Female sex, black race tied to increased stroke vulnerability in later-stage CKD

Among patients with chronic kidney disease (CKD) stages 4 and 5, women and individuals of black race are at increased risk of developing stroke, which is associated with shorter time to kidney failure or death, a study has found.

The analysis included 123,251 individuals with CKD 4 and 22,054 with CKD 5, with mean ages of 81.0 and 79.2 years, respectively. Researchers performed a matched analysis (stroke/no-stroke) to estimate cumulative incidence of incident kidney failure and death, treated as competing events. They also used a state transition model to simulate differences in expected time to kidney failure or death and death alone for stroke and nonstroke CKD 5 patients.

In Cox proportional hazard models, the following factors were associated with an increased risk of ischaemic stroke in CKD stages 4 and 5: female sex (hazard ratio [HR], 1.21, 95 percent confidence interval [CI], 1.12–1.31 and  HR, 1.39, 95 percent CI, 1.04–1.86, respectively) and black race (HR, 1.25, 95 percent CI, 1.12–1.39 and HR, 1.12, 95 percent CI, 0.80–1.58, respectively).

Rates for 30-day mortality were 13.3 percent in the CKD 4 group and 18.8 percent in the CKD 5 group. The corresponding 1-year mortality rates were 40.0 percent and 38.2 percent.

Among CKD stage 5 patients with ischaemic stroke, kidney failure or death occurred an average of 3.6 months earlier, while death (irrespective of kidney failure) took place a mean of 24.3 months sooner.

The study was limited by its retrospective nature, which prevented from determining causality, and lack of data on stroke severity.