Howard VJ, et al. - In this prospective cohort study, researchers investigated the incidence and risk factors for ischemic stroke by sex for black and white individuals. They found that, for both races, women were at lower risk of stroke at 45-64 years of age vs men, and there was no sexual difference at age ≥ 75 years. However, the pattern of sexual difference may vary by race from age 65-74 years. The risk factors associated with stroke risk varied by race-sex groups. The association of hypertension, diabetes, and heart disease with stroke risk varied by sex for white individuals but not black individuals. Some demographic subgroups might require earlier and more aggressive strategies while the need for primordial prevention, optimal management, and control of risk factors is universal across all age, racial/ethnic, and sex groups.

Methods

• Study participants included individuals aged ≥ 45 years who were stroke-free from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, enrolled from the continental US 2003-2007 with follow-up through October 2016.
• From March 2018 to September 2018, data were analyzed.
• Exposures included sex and race.
• Physician-adjudicated incident ischemic stroke, self-reported race/ethnicity, and measured and self-reported risk factors were included main outcomes and measures.

Results

• There were a total of 25,789 participants (14,170 women [54.9%]; 10,301 black individuals [39.9%]).
• Over 222,120 person-years of follow-up, there were 939 ischemic strokes: 159 (16.9%) in black men, 326 in white men (34.7%), 217 in black women (23.1%), and 237 in white women (25.2%).
• White women aged 45-64 years had a 32% lower risk of stroke vs white men, and black women had a 28% lower risk than black men.
• They observed that lower risk of stroke in women than men persisted in white individuals at ages 65-74 but not in black individuals.
• However, the race-sex interaction was not significant.
• There was no sex difference in stroke risk for either race at age ≥ 75 years.
• Associations of systolic blood pressure, diabetes, and heart disease with stroke risk were greater for women than men for white individuals.
• On the other hand, the association of antihypertensive medication use was greater among men vs women.
• There was no evidence of a sex difference for any risk factors in black people.