Effect of ambulatory blood pressuremonitoring guided antihypertensive treatment on renal progression in patients with chronic kidney disease: a randomized comparative study

Objectives: Adequate blood pressure (BP) control is pivotal for managing chronic kidney disease (CKD). The optimal approach for monitoring BP to delay CKD progression is not yet clear. Methods: Patients with hypertension and CKD stage 3-4 were randomized into ambulatory blood pressure monitoring (ABPM) or office BP groups. All patients had ABPM at baseline and 18 months, and the ABPM group additionally underwent ABPM at 3 and 6 months. Each ABPM result was notified only for the ABPM group. The BP target was daytime ABP less than 135/85mmHg for the ABPM group and office BP less than 140/90mmHg for the office BP group. The primary outcome was decrease in estimated glomerular filtration rate (eGFR) during 18 months. Results: A total of 146 patients were randomized into the ABPM (n = 69) and office BP groups (n = 77). Although office BP was comparable in the two groups at baseline, daytime ABP was higher in the ABPM group (median 140 vs. 132 mmHg). Initial eGFR was 35.7 +/- 12.5 ml/min per 1.73m(2) in the ABPM group and 34.6 +/- 12.0 ml/min per 1.73m2 in the office BP group. eGFR change was -5.5 [95% confidence interval (95% CI) - 7.7 to -3.4] ml/min per 1.73m(2) in the ABPM group and -5.0 (95% CI -6.9 to -3.0) ml/min per 1.73m(2) in the office BP group (P = 0.704). Renal events occurred in 10 patients (15.6%) from the ABPM group and five (7.1%) from the office BP group (P = 0.120). Conclusion: The present study did not show a beneficial effect of ABPM for controlling hypertension in CKD compared with conventional office BP monitoring in terms of renal outcomes.