Adiposity throughout adolescence and lung function at 18-19 years of age. 1993 birth cohort, Pelotas - RS.

Introdu????o: estudos transversais t??m apontado uma rela????o inversa entre circunfer??ncia de cintura (CC) e fun????o pulmonar (FP) em adultos e idosos; efeitos em longo prazo dessa associa????o e, em adolescentes, ainda n??o est??o esclarecidos. Objetivos: avaliar os efeitos, ao longo da adolesc??ncia, da CC e do percentual de gordura corporal na fun????o pulmonar. M??todos: estudo longitudinal da Coorte de Nascimentos de 1993, na cidade de Pelotas, Brasil, no acompanhamento dos 18 anos. A CC foi avaliada atrav??s da diferen??a dos 15 aos 18 anos, em desvios-padr??o, ajustado para altura nos dois per??odos. O percentual de gordura corporal foi avaliado atrav??s de pletismografia por deslocamento de ar. Espirometria foi realizada para obten????o do Volume Expirat??rio For??ado no 1?? segundo (VEF1) e a Capacidade Vital For??ada (CVF). Modelos de regress??o linear multivari??vel foram utilizados. Resultados: dos 5249 membros originais da coorte, foram acompanhados, aos 18 anos, 4129. Desses, 3859 realizaram testes de fun????o pulmonar. Houve rela????o inversa e estatisticamente significante entre a diferen??a de CC e VEF1 e, no sexo masculino, tanto para valores absolutos (β = -0,028 [IC 95% -0.053; -0.003]) como para valores previstos (β = -0.646 [IC 95% -1.247; -0.046]). Para o percentual de gordura corporal, tamb??m houve rela????o inversa para VEF1 e CVF, estatisticamente significantes em ambos os sexos. Conclus??o: a diferen??a de CC e o percentual de gordura corporal foram associados negativamente com FP. Entretanto, o percentual de gordura atual parece ser um determinante mais importante clinicamente para a fun????o pulmonar do que a diferen??a de CC.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