Increased platelet volume--sign of impaired thrombopoiesis in diabetes mellitus.

Increased functional properties of diabetic platelets might be already conditioned during thrombopoiesis in the stem cell system. This hypothesis was studied by recording the distribution characteristics of the peripheral platelet pool in 218 diabetic patients versus 51 controls. Furthermore, platelet membrane coating with the stem cell marker glycoprotein IB was analyzed in 41 diabetic subjects and compared to 23 healthy volunteers. A consistent, significant shift of the volume distribution to larger platelets was found in diabetics: Mean platelet volume (MPV) - 7.9 +/- 0.9 versus 7.2 +/- 0.8 [fl]; Megathrombocyte index (MTI) - 20.4 +/- 2.8 versus 18.1 +/- 2.5 [fl]. These deviations were present in all patient subsets, however did not correlate to parameters of glucose metabolism. Whole blood platelet count was increased in the patient group; 195.0 +/- 59.5 versus 184.0 +/- 37.5 x 10(3) plts/ul. Coating with glycoprotein IB receptors correlated significantly to platelet size in platelets of both controls and diabetics (r normal = 0.52 +/- 0.07; r diabetic = 0.46 +/- 0.1). The quantitative expression of glycoprotein IB was significantly enhanced in the diabetic group: 54,500 x 1.28 +/- 1 versus 39,100 x 1.3 +/- 1 molecules per platelet. In conclusion, these findings strongly support the assumption of diabetic stem cell dysfunction of the megakaryocytic series and progenitor cells resulting in platelets with primarily increased potency to adhere and aggregate in diabetes mellitus.