Administration of aspirin-dipyridamole reduces proteinuria in diabetic nephropathy

We assessed in a pilot study the effect on some aspects of renal function of 6 weeks' administration of a combination of aspirin-dipyridamole (990 mg/225 mg daily) administered on a double-blind crossover schedule in 16 insulin-dependent diabetic patients with nephropathy. Total 24-h urinary protein excretion (16 patients) was significantly reduced during aspirin-dipyridamole administration from a geometric mean (range) of 1.9 (0.4-7.7) g/24 h to 1.4 (0.5-9.9) g/24 h (2P less than 0.05). Indium-labelled platelet survival (eight patients), glomerular filtration rate and renal blood flow (eight patients) showed no significant change following aspirin-dipyridamole therapy, even though plasma creatinine concentration increased from 118 (65-371) to 130 (76-438) mumol/l (2P less than 0.05). Diabetic control and blood pressure remained unchanged throughout the study. Although the results showed that this treatment significantly reduced proteinuria in patients with diabetic nephropathy, the mechanism of action was not entirely clear.