The association between glomerular filtration rate and stroke in hypertensive patients in rural areas of China

Objectives: The present study is to explore the association between estimated glomerular filtration rate (eGFR) and stroke in hypertensive patients in rural areas of China. Methods: The prospective study was based on 3711 hypertensive patients who were aged at least 35 years, free from cardiovascular diseases, and had serum creatinine at baseline. eGFR was estimated using the Chronic Kidney Disease Epidemiology Collaboration equation. Results: During a median follow-up of 4.9 years, 176 first-ever strokes (98 ischemic, 75 hemorrhagic, and three were unspecified strokes) occurred. We found no independent association between eGFR and risk of hemorrhagic stroke. In contrast, with decreasing eGFR, the risk of total and ischemic stroke strongly increased; the sex and age-adjusted hazard ratios for overall and ischemic stroke were 3.34 [95% confidence interval (CI) 1.61-6.93] and 3.79 (95% CI 1.33-10.81) for patients with eGFR below 60 versus eGFR at least 90 ml/min per 1.73m(2), respectively. In addition, patients with an eGFR of 60-90 relative to eGFR at least 90 ml/min per 1.73m(2) had hazard ratios of 2.31 (95% CI 1.53-3.51) and 3.24 (95% CI 1.76-6.00) for overall and ischemic stroke after adjustment for sex and age, respectively. Adjustment for other cardiovascular factors only slightly attenuated the associations. Conclusions: The patients with decreased eGFR, also included those with eGFR range between 60 and 90 ml/min per 1.73m(2), had an independently increased risk of overall and ischemic stroke in hypertensive patients in rural areas of China.