Risk of stroke in long-term dialysis patients compared with the general population

Background: Patients undergoing maintenance dialysis are at increased risk of stroke.

Study design: We performed a nationwide retrospective cohort study to determine the risks for ischemic stroke and hemorrhagic stroke among incident hemodialysis (HD) and peritoneal dialysis (PD) patients in comparison to a reference group in Taiwan.

Setting & participants: Data for 74,192 HD patients, 5,974 PD patients, and 669,773 nondialysis individuals who were older than 18 years and had no history of stroke or cancer were retrieved from the National Health Insurance Research Database for 1998-2009.

Predictors: Patient demographics, comorbid conditions.

Outcome: First hospitalization for stroke, defined as a diagnosis at discharge (either primary or 1 of 4 secondary diagnoses) of ischemic or hemorrhagic stroke using International Classification of Diseases, Ninth Revision, Clinical Modification codes.

Results: HD and PD patients had higher incidences of hospitalized ischemic stroke (102.6 and 100.1/10,000 person-years) and hemorrhagic stroke (74.7 and 59.4/10,000 person-years) in comparison to the age- and sex-matched reference cohort (42.4 and 13.0/10,000 person-years, respectively). In addition to HD and PD therapy, older age, male sex, diabetes, and hypertension were found to be independent risk factors for both ischemic and hemorrhagic strokes. Using the HD group as the comparison group, we found that PD patients had a lower risk of hemorrhagic stroke (HR, 0.75; 95% CI, 0.58-0.96), and there was no significant difference in risks of ischemic stroke between PD and HD patients after adjusting for all potential confounders and competing risk of death, and matched by propensity scores.

Limitations: This was a retrospective study, and some important variables were not available.

Conclusions: Patients undergoing dialysis are at elevated risk of stroke. Patients undergoing PD appear to be less likely to develop hemorrhagic stroke than those undergoing HD. Comprehensive control of hypertension and diabetes is necessary when delivering dialysis treatment.