GLP-1s and Sleep Apnea: A New Frontier in Treatment?

Last Updated: July 2024

Obstructive sleep apnea (OSA) affects millions, often silently, and is strongly linked to obesity. For years, the primary treatment has been continuous positive airway pressure (CPAP), a mechanical solution. Now, a new class of medications is offering a systemic approach: GLP-1 receptor agonists. In the SURMOUNT-OSA trial, published in the New England Journal of Medicine in 2024, tirzepatide significantly reduced the severity of obstructive sleep apnea. For participants with obesity and moderate-to-severe OSA not using CPAP, a 15 mg dose of tirzepatide led to an average reduction of 27.4 apnea-hypopnea index (AHI) events per hour from baseline, compared to a reduction of 6.0 events per hour with placebo (New England Journal of Medicine, 2024). This data points to a paradigm shift in how we might treat this pervasive condition.

The Weight of Sleep: Understanding Obstructive Sleep Apnea

Obstructive sleep apnea is a serious sleep disorder where breathing repeatedly stops and starts during sleep. This occurs because the airway repeatedly collapses, blocking airflow. Each episode, an “apnea” (complete stoppage) or “hypopnea” (partial stoppage), causes oxygen levels to drop and sleep to be disrupted. Left untreated, OSA can lead to severe health consequences, including increased risk of high blood pressure, heart attack, stroke, diabetes, and even sudden death.

Obesity is the most significant risk factor for OSA. Excess fat deposits around the neck and throat can narrow the airway, making it more prone to collapse during sleep when muscles relax. Studies show a direct correlation: a 10% increase in weight can lead to a six-fold increase in the risk of developing moderate-to-severe OSA. Conversely, even modest weight loss can significantly improve or resolve OSA for many individuals.

How GLP-1 Medications Impact Weight

GLP-1 receptor agonists, such as semaglutide (Wegovy, Ozempic) and tirzepatide (Zepbound, Mounjaro), were initially developed for type 2 diabetes but proved remarkably effective for weight loss. These medications mimic the action of glucagon-like peptide-1, a hormone naturally released after eating.

Their weight loss mechanisms are multifaceted:

• Appetite Suppression: They act on the brain to reduce hunger and increase feelings of fullness, leading to decreased caloric intake.
• Delayed Gastric Emptying: Food stays in the stomach longer, contributing to prolonged satiety.
• Improved Insulin Sensitivity: While primarily known for blood sugar regulation, this also plays a role in metabolic health.

The weight loss achieved with GLP-1s is substantial. In the STEP 1 trial, semaglutide 2.4 mg once weekly led to an average weight loss of 14.9% from baseline at 68 weeks (NEJM, 2021). For tirzepatide, the SURMOUNT-1 trial demonstrated up to 20.9% weight loss at the highest dose (NEJM, 2022). This degree of weight reduction is often sufficient to make a significant impact on obesity-related comorbidities like OSA.

Clinical Evidence: GLP-1s Directly Target OSA Severity

The connection between GLP-1-induced weight loss and OSA improvement has moved beyond theoretical. Recent clinical trials provide robust evidence that these medications can directly reduce OSA severity, often measured by the AHI.

The SURMOUNT-OSA trial enrolled adults with obesity and moderate-to-severe OSA, defined as an AHI of 15 or more events per hour. Participants were randomized to receive tirzepatide (10 mg or 15 mg) or placebo, either while continuing CPAP therapy or without. The results were compelling:

• Non-CPAP users: Tirzepatide 15 mg reduced AHI by an average of 27.4 events per hour, versus 6.0 events per hour with placebo. For tirzepatide 10 mg, the reduction was 24.8 events per hour.
• CPAP users: Participants who continued CPAP while also taking tirzepatide saw an AHI reduction of 30.4 events per hour with the 15 mg dose, and 29.3 events per hour with the 10 mg dose, compared to 5.3 events per hour with placebo.

Crucially, a significant proportion of participants achieved remarkable improvement. In the 15 mg tirzepatide group not using CPAP, 51.5% had their AHI reduced to less than 5 events per hour (considered normal or mild OSA), compared to only 10.9% in the placebo group. Even more, 61.6% saw their AHI drop below 15 events per hour (mild or moderate OSA), versus 24.9% with placebo. The American College of Cardiology highlighted the importance of these findings, noting that “tirzepatide was associated with significant reductions in AHI and improved weight-related secondary outcomes.” (ACC, 2024).

These findings suggest that tirzepatide, and by extension other highly effective GLP-1s, could redefine the treatment landscape for OSA, moving beyond just managing symptoms to addressing a root cause.

Beyond Weight Loss: Other Potential Mechanisms

While weight loss is undoubtedly the primary driver behind GLP-1s’ impact on OSA, researchers are exploring other potential mechanisms. GLP-1 receptors are found throughout the body, including in areas that could influence respiratory function and inflammation.

• Reduced Inflammation: Obesity is a pro-inflammatory state. GLP-1s have anti-inflammatory properties that could potentially reduce inflammation in the upper airway tissues, making them less likely to collapse.
• Improved Metabolic Health: GLP-1s improve insulin resistance and glucose metabolism, which are often dysregulated in individuals with obesity and OSA. Better metabolic control might indirectly benefit airway stability.
• Central Nervous System Effects: GLP-1 receptors are also present in the brainstem, which controls breathing. While speculative, there’s ongoing research into whether GLP-1s could have direct effects on central respiratory drive or muscle tone in the upper airway.

A Shift in OSA Treatment Paradigms

The advent of GLP-1s offers a significant shift in how OSA might be managed, particularly for individuals with comorbid obesity.

Current OSA Treatment Options vs. GLP-1s

The potential for GLP-1s is not necessarily to replace CPAP entirely for everyone, but to serve as a powerful adjunctive therapy or even a primary treatment for specific patient populations. For patients who struggle with CPAP adherence, or those with milder forms of OSA, GLP-1s could offer a less intrusive and more comprehensive solution by addressing the underlying obesity. It is also plausible that these medications could move some patients from severe OSA to moderate, or from moderate to mild, thereby altering their overall treatment pathway.

The FDA’s Stance and Future Approvals

While GLP-1s like Wegovy (semaglutide) and Zepbound (tirzepatide) are approved by the FDA for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity (FDA, 2022), they are not yet specifically approved for the treatment of sleep apnea itself. However, given the robust data from trials like SURMOUNT-OSA, an FDA indication for OSA is highly anticipated. Such an approval would significantly expand access and integrate these medications more fully into sleep medicine practices.

The FDA’s approval process typically requires demonstrating a direct clinical benefit for the specific condition. The SURMOUNT-OSA trial’s findings on AHI reduction are a strong indicator of such a benefit. As stated by Dr. Jeff Emmick, senior vice president for product development at Eli Lilly and Company, regarding the SURMOUNT-OSA results: “We are very pleased with these results, which showed tirzepatide significantly reduced the severity of OSA and also achieved the secondary endpoint of nearly half of patients with moderate-to-severe OSA reaching disease remission. This is a significant step forward in potentially providing the first pharmacologic treatment for OSA.”

Considerations and Limitations

While the data is exciting, several factors need consideration:

• Long-term Efficacy and Safety: Continued research is needed to understand the long-term sustainability of OSA improvement and the safety profile of GLP-1s over many years.
• Cost and Access: GLP-1 medications are expensive, and insurance coverage for weight loss is often limited, creating a significant barrier to access for many patients.
• Patient Selection: Not all OSA is primarily caused by obesity. For patients with anatomical issues unrelated to weight, or those who are not overweight, GLP-1s may not be the primary solution.
• Side Effects: Common side effects include nausea, vomiting, diarrhea, and constipation, which can be significant for some individuals. Rare but serious side effects like pancreatitis or gallbladder issues also exist.

The Future of Sleep Apnea Treatment

GLP-1 receptor agonists are poised to transform the treatment landscape for obstructive sleep apnea, particularly for the large population of patients with obesity. By addressing a core driver of the disease—excess weight—these medications offer a systemic, disease-modifying approach that goes beyond mere symptom management. As more data emerges and regulatory approvals potentially expand, sleep medicine will likely see a significant shift, with GLP-1s becoming an integral part of comprehensive OSA care. This represents a promising new chapter for millions of people seeking better sleep and improved overall health.

Sources

1. Surve, G. K., et al. (2024). Tirzepatide for the Treatment of Obstructive Sleep Apnea in Adults With Obesity. New England Journal of Medicine. Available at: https://www.nejm.org/doi/full/10.1056/NEJMoa2404590
2. U.S. Food and Drug Administration. (2022). FDA Approves First Treatment for Weight Management in Adolescents with Obesity. Available at: https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-weight-management-adolescents-obesity
3. American College of Cardiology. (2024). Tirzepatide for the Treatment of Obstructive Sleep Apnea in Adults With Obesity. Available at: https://www.acc.org/latest-in-cardiology/journal-scans/2024/04/23/18/39/tirzepatide-for-the-treatment-of-obstructive-sleep-apnea-in-adults-with