Large and sustained weight loss might reduce asthma attacks and related healthcare utilizations, according to a study published online recently in the Journal of Allergy and Clinical Immunology.

Study lead author Kohei Hasegawa, MD, and colleagues conducted a self-controlled case series study of 2,261 obese patients with asthma aged 18 to 54 years who underwent bariatric surgery using the population-based emergency department (ED) and inpatient sample in three states: California, Florida, and Nebraska. The primary outcome was an ED visit or hospitalization for asthma exacerbation from 2005 through 2011. They used conditional logistic regression to compare each patient's risk of the outcome event during sequential 12-month periods using presurgery months 13 to 24 as the reference period.

One to two years before surgery, 22% of patients had an ED visit or hospitalization for asthma exacerbation. In the subsequent 12-month presurgery period, the risk did not materially change (21.7%; 95% CI, 20.0% to 23.4%), with an odds ratio (OR) of 0.98 (95% CI, 0.85-1.13) compared with the reference period.

“By contrast, significantly fewer ED visits or hospitalizations for asthma exacerbation occurred within 12 months after bariatric surgery (10.9%; 95% CI, 9.6% to 12.2%), corresponding to an OR of 0.42 (95% CI, 0.35-0.50). Similarly, in the subsequent period of 13 to 24 months after bariatric surgery, the risk remained significantly lower (10.9%; 95% CI, 9.6% to 12.2%), corresponding to an OR of 0.42 (95% CI, 0.35-0.50),” the authors wrote.

The study showed that bariatric surgery was associated with decreased risks of ED visit or hospitalization for asthma exacerbation. This risk reduction persisted for at least two years after bariatric surgery.

“Because the benefit of bariatric surgery may be offset by initial high cost and risks of surgical complications, our finding emphasizes the importance of developing safe, effective, non-surgical approaches to achieve major weight loss, which would likely benefit millions of obese individuals with asthma,” Hasegawa, an attending physician in the emergency department of Massachusetts General Hospital in Boston, tells Medical Economics.

Although it was not clear how much weight needs to be lost to make a difference in serious asthma symptoms, or if losing greater amounts of weight was linked to an even greater reduction in asthma flare-ups, Hasegawa says, “major weight reduction may be effective to decrease asthma attacks and related ED visits/healthcare utilizations.”

The study did not show that surgery or expected weight loss from the surgery actually caused the reduction in serious asthma symptoms, as it was designed only to find an association between weight-loss surgery and fewer asthma flare-ups, the authors pointed out.