Association between alcohol consumption and chronic pain: a systematic review and meta-analysis

Abstract

Introduction: Chronic pain and depression represent two global health problems with considerable economic consequences. While the existing literature reported on the relation between depression and pain conditions, meta-analytic evidence backing the mediating role of sleep disturbance as one of the main symptoms of depression is scarce. To examine the extent to which sleep disturbance mediates the depression- chronic pain association, we conducted a systematic review and meta-analysis of the associations of chronic pain, depression, and sleep quality. Methods: We systematically searched for literature in Medline and other relevant databases and identified cohort and case-control studies on depression, sleep disturbance, and chronic pain. Fourty-nine studies were eligible, with a total population of 120,489 individuals. We obtained direct and indirect path coefficients via two-stage meta-analytic structural equation modelling (TSSEM), examined heterogeneity via subgroup analyses, and evaluated primary studies quality. Results: We found a significant, partial mediation effect of sleep disturbance on the relation between depression and chronic pain. The pooled path coefficient (coef.) of the indirect effect was 0.03 (95% confidence interval (CI): 0.01-0.05) and accounted for 12.5% of the total effect of depression on chronic pain. This indirect effect also existed for cohort studies (coef. = 0.02, 95%CI: 0.002-0.04), European studies (coef. = 0.03, 95% CI: 0.004-0.05), and studies that adjusted for confounders (coef. = 0.04, 95% CI: 0.010.09). Conclusion: Sleep disturbance partially mediates the association between depression and pain. Although plausible mechanisms could explain this mediation effect, other explanations, including reverse causation, must be further explored.