Sleep Apnea Doubles Risk for Stroke Precursor in Elderly

Patients aged 65 years or older with moderate to severe obstructive sleep apnea (OSA) were at an increased risk for silent cerebral infarction and lacunar infarction, according to the results of a study titled Obstructive sleep apnoea as a risk factor for silent cerebral infarction, published in February in the Journal of Sleep Research.

Compared with patients without OSA, this patient group had an increased odds ratio (OR) for silent cerebral infarction of 2.44 (95% CI, 1.03-5.80) and an increased OR for lunar infarction of 3.48 (95% CI, 1.31-9.23). This association was maintained when data were isolated for patients with a body mass index of less than 27.5 kg/m², with an OR for silent cerebral infarction of 2.75 and an OR for lacunar infarction of 3.87.

Study authors note that “obstructive sleep apnea should be considered a risk factor for silent cerebral infarction independent of obesity,” and they suggested that early diagnosis and treatment of the condition may be an effective stroke prevention strategy.

Eo Rin Cho, MPH, of the Institute of Human Genomic Study at Korea University College of Medicine, Seoul, and colleagues conducted the cross-sectional study that included 746 participants aged 50 to 79 years. During the study, which was part of the Korean Genome and Epidemiology study, participants underwent polysomnography, brain MRI, and health screening examinations to help researchers determine whether obstructive sleep apnea was an independent risk factor for silent cerebral infarction.

Stroke is currently the leading cause of death and disability in Korea, occurring in 2.9% of patients aged 50 years or older and in 4.5% of patients aged 65 years or older, according to background information in the article.

About 12% of the patient population was classified as having moderate to severe OSA. Silent cerebral infarction occurred in 7.64% of patients. Those patients who had OSA had significantly higher apnea-hypopnea index, prevalence of silent cerebral infarction (15.56%), and lacunar infarction (13.33%; P<.001 for all) compared with patients without OSA.

Among the brain regions examined, silent cerebral infarction and lacunar infarcts were most likely to occur in the basal ganglia, the brain region responsible for “emotional, motivational and cognitive functions.” In this region, OSA was associated with increased odds of silent cerebral infarction in all age groups, but it was particularly increased among patients aged 65 years and older.

Cho ER, Kim H, Seo HS, et al. Obstructive sleep apnoea as a risk factor for silent cerebral infarction. J Sleep Res. 2013; doi:10.1111/jsr.12034.