Abstract
BACKGROUND: This study aimed to elucidate the nature and extent of the associations between diabetes mellitus (DM) and migraine through a systematic review and meta-analysis. METHODS: We searched the PubMed, Web of Science, and Scopus databases without a specified start date until June 2, 2024. Cross-sectional and cohort studies analyzing the risk of migraine in individuals with DM and vice versa were included. Studies without at least age and sex adjustments were excluded. Data were extracted to calculate odds ratios (ORs) and hazard ratios (HRs). Risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. RESULTS: Eight cross-sectional studies (131,361 patients with DM and 1,005,604 patients with migraine) and four cohort studies (103,205 patients with DM patients and 32,197 patients with migraine) were included. Meta-analyses of the cross-sectional studies showed no significant overall association between DM and migraine. Subgroup analyses revealed that type 1 diabetes reduced the odds of having migraine (OR 0.48, 95% confidence interval [CI] 0.30-0.77), while migraine without aura (MO) increased the odds of having DM (OR 1.19, 95% CI 1.02-1.39). The cohort studies indicated that DM decreased the risk of developing migraine (HR 0.83, 95% CI 0.76-0.90), and a history of migraine increased the risk of developing DM (HR 1.09, 95% CI 1.01-1.17). CONCLUSIONS: DM, particularly type 1 diabetes, is negatively associated with migraine occurrence, whereas migraine, especially MO, is positively associated with DM occurrence. However, most of the results remained at a low or very low level of evidence, indicating the need for further research.