Recent studies have shown that women under 45 are more likely to suffer a stroke than men. Most strokes are caused by so-called "traditional" vascular risk factors such as high blood pressure, hyperlipidemia, and diabetes. However, women have a lower prevalence of these risk factors than men. A recent study by Leppert and colleagues investigated which other non-traditional risk factors exist for strokes besides those already known.

A total of 2,618 patients with strokes (52% women; 73.3% ischemic strokes) and 7,827 controls were examined. All traditional risk factors were more common in the patients than in the controls. The most common traditional risk factors were hypertension (44.3%), hyperlipidemia (33%), and tobacco use (28.8%) in men, and hypertension (41.6%), tobacco use (32.8%), and hyperlipidemia (28.9%) in women. The most common non-traditional risk factors were migraine (24.2%), renal failure (15.5%), and thrombophilia (12.4%) in men, and migraine (43.6%), thrombophilia (13.5%), and malignant disease (11.4%) in women. Women with strokes were less likely to be pregnant but more likely to use oral contraceptives than the control group. Migraine has been associated with 20.1% and 34.5% of strokes in men and women, respectively.

The study shows that non-traditional risk factors were just as important as traditional risk factors in the development of strokes in both men and women. Hypertension was the most important traditional risk factor, increasing with age in both men and women and accounting for 27.8% and 26.7% of strokes in men and women aged 45 to 55, respectively. In contrast, migraine was the most important non-traditional risk factor, decreasing with age and causing 20.1% and 34.5% of strokes in men and women under 35, respectively. Non-traditional risk factors were found to be equally important for the development of strokes in young men and women. The results underscore the importance of considering non-traditional risk factors for strokes in young adults. In this study, migraine proved to be the most important non-traditional risk factor in young adults. This study shows for the first time the contribution of migraine to the total attributable risk of stroke in young adults, which amounted to half of the population-attributable risk in adults under 35 years of age.

There are many data-driven hypotheses that explain the association between migraine and stroke (see figure), ranging from (1) hypercoagulability due to elevated anticoagulants, exacerbated by smoking or exogenous estrogen, to (2) hypoperfusion caused by cortical spreading depression, (3) endothelial dysfunction caused by accelerated atherosclerosis, (4) embolisms triggered by right-to-left shunts, (5) genetic associations that cause both migraine and stroke, and (6) treatments used for migraine, including nonsteroidal anti-inflammatory drugs, triptans, and ergotamine. The extent to which each individual mechanism contributes to the overall risk of stroke in migraine patients, or whether migraine is a modifiable risk factor for stroke, remains unclear. To date, the only intervention to reduce the risk of stroke in migraine patients is the recommendation to avoid combined hormonal contraceptives in women with migraine with aura. However, migraine and stroke in young adults can present with similar clinical features, increasing the potential for misdiagnosis and complicating research.

The conclusion is that non-traditional risk factors are as important as traditional risk factors in the development of strokes in both young men and women. In adults aged 18 to 34, more strokes were associated with non-traditional than with traditional risk factors. Overall, non-traditional risk factors are as strongly associated with the development of strokes in young adults aged 18 to 44 as traditional risk factors. Further research is needed to better understand how migraine contributes to the stroke risk in young adults and to develop primary and secondary prevention strategies for migraine patients.

Source : Leppert MH, Poisson SN, Scarbro S, Suresh K, Lisabeth LD, Putaala J, Schwamm LH, Daugherty SL, Bradley CJ, Burke JF, Ho PM. Association of Traditional and Nontraditional Risk Factors in the Development of Strokes Among Young Adults by Sex and Age Group: A Retrospective Case-Control Study. Circ Cardiovasc Qual Outcomes. 2024 Mar 26:e010307. doi: 10.1161/CIRCOUTCOMES.123.010307. Epub ahead of print. PMID: 38529631