Genetic Risk of Alzheimer's Disease and Sleep Duration in Non‐Demented Elders

Growing evidence has suggested an association between sleep duration and Alzheimer's disease (AD), but it is unclear if sleep duration is a manifestation of the AD disease process. We studied whether genetic liability for AD predicts sleep duration using a genetic risk score (GRS) for AD (AD‐GRS), in 406,536 UK Biobank participants with European ancestry and without dementia at enrollment. Higher AD‐GRS score was associated with shorter sleep (b = −0.014, 95% confidence interval [CI] = −0.022 to −0.006), especially in those aged 55+. Using AD‐GRS as an instrumental variable for AD diagnosis, incipient AD reduced sleep duration by 1.87 hours (95% CI = 0.96, 2.78). Short sleep duration might be an early marker of AD. ANN NEUROL 2021;89:177–181