THE ROLE OF HOME BLOOD PRESSURE MONITORING IN THE ASSESSMENT OF HYPERTENSION IN PATIENTS UNDERGOING PERITONEAL DIALYSIS

Objective: Patients with kidney failure treated with peritoneal dialysis (PD) are educated to measure their blood pressure (BP) at home. However, the diagnostic performance of home BP measurements in the PD population remains unclear. In this study, we assess the accuracy of home versus clinic systolic BP (SBP) in diagnosing ambulatory hypertension in a large sample of patients receiving long-term PD. Design and method: In a total of 140 PD patients, hypertension was evaluated with 3 different approaches: (i) standardized BP measurements at the clinic environment (triplicate recordings obtained after a 5-minute seating rest period with a validated automatic device; HEM 705 CP, OMRON Healthcare); (ii) home BP monitoring (HBPM) (duplicate morning and evening BP measurements for 7 days with a validated automatic device); (iii) 24-hour ambulatory BP monitoring (ABPM) (20-min intervals; Mobil-O-Graph device, IEM, Germany). The sequence of measurements (HBPM-ABPM or vise versa) was random, according to the availability of the devices and the patient's preference. Results: The study included 86 males (61.4%) and 54 females (38.6%) with a mean age of 62.7±15.3 years and a median dialysis vintage of 21 months. In Bland-Altman analysis, standardized clinic SBP overestimated ambulatory daytime SBP on average by 4.9 mmHg with wide 95% limits of agreement (-26.3 to 36.1 mmHg). In contrast, the mean difference between home SBP and ambulatory daytime SBP was smaller in magnitude (mean difference: 3.1 mmHg; 95% limits of agreement: -19.1 to 25.2 mmHg). In receiver-operating-characteristic (ROC) analysis, the accuracy of home SBP [area under the ROC curve (AUC): 0.880; 95% confidence interval (CI): 0.817-0943] in diagnosing an ambulatory daytime SBP equal or greater than 135 mmHg was numerically higher but not significantly different from the accuracy of standardized office SBP (AUC: 0.807; 95% CI: 0.731-0.883) (P=0.15 for the comparison between AUCs). Conclusions: The present study shows that among patients on PD, home SBP averaged over 1 week is at least accurate as standardized office SBP in diagnosing hypertension, as confirmed by the reference-standard method of ABPM.