Effects of weight loss on pulmonary function in obese men with obstructive sleep apnoea syndrome.

The effects of long-term behaviour modification of obesity on pulmonary function was studied in eight men with obstructive sleep apnoea syndrome (initial mean body mass index [BMI] 41.8 kg m-2) before and after a mean weight loss of 20 +/- 7 (SD) kg. Mean arterial PCO2 fell from 6.3 +/- 1.2 to 5.5 +/- 0.6 kPa (P < 0.05) and concomitant significant improvements were found in vital capacity, total lung capacity, functional residual capacity and forced expired volume (FEV 1.0). The study suggests that weight loss per se, rather than the method of choice to achieve weight loss, results in clinically significant improvement of pulmonary function in obese men.