Severe Sleep Apnea Linked with Stroke and Death

A recent observational study of more than 1,000 participants at the Yale Center for Sleep Medicine found a significant correlation between sleep apnea and the risk of stroke or death. 68% of the enrolled participants had sleep apnea with at least five sleep disordered breathing events per hour. The participants were over the age of 50 and had no history of heart attack or stroke.

Follow-up with participants occurred after a median duration of 3.4 years and showed stroke or death occurred in 88 participants; 72 incidences of stroke or death occurred in the sleep apnea group and 16 in the control group. After accounting for other risk factors such as age, sex, race, smoking status, alcohol consumption, body-mass index (BMI) and hypertension, the association between severe obstructive sleep apnea and risk of stroke or death remained significant. Researchers also found that more severe cases of sleep apnea were associated with higher risk for stroke or death, even though many of the patients had been treated with various therapies for sleep apnea.

Several explanations may account for this result: First, patients may have had untreated sleep apnea for a number of years and/or the follow-up time after the first phase of the study may not have been lengthy enough to assess the full benefits of treatment. Second, participants’ failure to fully comply with continuous positive airway pressure (CPAP) may explain the lack of positive results. Finally, the population of participants included older individuals with a higher incidence of cardiovascular risk factors. Nevertheless, after taking into account other risk factors and confounding variables, the study provides significant evidence that severe sleep apnea puts individuals at a greater risk for stroke and death.