Background: Obesity is proposed to represent an important predisposing condition to serious respiratory disturbances including asthma. The effects of consistent weight loss on asthma control are not well known. We investigated the effect of weight reduction induced by bariatric surgery on asthma control in severely obese asthmatic patients.
Patients and methods: A consecutive series of 12 asthmatic obese females who had laparoscopic adjustable gastric banding (OB group) and 10 non-operated asthmatic obese females as control group (CG). Body mass index (BMI), Asthma Control Test (ACT), pulmonary function test (PFT), exhaled nitric oxide (NO) were evaluated at baseline and after 1 year.
Results: Mean BMI (kg/m(2)) of OB group decreased from 45.2+/-4.7 before surgery to 34.8+/-4.2 post-operatively. After surgery the overall ACT score in OB group significantly improved from 18.7 to 22.2 (p<0.001), while it remained unchanged in CG (from 18.8 to 18.6, p=0.73). In particular, in OB group the parameters of shortness of breath and rescue medication use were significantly improved respectively from 3.2 and 3.9 before surgery to 4.2 and 4.6 after surgery (always p<0.05). Accordingly, none of the CG who did not experience any weight loss was able to obtain a full asthma control. In the OB group after the surgery PFT significantly improved as compared to CG. No significant difference in exhaled NO was found both in OB group after surgery as compared to before surgery.
Conclusion: Consistent weight loss in severely obese patients with asthma is associated to improvement in respiratory symptoms and lung function. However, the mechanisms underlying the effect of large body mass changes on asthma would require further studies.