Relationship between blood pressure and kidney diseases in large randomized controlled trials: secondary analyses using SPRINT and ACCORD-BP trials

Hypertension is a risk factor for acute kidney injury. In this study, we aimed to identify the optimal blood pressure (BP) targets for CKD and non-CKD patients. We analyzed the data of the Systolic Blood Pressure Intervention Trial (SPRINT) and the Action to Control Cardiovascular Risk in Diabetes Blood Pressure trial (ACCORD BP) to determine the nonlinear relationship between BP and renal disease development using the Generalized Additive Model (GAM). Optimal systolic BP/diastolic BP (SBP/DBP) with lowest renal risk were estimated using GAM. Logistic regression was employed to find odds ratios (ORs) of adverse renal outcomes by three BP groups (high/medium/low). Both study trials have demonstrated a “U”-shaped relationship between BP and renal outcomes. For non-CKD patients in SPRINT trial, risk of 30% reduction in eGFR among intensive group patients with DBP ≤ 70 mmHg was significantly higher than the group with DBP between 71 and 85 mmHg (OR = 2.31, 95% CI = 1.51–3.53). For non-CKD patients in ACCORD trial, risk of doubling of serum creatinine (SCr) or >20 mL/min decrease in eGFR among intensive group patients with DBP ≤ 70 mmHg was significantly higher than the group with DBP between 71 and 85 mmHg (OR = 1.49, 95% CI = 1.12–1.99). For CKD patients in SPRINT trial, there are no significant differences in renal outcomes by different SBP/DBP levels. Our analysis of both SPRINT and ACCORD datasets demonstrated that lower-than-optimal DBP may lead to poor renal outcomes in non-CKD patients. Healthcare providers should be cautious of too low DBP level in intensive BP management due to poor renal outcomes for non-CKD patients.