Prediabetes comes with nearly triple the odds of sleep apnoea

Obstructive sleep apnoea, in which breathing repeatedly stops and restarts during sleep, has increasingly been tied to metabolic dysfunction. What has remained less clear is whether that connection begins earlier in the glucose story, at the prediabetes stage, when blood sugar is raised but has not yet crossed the diabetic threshold. Prediabetes is common and frequently silent, and sleep apnoea often goes undiagnosed, so if the two conditions routinely travel together the pairing would matter for who gets screened. This analysis set out to define how strongly prediabetes and objectively diagnosed sleep apnoea coexist in adults.

The researchers systematically searched PubMed, Embase and Web of Science for studies assessing prediabetes alongside objectively diagnosed obstructive sleep apnoea, rather than relying on symptom questionnaires alone. Eight studies met the criteria, together covering 18,040 adults, of whom 6,325, or 35.1%, had prediabetes. All eight captured people at a single point in time rather than following them over years. Odds ratios comparing the prevalence of sleep apnoea in people with prediabetes against normoglycaemic controls were pooled using methods that allow for differences between studies, and subgroup and sensitivity analyses probed how stable the overall result was.

People with prediabetes had 2.78 times the odds of obstructive sleep apnoea compared with those with normal blood sugar, a clearly significant result, though the individual studies varied considerably in how large the link appeared. Sensitivity analyses kept the estimate between 2.47 and 3.08 times the odds. The association showed up consistently across Asian and Western populations, in both community and high-risk groups, and regardless of how sleep apnoea was diagnosed. It was stronger in studies with younger participants, at 3.44 times the odds where mean age was under 55 versus 2.06 in older groups, and stronger when prediabetes was defined using composite criteria rather than a single test, at 3.40 versus 1.92.

Sleep-disordered breathing and diabetes are already known to run together; this analysis extends the connection back to the earlier prediabetic stage of glucose dysregulation and shows the overlap is substantial rather than marginal. Because every included study measured people at one moment rather than tracking them over time, the direction of the relationship stays open: disturbed sleep could worsen glucose control, early metabolic dysfunction could promote airway problems, or shared causes could drive both. The stronger link in younger adults is a notable and unexplained wrinkle. The authors argue the coexistence is frequent enough to support considering sleep apnoea screening in people with prediabetes.

If blood tests have flagged raised glucose that falls short of diabetes, this is a reason to take the possibility of sleep apnoea seriously, particularly because the condition often goes unnoticed by the person who has it. The finding is a pattern of coexistence, not proof that either condition causes the other, so it cannot say that treating one would prevent the other. What it does suggest is that early blood sugar trouble and disturbed breathing during sleep frequently arrive together, and the pairing looked strongest in younger adults in these data. That is context worth raising with a clinician rather than a prompt for any specific action.