Patients With Both Sleep Apnea and Diabetes Face Greater Stroke Burden

Obstructive sleep apnea (OSA) and diabetes may work together to substantially increase the risk of stroke and worsen recovery after cerebrovascular events, according to a new narrative review, underscoring the need for earlier screening and more integrated care strategies.¹ The review, published in Diabetology, examined how the 2 common conditions contribute independently, and synergistically, to cerebrovascular complications.

Researchers from the University of Miami Miller School of Medicine synthesized evidence from studies published between 2000 and 2024 using PubMed, MEDLINE, and the Cochrane Library. The review focused on mechanistic pathways linking OSA and diabetes to stroke, as well as implications for prevention, screening, and management.

Stroke Burden Continues to Rise Globally

Stroke remains one of the leading causes of death and disability worldwide.² Approximately 7.3 million deaths annually are attributed to stroke, with nearly 12 million new cases occurring each year. Between 1990 and 2021, incident strokes increased by 70%, while stroke prevalence rose by 86%.

At the same time, the prevalence of OSA and diabetes continues to climb.¹ The authors noted that OSA affects an estimated 10% to 30% of adults, although up to 90% of cases remain undiagnosed. Diabetes currently affects more than 530 million adults globally and is projected to impact 783 million people by 2045.

Importantly, the 2 disorders frequently coexist. Studies cited in the review found that 58% to 86% of individuals with type 2 diabetes have some degree of OSA, while 15% to 30% of those with OSA also have diabetes.

Shared Mechanisms May Amplify Cerebrovascular Injury

The review described multiple overlapping biological mechanisms that may explain why comorbid OSA and diabetes heighten stroke risk. OSA contributes to cerebrovascular disease through intermittent hypoxemia, oxidative stress, sympathetic nervous system activation, hypertension, endothelial dysfunction, arrhythmias such as atrial fibrillation, and prothrombotic changes. Diabetes promotes vascular injury through chronic hyperglycemia, accelerated atherosclerosis, cerebral small vessel disease, hypercoagulability, insulin resistance, and cardiac complications that increase the likelihood of cardioembolic stroke.

The authors emphasized that metabolic syndrome appears to serve as a central unifying pathway linking the 2 disorders. Obesity, dyslipidemia, insulin resistance, and hypertension collectively create a “pro-inflammatory and pro-thrombotic environment” that increases cerebrovascular vulnerability.

Patients with both OSA and diabetes demonstrated higher inflammatory marker levels, more endothelial dysfunction, and greater carotid intima-media thickness compared with patients who had either condition alone.

One large UK cohort study cited in the review found that patients with type 2 diabetes who later developed OSA had a 57% higher risk of stroke or transient ischemic attack compared with matched patients with diabetes alone.

OSA and Diabetes Also Linked to Worse Stroke Outcomes

Beyond increasing stroke incidence, both disorders were associated with poorer poststroke outcomes. The review noted that OSA is present in 44% to 95% of patients after stroke and has been linked to larger infarct size, greater disability, poorer functional recovery, and increased mortality.

Similarly, diabetes was associated with worse neurologic recovery, higher in-hospital mortality, and increased stroke recurrence risk. A cited meta-analysis found that diabetes increased recurrent stroke risk by approximately 50%. Hyperglycemia at stroke onset was also associated with larger infarcts and increased hemorrhagic transformation risk.

Weight Loss and CPAP Among Potential Interventions

The authors highlighted several interventions that may help mitigate cerebrovascular risk in patients with coexisting OSA and diabetes. Continuous positive airway pressure (CPAP) therapy remains a cornerstone treatment for moderate to severe OSA and may modestly improve glycemic control in patients with type 2 diabetes. A cited meta-analysis showed CPAP reduced hemoglobin A_1C by approximately 0.24%, with larger benefits seen in patients with higher baseline A_1C and better adherence.

Weight loss interventions also showed promise. Bariatric surgery was associated with significant reductions in OSA severity and lower ischemic stroke risk, with 45% to 65% of patients achieving OSA remission within 1 to 5 years after surgery.

The review additionally pointed to emerging therapies such as tirzepatide, which demonstrated meaningful improvements in body weight, blood pressure, and apnea-hypopnea index in patients with obesity-related OSA.

Researchers Call for Integrated Screening and Management

Given the substantial overlap between OSA, diabetes, obesity, and cardiovascular disease, the authors argued that clinicians should adopt more proactive and coordinated approaches to identifying and managing these conditions. They recommended screening high-risk patients using validated tools such as STOP-Bang questionnaires and considering polysomnography for definitive diagnosis.

The authors concluded that patients with severe OSA, poorly controlled diabetes, resistant hypertension, and metabolic syndrome may represent a particularly high-risk phenotype requiring aggressive multimodal treatment strategies to reduce cerebrovascular complications.

References

1. Varghese RT, Sharifi IA, Ayar UD, et al. The role of obstructive sleep apnea and diabetes mellitus in the development of cerebrovascular complications: a narrative review. Diabetology. 2026;7(3):60. doi:10.3390/diabetology7030060
2. GBD 2021 Stroke Risk Factors Collaborators. Global, regional, and national burden of stroke and its risk factors, 1990-2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet Neurol. 2024;23(10):973-1003. doi:10.1016/S1474-4422(24)00369-7.