Stroke remains a major cause of mortality and disability worldwide. Two common cardiometabolic conditions, obstructive sleep apnea (OSA) and diabetes mellitus (DM), frequently coexist and may contribute to cerebrovascular complications. A narrative review published in Diabetology summarized current evidence on the independent and combined contributions of OSA and DM to cerebrovascular risk, stroke outcomes, and clinical considerations.

The review examined literature identified through searches of PubMed, MEDLINE, and the Cochrane Library. The search covered English language studies published between January 2000 and December 2024. Included evidence comprised systematic reviews and meta-analyses, randomized controlled trials, and large prospective cohort studies. Smaller studies were also considered when they provided mechanistic insights. The analysis synthesized findings across several domains. These included OSA-related mechanisms, DM-related mechanisms, bidirectional interactions, metabolic syndrome, stroke outcomes, and clinical management considerations.

The summarized evidence indicated that OSA was associated with cerebrovascular risk through intermittent hypoxemia-related oxidative stress and inflammation, sympathetic activation with blood pressure surges, sustained hypertension, endothelial dysfunction, and atherosclerosis. Impaired cerebral autoregulation, atrial fibrillation, and prothrombotic changes were also described. Diabetes increases stroke risk through accelerated atherosclerosis, cerebral small vessel disease, endothelial injury, hypercoagulability, glycemic variability, and cardioembolic mechanisms.

Evidence also showed that OSA and DM frequently coexist. Their coexistence was associated with higher vascular injury markers, increased rates of cerebrovascular events, and poorer post stroke recovery. The review noted that these conditions share overlapping mechanisms related to metabolic syndrome, obesity, inflammation, vascular dysfunction, and thrombosis.