GLP-1 drugs did not lower new sleep apnea diagnoses in 47,315 people with type 2 diabetes

GLP-1 drugs such as tirzepatide can make existing sleep apnea less severe in trials. A large UK study asked whether they also stop it developing in people with diabetes and obesity, and found no sign that they do.

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Summary

An observational study of UK health records for adults with type 2 diabetes and obesity, 2007 to 2023.
It compared 47,315 people starting a GLP-1 drug with 159,066 starting a weight-neutral diabetes drug.
New sleep apnea diagnoses were about as common in both groups over up to three years.
In trials, the GLP-1 drug tirzepatide cut breathing pauses in people who already had sleep apnea.
Diagnoses depend on someone being tested, so undiagnosed sleep apnea was not counted.

Obstructive sleep apnea and type 2 diabetes often travel together, and excess weight drives both. Since GLP-1 drugs help people lose weight, and one of them has been tested successfully as a sleep apnea treatment in people with obesity, it seemed reasonable to expect that they might also stop sleep apnea from developing in the first place.

A study in the American Journal of Respiratory and Critical Care Medicine tested that in UK health records. Among people with diabetes and obesity, those who started a GLP-1 drug were diagnosed with sleep apnea at about the same rate as those who started a diabetes drug that does not cause weight loss.

What obstructive sleep apnea is

In sleep apnea, breathing stops and starts during sleep. MedlinePlus notes that breathing pauses can last from a few seconds to minutes, and that the most common type is obstructive sleep apnea, in which the airway narrows or closes. Being overweight is one of the main risk factors.

The consequences go beyond snoring and tiredness. People with sleep apnea are at higher risk for car crashes, work-related accidents, and other medical problems, and the condition is linked with heart disease. It is especially common in people with type 2 diabetes, who share many of the same risk factors.

What trials already showed about GLP-1 drugs and sleep apnea

The case for GLP-1 drugs comes mainly from the SURMOUNT-OSA trials of tirzepatide, published in 2024. They enrolled adults with moderate-to-severe sleep apnea and obesity, averaging around 50 breathing pauses an hour at the start.

After a year, the number of breathing pauses fell by about 25 to 29 an hour with tirzepatide, against about 5 with placebo. In the first trial, the estimated treatment difference of -20.0 events per hour was large enough to move many people into a milder category of sleep apnea. Those results show the drugs can treat existing sleep apnea in people with obesity.

How the GLP-1 prevention study worked

The new study asked a different question: prevention. The researchers used the UK Clinical Practice Research Datalink, a large database of family doctor records, from 2007 to 2023. They included adults with type 2 diabetes and a body mass index of 30 or more who started either a GLP-1 drug or a DPP-4 inhibitor, and excluded anyone already diagnosed with sleep apnea.

DPP-4 inhibitors were chosen as the comparison because they lower blood sugar without much effect on weight. MedlinePlus notes that there are several different medicines for type 2 diabetes, taken as pills, injections or both. Comparing two groups who both started a new diabetes drug makes them more alike than comparing users with non-users.

What happened to new sleep apnea diagnoses

The cohort included 47,315 GLP-1RAs and 159,066 DPP-4i initiators, meaning people starting GLP-1 drugs and DPP-4 inhibitors. Over up to three years, 612 people in the GLP-1 group and 1,197 in the DPP-4 group were newly diagnosed with sleep apnea.

That worked out at 5.8 and 5.4 diagnoses per 1,000 person-years, a measure that accounts for how long each person was followed. After balancing the groups on age, weight and health, the difference was small and could have been chance. The authors conclude that GLP-1RAs were not associated with a decreased incidence of OSA in people with type 2 diabetes. The result held across weight groups, in men and women, and for different GLP-1 drugs.

Why the treatment and prevention findings can both be true

The trials and the new study measured different things. Trials of existing sleep apnea test whether a drug reduces breathing pauses when people take it as directed for a year under close supervision, often with large weight loss.

Routine care is different. Doses may be lower, people may stop sooner, and weight loss is often smaller than in trials. Prevention also depends on diagnosis: sleep apnea is often missed, and people seeing doctors for weight-loss drugs may be more likely to be referred for a sleep test, which could make GLP-1 users look worse than they are.

What the sleep apnea records study cannot show

This was an observational study, so the groups may have differed in ways the records do not capture. Follow-up was short, three years at most, and the study could only count diagnoses, not the many people with sleep apnea who are never tested.

The study included only people with type 2 diabetes and obesity in the UK, and it compared GLP-1 drugs with another active medicine rather than with no treatment. Newer, more potent drugs such as tirzepatide were used by few people during the study period.

What this changes for GLP-1 drugs and sleep apnea

The study does not change what the trials showed: tirzepatide can reduce the severity of existing moderate-to-severe sleep apnea in people with obesity. It suggests that, in routine care, starting a GLP-1 drug for diabetes should not be expected to prevent sleep apnea on its own.

MedlinePlus notes that lifestyle changes, mouthpieces, surgery, and breathing devices can treat sleep apnea in many people. Diagnosis still depends on a sleep test, and snoring, witnessed breathing pauses or daytime sleepiness are the usual reasons people are referred for one.