Pulmonary ventilatory functions and obesity in Kuwait

To study the relationship between obesity and pulmonary ventilatory functions in Kuwaiti adults.

A total of 200 male and 180 female Kuwaiti adults aged 20-65 years were investigated in six medical centers from April 2004 to March 2006. Parameters measured included forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), FEV(1) as a percentage of FVC (FEV%); body mass index (BMI in kg/m(2)) and waist-to-hip ratio (W/H).

For the whole group, males or females, BMI (kg x m(2)) and W/H were poor individual predictors of pulmonary ventilatory functions. However, central adiposity (W/H) was associated with restrictive respiratory impairment (10.6-13.9% decrease in FEV(1) and 10-12.3% decrease in FVC), independent of sex, age or height. In obese females and males (BMI >30), increasing severity of obesity was significantly (p < 0.05, R(2) >0.6) [corrected] associated with increasing restrictive respiratory impairment (8.7-14.4% decrease in FEV(1) and 8-11.7% decrease in FVC), with no evidence of obstructive disease (FEV(1)/FVC >0.8).

In adult Kuwaiti males and females, increase in body fat at BMI >30 or W/H >1 was associated with a restrictive effect on pulmonary ventilation.