24-h ambulatory blood pressure variability and hypertensive nephropathy in Han Chinese hypertensive patients

Blood pressure (BP) is characterized by spontaneous oscillation over time, which is described as BP variability (BPV). The current study aimed to investigate whether short-term BPV was correlated with hypertensive nephropathy in Han Chinese individuals with hypertension. A single-center prospective cohort study of 300 Han Chinese participants with hypertension was conducted in Taiwan. Five different BPV parameters were derived from ambulatory BP monitoring (ABPM), including standard deviation (SD), weighted SD (wSD), coefficient of variation (CoV), successive variation (SV), and average real variability (ARV). Renal event was defined as > 50% reduction in baseline estimated glomerular filtration rate (eGFR). The average age of the participants was 63.5 years. The baseline eGFR was 84.5 mL/min/1.73 m(2). The participants were divided into two groups according to the wSD of systolic BP (SBP). Survival was assessed via a Kaplan-Meier analysis. During the 4.2-year follow-up, the participants with the highest SBP wSD tertile had a greater number of renal events (6.0%) than their counterparts (0.5%) (log-rank test, p = .007). The Cox proportional hazard regression model was used to assess the independent effects of BPV, and results showed that 24-h SBP (HR = 1.105; 95% CI = 1.020-1.197, p = .015) and 24-h DBP (HR = 1.162; 95% CI = 1.004-1.344, p = .044) were independently associated with renal events. However, BPV parameters were only associated with renal events univariately, but not after adjusting for baseline characteristics, 24-h mean BP, and office BP. Therefore, the risk of hypertensive nephropathy was independently associated with 24-h mean BP, but not with ambulatory BPV, in Han Chinese participants with hypertension.