Nighttime sleep, Chinese afternoon nap, and mortality in the elderly.

Division of Gerontology Research, National Health Research Institutes, Zhunan, Taiwan.
Sleep (Impact Factor: 5.06). 10/2007; 30(9):1105-10.
Source: PubMed

ABSTRACT Although many epidemiologic studies have shown that both short and long nighttime sleep durations are associated with increased mortality in the general population, limited data have been reported for older persons, especially those taking afternoon nap. Data from a prospective cohort study of the elderly in Taiwan were used to examine the relationship among nighttime sleep, Chinese afternoon nap, and mortality.
Prospective cohort study.
General population.
A nationally representative sample of 3079 Taiwanese community residents aged 64 and over was studied, using reported sleep related information collected in 1993 and subsequent 10-year mortality data.
Cox proportional hazards models, separated by sex, were computed to estimate mortality hazard ratios in relation to nighttime sleep duration and afternoon nap duration, adjusting for potential confounders. Compared to older adults sleeping 7-7.9 hours at night, those with longer sleeping time (> or = 10 hours in males and > or = 8 hours in females) had a significantly higher risk of total mortality. Afternoon nap alone was not associated with total mortality. When nighttime sleep duration and afternoon nap duration were considered together by adding the interaction term in the model or stratifying sleep hours and nap duration, the effect of afternoon nap on mortality risk remained insignificant.
Longer nighttime sleep duration increases mortality risk in older adults. Chinese afternoon nap is not an independent predictor of mortality. There is no significant benefit or harm of practicing afternoon nap in addition to the regular night sleep on elderly mortality.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Sleep quality is important to health, and increasingly viewed as critical in promoting successful, resilient aging. In this review, the interplay between sleep and mental and physical health is considered with a focus on the role of inflammation as a biological pathway that translates the effects of sleep on risk of depression, pain and chronic disease risk in aging. Given that sleep regulates inflammatory biologic mechanisms with effects on mental and physical health outcomes, the potential of interventions that target sleep to reduce inflammation and promote health in aging is also discussed.
    Interface focus: a theme supplement of Journal of the Royal Society interface 10/2014; 4(5):20140009. · 3.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective Our objective was to evaluate the association between habitual daytime napping and the prevalence of metabolic syndrome. Materials and Methods We conducted a population-based study of 8,547 subjects aged 40 years or older. Metabolic syndrome was defined according to a harmonized definition from a joint statement and the recommended thresholds for the Chinese population. Information about sleep duration was self-reported. Results The prevalence of metabolic syndrome in the no daytime napping group, the 0 to 1 hour daytime napping group and the more than 1 hour daytime napping group were 35.0%, 36.0% and 44.5% among the females (P < 0.0001). Increased daytime napping hours were positively associated with parameters of metabolic syndrome in the female subjects, including waist circumference, systolic blood pressure, triglycerides and fasting plasma glucose (P < 0.05 for all). Multivariate adjusted logistic regression analysis revealed that, compared to the no habitual daytime napping females, napping for more than 1 hour was independently associated with an increased prevalence of metabolic syndrome (odds ratio 1.39, 95% confidence interval, 1.13 - 1.72). Compared to the female subjects in the no daytime napping group, those habitually napped for more than 1 hour exhibited 46% and 26% increases in the prevalence of central obesity and hypertriglyceridemia (all P < 0.05). No statistically significant associations were detected between daytime napping hours and metabolic syndrome among the male subjects. Conclusion Daytime napping is associated with an increased prevalence of metabolic syndrome in middle-aged non-obese Chinese women.
    Metabolism 08/2014; · 3.61 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Epidemiologic studies have consistently shown an association of long sleep (≥8 hr) with mortality and multiple morbidities. However, there has been little experimental investigation of the effects of sleep extension. The aim of this study was to examine the effects of time in bed (TIB) extension, on depression, anxiety, sleepiness, and systemic inflammation. Following baseline, 14 healthy sleepers (31.79±10.94 years) were randomized to one of two one-week treatments: (1) a TIB extension treatment involving a fixed sleep schedule in which TIB was increased by 3 hours/night compared with the participants' median baseline TIB; (2) a control treatment involving a fixed schedule in which TIB was the same as the participants' median baseline TIB. Actigraphic recording of sleep was assessed throughout both weeks. Self-reported depression, state anxiety, sleepiness, and sleep quality, as well as blood pressure, and inflammation were assessed at baseline and following the treatment week. Compared with baseline, TIB increased by 127.12±3.92 min and total sleep time increased by 119.88±18.52 min during TIB extension, but decreased slightly in the control treatment. Depression was elevated more following TIB extension (effect size (ES)=-0.86) vs. control (ES=-0.50). Interleukin-6 levels increased by 2-fold following TIB extension (ES=-0.65), but did not change following the control treatment. Sleepiness increased after TIB extension, but decreased after the control treatment. The results revealed negative effects of TIB extension on mood and inflammation. Larger-scale studies involving more prolonged, but less profound sleep extension, are warranted.
    Journal of Sleep Medicine and Disorders. 08/2014; 1(1).

Full-text (2 Sources)

Available from
May 16, 2014