Systolic Blood Pressure Time in Target Range and Acute Kidney Injury in Patients With Hypertension

Acute kidney injury (AKI) is a serious complication of hypertension management. However, the association between systolic blood pressure (SBP) time in target range (TTR) and the risk of AKI remains unclear.

This is a post hoc analysis of the SPRINT (Systolic Blood Pressure Intervention Trial). Participants were randomly assigned to intensive (<120 mm Hg) or standard (<140 mm Hg) SBP treatment arms. SBP TTR was defined as 110 to 130 mm Hg for the intensive arm and 120 to 140 mm Hg for the standard arm over 3 months. The primary outcome was incident AKI. The secondary outcome was the severity of AKI based on the modified Kidney Disease: Improving Global Outcomes criteria. Competing risk models were used to estimate the relationship between SBP TTR and AKI.

Among 8985 participants, 258 developed AKI (incidence, 7.62 per 1000 person-years). Each 1-SD increase in SBP TTR was associated with a 14% lower risk of AKI (hazard ratio, 0.86 [95% CI, 0.75-0.97]; P=0.017). No significant interaction was observed between treatment assignment (P_interaction=0.930). Compared with participants with lower TTR (0%-<59%), those with higher TTR (59%-100%) had a lower risk of AKI events (hazard ratio, 0.69 [95% CI, 0.53-0.91]; P=0.008). By treatment arm, hazard ratios (95% CIs) for standard/lower versus intensive/lower, standard/higher, and intensive/higher were 1.70 (1.23-2.38; P=0.002), 0.68 (0.45-1.03; P=0.070), and 1.19 (0.81-1.75; P=0.470), respectively.

Higher SBP TTR was associated with a lower risk of AKI, independent of treatment intensity, underscoring the importance of sustained blood pressure management.

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01206062.