A study published in the Journal of Allergy and Clinical Immunology revealed that bariatric surgery for weight loss can significantly reduce the risk of asthma exacerbations in asthmatic obese patients. The study is entitled “Risk of an asthma exacerbation after bariatric surgery in adults” and was led by researchers at the Massachusetts General Hospital and Harvard Interfaculty Initiative in Health Policy.
Asthma is a common chronic inflammatory lung disease characterized by airflow obstruction that causes wheezing, shortness of breath, chest tightness and coughing. In severe asthma cases, the obstruction of the airways is exacerbated and individuals experience persistent breathing difficulty, limited physical activity and asthma attacks (exacerbations). Severe asthma is responsible for a significant number of emergency hospital admissions. It has been previously reported that overweight and obese individuals are more likely to develop asthma and experience asthma exacerbations.
Bariatric surgery is a weight loss surgery where the size of the stomach is reduced through a gastric band or through removal of part of the stomach. The surgery can result in substantial weight loss and has been shown to contribute to health improvements in obese patients and a decreased incidence of medical conditions like diabetes, heart attack, stroke and cancer.
The goal of the study was to determine whether bariatric surgery could also improve asthma symptoms. The research team analyzed data from emergency department visits or hospitalizations due to asthma exacerbation between 2005 and 2011 in the states of California, Florida and Nebraska. In total, 2,261 obese patients with asthma aged 18 to 54 years who had undergone bariatric surgery were identified. Clinical data on the two years prior and after bariatric surgery were available for all the patients.
Researchers found that during the two years prior to surgery, 22% of the patients had an asthma exacerbation that required medical care or hospitalization. In the 12 months prior to the surgery, this percentage did not change (21.7%). In contrast, within the 12 months after the surgery, and also the year after, there were fewer reports (10.9%) for visits or hospitalizations due to asthma exacerbations.
“We found that, in obese patients with asthma, the risk of emergency department visits and hospitalizations for asthma exacerbations decreased by half in the two years after bariatric surgery,” said the study’s lead author Dr. Kohei Hasegawa in a news release. “Although previous studies of non-surgical weight loss interventions failed to show consistent results regarding asthma risks, our result strongly suggests that the kind of significant weight loss that often results from bariatric surgery can reduce adverse asthma events.”
The research team concluded that the risk for serious asthma exacerbations and consequent medical visit or hospitalization in obese patients was reduced by half after bariatric surgery. The findings show for the first time that significant weight loss can improve asthma morbidity.
“The databases we had access to did not include the actual amount of weight lost by these patients, but it is well documented that bariatric surgery results in substantial weight loss, averaging around 35 percent of presurgical weight, (…) While we can’t currently say how much weight loss would be needed to reduce asthma risks, previous studies of non-surgical interventions indicate that modest weight loss is not enough” noted Dr. Hasegawa. “Bariatric surgery is a costly procedure that carries its own risks, factors that may offset the benefits regarding the risk of asthma exacerbation for some patients, (…) To decrease asthma-related adverse events in the millions of obese individuals with asthma, we probably will need to develop safe, effective non-surgical approaches to achieve major weight loss.”
The authors postulate that significant weight loss may decrease asthma-associated risks through the induction of a decrease in the body’s inflammatory state, gastroesophageal reflux conditions or physical changes in the airway.