Chronic kidney disease in type 2 diabetes: The size of the problem, addressing residual renal risk and what we have learned from the CREDENCE trial.

Chronic kidney disease (CKD) associated with type 2 diabetes (T2DM) is a global challenge; progression to end-stage kidney disease (ESKD) and increased risk of cardiovascular disease (CVD) associated with advancing nephropathy are a significant source of morbidity, mortality, and healthcare expenditure. Until recently, renin-angiotensin system (RAS) blockade was the mainstay of pharmacotherapy in diabetic kidney disease (DKD), representing a therapeutic paradigm shift towards interventions that delay disease progression independently of antihypertensive effects. However, a significant residual risk of DKD progression persisted in patients established on RAS blockade, highlighting the need for additional treatment options. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, originally licensed as glucose-lowering agents in people with T2DM, serendipitously demonstrated beneficial renal and cardiovascular outcomes in clinical trials designed primarily to evaluate their cardiovascular safety. The Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) trial was the first to study the effect of SGLT2 inhibition on a primary composite renal endpoint of ESKD, doubling of serum creatinine, or renal or cardiovascular death in 4401 people with T2DM and CKD established on RAS blockade. The trial was stopped early due to efficacy, demonstrating a 30% relative risk reduction in the primary endpoint in the canagliflozin group (hazard ratio 0.70, 95% confidence interval 0.59-0.82; p = 0.00001). Through discussion of the primary analysis from CREDENCE, and selected post hoc analyses, we review the significant benefits highlighted by this landmark study, its role in shaping clinical guidelines, and in re-establishing interest in interventions that reduce the residual risk of progression of DKD, alongside its interrelation with cardiovascular morbidity and heart failure. We also provide a brief narrative summary of key renal outcome trials since CREDENCE, which indicate emerging avenues for pharmacotherapy beyond SGLT2 inhibition.