Objective: To assess the influence of body mass index (BMI) on the prevalence, attack frequency, and clinical features of migraine.
Methods: In a population-based telephone interview study, the authors gathered information on headache, height, and weight. The 30,215 participants were divided into five categories, based on BMI: 1, underweight (< 18.5), normal weight (18.5 to 24.9), overweight (25 to 29.9), obese (30 to 24.9), and morbidly obese (> or = 35). Migraine prevalence and modeled headache features were assessed as a function of BMI, adjusting by covariates (age, sex, marital status, income, medical treatment, depression).
Results: Subjects were predominantly female (65% female) and in middle life (mean age 38.4). BMI group was not associated with the prevalence of migraine, but was associated with the frequency of headache attacks. In the normal weight group, 4.4% had 10 to 15 headache days per month, increasing to 5.8% of the overweight (odds ratio [OR] = 1.3), 13.6% of the obese (OR = 2.9), and 20.7% of the morbidly obese (OR = 5.7). The proportion of subjects with severe headache pain increased with BMI, doubling in the morbidly obese relative to the normally weighted (OR = 1.9). Similar significant associations were demonstrated with BMI category for disability, photophobia, and phonophobia.
Conclusion: Though migraine prevalence is not associated with body mass index, attack frequency, severity, and clinical features of migraine increase with body mass index group.