0098 A Model for a Chronic Napping in Older Adults at Risk for Alzheimer’s Disease

Abstract

Introduction: Theoretically, napping could have positive effects on health (e.g., by reducing stress and compensating for short night time sleep) or negative effects (e.g., by disrupting nighttime sleep or impairing circadian synchronization). Epidemiologic studies have produced mixed results regarding associations of napping with health. Causality can be better addressed with a randomized controlled trial of daily napping, as described herein. Methods: Participants were 12 older adults (70.8±4.4 years) with a first degree relative with Alzheimer's Disease. Inclusion criteria included normal cognitive function; stable sleep schedule; stable medication use; and self‐reported ease of taking naps, but with napping frequency of ≤2 days per week. Exclusion criteria included having a sleep disorder or high risk of obstructive sleep apnea; hypertension; sleeping pill use > once per week; MI or stroke within the past 3 years. Following a one week baseline involving a stable sleep/nap schedule consistent with usual habits, participants were randomized to one of two 21‐day treatments: (1) daily napping (1 h/day begun at 5‐7 h after arising) while keeping a stable night sleep schedule consistent with baseline (n=6); (2) a no‐napping control treatment in which participants read quietly for 1 h/day at the same time (n=6). Sleep for night sleep and napping (or non‐napping) was assessed via self‐report, actigraphy, and the Z‐machine. Results: ANOVA revealed a significant increase in napping minutes/ day (p=0.01) in the napping treatment (baseline: 14.5±21.1; 21‐day average: 42.1±19.1) compared with the control treatment (baseline: 2.2±5.5; treatment: 1.4±3.5). However, reported nightime sleep duration did not change significantly between the napping (from 7.1±1.2 to 7.4±1.0 h) and the control treatment (7.8±0.7 to 7.8±0.6 h). Actigraphic night sleep changed from 7.3±0.8 to 7.1±0.9 and 7.8±5 to 7.6±0.7 after napping and control, respectively. There were not significant treatment differences (nor notable effect size differences) for depressed mood, sleepiness, PSQI, amyloid beta, nor cardiovascular measures (e.g., blood pressure, flow mediated dilation, pulse wave velocity). Conclusion: The data indicate that older adults can undergo daily napping without significant impairment in nighttime sleep. Neither benefits nor detrimental effects on health‐related variables were shown in this small sample. A more prolonged intervention is needed.