White-coat hypertension and incident end-stage renal disease in patients with non-dialysis chronic kidney disease: results from the C-STRIDE Study

Background Controversy remains whether white coat hypertension (WCH) is associated with renal prognosis in patients with chronic kidney disease (CKD). Methods In the present multicenter, prospective study, we analyzed data of participants with CKD stage 1-4 from the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE). WCH was defined according to two criteria as follows: A, clinical blood pressure (BP) >= 140/90 mm Hg and average 24-h ambulatory BP < 130/80 mm Hg; B, clinical BP >= 130/80 mm Hg and daytime ambulatory BP < 130/80 mm Hg. Renal outcome was defined as initiation of renal replacement therapy. The association of WCH with renal events was evaluated by Cox regression model. Results A total of 1714 patients with CKD were included in the present analysis. The mean age of the population was 48.9 +/- 13.8 years and 56.8% were men. The mean baseline estimated glomerular filtration rate (eGFR) was 52.2 +/- 30.1 ml/min/1.73 m(2)and urinary protein was 1.0 (0.4, 2.4) g/day. The overall prevalence of WCH was 4.7% and 16.6% according to criteria A and B, respectively. Incidence rates of renal events were 49.58 and 26.51 according to criteria A and B, respectively, per 1000 person-years during a median follow-up of 4.8 years. After full adjustment, WCH was associated with an increased risk of renal event (criterion A: hazard ratio 2.36, 95% confidence interval 1.29-4.34; for criterion B: hazard ratio 1.90, 95% confidence interval 1.04-3.49) compared with patients with normal BP. Conclusions WCH is associated with a greater risk for renal events in non-dialysis dependent Chinese patients with CKD.