Does the Association of Fasting Blood Glucose With Stroke Risk Differ by Race and Sex?

There are sex differences in the association between impaired glucose metabolism and risk for ischemic stroke, as the strongest association between fasting blood glucose (FBG) and ischemic stroke is among White women and Black women, with weaker associations among White men and Black men, according to study results published in Neurology.

While prior studies have shown abnormal glucose metabolism and diabetes are associated with an increased risk for cardiovascular disease and stroke, less is known about the association by sex and race.

The objective of the current study was to determine sex and race differences in the association between FBG and risk for ischemic stroke using data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS), a national longitudinal cohort study that included adults 45 years of age and older enrolled between 2003 and 2007.

Of 30,239 participants in the full REGARDS cohort, a total of 20,338 participants (mean age, 64.5 years; 11,263 women) were included in the current analyses. Of these individuals, 7,880 (38.7%) participants were Black and 12,458 (61.3%) were White.

Overall, during a median follow-up of 11.4 years, a total of 954 ischemic stroke events were recorded.

Overall, FBG ≥ 150 mg/dL was associated with a 59% increased risk for ischemic stroke (hazard ratio [HR], 1.59; 95% CI, 1.21-2.08), compared with FBG < 100 mg/dL. This association varied by race and sex, with a 3-fold increased risk for ischemic stroke among White women (adjusted HR, 3.30; 95% CI, 1.20-9.10), and a 2-fold increased risk among Black women (adjusted HR, 2.02; 95% CI, 1.06-3.87). However, this association was not statistically significant in Black or White men.

When additional adjustment for history of ever using menopausal hormone therapy was completed, the risk for ischemic stroke in women with FBG ≥ 150 mg/dL was slightly higher among White women (adjusted HR, 1.84; 95% CI, 1.06-3.17) than for Black women (adjusted HR, 1.54; 95% CI, 0.96-2.48).

Analyses using FBG splines suggested that sex was the major contributor to differences by race/sex subgroups.

The study had several limitations, including the use of a single measurement of FBG which may not accurately reflect the long-term glucose control, small numbers of incident events among some subgroups, and lack of data on other vascular risk factors that may affect stroke risk.

“Sex differences in the strength and shape of the association between FBG and IS [ischemic stroke] are likely driving the significant differences in the association between FBG and IS across race/sex subgroups. These findings should be explored further and may inform tailored stroke prevention guidelines,” concluded the researchers.

Reference

Madsen TE, Long DL, Carson AP, et al. Sex and race differences in the risk of ischemic stroke associated with fasting blood glucose in REGARDS. Neurology. Published online August 17 2021. doi: 10.1212/WNL.0000000000012296