The effects of fatness and fat distribution on respiratory functions

Inverse relationships between respiratory function and indices of obesity and fat distribution have been reported, but it remains unclear which measure of obesity shows the strongest relationship with lung function.

The study assessed the effect of fatness and fat distribution on respiratory function.

A sample of 423 males and 509 females aged 40-50 years were examined in the Silesian Centre for Preventive Medicine, DOLMED, in Wrocław in 1995. The strength of influence of height, body mass index (BMI), wait-to-hip ratio (WHR) and abdominal and subscapular skinfolds upon forced vital capacity (FVC) and forced expiratory volume in a 1-s expiration (FEV1) was assessed by multiple regression analysis.

In males, FVC was strongly positively associated with height and BMI, but negatively associated with subscapular and abdominal skinfolds, WHR, and smoking. FEV1 showed a positive relationship with height, BMI and WHR. In females, both FVC and FEV1 showed significant positive associations with height, negative ones with subscapular skinfold, and no association with either WHR or abdominal skinfold. In males, respiratory function is affected to a similar extent by fat in the abdominal region and by fatness of the chest. In females, fatness of the thorax has the strongest relationship with respiratory function.

Fatness tends to impair respiratory function in both sexes but these effects show a different pattern in males and females. In males, respiratory functions are significantly, and to a similar extant, affected by fatness in the abdominal region, both subcutaneous and visceral, and by fatness on the chest. In females, it is primarily subcutaneous fat on the upper thorax that affects respiratory functions, while visceral and subcutaneous abdominal fatness play little or no role.