Detecting a microalbuminuria in a diabetic patient is enough to diagnose a diabetic glomerulopathy (which is more properly termed diabetic nephropathy). To appreciate exactly means to know what are the lesions of mesangium matrix and interstitial tissue; therefore, a renal biopsy is useful, (but needs to be examined by quantitative histo-morphometry). Numerous factors facilitate the progression of renal insufficiency in these patients: high blood pressure, poor glycemie control, high protein diet. Avoiding each of these factors allows to delay the time of dialysis and renal transplantation. Now diabetics represent the large group of patients in renal replacement therapy world-wide. These therapies are twice to thrice as expensive as they are for non diabetic patients.