Background: The number of cesarean sections (CSs) is increasing in many countries, and there are concerns about their short- and long-term effects. A recent Brazilian study showed a 58% higher prevalence of obesity in young adults born by CS than in young adults born vaginally. Because CS-born individuals do not make contact at birth with maternal vaginal and intestinal bacteria, the authors proposed that this could lead to long-term changes in the gut microbiota that could contribute to obesity.Objective: We assessed whether CS births lead to increased obesity during childhood, adolescence, and early adulthood in 3 birth cohorts.Design: We analyzed data from 3 birth-cohort studies started in 1982, 1993, and 2004 in Southern Brazil. Subjects were assessed at different ages until 23 y of age. Poisson regression was used to estimate prevalence ratios with adjustment for ≤15 socioeconomic, demographic, maternal, anthropometric, and behavioral covariates.Results: In the crude analyses, subjects born by CS had ∼50% higher prevalence of obesity at 4, 11, and 15 y of age but not at 23 y of age. After adjustment for covariates, prevalence ratios were markedly reduced and no longer significant for men or women. The only exception was an association for 4-y-old boys in the 1993 cohort, which was not observed in the other 2 cohorts or for girls.Conclusion: In these 3 birth cohorts, CSs do not seem to lead to an important increased risk of obesity during childhood, adolescence, or early adulthood.

Two diagonal quadrants protocol may be effective in identifying the risk factors for the most relevant periodontal outcomes in adolescence and in young adulthood.

BackgroundPhysical activity is likely to be determined as a complex interplay between personal, interpersonal, and environmental factors. Studying the built environment involves expanding the focus from the individual perspective to a public health one. Therefore, the objetive of this study was to examine the association between the built environment and objectively-measured physical activity among youth.MethodsCross-sectional analysis of data from of a Brazilian birth cohort during adolescence. Physical activity was measured using accelerometers (GENEActiv) and self-report (International Physical Activity Questionnaire, long version). Participants’ home addresses were geocoded and built environment characteristics such as streets’ pattern and quality, and public open spaces attributes for physical activity practice were evaluated in a 500-m circular buffer surrounding their homes.ResultsA total of 3379 participants were included. Street lighting (β = 2.2; 95%CI: 0.5; 3.9) was positively associated with objectively-measured moderate-vigorous physical activity (MVPA) and proportion of paved streets and buffer’s average family income were associated with lower MVPA. Living near the beach increased the odds of leisure-time MVPA practice by 3.3 (95%CI: 1.37; 8.02) times. There was a built environment-by-socioeconomic status (SES) interaction for the associations with commuting physical activity; street lighting [Odds ratio (OR) = 1.22; 95%CI: 1.01; 1.47] and presence of cycle lanes (OR = 1.77; 95%CI: 1.05; 2.96) were positively associated with commuting physical activity only among the intermediate SES tertile.ConclusionBeachfront, street lighting, paved streets and cycle lanes were associated with physical activity patterns. This suggests that infrastructure interventions may influence physical activity levels of Brazilian adolescents.

BackgroundWe 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.MethodsAll 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.ResultsIndependent 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.ConclusionsAdequate evaluation of maternal anthropometric characteristics during pregnancy may prevent high levels of blood pressure among adolescent children.

Resumo ObjetivoAvaliar a tendência temporal do tabagismo em estudantes de medicina nos últimos dez anos. Métodos Realizou-se estudo transversal com estudantes do primeiro ao quinto ano do curso de medicina, em 1996. A amostra foi de 449 alunos que responderam a questionário auto-aplicável. Fumante era aquele que fumava um ou mais cigarros por dia há pelo menos um mês; ex-fumantes foram aqueles que, no período da entrevista, não eram fumantes regulares, mas o haviam sido anteriormente. Pesquisa similar foi realizada em 1986 e 1991. Resultados/Conclusões A prevalência de tabagismo foi de 11%, comparada com 14% em 1991 e 21% em 1986. Apesar da redução do tabagismo nas três séries estudadas, a queda percentual entre 1996 e 1991 foi menor do que aquela observada entre 1991 e 1986. Em 1996, a prevalência do vício de fumar aumentou conforme o ano cursado. Não houve diferenças significativas quanto ao sexo. A maioria dos alunos mostrou-se favorável à proibição do fumo em locais de ensino e assistência e afirmaram que o tema era pouco valorizado no currículo da faculdade. 11% compared with 14% in 1991 and 21% in 1986. Although there was a significant reduction of smoking in the last three years, the actual decrease Abstract Objective