The influence of chronotype on pain: a systematic review and meta-analysis

Sleep and circadian rhythms play critical roles in pain regulation, yet the influence of chronotype remains underexplored. This systematic review and meta-analysis synthesized evidence across 43 studies (cross-sectional, cohort, and Mendelian randomization designs) investigating associations between chronotype and pain outcomes. Participants ranged from small clinical cohorts to large-scale biobanks and represented diverse pain conditions, including fibromyalgia, temporomandibular disorders, migraine, musculoskeletal pain, and rheumatoid arthritis. Qualitative synthesis indicated that evening chronotypes were more frequently associated with adverse pain outcomes, including higher pain prevalence, greater intensity, and increased interference. These associations were particularly consistent in musculoskeletal pain and headache disorders, although some studies reported worse outcomes in morning types or bimodal chronotypes. A meta-analysis of 10 studies revealed that evening chronotypes had significantly higher odds of reporting chronic pain than non-evening types (odds ratios = 1.67, 95% confidence intervals: 1.40-1.99). In contrast, pooled results for pain intensity across 6 studies showed only a nonsignificant trend toward greater pain in evening chronotypes, with substantial heterogeneity and sensitivity to influential studies. Certainty of evidence was graded as moderate for pain prevalence and low for pain intensity. Findings support chronotype as a relevant circadian marker of pain vulnerability, likely mediated by circadian misalignment, sleep disturbance, and affective dysregulation. Future research should integrate objective circadian phase measures, longitudinal designs, and disorder-specific chronobiological profiles. Recognizing evening chronotype and misalignment as modifiable risk factors may inform tailored interventions, such as light therapy or behavioral schedule adjustments, to reduce pain burden.