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Avaliou-se a prevalência de sobrepeso em adolescentes e sua distribuição segundo varíaveis demográficas, sócio-econômicas, comportamentais e biológicas. Foram entrevistados 810 adolescentes entre 10 e 19 anos, residentes na zona urbana de Pelotas, Rio Grande do Sul, Brasil. O sobrepeso foi definido de acordo com a OMS (IMC > ou = Percentil 85, segundo idade e sexo conforme a população de referência do I National Health and Nutrition Examination Survey). O processo amostral foi por conglomerados e as análises bruta e ajustada (Regressão de Poisson) levaram em conta o efeito de delineamento. A prevalência de sobrepeso em adolescentes foi de 19,3% (IC95%: 16,6-22,0) e não houve diferença entre os sexos. Adolescentes pertencentes aos níveis econômicos mais elevados, que realizaram dieta para emagrecer nos três meses anteriores à entrevista, que assistiam quatro horas ou mais de televisão por dia e que realizavam apenas uma ou duas refeições diárias apresentaram maior proporção de sobrepeso. Na análise ajustada, o sobrepeso nos meninos esteve diretamente associado com nível econômico e, nas meninas, com as variáveis dieta para emagrecer, número de horas diárias assistindo à televisão e inversamente associado com o número de refeições.

Abstract 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.

Abstract 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.

OBJECTIVE: To analyze the association between mental health problems and smoking in adolescents. METHODS: A total of 4,325 adolescents aged 15 from the 1993 birth cohort of the city of Pelotas, Southern Brazil, was studied. Smoking was defined as having smoked one or more cigarettes in the previous 30 days. Mental health was assessed according to the total score of the Strengths and Difficulties Questionnaire. Score = 20 points was considered positive. Data were analyzed using Poisson regression with adjustment for robust variance. RESULTS: Smoking prevalence was 6.0% and about 30% of the adolescents presented some mental health problem. In the crude analysis, the prevalence ratio for smoking was 3.3 (95%CI 2.5; 4.2). After the adjusted analysis (for sex, age, skin color, family income, mother's level of schooling, group of friends who smoke, employment in the previous year, school failure, physical activity during leisure time and experimental use of alcohol), it decreased to 1.7 (95%CI 1.2; 2.3) among those with mental health problem. CONCLUSIONS: Mental health problems in adolescence may be related to tobacco consumption. [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]

Copyright of Cadernos de Saude Publica is the property of Escola Nacional de Saude Publica Sergio Arouca and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cadernos de Saude Publica is the property of Escola Nacional de Saude Publica Sergio Arouca and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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]

Objective: To investigate the effect of demographic, socioeconomic, educational and family variables on HIV/AIDS knowledge among adolescents aged 11 years., Methods: 3,949 adolescents born in Pelotas (Brazil). HIV/AIDS knowledge was assessed through a self-administered questionnaire and measured through five questions about HIV transmission: heterosexual intercourse, homosexual intercourse, needle sharing, open-mouth kissing and hugging someone with AIDS. All the analyses were adjusted based on a hierarchical model, using Poisson regression with robust adjustment of variance., Results: Prevalence of wrong answers to the examined questions were 17.2% for heterosexual transmission, 44.1% for homosexual intercourse, 34.9% for needle sharing, 25.6% for kiss on the mouth and 16.2% for hugging someone with AIDS. In adjusted analysis, lower knowledge levels were more prevalent among boys, adolescents with lower socioeconomic status and with less maternal education level, among those who had not talked about sex with mother and without sexual education lessons at school. Knowledge was not associated with school type (public or private), skin color or talk about sex with father., Conclusion: Providing information to adolescents is essential to improve knowledge about HIV and other sexually transmitted infections, especially among young males, with lower socioeconomic status and with lower maternal education level. Public policies aimed to reducing HIV infection should consider maternal and school relevance to improve knowledge on adolescents.

Purpose: To evaluate the associations between family socioeconomic trajectories from 0 to 11 years of age and risk factors for noncommunicable disease at 15 years., Methods: Individuals 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., Results: Of 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., Conclusions: Adolescent 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., (Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

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., (Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: To 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., Methods: The 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., Results: From 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)., Conclusions: Since 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., (Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: We explored predictors of nutritional status change from 11 to 15 years of age by analyzing prospective data., Methods: We 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., Results: Of 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., Conclusions: BMI 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., (Copyright © 2012. Published by Elsevier Inc.)

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.

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.

Background: Valid measurements of blood pressure, both at clinical and community settings, are essential for monitoring this variable at the population level., Objective: To evaluate the validity of a wrist digital monitor for measuring blood pressure among adolescents in comparison to a mercury sphygmomanometer., Methods: A validation study was carried out in the city of Pelotas, Southern Brazil. Blood pressure was measured twice using two different sphygmomanometers; an OMRON wrist digital and a desktop BD mercury one. Half of the sample was measured first with the digital manometer and subsequently with the mercury one, whereas the remaining half was evaluated in the opposite order. Agreement between both measures was evaluated using the Bland and Altman method., Results: 120 adolescents aged 14 to 15 years were included (50% of each sex). Mean systolic blood pressure among boys was 113.7 mmHg (SD 14.2) when using the mercury manometer and 115.5 mmHg (SD 15.2) when using the digital one. Equivalent values for diastolic blood pressure were 61.5 mmHg (SD 9.9) and 69.6 mmHg (10.2), respectively. Among girls, the mean systolic blood pressure was 104.7 mmHg (SD 10.1) when using the mercury manometer and 102.4 mmHg (SD 11.9) when using the digital device. Values for diastolic blood pressure were 60.0 mmHg (SD 10.4) and 65.7 mmHg (SD 7.7), respectively., Conclusions: The digital device showed a high level of agreement with the mercury manometer when measuring systolic blood pressure. The level of agreement was lower for diastolic blood pressure. The use of correction equations may be an alternative for studies using this wrist digital monitor in adolescent patients.

Objective: To describe the level of physical activity in adolescents born in 1993 in the city of Pelotas, Brazil, and to evaluate the effect of sociocultural variables on those levels., Methods: A combined ethno-epidemiological methodology was employed. In the epidemiological study, 4 452 adolescents born in 1993 were interviewed. Physical activity level was evaluated by means of a questionnaire. Adolescents with fewer than 300 minutes of physical activity per week were classified as sedentary. The ethnographic study included 69 adolescents randomly selected from among all cohort participants. On average, three in-depth interviews were carried out (about one every 6 months), with mothers and adolescents being interviewed separately., Results: The prevalence of a sedentary lifestyle was 48.7% (95%CI: 46.5 to 50.8) in boys and 67.5% (95%CI: 65.6 to 69.5) in girls (P < 0.001). The independent variable presenting the strongest association with physical activity level was the weekly frequency with which the adolescent met friends outside of school. The ethnographic study showed that boys have more social and family support to engage in physical activities in adolescence, but that many parents associate poor school performance with the amount of time spent outside the home., Conclusions: This study suggests that physical activity is often viewed as competing with family values in adolescence. This perspective should be explored in future studies and discussed with families so that physical activity may be adopted as a cultural norm.

Background: Many asthma studies are available in the literature, but few investigated whether risk factors for asthma differ by sex., Objective: To evaluate risk factors for wheezing in early adolescence, with emphasis on sex differences., Methods: A prospective birth cohort study was initiated in 1993; 87.5% of the original cohort was traced at 11 years, totaling 4,452 adolescents. Current wheezing was defined as at least 1 crisis in the previous 12 months. The following independent variables were analyzed: maternal smoking during pregnancy, wheezing at 4 years, maternal wheezing, and adolescent body mass index., Results: Current wheezing affected 13.5% (95% confidence interval [CI], 12.4%-14.5%) of the cohort. The prevalence of current wheezing was 15.3% (95% CI, 13.7%-16.8%) in boys and 11.7% (95% CI, 10.4%-13.1%) in girls (P < .001). Maternal smoking was related to an increased risk of wheezing for boys but not for girls. There was a significant tracking of wheezing from 4 to 11 years in both sexes, although the magnitude was stronger for boys. A dose-response association between maternal wheezing and adolescent wheezing was observed in boys but not in girls. Finally, obesity was associated with an increased risk of wheezing in boys but not in girls., Conclusions: The variables explored in this investigation had a stronger effect on adolescent wheezing in boys than in girls. Public health strategies aimed at minimizing the burden of wheezing should take these sex differences into account.

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.

Background: Physical inactivity is one of the leading causes of morbidity and mortality worldwide. Walking, an inexpensive and accessible activity, is protective against unhealthy outcomes. Little data on walking practices are available outside developed countries. This study estimated the prevalence and correlates of compliance with physical activity recommendations through leisure-time and all-domain (combined leisure time, commuting, and work-related) walking in individuals aged > or =20 years in a southern Brazilian city., Methods: Data from two population-based surveys carried out in 2002 and 2003 in Pelotas, Rio Grande do Sul, were compared and analyzed in 2004. Multistage sampling procedures were undertaken in both surveys. Compliance with physical activity recommendations was defined as > or =150 minutes/week of walking during the previous week, although other cut-off points were estimated. The International Physical Activity Questionnaire was used in both studies., Results: Samples comprised 3182 (2002 study) and 3100 (2003 study) individuals. Nonresponse rates were 5.6% and 3.5%, respectively. Both prevalence and correlates of leisure-time and all-domains walking were markedly different. Compliance with physical activity guidelines (> or =150 minutes/week) through walking was 40.6% (all domains) and 15.0% (leisure time). Poor and uneducated participants had a lower likelihood of walking than higher-income and more educated people, particularly in leisure time. Walkers were also more likely to practice other vigorous and moderate-intensity activities., Conclusions: Although the results derive from a single Brazilian city, they are likely to be relevant to similar environments/locales in middle-income countries, where the obesity epidemic is rapidly increasing. Due to the low levels of walking detected, particularly during leisure time, healthcare professionals are encouraged to recommend walking to their patients.