Abnormal night sleep duration and poor sleep quality are independently and combinedly associated with elevated depressive symptoms in Chinese rural adults: Henan Rural Cohort

Abstract Objective To assess the independent and combined effects of night sleep duration and sleep quality on depressive symptoms. Methods A total of 28202 participants (11236 males and 16966 females) aged 18-79 years from Henan Rural Cohort were included in current study. Night sleep duration and sleep quality were defined by Pittsburgh Sleep Quality Index (PSQI). Logistic regression and restricted cubic splines were applied to evaluate the association of night sleep duration and sleep quality with depressive symptoms. Results A U-shaped dose-response relationship between night sleep duration and depressive symptoms along with a J-shaped relationship between sleep quality and depressive symptoms was observed. Compared with reference group (7- =10h) were associated with increased risk of depressive symptoms in male (short sleep: Odds Ratio (OR) = 1.84, 95% confidence interval (CI), 1.34-2.52; long sleep: OR = 1.56, 95%CI, 1.01-2.42) and female (short sleep: OR = 2.19, 95%CI, 1.77-2.70; long sleep: OR = 1.51, 95%CI, 1.10-2.10). Compared with good sleepers, poor sleepers were 4.23-fold (95%CI:3.54-5.06) and 3.87-fold (95%CI: 3.41-4.40) increased odds of depressive symptoms in male and female. Furthermore, participants with longer night sleep duration (>=10h) and poorer sleep quality had strongest effect on depressive symptoms (male: OR = 6.64, 95%CI, 3.21-13.74; female: OR = 7.76, 95%CI, 5.00-12.02). Conclusions Extreme night sleep duration and poor sleep quality were independently and combinedly related to elevated depressive symptoms, suggesting that keeping optimal night sleep duration and good sleep quality maybe benefit for maintaining mental health. Trial Registration Chinese Clinical Trial Register. Registration number: ChiCTR-OOC-15006699.