Background and Purpose—We examined the impact of hyperglycemia on ischemic and hemorrhagic stroke incidence comparing criteria based on fasting plasma glucose (FPG) and 2-hour plasma glucose (2-hour PG).

Methods—Data from 9 European cohorts comprising 18 360 individuals between 25 to 90 years of age were collaboratively analyzed. The maximum length of follow-up varied between 4.9 to 36.8 years. Hazards ratios (95% confidence intervals) for stroke incidence were estimated using Cox-proportional hazards model adjusting for known risk factors.

Results—In individuals without a prior history of diabetes, the multivariate-adjusted hazards ratio for ischemic stroke corresponding to 1 SD increase in FPG was 1.12 (1.02 to 1.22) and in 2-hour PG 1.14 (1.05 to 1.24). Adding 2-hour PG to the model with FPG significantly improved the prediction of the model for the incidence of ischemic stroke (²=4.72, P=0.03), whereas FPG did not improve the 2-hour PG model prediction (²=0.25, P=0.62). A significantly increased hazard ratio was also observed for previously diagnosed diabetes (2.26 [1.51 to 3.38]) and for screen-detected diabetes defined by FPG (1.48 [1.08 to 2.02]) and 2-hour PG (1.60 [1.18 to 2.16]). None of the criteria predicted hemorrhagic stroke.

Conclusions—Diabetes defined by either of the criteria predicted the future risk of ischemic stroke but not the hemorrhagic stroke. The prediction is stronger for elevated 2-hour PG than for FPG levels.