The impact of visit-to-visit systolic blood pressure variability on residual renal function and left ventricular hypertrophy in peritoneal dialysis patients

Background/aim: Blood pressure (BP) variability is more closely associated with adverse outcomes than 'usual' BP in the general population. Residual renal function (RRF) and left ventricular hypertrophy (LVH) are thought to be predictors of poor outcome in dialysis patients. However, only a few studies have focused on BP variation and its link to RRF, LVH, and outcome in peritoneal dialysis (PD) patients. Therefore, we aimed to explore the effect of visit-to-visit BP variability on RRF and LVH in continuous ambulatory PD (CAPD) patients. Materials and methods: We performed an observational study that included all prevalent PD patients between 1 February 2006 and 31 January 2007. All patients underwent BP measurements, pulse wave velocity (PWV), cardiac ultrasound, and biochemical examination during the 1-year observation. Patients were divided into the HBPV group (higher BP variability) and LBPV group (lower BP variability) based on the standard deviation of systolic BP (SBP). Results: There were 70 patients recruited for the final analysis. Patients with HBPV had a higher SBP as compared to patients with LBPV at baseline. Renal Kt/V decreased significantly from 0.50 +/- 0.49 to 0.32 +/- 0.35 (P < 0.01) in HBPV group (but not in the LBPV group) during follow-up. Patients with HBPV also showed a higher left ventricular mass index (LVMI) and PWV than those with LBPV at the end of follow-up. Conclusion: Our study suggests that BP variability may affect RRF in PD patients. PD patients with HBPV had a faster decline in RRF and higher PWV and LVH.