Impact of introduction of continuous ambulatory peritoneal dialysis on blood pressure: analysis of 24-hour ambulatory blood pressure.

Introduction of continuous ambulatory peritoneal dialysis (CAPD) induces a variety of hemodynamic changes in patients with end-stage renal failure. Among them, blood pressure (BP) control is likely to be the most important in determining long-term survival. The aim of our study was to use 24-hour ambulatory blood pressure monitoring (24 ABPM) to evaluate the previous and present BP status of patients on CAPD. We studied 18 non diabetic hypertensive patients who were introduced onto CAPD. At least 3-6 months before the introduction of CAPD, recordings of 24 ABPM were obtained. These recordings were then compared to others obtained 2-3 months after the introduction of CAPD. The average BP was higher before CAPD than after (160/91 +/- 10/5 mmHg vs 154/88 +/- 6/3 mmHg, p < 0.01). In addition, the doses and number of antihypertensive drugs used by the patients were reduced. Analysis of 24 ABPM revealed BP reduction predominantly in the daytime and less in the nighttime after introduction of CAPD. These results indicate that introduction of CAPD cannot reduce susceptibility of cardiovascular events, because nocturnal elevation of BP remains unchanged. We are therefore reminded that, after introduction of CAPD, casual BP measurements confined to the daytime may underestimate cardiovascular risk.