REGROUP: Renohemodynamic Effects empaGliflozin in vaRiOUs Populations

Worldwide, diabetic kidney disease (DKD) is the most common cause of chronic and end stage kidney disease. Large-sized prospective randomized clinical trials indicate that intensified glucose and blood pressure control, the latter especially by using agents that interfere with the renin-angiotensin-aldosterone system (RAS), halts the onset and (particularly) the progression of DKD, in both type 1 Diabetes Mellitus (T1DM) and type 2 Diabetes Mellitus (T2DM) patients. However, despite the wide use of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs), a considerable amount of patients develop DKD (20-40%), indicating an unmet need for renoprotective therapies as DKD largely causes the increased mortality risk from cardiovascular disease (CVD) in people with diabetes. Sodium-glucose linked transporters (SGLT-2) inhibitors are a relatively novel glucose-lowering drug for the treatment of T2DM as they lower plasma glucose levels by blocking renal glucose reabsorption. In addition, these agents exert pleiotropic actions beyond glucose control. As such, SGLT-2 inhibitors decrease proximal sodium reabsorption, reduce blood pressure, body weight and uric acid. In large trials and likely through these pleiotropic effects, SGLT2 inhibitors reduce cardiovascular mortality, hospitalization for heart failure and reduce end stage kidney disease. At this point in time, the renoprotective mechanisms involved with SGLT-2 inhibition still remain speculative, though a consistent finding is that SGLT-2 inhibitors reduce estimated eGFR after first dosing, which is reversible after treatment cessation. This "dip" indicates a renal hemodynamic phenomenon reminiscent of the RAS blockers and is thought to reflect a reduction in intraglomerular pressure. The mechanisms of this observation have only been partially investigated by us and others. From studies in peolpe with T1DM it is hypothesized that SGLT-2 inhibition increases sodium chloride delivery to