Improved glycemic control and platelet function abnormalities in diabetic patients with microvascular disease

Patients with diabetes mellitus have a variety of platelet and coagulation system dysfunctions. At least theoretically, these can contribute to microv ascular complications. Intensive glycemic control has been demonstrated to decrease microvascular complications in type 1 diabetics. We studied 16 pat ients with type 1 diabetes mellitus (11 men and five women; mean age, 39 ye ars) with albuminuria greater than 0.1 g/d and/or proteinuria greater than 0.3 g/d and a creatinine clearance rate higher than 30 mL/min. They receive d a regimen including three to four injections of insulin per day with or w ithout a weekly infusion of intravenous insulin, and were evaluated for 6 m onths. We compared the plasma level of von Willebrand factor, platelet aggr egation responses to adenosine diphosphate (ADP), epinephrine, and collagen , and platelet adhesion at the beginning of the study and at follow-up inte rvals. Glycemic control improved significantly. There were no significant d ifferences in the platelet aggregation responses to ADP (1.59 +/- 0.34 v 1. 88 +/- 0.23 mmol/L, P = .3; normal, 4.6 +/- 0.2), epinephrine (0.50 +/- 0.2 0 v 1.11 +/- 0.31 mmol/L, P = .06; normal, 7.6 +/- 1.5), or collagen (92.4 +/- 6.61 v 82.60 +/- 3.78 seconds, P = .6; normal, 79.1 +/- 3.1) or in plat elet adhesion (126.31 +/- 16.95 v 195.08 +/- 30.2 platelets, P = .34; norma l, 68.6 +/- 1.4). Baseline von Willebrand factor increased, but not signifi cantly (166.38% +/- 10.6% v 142.72% +/- 14.73%, P = .21; normal, 102.0% +/- 6.0%), In type 1 diabetic patients with established microvascular complica tions of nephropathy, a statistically significant improvement in glycemic c ontrol did not improve the in vitro platelet function abnormalities. Improv ed glycemic control delays the progression of microvascular disease through mechanisms not measured by tests of platelet function. Copyright (C) 2000 by W.B. Saunders Company.