Chronic pain and risk of gastrointestinal diseases in middle-aged and elderly Chinese adults: The roles of depression and sleep.

Chronic pain and gastrointestinal (GI) diseases are prevalent among aging populations. However, their relationship and the potential psychological and behavioral mechanisms remain underexplored. We analyzed data from the 2011 to 2020 China Health and Retirement Longitudinal Study, a nationally representative cohort of adults aged 45 years and older. The cross-sectional analysis (n = 8122) assessed the association between chronic pain and GI diseases, while the longitudinal analysis (n = 4982) examined whether chronic pain predicted incident GI diseases over a 9-year follow-up. Multivariate logistic regression models estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup and interaction analyses were conducted to identify potential effect modifiers. Causal mediation analysis using nonparametric bootstrap methods was employed to quantify the mediating effects of depression and sleep duration. Chronic pain was significantly associated with an increased risk of GI diseases in both cross-sectional (adjusted OR: 2.124, 95% CI: 1.890-2.386, P < .001) and longitudinal (adjusted OR: 1.365, 95% CI: 1.161-1.606, P < .001) analyses. Findings were robust in sensitivity analyses, including a dose-response by pain severity and persistence after excluding baseline stomach pain. Depression and sleep duration mediated 23.0% (95% CI, 10.1-46.0%; P < .001) and 3.5% (95% CI, 0.3-10.0%; P < .05) of the total effect, respectively. Age significantly moderated the association (P for interaction < .05), with middle-aged adults showing a stronger relationship than older adults. Chronic pain is an independent risk factor for GI diseases, partially mediated by depression and sleep. These findings underscore the need for integrated public health strategies addressing pain, mental health, and sleep to reduce gastrointestinal morbidity in aging populations.