Study in Spain Shows Weight Loss Surgery Contributed to Significantly Lower Asthma Inhaler Use

According to a retrospective chart review and longitudinal cohort study of 505 patients, morbidly obese patients with asthma may require less inhaler therapy post-surgery. Among the patients studied who used a type of inhaler therapy before surgery, one or more classes of said inhalers were discontinued in 30%. Dr. Randall Schwartz, the study’s main author, reported their findings at the word congress of the American College of Chest Physicians.

About the Study

The study reports that short-acting beta agonist (SABA) use decreased in nearly 13.1% of patients from the baseline (64.5% to 51.4%) and the long-acting beta agonist or inhaled corticosteroid or LABA/ICS combinations reduced by 8.1%. Fewer patients were on muscarinic anatagonists (SAMA/LAMA); however there still was a minor decline in those instances of 1.6% (9.4% to 7.8%).

Of the 505 patients, 8 patients required SABA treatment, 12 LABA/ICS and 7 for SAMA/LAMA. The study is the first to look at the decrease in asthma severity after gastric surgery with inhaler usage. Dr. Schwartz, chief internal medical resident of the Cleveland Clinic Florida mentioned that while there was a 30% reduction of inhaler use, but 10% of patients actually required more inhaler therapy post-surgery. The study’s researchers believe that the majority of these patients with asthma problems are because of their obesity itself. Neutrophilic mediated inflammation occurs in these individuals, while patients with existing asthma before surgery have eosinophilic-mediated asthma.

Only 203 of the 505 patients studied had formal pulmonary function tests or PFT tests done. Also, only 9 of those same patients had fractional exhaled nitric oxide measured. Dr. Schwartz believes that nitric oxide would be a non-invasive and simple thing to do in follow-up with patients. He believes that tests results would show a disproportionate number of elevated phenotypes in those who had to increase their inhaler use and not significant eosinophilic inflammation in the majority of other patients, particularly those who did reduce or eliminate their inhaler use. Of those who started inhaler use after surgery, nearly 72% had already used them once in their lifetime before surgery, just weren’t using it at the time surgery was performed. There also was a 20% reduction in postoperative inhaler use

Because the study is one of a retrospective nature, it isn’t possible to determine whether the type of bariatric surgery performed or the amount of weight loss that occurs included inhaler use. Other possible factors in inhaler use are improved overall health and body mechanics and decreased inflammation in the body because of less adipose tissue.

The patients underwent either gastric bypass surgery or gastric sleeve surgery. The average BMI of these patients was 50.7 kg/m2 with an average forced expiratory volume in 1 second was 79%.

The study’s researchers hope to perform follow-up testing on patients to determine post-gastric bypass inhaler use in more details including the severity of the condition. They also want to perform a cost-benefit analysis and fractional exhaled nitric oxide testing on many patients.