PT  - JOURNAL ARTICLE
AU  - Andrew J. Westwood
AU  - Alexa Beiser
AU  - Nikita Jain
AU  - Jayandra J. Himali
AU  - Charles DeCarli
AU  - Sanford H. Auerbach
AU  - Matthew P. Pase
AU  - Sudha Seshadri
TI  - Prolonged sleep duration as a marker of early neurodegeneration predicting incident dementia
AID  - 10.1212/WNL.0000000000003732
DP  - 2017 Mar 21
TA  - Neurology
PG  - 1172--1179
VI  - 88
IP  - 12
4099  - http://n.neurology.org/content/88/12/1172.short
4100  - http://n.neurology.org/content/88/12/1172.full
SO  - Neurology2017 Mar 21; 88
AB  - Objective: To evaluate the association between sleep duration and the risk of incident dementia and brain aging.Methods: Self-reported total hours of sleep were examined in the Framingham Heart Study (n = 2,457, mean age 72 ± 6 years, 57% women) as a 3-level variable: <6 hours (short), 6–9 hours (reference), and >9 hours (long), and was related to the risk of incident dementia over 10 years, and cross-sectionally to total cerebral brain volume (TCBV) and cognitive performance.Results: We observed 234 cases of all-cause dementia over 10 years of follow-up. In multivariable analyses, prolonged sleep duration was associated with an increased risk of incident dementia (hazard ratio [HR] 2.01; 95% confidence interval [CI] 1.24–3.26). These findings were driven by persons with baseline mild cognitive impairment (HR 2.83; 95% CI 1.06–7.55) and persons without a high school degree (HR 6.05; 95% CI 3.00–12.18). Transitioning to sleeping >9 hours over a mean period of 13 years before baseline was associated with an increased risk of all-cause dementia (HR 2.43; 95% CI 1.44–4.11) and clinical Alzheimer disease (HR 2.20; 95% CI 1.17–4.13). Relative to sleeping 6–9 hours, long sleep duration was also associated cross-sectionally with smaller TCBV (β ± SE, −1.08 ± 0.41 mean units of TCBV difference) and poorer executive function (β ± SE, −0.41 ± 0.13 SD units of Trail Making Test B minus A score difference).Conclusions: Prolonged sleep duration may be a marker of early neurodegeneration and hence a useful clinical tool to identify those at a higher risk of progressing to clinical dementia within 10 years.AD=Alzheimer disease; CI=confidence interval; DSM-IV=Diagnostic and Statistical Manual of Mental Disorders, 4th edition; FHS=Framingham Heart Study; HR=hazard ratio; MCI=mild cognitive impairment; PAI=Physical Activity Index; TCBV=total cerebral brain volume