Short, Long Sleep Duration Associated With Increased Mortality

Main Category: Sleep / Sleep Disorders / Insomnia
Article Date: 01 Dec 2007 - 12:00 PDT

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Both a decrease and an increase in sleep duration are associated with an elevated risk of mortality by cardiovascular and non-cardiovascular means, respectively.

The study, authored by Jane E. Ferrie, PhD, of the University College London Medical School in London, U.K., focused on 10,308 participants between 35 and 55 years of age. Baseline screening (Phase 1), conducted between 1985 and 1988, involved a clinical examination and a self-administered questionnaire. Data collection at Phase 3 (1992-1993) also included a clinical examination (8,104 participants) and questionnaire (8,642 participants).

According to the results, U-shaped associations were observed between sleep at Phase 1 and Phase 3 and subsequent all-cause, cardiovascular and non-cardiovascular mortality. A decrease in sleep duration among participants sleeping six, seven or eight hours at baseline was associated with a 110 percent excess risk of cardiovascular mortality. However, an increase in sleep duration among those sleeping seven or eight hours at baseline was associated with a 110 percent excess risk of non-cardiovascular mortality. Adjustment for the socio-demographic factors, existing mortality and health-related behaviors measured left these associations largely unchanged.

"In terms of prevention, our findings indicate that consistently sleeping seven or eight hours per night is optimal for health," said Dr. Ferrie. "The indication that mortality rates are lower in participants who slept five to six hours or less at Phase 1 but who reported extended hours of sleep at Phase 3 implies that increasing sleep duration in short sleepers is likely to have health benefits. In contrast to this, the finding that an increased duration of sleep among those sleeping seven to eight hours is associated with higher levels of mortality implies that sleep restriction should at least be considered."

SLEEP is the official journal of the Associated Professional Sleep Societies, LLC, a joint venture of the AASM and the Sleep Research Society.

SleepEducation.com, a patient education Web site created by the AASM, provides information about various sleep disorders, the forms of treatment available, recent news on the topic of sleep, sleep studies that have been conducted and a listing of sleep facilities.

http://www.aasmnet.org