are dimensionally distributed in the population. This study aimed to assess the role of the catechol-O-methyltransferase (COMT) and of the dopamine transporter (DAT1) genes on ADHD symptoms in the general population. Methods: We investigated 4101 individuals from the 1993 Pelotas Birth Cohort Study using the parent version of the Strengths and Difficulties Questionnaire (SDQ) at ages 11 and 15 years. The SDQ hyperactivity/inattention scores were the main outcomes. Results: Linear regression analyses demonstrated that the increasing number of COMT158Val and DAT1 10R alleles significantly predicted increasing SDQ hyperactivity/inattention scores in boys at both 11 and 15 years of age (β coefficient = 0.049, f = 2.189, p = 0.029, R² = 0.012, and β coefficient = 0.064, f = 2.832, p = 0.005, R² = 0.008, respectively). The presence of both COMT158Val and DAT1 10R alleles was also associated with full categorical ADHD diagnosis at 18 years of age in boys (χ² = 4.561, p = 0.033, odds ratio 2.473, 95% confidence interval 1.048-5.838) from this cohort. We did not observe these associations in girls. Limitations: Our analyses of SDQ hyperactivity/inattention scores were not corrected for SDQ scores of conduct problems because these variables were highly correlated. Conclusion: This study demonstrates a role for COMT and DAT1 genes on hyperactivity/inattention symptoms and provides further support for ADHD as the extreme of traits that vary in the population. It also confirms previous evidence for sexual dimorphism on COMT and DAT1 gene expression. [ABSTRACT FROM AUTHOR]

Background: Attention-deficit/hyperactivity disorder (ADHD) symptoms are dimensionally distributed in the population. This study aimed to assess the role of the catechol-O-methyltransferase (COMT) and of the dopamine transporter (DAT1) genes on ADHD symptoms in the general population. Methods: We investigated 4101 individuals from the 1993 Pelotas Birth Cohort Study using the parent version of the Strengths and Difficulties Questionnaire (SDQ) at ages 11 and 15 years. The SDQ hyperactivity/inattention scores were the main outcomes. Results: Linear regression analyses demonstrated that the increasing number of COMT158Val and DAT1 10R alleles significantly predicted increasing SDQ hyperactivity/inattention scores in boys at both 11 and 15 years of age (β coefficient = 0.049, t = 2.189, p = 0.029, R2 = 0.012, and β coefficient = 0.064, t = 2.832, p = 0.005, R2 = 0.008, respectively). The presence of both COMT158Val and DAT1 10R alleles was also associated with full categorical ADHD diagnosis at 18 years of age in boys (χ2 = 4.561, p = 0.033, odds ratio 2.473, 95% confidence interval 1.048–5.838) from this cohort. We did not observe these associations in girls. Limitations: Our analyses of SDQ hyperactivity/inattention scores were not corrected for SDQ scores of conduct problems because these variables were highly correlated. Conclusion: This study demonstrates a role for COMT and DAT1 genes on hyperactivity/inattention symptoms and provides further support for ADHD as the extreme of traits that vary in the population. It also confirms previous evidence for sexual dimorphism on COMT and DAT1 gene expression. [ABSTRACT FROM AUTHOR]

Objective: To assess the stability and changes in fruit and vegetable (FV) consumption over a 3-year period during adolescence in a population-based birth cohort.Design: Longitudinal descriptive study. FV consumption was collected in 2008 and 2011/12 using an FFQ. We conducted descriptive analyses of medians to assess the trends in FV intake over time. Stability of FV intake was assessed by percentage of agreement and kappa coefficients.Setting: Pelotas, Rio Grande do Sul, Brazil.Subjects: Adolescents from 15 to 18 years of age (n 3915).Results: We observed an overall slight decrease in FV consumption during adolescence and also a moderate stability, especially in those with higher socio-economic status (proportion of agreement 38.6% and 40.5% for boys and girls, respectively). About a half of those consuming low levels of FV at 15 years of age still consumed low levels 3 years later.Conclusions: Our results showed that FV consumption presented a moderate stability across a 3-year period during adolescence, especially in those with higher socio-economic status. Given the great proportions of non-communicable diseases such as CVD, diabetes and obesity, knowledge about the patterns of FV consumption during adolescence has implications for health promotion interventions. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to examine the prospective associations of physical activity at 11, 15, and 18 yr of age with cognitive performance in young adulthood in a large birth cohort study from Brazil. Methods: Participants were part of a large birth cohort study in Pelotas, Brazil (n = 3235 participants). Physical activity was self-reported at 11, 15, and 18 yr and was also objectively measured at 18 yr. Cognitive performance was assessed using an adapted Brazilian version of the short form of the Wechsler Adult Intelligence Scale at 18 yr. Results: At 11 yr, participants in the middle tertile of self-reported physical activity presented a significantly higher cognitive performance score as compared with the lowest tertile. Physical activity at 15 yr of age was unrelated to cognitive performance at 18 yr. Self-reported physical activity was cross-sectionally positively associated with cognitive performance at 18 yr (P < 0.001). Data from objectively measured physical activity at 18 yr showed that those in the highest moderate-to-vigorous physical activity tertile presented lower cognitive performance scores at 18 yr as compared with those in the lowest tertile (-2.59; 95% confidence interval (CI), -3.41 to -1.48). Analyses on changes in tertiles of physical activity showed that maintaining an intermediate physical activity level from 11 to 18yr and from 15 to 18 yr was associated with a higher cognitive performance score of 2.31 (95% CI, 0.71-3.91) and 1.84 score (95% CI, 0.25-3.42), respectively. Conclusions: Physical activity throughout adolescence is associated with cognitive performance before adulthood. Adolescents who are active at moderate levels, specifically those who maintain these levels of physical activity, tend to show higher cognitive performance. However, high levels of physical activity might impair cognitive performance. [ABSTRACT FROM AUTHOR]

Objective: Replication of scientific findings is a major challenge in biomedical research. In psychiatry, the identification of measured gene-environment interactions (G×E) has promoted a heated debate over the past decade, with controversial results about its influence on disorders such as major depression. The authors sought to replicate a 2003 study on G×E in youth depression in a large birth cohort from a diverse setting.Method: Using data from the 1993 Pelotas Birth Cohort Study, and adopting a design as similar as possible to that of the original study, the authors tested whether the relationship between childhood maltreatment and a subsequent depressive episode diagnosis was moderated by 5-HTTLPR genotype. Of 5,249 individuals assessed at birth and followed up to age 18, data on the evaluation for depressive episodes in early adulthood, on childhood maltreatment, and on genotype were available for 3,558 participants, of whom 2,392 remained after conservative screening for previous depressive symptoms. Associations were investigated with logistic regression analyses and controlling for potential confounders.Results: The results replicated important findings of the original study, this time in a sample of young adults from a middle-income country: there was a differential dose-response relationship between childhood maltreatment and major depression according to 5-HTTLPR genotype.Conclusions: After following a research strategy as comparable as possible to that of the original study, the results corroborated the existence of a measured G×E, now in a large sample from a different sociocultural context. These findings provide further evidence that a genetic variant in the 5-HTTLPR moderates the link between childhood maltreatment and youth depression. [ABSTRACT FROM AUTHOR]

Background We examined the associations of maternal age with low birthweight ( LBW) and preterm birth in four cohorts from a middle- and a high-income country, where the patterning of maternal age by socio-economic position ( SEP) is likely to differ. Methods Population-based birth cohort studies were carried out in the city of Pelotas, Brazil in 1982, 1993, and 2004, and in Avon, UK in 1991 [ Avon Longitudinal Study of Parents and Children ( ALSPAC)]. Adjustment for multiple indicators of SEP were applied. Results Low SEP was associated with younger age at childbearing in all cohorts, but the magnitudes of these associations were stronger in ALSPAC. Inverse associations of SEP with LBW and preterm birth were observed in all cohorts. U-shaped associations were observed between maternal age and odds of LBW in all cohorts. After adjustment for SEP, increased odds of LBW for young mothers (<20 years) attenuated to the null but remained or increased for older mothers (≥35 years). Very young (<16 years) maternal age was also associated with both outcomes even after full SEP adjustment. SEP adjusted odds ratio of having a LBW infant in women <16 years and ≥35 years, compared with 25-29 years, were 1.48 [95% confidence interval ( CI) 1.00, 2.20] and 1.66 [95% CI 1.36, 2.02], respectively. The corresponding results for preterm birth were 1.80 [95% CI 1.23, 2.64)] and 1.38 [95% CI 1.15, 1.67], respectively. Conclusion Confounding by SEP explains much of the excess risk of LBW and preterm among babies born to teenage mothers as a whole, but not for mothers aged <16 or ≥35 years. Given that the proportion of women becoming pregnant at <16 years is smaller than for those ≥35 years, the population burden is greater for older age. [ABSTRACT FROM AUTHOR]

The dopamine receptor D4 (DRD4) is one of the most studied candidate genes for Attention-Deficit/Hyperactivity Disorder (ADHD). An excess of rare variants and non-synonymous mutations in the VNTR region of 7R allele in ADHD subjects was observed in previous studies with clinical samples. We hypothesize that genetic heterogeneity in the VNTR is an important factor in the pathophysiology of ADHD. The subjects included in the present study are members of the 1993 Pelotas Birth Cohort Study (N=5,249). We conducted an association study with the 4,101 subjects who had DNA samples collected. The hyperactivity-inattention scores were assessed through the parent version of the Strengths and Difficulties Questionnaire at 11 and 15 years of age. The contribution of allele’s length and rare variants to high hyperactivity/inattention scores predisposition was evaluated by multivariate logistic regression. No effect of allele length was observed on high scores of hyperactivity-inattention. By contrast, when resequencing/haplotyping was conducted in a subsample, all 7R rare variants as well as non-synonymous 7R rare variants were associated with high hyperactivity/inattention scores (OR=2.561; P=0.024 and OR=3.216; P=0.008 respectively). A trend for association was observed with 4R rare variants. New coding mutations covered 10 novel motifs and many of them are previously unreported deletions leading to different stop codons. Our findings suggest a contribution of DRD4 7R rare variants to high hyperactivity-inattention scores in a population-based sample from a large birth cohort. These findings provide further evidence for an effect of DRD4 7R rare variants and allelic heterogeneity in ADHD genetic susceptibility. [ABSTRACT FROM AUTHOR]

Background: Physical inactivity is responsible for 5.3 million deaths annually worldwide. To measure physical activity energy expenditure, the doubly labeled water (DLW) method is the gold standard. However, questionnaires and accelerometry are more widely used. We compared physical activity measured by accelerometer and questionnaire against total (TEE) and physical activity energy expenditure (PAEE) estimated by DLW. Methods: TEE, PAEE (TEE minus resting energy expenditure) and body composition were measured using the DLW technique in 25 adolescents (16 girls) aged 13 years living in Pelotas, Brazil. Physical activity was assessed using the Actigraph accelerometer and by self-report. Physical activity data from accelerometry and self-report were tested against energy expenditure data derived from the DLW method. Further, tests were done to assess the ability of moderate-to-vigorous intensity physical activity (MVPA) to predict variability in TEE and to what extent adjustment for fat and fat-free mass predicted the variability in TEE. Results: TEE varied from 1,265 to 4,143 kcal/day. It was positively correlated with physical activity (counts) estimated by accelerometry (rho  = 0.57; p = 0.003) and with minutes per week of physical activity by questionnaire (rho  = 0.41; p = 0.04). An increase of 10 minutes per day in moderate-to-vigorous intensity physical activity (MVPA) relates to an increase in TEE of 141 kcal/day. PAEE was positively correlated with accelerometry (rho  = 0.64; p = 0.007), but not with minutes per week of physical activity estimated by questionnaire (rho  = 0.30; p = 0.15). Physical activity by accelerometry explained 31% of the vssariability in TEE. By incorporating fat and fat-free mass in the model, we were able to explain 58% of the variability in TEE. Conclusion: Objectively measured physical activity significantly contributes to the explained variance in both TEE and PAEE in Brazilian youth. Independently, body composition also explains variance in TEE, and should ideally be taken into account when using accelerometry to predict energy expenditure values. [ABSTRACT FROM AUTHOR]

Background: The study of gene-environment interactions (G × E) is one of the most promising strategies to uncover the origins of mental disorders. Replication of initial findings, however, is essential because there is a strong possibility of publication bias in the literature. In addition, there is a scarcity of research on the topic originated from low- and middle-income countries (LMIC). The aim of this study was to replicate G × E hypotheses for externalizing problems among adolescents in a middle-income country. Methods: As part of the Pelotas 1993 Birth Cohort Study, 5,249 children were enrolled at birth and followed up to the age of 15 years, with an 85.7% retention rate. We sought an interaction between the homozygosity of the 10-repeat allele at the dopamine transporter ( DAT1) gene and prenatal maternal smoking in the development of hyperactivity problems during adolescence assessed by the Strengths and Difficulties Questionnaire. We also tested for an interaction between the uVNTR polymorphism at the monoamine oxidase A ( MAOA) and the experience of childhood maltreatment in the occurrence of conduct problems among adolescent boys. Results: Although there was a clear association between prenatal maternal smoking and hyperactivity scores in adolescence ( p < 0.001), no main genetic or interaction effects for the DAT1 gene were detected. Similarly, childhood maltreatment showed to be associated with conduct problems among boys ( p < 0.001), with no observable main genetic or interaction effects for the MAOA gene. Conclusions: In the largest mental health G × E study performed in a LMIC to date, we did not replicate previous positive findings from the literature. Despite the presence of main environmental effects, there was no evidence of effect modification by genotype status. Additional replication efforts to measure G × E are needed to better understand the origins of mental health and illness, especially in LMIC. [ABSTRACT FROM AUTHOR]

Objective: To investigate the predictors of change in physical activity (PA) from early to mid adolescence in a cohort of adolescents.Design: Prospective, population-based birth cohort study. PA level was evaluated by means of questionnaire, and was analysed in continuous form (min/week) and as a trajectory (inactive-inactive, inactive-active, active-inactive, active-active) based on the cut-off point of 300 min/week.Setting: Pelotas, a city of 340 000 inhabitants in southern Brazil.Subjects: Adolescents (n 4120) followed from 11 to 15 years of age.Results: Maternal PA change and more exposure to outdoors were directly associated with a positive change in PA level (min/week) for both genders. Higher maturation status (among boys) and later menarche were also associated with positive PA change in min/week. Predictors to remain inactive were: maternal PA change (inverse association), more exposure to outdoors, higher socio-economic level, fear of living in the neighbourhood and non-overweight girls. Predictors to become inactive were higher socio-economic level among boys and increase in screen time among girls.Conclusions: The study demonstrates that social, family, biological, behavioural and environmental factors exert an important role in the PA change among youngsters as they move into adolescence. These findings may be relevant to the design of policies and intervention programmes aimed at promoting PA in teenagers. [ABSTRACT FROM AUTHOR]

Objective. To evaluate the occurrence of grade retention until 11 years of age and the factors associated with retention. Methods. This prospective study included 4 452 adolescents from the 1993 city of Pelotas birth cohort (state of Rio Grande do Sul, Brazil). This sample represents 87.5% of the original cohort. Grade retention was defined as the repetition of at least one school grade until the date of the interview. The following independent variables were analyzed: sex, skin color, birth weight, ownership of goods, age, maternal schooling, type of school (private, state, or city), age at school entry, and employment. Results. The overall frequency of grade retention was 36.3%, vs. 42.8% for boys and 30.0% for girls. The adjusted analysis showed that the lower the level of maternal schooling, ownership of goods, and birth weight, the higher the risk of grade retention for both boys and girls. Black/brown adolescents, those studying in public schools, and those who were 7 years of age or older at school entry had a higher risk of grade retention. For boys, childhood labor was associated with grade retention. Conclusions. Low socioeconomic and low maternal schooling levels were the factors most strongly associated with grade retention. Strategies to reduce this situation must take into account demographic and socioeconomic characteristics. [ABSTRACT FROM AUTHOR]

Objective. To evaluate the prevalence of and factors associated with discrimination self-reported by adolescents. Methods. Cross-sectional analysis of adolescents belonging to a cohort of live births in 1993 in the city of Pelotas, Brazil. From the 5 249 members of the cohort, information was collected from 4 452 adolescents in 2004 and 2005 regarding self-reported discrimination, sociodemographic variables, physical attributes, and nutritional status. A Poisson regression was utilized in the raw and adjusted analyses to estimate prevalence rates (RP). Results. The global prevalence of self-reported discrimination was 16.4%. In the adjusted analysis, discrimination was reported more by the following groups: girls (RP = 1.27, 95%CI: 1.10-1.48), people identified by others as black (RP = 1.28, 95%CI: 1.04-1.57), poorer adolescents (RP = 1.58, 95%CI: 1.23-2.02), those who perceived themselves to be very thin or very fat (RP = 1.81 and 1.54 respectively), those whose families had financial trouble (RP = 1.76, 95%CI: 1.49-2.08), those who wore glasses (RP = 1.74, 95%CI: 1.45-2.10), those who thought their teeth looked bad (RP = 1.58, 95%CI: 1.21-2.07), those who had been reprimanded in school (RP = 1.23, 95%CI: 1.01- 1.51), and those who had been involved in fights in the past year (RP = 1.62, 95%CI: 1.36-1.94). The association between discrimination and nutritional status varied by sex (interaction P = 0.009). Thin children reported greater discrimination than those who were overweight or obese. Discrimination on the basis of obesity was higher among girls, with this effect more strongly felt among rich girls than among poor ones. Conclusions. Self-reported discrimination was prevalent and unequally distributed among the population. Actions to reduce experiences of discrimination must be implemented during the initial stages of life. [ABSTRACT FROM AUTHOR]

Background: The Developmental Origins of Health and Disease hypothesis suggests that intrauterine, infancy and early childhood variables play a key role at programming later health. However, little is known on the programming of behavioral variables, because most studies so far focused on chronic disease-related and human capital outcomes. The aim of the present study was to evaluate the effects of prenatal, infancy and childhood weight and length/height gains on objectively-measured physical activity (PA) in adolescence. Methods: This is a prospective birth cohort study in Pelotas, Brazil, including 457 adolescents (mean age: 13.3 years) with weight and length/height data at birth, one, three and six months, one and four years of age. PA was measured using a GT1M Actigraph accelerometer, and expressed as (a) minutes per day spent on sedentary, light, moderate, vigorous and very-vigorous activities; (b) total counts per day. Results: 61.3% of the adolescents accumulated 60+ minutes of moderate-to-vigorous PA per day. Weight and length/height trajectories in infancy and childhood were similar between those classified as active or inactive at 13.3 years. However, those classified as inactive were heavier and taller at all ages; differences were statistically significant only in terms of length at three, six and 12 months. Conclusions: Weight gain in infancy and childhood did not predict variability in adolescent PA, but those active in adolescence showed somewhat smaller average gains in length in infancy. These findings suggest that PA may partially be sensitive to early hormonal programming, or that genetic factors may affect both early growth and later metabolism or predisposition for PA. [ABSTRACT FROM AUTHOR]

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 TaqManW, 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: To investigate the main dental caries life course determinants and predictors of dental caries at age 12. Methods: 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 (DMFT ≥ 1) at 12 years old was tested using logistic regression analyses. Results: 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. Conclusions: 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]