Vascular Effects of SGLT2i in Non-diabetic CKD

Overall Strategy: The investigators propose a randomized, double-blind, placebo-controlled, phase-II study in 52 Veterans with non-diabetic CKD without heavy albuminuria (\<300 mg/g) and eGFR 20-59 mL/min/1.73m2 to investigate if empagliflozin, a selective SGLT2i, can improve vascular function, functional capacity, and plasma biomarkers of inflammation, oxidative stress, and nitric oxide (NO). Veterans will be recruited from the Salt Lake City VA and randomized to 10 mg of empagliflozin or placebo at 1:1 ratio and treated for 16 weeks. Overarching Hypothesis: SGLT2 inhibition improves endothelial function in both macro- and micro-vasculature, in part, by mitigating inflammation and oxidative stress and augmenting NO bioavailability in patients with CKD, even in the absence of heavy albuminuria. The improved vascular function contributes to increased functional capacity. Specific Aim 1: Comprehensively evaluate the efficacy of empagliflozin to improve vascular health, as determined by conduit artery endothelium-dependent vasodilation (flow-mediated dilation, FMD), peripheral microvasculature reactivity (passive limb movement, PLM), and arterial stiffness (carotid-femoral pulse wave velocity, PWV), in non-diabetic Veterans with CKD and albuminuria \<300 mg/g. Specific Aim 2: Evaluate the efficacy of empagliflozin to improve functional capacity using (a) handgrip exercise and (b) mobility tests (Timed Up-and-Go test, gait speeds, and 6-minute walk). Specific Aim 3 (Exploratory): Evaluate the efficacy of empagliflozin to (a) reduce plasma biomarkers of systemic inflammation (C-reactive protein, interleukin-6, tumor necrosis factor- ) and oxidative stress (free radical concentration assessed by electron paramagnetic resonance spectroscopy) and (b) increase plasma NO, as reflected by plasma nitrite and nitrosyl hemoglobin levels.