Low Achieved Systolic Blood Pressure Related to Kidney Protection in Diabetic and Non-Diabetic High-Risk Hypertensive Patients.

Abstract

Background: Protecting the kidneys by lowering systolic blood pressure (SBP) in hypertensive patients is not unequivocally settled. We tested the hypothesis that achieving lower average SBP in middle-aged and older high-risk hypertensive patients with and without type-2 diabetes mellitus through several years would clarify kidney protection.

Methods: We analyzed patients 50-80 years with no cardiovascular events during the first 6 months of drug up-titration after randomization to valsartan or amlodipine, and with 3 or more visits onwards with standardized BP measurements. Adjusted Cox analyzes compared worsened kidney function defined as 50% rise in se-creatinine on a minimum of two occasions at least 4 weeks apart or end-stage kidney disease (ESKD) in achieved SBP quartiles and in patients who achieved SBP <130 and 130-139 mmHg with patients whose SBP remained >140 mmHg.

Results: 13,803 patients were investigated of whom 4,655 had DM. Patients with DM had less worsened kidney function at SBP 130-139 mmHg (HR=0.524, 95% CIs 0.375-0.733, n=1849, p<0.001) and at SBP <130 mmHg (HR=0.538, CIs 0.316-0.915, n=674, p=0.022) compared with patients at ≥140 mmHg. They also had less ESKD at SBP 130-139 mmHg (HR=0.442, CIs 0.196-1.000, p=0.050) with a similar trend at SBP <130 mmHg and in quartile analysis with only 1 ESKD in the lowest quartile. Findings in patients without DM (n=9,148) were similar to DM.

Conclusions: In high-risk hypertensive patients of 50-80 years, with and without DM, targeting SBP of 130-139 mmHg confers kidney protection with possible further benefit at the lower target of SBP <130 mmHg.