Hypertension and migraine comorbidity: prevalence and risk of cerebrovascular events: evidence from a large, multicenter, cross-sectional survey in Italy (MIRACLES study).

To estimate the prevalence of hypertension-migraine comorbidity; to determine their demographic and clinical characteristics versus patients with hypertension or migraine alone; and to see whether a history of cerebrovascular events was more common in the comorbidity group.The MIRACLES, multicenter, cross-sectional, survey included 2973 patients with a known diagnosis of hypertension or migraine in a general practitioner setting in Italy.Five hundred and seventeen patients (17\%) suffered from hypertension-migraine comorbidity, whereas 1271 (43\%) suffered from hypertension only, and 1185 (40\%) from migraine only. In the comorbidity group, the onset of comorbidity occurred at about 45 years of age, with migraine starting significantly later than in the migraine-only group, and hypertension significantly before than in the hypertension-only group; a familial history of both hypertension and migraine had a significantly higher frequency as compared with the hypertension and migraine group. Compared to hypertension (3.1\%) and migraine (0.7\%), the comorbidity group had a higher prevalence (4.4\%) of history of cerebrovascular events, with an odds ratio of a predicted history of stroke/transient ischemic attack (TIA) of 1.76 [95\% confidence interval (CI) 1.01-3.07] compared to the hypertension group. In patients without other recognized risk factors for stroke, stroke/TIA occurred more frequently in the comorbidity group, compared to the hypertension group. In the age range 40-49 years, prevalence of history of stroke/TIA was five-fold greater (4.8\% in comorbidity vs. 0.9\% in hypertension group).This cross-sectional study indicates that the prevalence of comorbidity hypertension-migraine is substantial and that patients with comorbidity have a higher probability of history of cerebrovascular events, compared to hypertensive patients.