The relationship between glycemic control and platelet activity in type 2 diabetes mellitus.

AIMS: Platelet activity and aggregation potential, which are essential components of thrombogenesis and atherosclerosis, can be conveniently estimated by measuring mean platelet volume (MPV) as part of whole blood count. It has been shown that MPV was significantly higher in diabetes mellitus (DM); however, the effect of glycemic control on MPV has not been studied. The aim of this study was to investigate the relationship among MPV, glycemic control, and micro- and macrovascular complications in type 2 DM.

METHODS: Seventy patients with type 2 DM and 40 age- and sex-matched healthy individuals were enrolled. Diabetic patients were grouped into those with glycated hemoglobin (HbA1c) levels <or=7% (Group A, n=35 patients) and those with HbA1c >7% (Group B, n=35 patients). Initially, both groups were compared with regard to MPV, HbA1c, serum lipid levels, coronary artery disease, retinopathy, neuropathy, and nephropathy. Thereafter, Group B was called to monthly visits to obtain improved control glycemic control, which was defined as achievement of HbA1c <or=7%. At the end of 3 months of follow-up, Group B was reevaluated.

RESULTS: MPV was significantly higher in patients with DM than in controls (8.7+/-0.8 fl vs. 8.2+/-0.7 fl, P=.002). In diabetic patients, there was a significant positive correlation between MPV and HbA1c levels (r=.39, P=.001) but not diabetic vascular complications. When we compared the two diabetic groups, Group B patients had significantly higher MPV than Group A (9.0+/-0.7 fl vs. 8.4+/-0.8 fl, P=.01). Thirty patients (86%) of Group B achieved improved glycemic control at the end of the 3 months. MPV of the patients with improved glycemic control were significantly decreased compared to baseline MPV (8.4+/-0.8 fl vs. 9.0+/-0.7 fl, P=.003).

CONCLUSIONS: Our results suggested a close relationship between poor glycemic control and increased platelet activity in patients with type 2 DM. Furthermore, platelet activity recovered through improved glycemic control, which may prevent the possible role of platelets in cardiovascular events in these patients.