Abstract 128: Visit-to-visit Variability of Systolic BP and Renal Outcomes in the SPRINT Trial

Abstract

Increased visit-to-visit variability (VVV) in systolic blood pressure is a known predictor of adverse CV events & in diabetics, is associated with higher risk of incident albuminuria & chronic kidney disease. However, the impact of VVV in SBP on renal outcomes in the absence of diabetes is unknown. We investigated the association between VVV in SBP & adverse CVE & renal events among non-diabetic participants in SPRINT cohort. Methods: Primary exposure was quartile of within-person standard deviation of systolic blood pressure (SDBP). Primary outcomes 1) primary composite CV outcome from SPRINT study, 2) primary SPRINT renal outcome among those without CKD 3) incident albuminuria among those with & without CKD. We compared covariates by SDBP quartile, using ANOVA or chi-square tests. We fit incremental Cox hazards models to examine associations between SDBP & events. We performed sensitivity analyses for # visits in all models. Results: Among 9361 participants, 8589 (92%) met inclusion criteria & comprised the primary analytic sample. The mean SBP across all quartiles was similar (137 - 141 mmHg). There was no association between quartile of SDBP and the primary composite cardiovascular outcome. There was a significant association between quartile of SDBP and incident CKD among those without baseline CKD. Among 3350 participants without baseline CKD and 942 participants with CKD, higher VVV in SBP was independently associated with increased risk of incident albuminuria, regardless of baseline CKD status. This association was robust after adjustment for the number of visits. The interaction between SDBP and the primary intervention was not statistically significant in the no CKD (p=0.11) or CKD groups (p=0.93). Discussion: In this post-hoc analysis of SPRINT, we found that higher VVV in SBP is associated with greater risk of incident albuminuria among non-diabetic adults with and without baseline CKD. This association remained significant after adjustment for numerous potential confounders across follow-up. Our analysis demonstrates a significant association between VVV of SBP and incident albuminuria in patients with and without baseline CKD. This novel finding in an exclusively non-diabetic, hypertensive population deserves further investigation.