Adiposity: determinant of peak expiratory flow rate in young Indian adults male.

Background: Although several factors such as respiratory muscle strength, lung compliance, resistance to airflow, and even obesity affect the lung functions, the nature of relationship with markers of adiposity is not clear. We hypothesised that central pattern of fat distribution is a significant predictor of decreased peak expiratory flow rate (PEFR). The present study was designed with the aim to examine the effects of adiposity on PEFR in males.

Methods: One hundred young healthy male volunteers were analysed in the study. They were classified into non-obese, and obese groups based on body mass index (BMI) (obese > or = 30 Kg/m2 and non-obese < 30 Kg/m2). The PEFR was measured by using Wright's peak flow meter. Data was analysed using unpaired 't' test for statistical significance of differences between the non-obese and the obese, stratified into age groups of 20 to 30 years and 30 to 40 years. A partial correlation adjusted to age, height and BMI followed by regression analysis was conducted using adiposity markers as a predictor of PEFR.

Results: The model adjusted to age, height, weight and BMI revealed waist hip ratio (WHR) as the only parameter which shows significant variance in PEFR with a Pearson's r=-0.59, F (1, 100)=12.23, p=0.04. The resulting linear regression equation is y=-388.72xWHR+850.68.

Conclusions: Our findings suggest that obesity itself and especially the pattern of body fat distribution have independent effects on PEFR. These results suggest that abdominal adiposity, measured as WHR, is a better predictor of expiratory flow than weight or BMI.