[Relationship between sleep quality and the risk of all-cause mortality in elderly people aged 60 and above in Shanghai: a prospective cohort study].

Objective: To explore the relationship between sleep quality and the risk of all-cause mortality based on a large-scale prospective cohort of elderly people aged 60 and above in Shanghai community. Methods: In 2019, 17 948 community elderly people aged 60 and above were recruited to participate in the Shanghai Community Elderly Cohort. Baseline information of cohort members was collected through face-to-face questionnaires, and sleep information during the most recent month was collected using the Pittsburgh Sleep Quality Index (PSQI) scale. The association between sleep quality and risk of all-cause mortality was analyzed using multifactorial Cox regression models. Restricted cubic spline (RCS) model was used to analyze the relationship between sleep duration and all-cause mortality risk. Results: A total of 16 271 individuals were included in the analysis, aged (68.4±5.9) years, 46.25% (n=7 525) were males, and after a mean follow-up of 4.49 years, 700 deaths were observed. Using a sleep duration of 6 to<7 h/d as a reference, the risk of all-cause mortality was increased for sleep duration<6 h/d (HR=1.51, 95%CI: 1.01 to 2.26), and the risk of all-cause mortality was also increased for sleep durations of 7 to <8, 8 to <9, and ≥9 h/d, with HR (95%CI) of 1.40 (1.08 to 1.82), 1.51 (1.16 to 1.96) and 2.08 (1.58 to 2.73), respectively. The associations of PSQI score, self-reported sleep quality, time to sleep score, sleep efficiency, sleep disorder score, number of hypnotic medications used per week, daytime dysfunction score, and length of daytime naps with the risk of all-cause mortality were not statistically significant (all P>0.05). Analysis of the RCS model showed that sleep duration was associated with the risk of all-cause mortality in a "J" pattern, with the lowest risk at 7 h/d of sleep duration (P for nonlinear=0.048). Above a sleep duration of 7 h/d, the risk of all-cause mortality increased by 22% for each 1 h/d increase in sleep duration, with an HR (95%CI) of 1.22 (1.13 to 1.31). Conclusion: There is a J-shaped association between daily hours of sleep and risk of all-cause mortality among elderly people aged 60 and above in the Shanghai community, and the elderly who slept 7 hours per night have the lowest risk of all-cause mortality.