Age- and ethnic-specific sex differences in stroke risk

Abstract

Background: In white populations, age seems to modify the effect of sex on stroke risk, and compared with men, women are protected from stroke until approximately age 75 to 85 years, after which the protection is lost or reversed. Compared with non-Hispanic whites (NHWs), Mexican Americans (MAs) are at higher risk of stroke; however, age- and sex-specific stroke incidence data are currently not available for this population.

Objective: This study was performed to compare the age-specific sex differences in stroke risk in MAs and NHWs.

Methods: Data were derived from the BASIC (Brain Attack Surveillance in Corpus Christi) Project, a population-based stroke surveillance study conducted in Nueces County Texas. Incident strokes (n = 2421, including ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage) that occurred between January 1, 2000 and May 25, 2007 in individuals aged 45 years or older were included in the analysis. Poisson regression using the generalized additive models framework was used to analyze the relationship between sex, age (5-year intervals), and race/ethnicity (NHW or MA) and incident stroke risk.

Results: Among both NHWs and MAs aged 45 to 79 years, men were at higher risk of stroke than women were. The magnitude of increased stroke risk in men compared with women diminished with age, and after age 79 years, no sex difference in stroke risk was observed.

Conclusions: Reasons for the loss of protection from stroke in aging women of all races/ethnicities are not fully understood, and further study is warranted.