Influence of weight loss on pulmonary function and levels of adipokines among asthmatic individuals with obesity: One-year follow-up

Background: Individuals with obesity are more likely to develop asthma, but the exact mechanism is still uncertain and several hypotheses have been raised, such as the release of inflammatory mediators secreted by adipose tissue. Objective: To assess the effects of weight loss in patients submitted to bariatric surgery on pulmonary and systemic inflammation. Method: The study evaluated patients undergoing bariatric surgery (Roux-en-Y gastric bypass) with the diagnosis of asthma, except smokers. The patients were evaluated at the time of entry into a preoperative weight loss group (T1), just before bariatric surgery (T2), six months after surgery (T3), and 12 months after surgery (T4). The following were measured: anthropometric data, dosage of systemic inflammatory markers by means of blood collection, pulmonary inflammatory markers obtained by induced sputum collection, pulmonary function parameters, and asthma activity assessed by a Asthma Control Test (ACT) questionnaire. Results: Nineteen patients participated in the study. There were significant reductions in the systemic levels of interleukin (IL)-8 (p = 0.002), C-reactive protein (CRP) (p = 0.003), leptin (p = 0.001) and tumor necrosis factor (TNF)-alpha (p = 0.007), and significant increase in the systemic levels of IL-6 (p = 0.004) over time and adiponectin in T2 (p = 0.025). In regards to pulmonary inflammation, there were significant reductions in the sputum levels of TNF-alpha (p < 0.001). There was no significant improvement of the pulmonary function parameters (p > 0.05) and significant improvement in asthma activity scores (p < 0.0001). Conclusion: Weight loss was associated with significant changes in the systemic and pulmonary inflammatory profiles of individuals with asthma, leading to a better asthma control as a result of an increase in some anti-inflammatory mediators and a reduction of pro-inflammatory mediators.