Visit-to-visit variability in blood pressure and the development of chronic kidney disease in treated general hypertensive patients

Background. Data on the association between visit-to-visit variability (VVV) in blood pressure (BP) and the risk of chronic kidney disease (CKD) in general treated hypertensive patients were limited. We aimed to evaluate the relation of VVV in BP with the development of CKD, and examine any possible effect modifiers in hypertensive patients without prior cardiovascular diseases (CVDs) or CKD. Methods. This is a post hoc analysis of the Renal Sub-study of the China Stroke Primary Prevention Trial (CSPPT). A total of 10 051 hypertensives without CVD and CKD and with at least six visits of BP measurements from randomization to the 24month visit were included. The main VVV in BP was expressed as standard deviation (SD). The primary outcome was the development of CKD, defined as a decrease in estimated glomerular filtration rate >= 30% and to a level of <60mL/min/1.73 m(2), or end-stage renal disease. Results. The median treatment duration was 4.4 years. After multivariable adjustment, including baseline systolic blood pressure (SBP) and mean SBP during the first 2-year treatment period, there was a significantly positive relationship of SD of SBP with the risk of CKD development (per SD increment; odds ratio, 1.27; 95% confidence interval: 1.10-1.46). The results were similar for coefficient of variation (CV) of SBP. Results across various subgroups, including age, sex, SBP at baseline, treatment compliance, concomitant antihypertensive medications and mean SBP during the first 24-month treatment period, were consistent. Conclusions. SBP variability, irrespective of mean BP level, was significantly associated with the development of CKD in general treated hypertensive patients.