A new study seeks to quantify the association between the percent change in body weight and the percent change in AHI.
Interview by Alyx Arnett
Obesity is widely recognized as a major contributor to the development of obstructive sleep apnea (OSA). A 10% increase in weight can multiply the risk of OSA sixfold.1 Weight loss, on the other hand, is often recommended to lessen the condition’s severity.
While the bidirectional relationship between obesity and OSA has been well-documented, it hasn’t been adequately quantified, according to Atul Malhotra, MD, research chief of pulmonary, critical care, and sleep medicine at the University of California, San Diego.
In a new study, Malhotra and co-investigators aimed to determine the relationship between the percentage of weight change and the percentage of change in the apnea-hypopnea index (AHI) by examining existing literature.
The investigators developed a linear meta-regression model. It indicated that, on average, a 1% weight loss could lead to a 2.6% decrease in AHI. However, the data’s variability made it challenging to pinpoint a precise relationship. This variability is evident when considering that a 20% weight loss might lead to an average AHI reduction of 52.8%. But, due to relatively wide prediction intervals, this reduction could range from 15.8% to 89.8%, the investigators found.
Malhotra discussed the study, which was presented at SLEEP 2023 and is currently under peer review for publication, with Sleep Review over email.
[Editor’s Note: Read the abstract, Weight reduction and the impact on apnea-hypopnea index: a meta-analysis, in Sleep.]
What led you to investigate the impact of weight reduction on AHI?
I am involved in studies to reduce body weight using newer medications. It was important for us to have a sense of how much weight loss is enough to yield a meaningful impact on OSA.
What were the main findings of your study?
Not surprisingly, weight loss improves sleep apnea, and with substantial weight loss, some OSA resolves.
Were there unexpected findings?
I was a little surprised at how few studies there are in this area and, in general, how small they are.
How does this meta-analysis add to the broader understanding of the relationship between weight and AHI?
Many sleep providers ignore body weight and just give obese people CPAP without addressing the underlying problem. I use the analogy that it would be like giving smokers inhalers without trying to help them quit smoking.
What are the clinical implications?
The standard of care should be to address diet and exercise with most OSA patients. Even lean ones are at risk of weight gain with (CPAP) therapy. Newer medications are currently being studied to facilitate weight loss in OSA.
What future research should be done?
Newer medications, including GLP1 receptor agonists, are now being studied. In fact, I am helping Eli Lilly run a trial in full disclosure. My hope is we will be able to treat OSA and associated cardiometabolic risk via weight loss in the future.
- The link between obesity and obstructive sleep apnea. American Academy of Sleep Medicine. Available at https://aasm.org/wp-content/uploads/2022/07/ProviderFS-Obesity-and-Obstructive-Sleep-Apnea.pdf