Self‐Reported Sleep Apnea and Dementia Risk: Findings from the Prevention of Alzheimer's Disease with Vitamin E and Selenium Trial

Objectives To investigate the association between baseline sleep apnea and risk of incident dementia in the Prevention of Alzheimer's Disease with Vitamin E and Selenium ( PREADV i SE ) study and to explore whether the association depends on apolipoprotein E ( APOE ) ɛ 4 allele status. Design Secondary analysis based on data collected during PREADV i SE . Setting Participants were assessed at 128 local clinical study sites during the clinical trial phase and later were followed by telephone from a centralized location. Participants Men enrolled in PREADV i SE (without dementia or other active neurological conditions that affect cognition such as major psychiatric disorders, including depression; N = 7,547). Measurements Participants were interviewed at baseline for sleep apnea. The Memory Impairment Screen ( MIS ) was administered to each participant annually. Subjects who failed this initial screen were tested with secondary screening tests. Medical history and medication use were determined, and the AD 8 dementia screening instrument was used. Results The effect of self‐reported sleep apnea on dementia risk depended on APOE ɛ 4 status. When the allele was absent, baseline self‐reported sleep apnea was associated with a 66% higher risk of developing dementia (95% confidence interval = 2–170%), whereas self‐reported sleep apnea conferred no additional risk for participants with an ɛ 4 allele. Conclusion Sleep apnea may increase risk of dementia in the absence of APOE ɛ 4. This may help inform prevention strategies for dementia or AD in older men with sleep apnea. Registration: PREADV i SE is registered at ClinicalTrials.gov: NCT 00040378.