Association between blood pressure variability and risk of kidney function decline in hypertensive patients without chronic kidney disease: a post hoc analysis of Systolic Blood Pressure Intervention Trial study

BACKGROUND: Blood pressure variability (BPV) is a risk factor for poor kidney function independent of blood pressure (BP) in chronic kidney disease (CKD). Little is known about the association between kidney function decline and BPV in hypertensive patients without CKD. METHODS: A post-hoc analysis of the Systolic Blood Pressure Intervention Trial (SPRINT) was performed. BPV was measured as standard deviation (SD) and average real variability (ARV). Cox proportional hazard models were employed to explore the relationship between BPV and incident CKD and albuminuria. RESULTS: A total of 5700 patients were included, with a mean age of 66.4 years old. During a median of 3.29 years follow-up, 150 (2.6%) patients developed CKD and 222 (7.2%) patients developed albuminuria. Patients were divided into four groups according to the quartiles of BPV. Compared with SBPV Q1, the incidence of CKD was higher in SBPV Q2-Q4; hazard ratios and 95% confidence interval were 1.81 (1.07-3.04), 1.85 (1.10-3.12) and 1.90 (1.13-3.19), respectively. The association between incident CKD and albuminuria with DBPV was less significant than SBPV. Similar results were found when measuring BPV as ARV and SD. No interaction was detected in BP-lowering strategy and SBPV on incident CKD and albuminuria ( P > 0.05). CONCLUSION: This study found that BPV was a risk factor for incident CKD and albuminuria in patients without CKD, especially SBPV. Although intensive BP control increased the risk of CKD, the association between SBPV and kidney function decline did not differ between the two treatment groups. REGISTRATION: URL: https://clinicaltrials.gov/ , Unique identifier: NCT01206062.