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.