The Mediating and Regulating Effect of Night Sleep Duration on Low Back Pain and Depression in Rural Old People

Objective: To investigate the relationship between nighttime sleep duration and low back pain and depression among rural elderly people in China, and provide evidence for promoting their health. Methods: Based on the China Health and Retirement Longitudinal Study (CHARLS) database, a mediation model was used to analyze the role of nighttime sleep and nap time in the relationship between low back pain and depression. Results: The study found that more than half of the participants were female (56.02%), with depressive symptoms (51.05%) and low back pain (62.54%) being more common. There was a significant gender difference, with significantly higher proportions of men without low back pain and depression than women (p<0.001). Nighttime sleep duration acted as a mediator between low back pain and depression in both the overall and sex-stratified models (95%CI: 0.013 ~ 0.028; 0.003 ~ 0.019; 0.011 ~ 0.035), and gender moderated this mediation path, with a significantly higher indirect effect among women than men. Conclusion: Nighttime sleep duration plays a mediating role in the relationship between low back pain and depression, and gender moderates this effect, with women being more affected. The study provides data support for the treatment and prevention of low back pain and depression.