Experiências adversas na infância e suas influências sobre a composição corporal na adolescência.

Abstract

Adverse childhood experiences (ACEs) are sources of stress which can occur especially before 18 years, and can affect people’s health and wellbeing not only at the time the ACEs are experienced, but also later in the lifecourse. Such experiences include multiple types of abuse (physical, sexual, and psychological), neglect, and several sorts of family dysfunction, and have been associated to health risk behaviors, obesity, cardiovascular diseases, cancer and diabetes. Studies have shown a positive association between ACEs and both overweight and obesity particularly in adults. However, the results are inconclusive in adolescents, and little is known about the repercussion of ACEs on body composition. Thus, this thesis aimed to describe the occurrence of ACEs among the participants of the 1993 Pelotas Birth Cohort (93C) and to assess the association between ACEs and adiposity in adolescents. Besides the research project, this thesis has three articles. The first described the prevalence of ACEs occurred up to age 18, the related socioeconomic factors and the interrelationship among ACEs in the 93C. The most common ACE was parental separation (42%), followed by emotional neglect (19.7%) and domestic violence (10.3%). Approximately 85% of the adolescents experienced at least one ACE, and females reported a higher number of adversities. Non-white skin color, low family income, low maternal schooling, absence of mother’s partner, maternal smoking during pregnancy, and poor maternal mental health were associated to the occurrence of ACEs. A strong interrelationship was observed among the ACEs, showing that they tend to co-occur. The second article assessed the association between ACEs (up to 15 years) and adiposity in adolescence (15 and 18 years), using a cross-cohort comparison from two distinct socioeconomic backgrounds: 93C, in Brazil, and the Avon Longitudinal Study of Parents and Children (ALSPAC), in the United Kingdom. The adiposity measures assessed were: body mass index (BMI), waist circumference (WC), fat mass index (FMI) and android fat percentage. Few associations were observed between ACEs and adiposity in adolescence, however they were not consistent across cohorts. In ALSPAC, physical abuse had a positive association with WC at 15 years, and domestic violence had a positive association with WC and BMI at 15 years. However, in Pelotas no associations were found after adjustment for confounders. In the third article we assessed the association between parental separation (up to age 18) and cardiometabolic risk factors (blood pressure, physical activity, BMI, FMI, smoking and alcohol use) using data from 93C and ALSPAC. Few associations were observed between parental separation and Cardiometabolic risk factors, and higher odds of daily smoking was observed in both cohorts for those adolescents whose parents separated (OR 1.46 in ALSPAC and 1.98 in Pelotas). Some additional associations were observed in Pelotas, but in the opposite direction to our a priori hypothesis: i.e. parental separation was associated with lower blood pressure and FMI, and more physical activity. No consistent differences were observed when analyses were stratified by child’s age at parental separation or parental conflict. Despite the robust association observed between ACEs and adiposity in adults, little evidence was found in adolescents. Besides the incubation period suggested by some authors, residual confounding by socioeconomic position or context-specific relationships could explain the different patterns of associations observed.