P076 Effectiveness of melatonin on musculoskeletal pain: a systematic review

Abstract Introduction Musculoskeletal (MSK) pain and poor sleep influence each other in a bidirectional relationship. Melatonin is primarily used to improve sleep quality, however, findings from randomised controlled trials (RCTs) suggest it also has analgesic effects, making it a potential treatment for individuals with MSK pain. This systematic review with meta-analysis aimed to evaluate the effects of melatonin on pain intensity and sleep quality in people with MSK pain. Methods We systematically searched six electronic databases (Cochrane Library, MEDLINE [Ovid], EMBASE [Ovid], PsycINFO, CINAHL, and Web of Science) from inception to 7 March 2024 for RCTs investigating melatonin for managing MSK pain (e.g., low back pain, osteoarthritis). Pain intensity was the primary outcome, and sleep quality the secondary. Meta-analyses were conducted for both efficacy (melatonin vs. placebo) and effectiveness (melatonin vs. other interventions). Results Twenty-three RCTs involving 2028 participants met the inclusion criteria. When chronic MSK conditions were pooled, melatonin significantly improved pain intensity (mean difference [MD]: -6.78/100; 95% confidence interval [CI]: -13.24 to -0.31; p=.04) and sleep quality (MD: -13.25/100; 95% CI: -24.32 to -2.18; p=.02) compared to placebo. In surgical conditions, melatonin significantly reduced pain (MD: -2.53/100; 95% CI: -4.20 to -0.86) and improved sleep quality (MD: -3.42/100; 95% CI: -6.84 to 0.00) compared to placebo. Conclusions Melatonin may be a beneficial treatment for reducing pain intensity and improving sleep quality in individuals with MSK pain. Further high-quality trials with larger sample sizes are needed to confirm these findings and better understand its clinical utility.