Does diabetes have a protective effect on migraine?

BACKGROUND: Diabetes is associated with an increased risk of several other chronic diseases. In contrast, a previous study found an inverse relation between diabetes and migraine, whereas another large population-based study showed that the prevalence of migraine among patients with diabetes varied strongly depending on age. We aimed to investigate how the prevalence of medically treated migraine in patients with diabetes varied depending on diabetic drug treatment, sex, and age in the complete Norwegian population.
METHODS: Data on all persons in Norway being prescribed medication for diabetes (n =124,649) or migraine (n = 81,225) in 2006 were obtained from the National Register of Prescriptions and analyzed in a cross-sectional design.
RESULTS: Persons using diabetic drugs had an overall reduced prevalence of medically treated migraine when compared with the nondiabetic population (odds ratio [OR] = 0.72 [95% confidence interval = 0.68-0.75]). The OR was strongly associated with age. Although young persons receiving oral diabetic medication had, in fact, an increased prevalence of medically treated migraine, the prevalence declined with increasing age to about the same reduced prevalence (OR = 0.4-0.6) for all types of diabetes treatment in patients 60 to 69 years of age. The prevalence was equally decreased between men and women.
CONCLUSIONS: The results suggest a markedly reduced prevalence of migraine among older patients with diabetes, when compared with the general population. One may speculate that the seemingly protective effect of diabetes on migraine could be a result of neuropathy.