Internal Medicine: Open Access
Open Access

Abstract

Obstructive Sleep Apnea Syndrome and Dementia: is there a link?

Chitra Lal

The prevalence of Obstructive Sleep Apnea Syndrome (OSAS) increases with age. Since dementia is also considered a disease of aging, the question arises as to whether there is a link between these two disorders. Does co-morbid OSAS cause further worsening of cognitive functioning and would its treatment with continuous positive airway pressure (CPAP) improve these neurocognitive deficits? In a recent, prospective study of 298 women without dementia, with a mean age of 82.3 years, women with sleep-disordered breathing (as defined in this study by an apnea-hypopnea index, i.e., AHI, of 15 or more events per hour of sleep) were found to have an increased risk of developing cognitive impairment as compared to women who had no sleep-disordered breathing [1]. Another cross-sectional study of 448 community dwelling women with a mean age of 82.8 years, found a significant association between objectively measured sleep-disordered breathing by polysomnography and cognitive impairment. In addition, the association between AHI and the Mini-Mental State Examination score was much greater in carriers of Apolipoprotein E epsilon4 (ApoE4) allele [2]. ApoE4 allele has been linked in prior studies to a higher risk of developing OSAS as well as early-onset Alzheimer’s dementia.