Adiposidade corporal ao longo da adolescência e função pulmonar aos 18-19 anos de idade. Coorte de Nascimentos de 1993, Pelotas RS.

Abstract

Background: cross-sectional studies have shown an inverse relationship between waist circumference (WC) and lung function in adults and elderly. The long term effects of such association, as well as its relation to adolescence are not yet established. Objectives: to evaluate the effects of WC and percentage of fat mass on lung function parameters in adolescence. Methods: a longitudinal study of the 1993 Birth Cohort, in Pelotas, Brazil, at the 18 years old follow-up. WC was evaluated using the difference, in standard deviation, between 15 and 18 years old, adjusted for height in both periods. Percentage of fat mass was evaluated using air-displacement pletismography. Spirometry was performed to obtain Forced Expiratory Volume in 1 second (FEV1) and Forced Vital Capacity (FVC). Multivariate Linear regression models were performed. Results: out of 5,249 original members, 4,129 were evaluated at 18 years old. Spirometry was performed in 3,859 individuals. There was a statistically significant inverse relationship between the WC difference and FEV1 and among men, both for absolute values (β = -0,028 [IC 95% -0.053; -0.003]) and for predicted values (β = - 0.646 [IC 95% -1.247; -0.046]). An inverse relationship between percentage of fat and FEV1 and CVF was also statistically significant for both sexes. Conclusion: WC difference and percentage of fat mass were negatively associated with lung function. However, the actual body fat mass seems to be a more important determinant for lung function than WC difference.