Prospective Findings From the 1993 Pelotas (Brazil) Birth Cohort Study

Abstract

EditorialProspective Findings From the 1993 Pelotas (Brazil) Birth Cohort Study This supplement to the Journal of Adolescent Health is devoted to understanding the health and well-being of adolescents by taking the long view of this period of the life cycle. The articles herein analyze data collected from conception through age 15 from 4,500 individuals born in the city of Pelotas, Brazil, in 1993. The analyses provide us with not just a snapshot of adolescents' current health status, but rather an entire movie depicting the life-course trajectories and the emergence of health outcomes of this population during adolescence.The first four articles of the supplement focus on early-life predictors of later health and behavior [1][2][3][4]. Wells et al show that infant weight and length gains were associated primarily with larger size in adolescence rather than increased adiposity, although later childhood gains in weight and height were predictors of fat mass [1]. In the second article, MartÎnez-Mesa et al report that maternal smoking during pregnancy negatively affects an offspring's height in adolescence [2]. The third and fourth articles report on the effect of socioeconomic change from birth to adolescence [3,4]. Hallal et al show that adolescents born to high-income families had half the odds of walking or cycling to school compared with those whose families became wealthy during adolescence, suggesting that the habit of commuting to school under one's own power was "built" early in life [3]. Anselmi et al examine the influence of poverty on mental health, showing that both persistent poverty and becoming poor over time were associated with a greater likelihood of developing conduct disorders in adolescence [4].The next three articles focus on the health effects of behavioral changes during adolescence [5][6][7]. Menezes et al report a positive association between self-reported physical activity practice in adolescence and effort-dependent lung function, particularly among girls [5]. In contrast, Rombaldi et al show that too much time dedicated to physical activity (Ͼ 1,000 min/wk) may jeopardize school performance [6]. In addition, Noal et al report that the prevalence of wheezing at 15 years of age was 53% greater among obese versus nonobese adolescents [7].The next three articles further explore environmental factors that influence obesity and perceptions of obesity from the perspective of parents and adolescents [8 -10]. AssunÈÄo et al explore predictors of nutritional status change, finding that low-income girls were more likely than high-income girls to become obese from 11 to 15 years, and that high-income boys were more likely than low-income boys to cease being obese during adolescence [8]. Body mass index tracked strongly during adolescence, suggesting that interventions need to start as early as possible. Dumith et al provide more information on the predictors and health consequences of screen time during adolescence. Screen time increased from 11 to 15 years of age, particularly among boys and high...