HYPERTENSION AND KIDNEY DISEASE

Objective: To analyze the effect of intensive blood pressure (BP) control on renal outcomes among non-CKD and CKD patients at baseline.Design and method: We conducted a post-hoc analysis on the data set from two landmark studies - SPRINT and ACCORD-BP. Hypertensive patients were randomly assigned to a systolic BP (SBP) treatment target of < 120 (intensive treatment) or < 140 (standard treatment). In SPRINT, there were 4678 patients in intensive as compared to 4683 in standard group. In ACCORD-BP, we included only those with standard glycemic control (glycated hemoglobin of 7.0–7.9%) that resulted in 1184 patients on intensive arm and 1178 patients on standard arm. We further categorized BP over time into 3 tiers, by low (SBP < 120 and DBP < 70), medium (SBP = 120–140 and DBP = 70–85) and high (SBP > 140 and DBP > 85) and compared the renal outcomes. Generalized Estimating Equation and smoothing spline fitting method was used to find the relationship between BP and renal outcomes over time. Results: In SPRINT, non-CKD patients in intensive group had a higher chance of 30% reduction of eGFR (OR = 3.68, 95% CI = 2.51–5.40) than in standard group. Medium DBP (71–85), in comparison to low DBP (<70), significantly decreased 30% reduction in eGFR in non-CKD patients (OR = 0.63, P-value < 0.01) and significantly decreased 50% reduction in EGFR (OR = 0.55, p = 0.01) as well as CKD composite (OR = 0.53, p < 0.01) among CKD patients. In ACCORD-BP, patients in intensive group had higher chance of doubling of serum creatinine or > 20 mL/min decrease in eGFR (OR 1.83, 95% CI = 1.76–1.90) than in standard treatment group. Both high SBP (>140) and medium SBP (120–140) as compared to low SBP (<120) level, significantly reduced the chance of serum creatinine doubling or > 20 ml/min decrease in eGFR (OR = 0.79, p < 0.0001). Curve fitting the results are illustrated in figure. Conclusions: Post-hoc analyses of both SPRINT and ACCORD-BP dataset show that intensive BP management consistently increases the risk of 30–50% reduction in eGFR, and interestingly, the major driver of this outcome was low DBP in SPRINT study where as it was low SBP in ACCORD study. It further highlights the importance of optimizing DBP among patients with CKD at baseline.