The impact of weight loss beyond lung function: benefit with respect to asthma outcomes

We evaluated the effect of weight loss (WL) on lung function (LF) in obese individuals who underwent bariatric surgery, and on asthma control, quality of life, LF, and controller medication in a sub-group of obese asthma (OA) patients.

Obese individuals who underwent bariatric surgery between July 2015 and July 2017 were included in this prospective longitudinal study. They were classified as OA or obese non-asthmatics (O-NA). LF was assessed preoperatively and 6-9 months postoperatively. In OA patients, asthma control, quality of life, and treatment step were evaluated. P < 0.05 was considered significant.

Twenty-six patients (OA: n = 8; O-NA: n = 18), 84.6% with class III obesity were enrolled. Preoperatively, OA patients showed worse values of LF parameters, with upper and lower airway CARAT scores of 6.1 ± 3.1 and 13.4 ± 4.1, respectively, and 75% were in step 4 of treatment. After WL, improvements in dynamic volumes, lung capacities, and total resistance were observed in both groups. Despite greater increases in OA patients, no significant differences were observed between groups. In OA patients, improvements in CARAT score of upper (3.9 ± 1.9, p = 0.017) and lower (4.2 ± 4.4, p = 0.027) airways, and in Asthma Life Quality scores (8.1 ± 5.6, p = 0.017) were observed along with a decrease (-1.8 ± 1.0, p = 0.017) in treatment step.

All LF parameters improved after WL. Although the improvement was greater in OA patients, the difference between groups was not significant. Significant improvement from baseline in uncontrolled symptoms of OA patients and quality of life was observed after WL, along with a significant decrease in treatment step.