Impact of visit-to-visit variability of blood pressure on deterioration of renal function in patients with non-diabetic chronic kidney disease.
An association between visit-to-visit variability (VVV) of blood pressure (BP) and renal damage was recently reported in a cross-sectional study. We aimed to clarify the longitudinal effect of VVV of BP on deterioration of renal function in patients with non-diabetic chronic kidney disease (CKD). We retrospectively studied 56 patients with non-diabetic CKD (stage 3 or 4) who visited our nephrology clinic between September 1994 and May 2011. VVV of BP was defined as the standard deviation and coefficient of variation (CV) of office BP measured at 12 consecutive visits. Main outcomes were the annual decline in the estimated glomerular filtration rate (eGFR) and the composite renal end point defined as a doubling of serum creatinine or the need for dialysis. The median observation period was 83 months. Standard deviation and CV of office systolic BP (SBP) were significantly associated with the slope of the eGFR after adjustments for confounders. The adjusted risk for composite renal end points more than doubled for each increment of 1-standard deviation of the standard deviation of office SBP (hazard ratio (HR) 2.20, P=0.001), and for each increment of 1-standard deviation of the CV of office SBP (HR 2.12, P=0.002). The present study demonstrated that the visit-to-visit variability of BP is an independent determinant of deterioration of renal function in patients with non-diabetic CKD.