Harnessing basic and clinic tools to evaluate SGLT2 inhibitor nephrotoxicity

Abstract

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are a new class of medications that target the transporter that reabsorbs ~90% of glucose in the S1 segment of the proximal convoluted tubule. As a result, SGLT2 inhibition increases urinary glucose excretion, effectively lowering plasma glucose levels. In addition to reducing hemoglobin A1c levels, these drugs also lower body weight, blood pressure, and uric acid levels in Type 2 diabetes mellitus (T2DM) patients. Importantly, empagliflozin has been observed to slow progression of kidney disease and reduce dialysis requirements in T2DM patients. However, the Food and Drug Administration (FDA) Adverse Events Reporting System (FAERS) has collected over 100 cases of acute kidney injury (AKI) for canagloflozin and dapagliflozin since their approval. Of the 101 patients, 96 required hospitalization, 22 required intensive care unit admission, and 15 underwent hemodialysis. The FDA now requires that AKI be listed as a potential side effect of the SGLT2 inhibitors along with cautious prescription of these drugs with other medications, such as renin-angiotensin-system antagonists, diuretics, and NSAIDs. It is unclear, however, whether this FAERS reported "AKI" actually represents structural kidney injury, as randomized, controlled trials of these drugs do not describe AKI as an adverse event despite coprescription with RAS blockers and diuretics. As a result of this FDA warning, diabetic patients with early-stage CKD may not be prescribed an SGLT2 inhibitor for fear of AKI. Thus, it is imperative to ascertain whether the reported AKI represents true structural kidney injury or a functional decline in glomerular filtration rate. We propose using readily available clinical tools with experimental biomarkers of kidney injury and kidney-on-a-chip technology to resolve this question and provide solid evidence about the AKI risk of these drugs for healthcare providers.

Keywords: SGLT2 inhibitors; acute kidney injury; biomarkers; nephrotoxicity; urine microscopy.