Platelet survival in patients with diabetes mellitus.

Platelet survival by 51chromium labeling was determined in six normal control subjects and in twelve patients with diabetes mellitus, before and after improved glucose control (mean HbA1c 10.5 +/- 2.2% and 7.1 +/- 1.8%, respectively). Mean platelet survival was 9.47 +/- 0.85 days for the normal subjects and 9.04 +/- 1.40 and 9.90 +/- 1.05 for the diabetic subjects in hyperglycemic and improved glycemic states, respectively. The differences between these values were not statistically significant. However, platelet survivals performed in three diabetic patients who had severe retinal disease requiring photocoagulation were significantly shortened compared with nonsmoking control subjects (P less than 0.05) or to patients without severe retinopathy (P less than 0.01). These observations imply that measurable changes in in vivo platelet survival occur after the development of small vessel disease. It remains to be determined whether abnormalities described for diabetic platelets in vitro or changes in in vivo platelet physiology contribute to the initiation or propagation of vascular disease in the hyperglycemic individual.