Mineralocorticoid Receptor Antagonism in Diabetic Kidney Disease: From Pathophysiological Mechanisms to Clinical Paradigm Shifts

Diabetic kidney disease (DKD) remains a primary driver of end-stage kidney disease and cardiovascular morbidity despite the optimized use of renin–angiotensin system (RAS) inhibitors and sodium-glucose cotransporter-2 (SGLT2) inhibitors. Recent evidence identifies the overactivation of the mineralocorticoid receptor (MR) as a critical, independent pathway leading to persistent renal inflammation and fibrosis. In the diabetic milieu, MR overactivation—driven by both aldosterone and ligand-independent factors such as Rac1 GTPase and oxidative stress—triggers pro-inflammatory and pro-fibrotic gene networks. Unlike traditional steroidal mineralocorticoid receptor antagonists (MRAs), the novel non-steroidal MRA finerenone exhibits a distinct binding mode that more effectively blocks the recruitment of transcriptional co-activators, thereby silencing detrimental downstream signaling in podocytes, fibroblasts, and myeloid cells. Preclinical models have demonstrated that MR blockade significantly reduces albuminuria and preserves podocyte integrity independent of systemic blood pressure. These findings translated into landmark clinical trials; the FIDELIO-DKD and FIGARO-DKD trials established that finerenone significantly reduces the risk of kidney disease progression and cardiovascular events across a broad spectrum of chronic kidney disease stages in type 2 diabetes. Furthermore, recent data from the FINEARTS-HF and CONFIDENCE trials suggest a synergetic benefit when combined with SGLT2 inhibitors, offering more robust cardiorenal protection with a manageable risk of hyperkalemia. This review synthesizes the current understanding of MR pathophysiology and clinical evidence, providing a comprehensive framework for the integration of MRAs into the evolving standard of care for patients with diabetic kidney disease.