Prehypertension and Chronic Kidney Disease in Chinese Population: Four-Year Follow-Up Study

Hypertension is a well established cause of chronic kidney disease (CKD). However, the effect of prehypertension on risk of CKD is controversial. The aim of this study is to determine whether prehypertension increases the risk of CKD events in the Chinese population. We enrolled 20,034 with prehypertension and 12,351 with ideal blood pressure in this prospective study. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min 1.73m(2). The new occurrences of CKD events were collected during follow-up. Cumulative survival and freedom for the occurrence of new CKD events was analyzed using the Kaplan-Meier approach. Multivariate Cox Regression was used to analyze the effect of prehypertension on CKD. The median follow-up time was 47 (interquartile range 44-51) months. 601 new onset CKD events occurred during the follow-up period. The cumulative incidence of new CKD events was higher in the prehypertensive population than that in the ideal blood pressure population (2.10% vs 1.46%, P = 0.0001). Multivariate Cox Regression showed that relative risks (RRs) for the new onset CKD events in the prehypertensive population were 1.69 (95% confidence intervals (CI): 1.41 similar to 2.04, P = 0.001) higher than those in the ideal blood pressure population. Similarly, the risks were 1.68 (95% CI: 1.33 similar to 2.13 P = 0.001) times higher in females and 2.14 (95% CI: 1.58 similar to 2.91 P = 0.001) times higher in males by adjustment for traditional CV risk factors. Our findings demonstrated prehypertension is an independent risk factor for the occurrence of new CKD events in the Chinese population.