Effects of Rosiglitazone on Renal Hemodynamics and Proteinuria of Type 2 Diabetic Patients With Renal Insufficiency Due to Overt Diabetic Nephropathy
Effects of Rosiglitazone on Renal Hemodynamics and Proteinuria of Type 2 Diabetic Patients With Renal Insufficiency Due to Overt Diabetic Nephropathy
Objective:
To evaluate how rosiglitazone does influence the renal plasma flow, the glomerular filtration rate and the degree of proteinuria in type 2 diabetic patients with renal insufficiency due to overt diabetic nephropathy.
Background:
Diabetic nephropathy is a world wide public health concern of increasing proportions. It has become the most common single cause of end-stage renal disease in the United States and in Europe. Previous studies have already found agents modifying the renin-angiotensin-system (ACE inhibitors and angiotensin receptor blocker) to retard diabetic nephropathy. These agents are likely to exert multiple effects in the kidney. One of them appear to be their known ability to improve endothelial function and to change renal glomerular hemodynamics.
In a previous study we demonstrated an improvement of renal endothelial dysfunction in type 2 diabetic patients without end organ damage after treatment with rosiglitazone. In that study, rosiglitazone significantly reduced glomerular hyperfiltration. This was associated with a reduction of urinary albumin excretion. The observed effects are potentially important in the context of renal protection, provided that a similar beneficial effect of rosiglitazone is demonstrable in overt diabetic nephropathy (renal insufficiency, hypertension, proteinuria).
Hypothesis Rosiglitazone decreases proteinuria and improves renal hemodynamic function in patients with chronic renal insufficiency due to overt diabetic nephropathy.
Inclusion Criteria:
type 2 diabetes mellitus -age between 40 and 75 years -well controlled HbA1c (< 7.5%) -chronic renal failure (creatinin clearance between 70 and 30 mL/(min x 1.73 m²) according to the Cockroft equation) -proteinuria > 300 mg / 24 hours
Exclusion Criteria:
type 1 diabetes -poorly controlled type 2 diabetes (HbA1c > 7.5%) or unstable blood glucose during the day (capillary blood glucose self monitoring) -elevation of ALT, AST or GGT more than 2.5 fold the upper normal value -CHF (more than grade 1 of NYHA) -uncontrolled hypertension -malignant tumorous disorder -hyper- or hypothyroidism -pregnant women -nursing women