Impact of proteinuria and glomerular filtration rate on risk of ischaemic and intracerebral hemorrhagic stroke: a result from the Kailuan study

Background and purposePersons with chronic kidney disease, defined by a reduced estimated glomerular filtration rate and proteinuria, have an increased risk of cardiovascular disease including stroke. However, data from developing countries are limited. Our aim was to assess the relationship between chronic kidney disease and risk of stroke and its subtypes in a community-based population in China. MethodsThe study was based on 92013 participants (18-98years old; 73248 men and 18765 women) of the Kailuan study who at baseline were free from stroke and myocardial infarction and had undergone tests for serum creatinine or proteinuria. Glomerular filtration rate was estimated using the Chronic Kidney Disease Epidemiology Collaboration formula and proteinuria by the urine dipstick result in laboratory databases. The primary outcome was the first occurrence of stroke. Data were analyzed using Cox proportional hazards models adjusted for relevant confounders and results are presented as hazard ratios (HRs) with 95% confidence intervals (CIs). ResultsDuring a follow-up of 4years, 1575 stroke events (1128 ischaemic, 406 intracerebral hemorrhagic and 41 subarachnoid hemorrhagic strokes) occurred. After adjustment for variable confounders, patients with proteinuria were found to have increased HRs for the total and subtypes of stroke events (HR 1.61; 95% CI 1.35-1.92 for total stroke; HR 1.53; 95% CI 1.24-1.89 for ischaemic stroke; and HR 1.90; 95% CI 1.35-2.67 for hemorrhagic stroke). However, estimated glomerular filtration rate was not associated with incident stroke after adjustment for established cardiovascular risk factors. ConclusionsProteinuria increased the risk of stroke in a general Chinese population.