BY LIZETTE BORRELI
Migraine has been tied to factors related to insulin resistance and type 2 diabetes. Despite the high prevalence of both diseases, the link between migraine and type 2 diabetes remains unknown. Now, a new analysis suggests women with migraine have a lower risk of developing type 2 diabetes.
Prior studies have suggested an association between migraine and the risk of overall specific cardiovascular events; others have not found associations between migraine and incident diabetes. But in a prospective longitudinal study published online on December 17 in JAMA Neurology, researchers found women with migraine were 30 percent less likely to develop type 2 diabetes mellitus (T2DM) than women without a history of migraine.
Among women who developed incident diabetes during the study, the prevalence of migraine declined in the years long before and plateaued after a diabetes diagnosis.
The research team noted that the mechanisms behind the association between migraine and lower risk for diabetes remains unclear. But they proposed that hyperglycemia and hyperinsulinism could potentially have an impact on migraine occurrence, and that calcitonin gene related peptide (CGRP) may be a factor in that association.
"CGRP is a well-established potent vasodilator and has a vascular protective role. In animal models, diabetic impairment of sensory nerves with reduced expression of CGRP has been reported. We may speculate that the vasodilation and the nociceptive effects induced by CGRP are impaired after diabetes appears, which may explain the reduced prevalence of active migraine," the researchers, led by Guy Fagherazzi, PhD, of the Center for Research in Epidemiology and Population Health in Villejuif, France, wrote.
For their analysis, the researchers examined data from the E3N-EPIC cohort, a French prospective study of women born between 1925 and 1950 who are insured by a health insurance plan that covers mainly teachers.
At baseline, the 74,247 women in the analysis had mean age of 61 years and no diagnoses of diabetes.
Participants completed self-administered biennial questionnaires beginning in 1990; the health insurance plan provided information about all outpatient reimbursements for health expenditures since 2004, such as dosages and dates of drug purchases.
After adjusting for such factors as level of education, family history of diabetes, body mass index, smoking status, hypertension, the researchers found women with active migraine had a lower risk of incident type 2 diabetes than those without migraine history (HR 0.80, 95% CI 0.60-0.96.
The researchers grouped the women in three main categories based on questionnaire data: no migraine history; active migraine (women who self-reported migraine on the current questionnaire); and prior migraine (women who reported migraine in at least one past questionnaire but not currently).
From 2004 to 2014, a total of 2,372 women had incident cases of type 2 diabetes: 1,562 had no migraine history; 681 had prior migraine; and 129 had active migraine.
The researchers defined type 2 diabetes as a patient who was treated pharmacologically with type 2 diabetes-specific medications at least twice with the date of diagnosis defined as the date of the first drug reimbursement.
Over time, they observed a clear linear decrease in the two-year prevalence of migraine from 24 years before diagnosis (22 percent [95% CI, 16%-27%]) to the date of diagnosis (11 percent [95% CI, 10%-12%]). After the type 2 diabetes diagnosis, there was a plateau ion the prevalence of migraine (10 to 11 percent) that persisted up to 22 years after diagnosis.
The researchers concluded: "The linear decrease of migraine prevalence long before and the plateau long after type 2 diabetes diagnosis is novel and the association deserves to be studied in other populations."
Study limitations included migraine status was based on participants' self-reports; no information about self-medication was available. In addition, the E3N sample comprised mostly of women who were mainly white, health-conscious women, and mostly teachers. Therefore, it's unclear whether the findings would be applicable to men or those who come from other ethnic/racial or socioeconomic backgrounds.
The Mutuelle Generale de l'Education Nationale, European Community, French League against Cancer, Gustave Roussy, and the French Institute of Health and Medical Research supports the E3N cohort. The French Research Agency also supported the study.
The researchers reported relationships with CoLucid, Amgen, Lilly, Novartis, and Daiichi Sankyo.
LINK UP FOR MORE INFORMATION:
Fagherazzi G, El Fatouhi D, Fournier A, et al. Associations between migraine and type 2 diabetes in women: Findings from the E3N cohort study. JAMA Neurol 2018; Epub 2018 Dec 17.