Pentoxifylline Effect in Patients With Diabetic Nephropathy.(PENFOSIDINE STUDY)

Patients will be randomly selected from the outpatient family medicine clinics. Once included, patients will be randomly allocated (by a computer-generated randomization list) to a study or control group. Over a period of 2 years, patients of the study group will receive one PTX tablet (400 mg) orally three times a day (at dinner time), whereas controls will receive one cellulose identical tablet on the same schedule. All patients will continue with their usual treatment prescribed by their family doctor. Monthly visits will be scheduled for clinical and biochemical evaluations. A blood sample will be taken at baseline and every six months up to 24 months, for measurement of complete blood count, urea, creatinine, glucose, albumin, lipids, electrolytes, liver function tests, serum total proteins, (will be measure by usual methods). In serum samples at 0, 6, 12, 18 and 24 months, high sensibility C reactive protein will be measured by nephelometry, Brain natriuretic peptide and Serum Cystatin C will be measured by ELISA. Glomerular filtration rate (GFR) will be calculated based in Cystatin C level Grubb's equations. Vitamin C will be measured by HPLC. A 24 h ambulatory blood pressure monitoring (24 h ABPM), M-mode and two-dimensional echocardiographic, and an analysis of body composition by bioelectrical impedance will be done at baseline 6, 12, 18 and 24 months. To investigate health-related quality of life the short-form 36 (SF-36) questionnaire will be applied. Treatment compliance will be recorded by counting tablets left in the container at the end of each monthly visit and by the Morinsky Green test.