As kidney disease progresses, so does risk of stroke

Individuals with chronic kidney disease (CKD) are at increased risk of stroke and more likely to die as a result of stroke than the general population, and those with end-stage renal disease (ESRD) are especially at risk, according to a study published in PLOS One.

“Recent improvements in dialysis techniques prolong lifespans, but these uremic patients develop atherogenic changes, endothelial dysfunction, and vascular calcification,” wrote Yih-Giun Cherng, MD, and colleagues. “Due to these changes, stroke becomes a major health issue for patients with impaired renal function.”

The researchers used a national Taiwan insurance database to study 1,378 patients with ESRD and 5,512 with CKD. Those individuals were matched by age and sex to a control group of 11,024.

Compared to the controls, the adjusted risk for stroke was 49 percent higher in the CKD group and 2.39 times higher among ESRD patients. After propensity-score matching was performed to further eliminate confounding, the excess risks were 51 percent for CKD and 108 percent for ESRD.

Using a separate analysis, Cherng et al. found mortality rates were also worse for patients with kidney disease. Among more than 300,000 patients hospitalized for stroke, those with CKD demonstrated a 1.44-fold risk of death compared to a control group while ESRD individuals had a 2.62-fold mortality risk.

“In our investigation, CKD or ESRD patients with hypertension or diabetes exhibited higher risk of stroke,” the authors wrote. “Uremia represents a risk complex with multiple etiologies and comorbidities associated with vascular change and dialysis-related problems. Although traditional stroke risk factors are more prevalent in uremic patients than in the general population, the increased risk of stroke observed in uremic patients could not be explained solely by higher comorbidity prevalence.”

The researchers also noted concomitant cardiovascular disease was associated with worse outcomes. They included a several potential explanations tying kidney dysfunction to stroke outcomes, but identified a few specific factors that were more relevant as severity progressed from CKD to ESRD.

“Among all listed risk factors, anemia, hyperlipidemia, and liver cirrhosis did not exhibit significant influence on stroke incidence in patients with CKD, but showed some effect in patients with ESRD,” Cherng and colleagues wrote. “Different degrees of kidney dysfunction severity and various effects of treatment for coexisting clinical conditions may account for these discrepancies.”