Stroke incidence and chronic kidney disease: A hospital‐based prospective cohort study

AIM: This prospective cohort study aimed to (i) examine stroke incidence and stroke subtypes by chronic kidney disease (CKD) stage, (ii) examine whether CKD patients with or without proteinuria have a high risk of stroke independent of traditional cardiovascular risk factors, and (iii) determine precise estimates of stroke risk by CKD stage while accounting for competing mortality risk. METHODS: Participants were 2023 patients enrolled in the Project in Sado for Total Health between June 2008 and December 2016 (55% men; mean age, 69 years), of whom 52% had CKD (stage 1-2, 10%; G3a, 48%; G3b, 17%; G4-5, 11% and G5D, 14%). RESULTS: During a median follow-up of 5.7 years, 157 participants developed stroke and 448 died without developing stroke. Most stroke cases were ischaemic among non-dialysis-dependent CKD participants, but the relative frequency of ischaemic stroke was near that of intracerebral haemorrhage among dialysis-dependent CKD participants. After adjustment, stage 1-2 (hazard ratio HR, 2.97; 95% confidence interval CI, 1.60-5.51) and stage G3-5 participants with proteinuria (HR, 2.50; 95% CI, 1.56-4.02), but not stage G3-5 participants without proteinuria (HR, 0.64; 95% CI, 0.38-1.08), had a higher stroke risk compared to non-CKD participants. In competing risk analyses, the association was attenuated but remained significant. CONCLUSION: Although the distribution of stroke subtypes differed, CKD participants with proteinuria and those with CKD stage 5D had a 2- and 4-times higher risk of stroke, respectively, than that of non-CKD participants, after accounting for competing mortality risk and traditional risk factors.