Sleep Duration, Mortality, and High-Risk Populations: A Nationwide Study in the United States

Objectives: Both insufficient and excessive sleep durations have been recognized as important risk factors for mortality. Nevertheless, the impact of sleep duration on cause-specific mortality and potential effect modifiers has not been investigated extensively. Therefore, this study aimed to assess the association between sleep duration and mortality categorized by cause of death and potential effect modifiers using data from the National Health and Nutrition Examination Survey (NHANES). Methods: We established a prospective cohort based on NHANES participants aged 50 years or older, linked to the National Death Index (NDI) in the United States between 2009 and 2018. The NDI included all-cause, cardiovascular, and respiratory deaths. Sleep duration was assessed during the NHANES examination period. A survey-weighted Cox proportional hazards model was used to evaluate the association between sleep and mortality. Results: A total of 13,947 participants with available NHANES data were included in this study. A U-shaped association between sleep duration and mortality was observed for all-cause and cardiovascular mortality, meanwhile, respiratory mortality was linked to moderately short sleep (>5 and <7 hours). For total mortality, the association with severe short sleep (5 hours or less; p<0.01) was generally stronger than the association with long sleep (>8 hours; p=0.029), with the effect of severe short sleep being significantly prominent in males (p<0.01), non-Hispanic White (0.001), high-income (0.056), and those with a body mass index ≥23.0 kg/m2 (0.001) than those in their counterparts. Conclusions: This study suggests that sleep duration is associated with the mortality risk. Our results provide evidence for a more targeted allocation of public health resources to improve sleep and health.