Sleep and neurocognitive decline in the Hispanic Community Health Study/Study of Latinos.

INTRODUCTION

To determine if sleep-disordered breathing (SDB), daytime sleepiness, insomnia, and sleep duration predict seven-year neurocognitive decline in US Hispanics/Latinos (N = 5247).

METHODS

The exposures were baseline SDB, daytime sleepiness, insomnia, and sleep duration. The outcomes were change in episodic learning and memory (B-SEVLT-Sum and SEVLT-Recall), language (word fluency [WF]), processing speed (Digit Symbol Substitution), and a cognitive impairment screener (Six-item Screener [SIS]).

RESULTS

Mean age was 63 ± 8 years, with 55% of the population being female with 7.0% Central American, 24.5% Cuban, 9.3% Dominican, 35.9% Mexican, 14.4% Puerto Rican, and 5.1% South American background. Long sleep (>9 hours), but not short sleep (<6 hours), was associated with decline (standard deviation units) in episodic learning and memory (βSEVLT-Sum= -0.22 [se = 0.06]; P < .001; βSEVLT-Recall = -0.13 [se = 0.06]; P < .05), WF (Pwf = -0.20 [se 5 0.06]; P < .01), and SIS (βSIS = -0.16 [se = 0.06]; P < .01), but not processing speed, after adjusting for covariates. SDB, sleepiness, and insomnia were not associated with neurocognitive decline.

CONCLUSION

Long sleep duration predicted seven-year cognitive decline.