Abstract
OBJECTIVE: This study was conducted to investigate the association between migraine frequency and insomnia severity. BACKGROUND: Migraine and insomnia frequently co-occur, yet the relationship between migraine characteristics and insomnia severity remains poorly understood. Both conditions substantially impair quality of life and daily functioning, potentially because of shared pathophysiological mechanisms. In this study, we investigated the association between migraine frequency and insomnia severity and examined the impact of aura, psychological factors, and restless legs syndrome (RLS). METHODS: This cross-sectional controlled study included 2155 participants (1954 individuals with migraine and 201 controls) who visited the neurology outpatient department of a tertiary medical center between January 2019 and October 2023. Migraine diagnosis adhered to the International Classification of Headache Disorders, 3rd edition criteria, with all participants evaluated by a board-certified neurologist and headache specialist. Insomnia severity was assessed using the Insomnia Severity Index (ISI), and psychological factors were measured using the Beck Depression Inventory-II and Hospital Anxiety and Depression Scale. RLS was diagnosed as per international criteria, and individuals with migraine were stratified by headache frequency (1-7, 8-14, or ≥15 days/month) and aura status. RESULTS: High migraine frequency was associated with increased ISI scores (adjusted regression coefficient [β] = 0.75, 95% confidence interval [CI], 0.50-1.01) and increased prevalence of clinical insomnia (ISI ≥ 15) (adjusted odds ratio [aOR] = 1.34; 95% CI, 1.17-1.53) after controlling for demographic, lifestyle, and clinical factors. In the univariate analysis, patients with migraine with aura showed higher ISI scores than those without aura (p < 0.001); however, this difference was no longer significant after adjustment for migraine frequency, depression, anxiety, RLS, and other confounders (adjusted β = 0.48; 95% CI, -0.24 to 1.20; p = 0.191). Multivariable analyses revealed significant associations between ISI total score and depression (adjusted β = 0.21; 95% CI, 0.17-0.24), anxiety (adjusted β = 0.34; 95% CI, 0.27-0.41), and RLS (adjusted β = 1.02; 95% CI, 0.53-1.51). RLS prevalence was significantly higher in the migraine group than in the control group (32.4% vs. 12.9%). CONCLUSIONS: Migraine frequency showed a graded association with insomnia severity, with additional independent contributions from psychological factors and RLS, but not from aura status. These findings underscore the multifactorial nature of sleep disturbances in migraine and the need for comprehensive management strategies that address both headache-specific factors and comorbid conditions.