Sex differences seen in stroke incidence among younger adults

Young women are more likely to develop stroke than young men, according to a study, highlighting the importance of sex-mediated risk factors.

The study used data from a nationally representative claims database of insured Americans and included 20,554 index strokes (mean age, 63 years). Half of these events (50.4 percent) occurred in women, and 5,198 in young adults (age, <55 years).

Poisson rate models with time varying covariates for 2-year periods showed that the index stroke rate increased with age in both men and women. Stroke incidence was comparable between men and women in the youngest and oldest age groups (15–24 and ≥75 years).

However, a larger number of women than men had stroke in the following age groups: 25–34 years and 35–44 years. Conversely, men had a higher stroke incidence than women in the older age groups: 45–54 years, 55–64 years, and 65–74 years.

The discrepancies between the sexes in the incidence of stroke have several potential explanations. One is that endogenous oestrogen may confer a protective benefit for cardiovascular events in premenopausal women. This holds water for acute myocardial infarction, where incidence is much lower in young women. [J Cereb Blood Flow Metab 2018;38:2179-2191; J Am Coll Cardiol 2014;64:337-345]

Also, there may be noncardiovascular risk factors for stroke, which are unique to or more prevalent in women. Some of these include pregnancy, oral contraception, and other female-predominant medical conditions such as migraine headaches and autoimmune disorders. [N Engl J Med 2014;370:1307-1315; JAMA 2000;284:72-78]

More studies are needed to shed light on the causes and risk factors for strokes in young women, which can lead to better prevention.