Association of Midday Napping with All-Cause Mortality in Chinese Adults: A 8-Year Nationwide Cohort Study

This study aimed to investigate the longitudinal association of estimated daytime nap duration with all-cause mortality in Chinese adults. We conceived a prospective cohort design using adult survey data of the baseline and four follow-up waves (2010-2019) from China Family Panel Studies. Cox frailty models with random intercepts for surveyed provinces were used to estimate risks of all-cause mortality associated with midday napping. Trend and subgroup analyses were also performed stratified by demographic, regional and behavioral factors. Compared with non-nappers, those who reported a long napping duration (>= 60 min/day) had an increased risk of all-cause mortality, while shorter napping (<60 min) showed no association with mortality. We observed significant trends for greater risks of mortality associated with longer nap duration. Long nap-associated higher risk of all-cause mortality was seen in a group of nocturnal sleep duration >= 9 h. We identified stronger associations of long nap with mortality among adults aged over 50 years, those with lower BMI (<24 kg/m(2)), residents in rural regions and unregular exercisers. Long midday napping is independently associated with higher risks of all-cause mortality in Chinese adults.

Automated summary

This study aimed to investigate the longitudinal association of estimated daytime nap duration with all-cause mortality in Chinese adults. The results showed that long nap duration (>= 60 min/day) was associated with an increased risk of all-cause mortality, while shorter nap duration (<60 min) showed no association with mortality. There was a significant trend for greater risks of mortality associated with longer nap duration. Among individuals with nocturnal sleep duration >= 9 h, long napping was independently associated with higher risks of all-cause mortality. The associations between long nap duration and mortality were stronger among adults aged over 50 years, those with lower BMI (<24 kg/m(2)), residents in rural regions, and irregular exercisers.