Study on the Independent and Joint Effects of Physical Activity and Sleep on Low Back Pain in Middle-aged and Elderly Adults

Abstract

Background Low back pain (LBP) in middle-aged and elderly adults has become a significant public health issue worldwide. Physical activity and sleep are two core components of the 24-hour lifecycle, and maintaining adequate physical activity and good sleep are crucial for health, both of which are associated with LBP. Objective To investigate the prevalence of LBP in middle-aged and elderly adults in China, analyze the independent and combined effects of physical activity and sleep on its occurrence, and provide scientific evidence for behavioral health. Methods Based on the 2018 China Health and Retirement Longitudinal Study, participants without demographic, physical activity, sleep, and LBP data were excluded. A total of 13 496 eligible individuals aged 45 to 69 were included, and their demographic and behavioral information was collected. Binary logistic regression and multiple linear regression were used to examine the relationship between physical activity, sleep duration, and LBP, and a mediation model was constructed to analyze the mediating effect of sleep duration on the association between physical activity and LBP. Results The prevalence of LBP among the 13 496 participants was 39.0% (n=5 269). Inadequate sleep (<7 hours) was reported by 57.1% (n=7 704) of middle-aged and elderly adults in China, with 11.6% (n=1 561) engaging in mild physical activity and 88.4% (n=11 935) engaging in moderate to high-intensity physical activity. The multicollinearity diagnosis results for confounding variables (gender, age, alcohol consumption, and smoking) showed that all variance inflation factors were less than 5, indicating no collinearity. Regression analysis revealed a positive correlation between physical activity and LBP (β=0.120, P<0.05), a negative correlation between sleep duration and LBP (β=-0.220, P<0.01), and a negative correlation between physical activity and sleep duration (β=-0.081, P<0.05). The mediation analysis of categorical variables indicated Z=2.223>1.96, and the path from physical activity to LBP was not significant (β=0.105, P>0.05), suggesting a complete mediating effect of sleep duration on the association between physical activity and LBP. Conclusion Over one-third of middle-aged and elderly adults in China suffer from LBP. Higher levels of physical activity or shorter sleep duration are associated with increased risk of LBP. Sleep duration plays a complete mediating role in the association between physical activity and LBP, where the increased risk of LBP associated with high-intensity physical activity is completely transmitted through reduced sleep duration. Adequate sleep duration plays an important role in reducing the risk of LBP associated with high-intensity physical activity. This study suggests that older adults should adjust their exercise intensity according to their own conditions and maintain adequate sleep duration to reduce the risk of LBP.

Keywords

• low back pain|physical activity|sleep duration|middle-aged and elderly adults|root cause analysis