Long-term changes in lung function after Roux-en-Y gastric bypass in patients with severe obesity.

Obesity can decrease the lung function. The proposed mechanisms of reduced lung function in persons with obesity have been altered mechanical properties in the lung and chest wall, airway narrowing and increased respiratory resistance. The aim of this current study was to analyse the long-term results after gastric bypass surgery in patients with reduced lung function. The bariatric surgery observation study invited patients to a follow up 10 years after gastric bypass surgery. We compared the spirometry results before surgery to the spirometry 10 years after surgery. Thirty percent of 198 participants had reduced lung function before surgery. There was no significant relation between body mass index before surgery and lung function. Seventy-three percent of the participants with reduced lung function had normal lung function 10 years after surgery. There was no significant relation between the degree of weight loss and the improvement in lung function. Most participants with reduced lung function had normal lung function 10 years after gastric bypass surgery. There was no significant correlation between weight loss and improvement in lung function.