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.

The Author(s). Published by S. Karger AG, Basel