C-reactive protein and prospective cardiometabolic risk: observational and Mendelian randomization study of ischemic stroke and all-cause death.

BACKGROUND AND

objectivesElevated C-reactive protein (CRP) is a well-established marker of low-grade systemic inflammation often accompanying cardiometabolic diseases like type 2 diabetes. We sought to determine if plasma CRP concentrations can be used as a predictive marker of risk for ischemic stroke and all-cause death in the general population, and to investigate whether elevated plasma CRP has a causal effect on ischemic stroke and all-cause death.

methodsObservational and one-sample Mendelian randomization analyses were performed in 113,491 individuals from the Copenhagen City Heart Study and the Copenhagen General Population Study. Two-sample Mendelian randomization analyses were performed in up to 575,531 individuals with publicly available data from the CHARGE CIWG, UKBB, FinnGen, and MEGASTROKE.

resultsObservationally in the Copenhagen studies, higher CRP concentrations associated with stepwise higher risk of ischemic stroke and all-cause death with the highest hazard ratios of 1.51(95% confidence interval: 1.34, 1.71) and 1.69(1.60, 1.79), respectively. The cumulative incidence of ischemic stroke at age 72 was 57% higher and the cumulative incidence of all-cause death at age 80 was 62% higher in individuals with a plasma CRP ≥ 2 mg/L compared to individuals with a plasma CRP < 2 mg/L. One- and two-sample Mendelian randomization analyses did not support a causal effect of CRP on risk of ischemic stroke, nor of CRP on risk of all-cause death, with odds ratios in studies combined of 1.01(0.98, 1.05) and 1.01(0.98, 1.05), respectively.

conclusionIn this observational and one- and two-sample Mendelian randomization study, we found that elevated CRP concentrations above the population median of 1.4 mg/L predicted risk of ischemic stroke and all-cause death. There was no causal genetic effect of C-reactive protein on risk of stroke or all-cause death.