Nightime sleep, Chinese afternoon nap, and mortality in the elderly

Division of Gerontology Research, National Health Research Institutes, Zhunan, Taiwan.
Sleep (Impact Factor: 4.59). 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.

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Available from: Tzuo-Yun Lan, Apr 22, 2014
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    • "Considering gender, in a study in Mediterranean countries , long sleep duration was found to be a significant predictor of all-cause mortality among men aged 50 and over, whereas same-aged women were not affected (Burazeri et al. 2003). Analysis performed among Taiwanese older people (64? years) showed a significant association between long sleep duration and mortality for both genders where the hazard ratio was higher among women (Lan et al. 2007). The Shirakawa study (Japan) showed that longer and shorter sleep controlled for several confounders (like present and past medical history, use of sleep pills, smoking and drinking habits) was significantly related to an increased risk of total mortality among males (Kojima et al. 2000). "
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    ABSTRACT: The aim of this study was to assess the relationship of sleep duration and all-cause mortality among 2,449 Polish community-dwelling older citizens of Krakow observed during 22 years of follow-up. In particular, the role of some demographic, psychosocial and health-related conditions were investigated in terms of modification effect. In the prospective study, background information was gathered by face-to-face interview. Vital data were obtained from the population registry. Cox regression models were used to assess the role of sleep duration in mortality, in the analyses of potential effect modifiers and the shape of the relationship. Sleep duration was observed to be a significant predictor of all-cause mortality. Life-weariness, functional activity, total number of chronic diseases and age (65–79, 80+) were found to be effect modifiers for the relationship between sleep duration and mortality. Further investigation showed a U-shaped mortality risk associated with the duration of sleep among individuals with a high level of life-weariness, high functional activity and in individuals aged 80 and over. On the other hand, a linear relationship between longer sleep duration and mortality was observed among older people with no experience of life-weariness, without chronic diseases, with medium functional activity and aged 65–79, but also among those who reported three and more chronic conditions. Results of our study support available evidence showing the relationship between sleep duration and mortality among older adults and suggest that any public health intervention in this area should consider also other coexisting modifiable psychosocial and functional determinants.
    European Journal of Ageing 06/2014; 12(2). DOI:10.1007/s10433-014-0318-8 · 1.27 Impact Factor
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    • "Four examples of activity plots, the Rotterdam Study, the Netherlands, 2004–2007. Plots show activity rhythms of participants from the Rotterdam Study. "
    Sleep Medicine 12/2013; 14:e29. DOI:10.1016/j.sleep.2013.11.031 · 3.15 Impact Factor
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    • "In elderly subjects, increased mortality has been associated more with long,18–20 versus short,18 sleep durations, although not all studies found significant associations.21,22 Studies replicating significant associations between sleep duration and mortality risk have been conducted in Japan,23–27 Taiwan,28 Singapore,29 Israel,30 Sweden,31 Finland,32 Brazil,33 the UK,34–36 and the US.37–43 "
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    ABSTRACT: Habitual sleep duration has been associated with cardiometabolic disease, via several mechanistic pathways, but few have been thoroughly explored. One hypothesis is that short and/or long sleep duration is associated with a proinflammatory state, which could increase risk for cardiovascular and metabolic diseases. This hypothesis has been largely explored in the context of experimental sleep deprivation studies which have attempted to demonstrate changes in proinflammatory markers following acute sleep loss in the laboratory. Despite the controlled environment available in these studies, samples tend to lack general-ization to the population at large and acute sleep deprivation may not be a perfect analog for short sleep. To address these limitations, population based studies have explored associations between proinflammatory markers and habitual sleep duration. This review summarizes what is known from experimental and cross-sectional studies about the association between sleep duration, cardiovascular disease, and proinflammatory biomarkers. First, the association between sleep duration with both morbidity and mortality, with a focus on cardiovascular disease, is reviewed. Then, a brief review of the potential role of proinflammatory markers in cardiovascular disease is presented. The majority of this review details specific findings related to specific molecules, including tumor necrosis factor-α, interleukins-1, -6, and -17, C-reactive protein, coagulation molecules, cellular adhesion molecules, and visfatin. Finally, a discussion of the limitations of current studies and future directions is provided.
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