Apoio social e índice de massa corporal: um estudo de base populacional

Abstract

Obesity is a health condition that represents a risk to a wide range of physiological and social changes on individual s life. The increase in the prevalence of obesity both in world and in Brazilian population is considered one of the major public health problems. Obesity is associated with multiple factors, such as biological, individual, environmental and social and the importance of the socials factors has been widely discussed. Social support, which has as one of its definitions, the perception of available resources provided by others individuals to face adverse situations is one of the social factors associated with obesity and other health outcomes. This concept is a well-documented factor linked to many health outcomes over the past thirty years, nevertheless, there is a gap about its relation with body mass index (BMI). Within this context, the present study has the aim to assess an association between social support dimensions and BMI in individuals resident in the city of Duque de Caxias. Our hypothesis is that lower levels of social support are linked to highest BMI. The main outcome was BMI and the predictors were the four dimensions of social support (affective, material, emotional/information and positive interaction). This study was based on a sample of 1465 adults, from 20 to 59 years old, from a cross-sectional population-based survey called Grupo de Pesquisas sobre Segurança Alimentar e Nutricional em Duque de Caxias SANDUC. BMI was calculated from the measurements of height and weight taken by trained interviewers. The instrument used to assess social support has been developed for the Medical Outcomes Study (MOS), having been previously adapted to the Portuguese and validated for the Brazilians. The statistical model used was multiple linear regression and the statistical analyses were performed using SAS version 9.3 for survey data and took into account the weighting factor and complex sampling design. About half of the subjects were female (54.94%) and the prevalence of obesity was 27% (CI 95%: 22.4 31.8) among women and 16,0% (CI 95%: 12.4 19.7) among men. In relation to social support, the mean of the scores of the dimensions stood at 84 and 90 points, for women and for men, respectively. Among men there was no association statistically significant between the dimensions of social support and BMI (affective support: β= -0.81 and p=0.16; material support: β= 0.20 and p=0.72; emotional/information support: β= -0.29 and p=0.61; positive interaction support: β= -0.23 and p=0.72). Although, among women, both affective support and support positive interaction were negatively associated with BMI (affective support: β= -1.02 and p=0.04; positive interaction support: β= -1.18 and p=0.01). The present study suggests that among women occurs inverse association between social support, specifically affective support and positive interaction support, and the BMI.