Mineralocorticoid Receptor-Associated Mechanisms in Diabetic Kidney Disease and Clinical Significance of Mineralocorticoid Receptor Antagonists

BACKGROUND: Diabetic kidney disease (DKD) is a common disorder with multiple serious clinical implications, including an increased risk of end-stage kidney disease (ESKD), cardiovascular complications, heart failure, onset or worsening of hypertension, and premature death. Patients with DKD frequently require dialysis or kidney transplantation to manage their ESKD. SUMMARY: Upregulation of the renin-angiotensin-aldosterone system is an important contributor to kidney disease progression, as highlighted by the results of trials evaluating angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in patients with albuminuria. Increasing evidence suggests the existence of a multidirectional network that involves aldosterone, the mineralocorticoid receptor (MR), and the Ras-related C3 botulinum toxin substrate 1 (Rac1) as driving forces in the generation of reactive oxygen species and oxidative stress-induced injury in the initiation of interstitial nephritis and eventual fibrosis in chronic kidney disease and DKD. The MR is a key element of this triangle, as highlighted by the beneficial effect of MR antagonists in preventing or reducing aldosterone- or Rac1-related effects in basic science studies, and the improved patient outcomes observed in clinical studies. KEY MESSAGES: Aldosterone can promote kidney disease in diabetes via the MR and via MR-independent actions through Rac1. However, the MR remains a key element of this triangle, with clinical data supporting the use of MR antagonists in delaying the progression of kidney disease in diabetes.