The presence of diabetes — both type 1 and type 2 — may be associated with a reduced risk for migraine, according to a long-term nationwide Norwegian study published in Cephalalgia.
Study investigators evaluated patients with type 1 diabetes (n=7883) and type 2 diabetes (n=93,600) who were included in the Norwegian Prescription Database, the Norwegian National Registry, and the Norwegian National Education Database
Individuals treated with ≥180 defined daily doses of insulin without oral antidiabetic drugs were classified as having type 1 diabetes and patients treated with ≥180 defined daily doses of oral antidiabetic drugs with or without insulin were categorized as having type 2 diabetes.
The investigators evaluated the incidence of migraine in this population by examining the rate of new ergotamine and/or triptan prescriptions during follow-up.
At the 10-year follow-up, both type 1 and type 2 diabetes were found to be associated with a lower risk for migraine, even after adjustments for age and sex (type 1: risk ratio [RR], 0.74; 95% CI, 0.61-0.89; type 2: RR, 0.89; 95% CI, 0.83-0.95). The incidence of type 2 diabetes in individuals <60 years of age was associated with a greater risk for migraine during 10 years (P <.001).
Although no significant association was found between migraine treatment and type 1 diabetes risk (RR, 0.90; 95% Cl, 0.75-1.07), the investigators observed a slightly increased risk for type 2 diabetes in patients in whom migraine developed (RR, 1.12; 95% Cl, 1.06-1.17).
Because new prescriptions were used as the classification system for disease incidence, the investigators may have included misclassified migraine and/or diabetes. In addition, the investigators did not adjust for potential genetic and environmental factors that may have affected risks for both diabetes and migraine.
Results from this study suggest, “that diabetes or treatment of diabetes could have a protective role on migraine,” according to the investigators, who hypothesize that, “Diabetes may involve biological mechanisms relevant to the pathogenesis of migraine,” thus underlying the observed association between diabetes and reduced risk for migraine.
The authors cite diabetes-related neuropathy that leads to “nerve damage with consequent reduction of pain sensitivity which may reduce the sensation or affect the threshold of pain involved in migraine.”
Antonazzo IC, Riise T, Cortese M, et al. Diabetes is associated with decreased migraine risk: a nationwide cohort study [published online January 1, 2018]. Cephalalgia.