Effect of glycaemic control, metformin and gliclazide on platelet density and aggregability in recently diagnosed type 2 (non-insulin-dependent) diabetic patients.

Platelet density profiles, intraplatelet nucleotides, intraplatelet beta thromboglobulin (beta TG), plasma beta TG levels, intraplatelet cyclic AMP (cAMP) levels, platelet release reaction, platelet thromboxane (TX)B2 production and plasma fibrinogen levels were investigated in 24 newly diagnosed, non-insulin-dependent diabetic patients and 12 comparable controls. These variables were measured at diagnosis, after a 3-6 week dietary run-in period, and again after 6 months on treatment with either metformin or gliclazide therapy. With dietary restriction of refined carbohydrate and oral hypoglycaemic therapy, there was a reduction in platelet density (p less than 0.05), intraplatelet nucleotides (p less than 0.001), intraplatelet beta TG (p less than 0.001), plasma beta TG (p less than 0.001) and there was an increase in intraplatelet cAMP levels (p less than 0.05). Although these platelet variables returned towards normal, only the platelet density mean returned to within the normal range. There was no significant change in the platelet TXB2 production and plasma fibrinogen levels with treatment. Metformin and gliclazide were equally effective in the glycaemic control of non-insulin-dependent diabetes, and there was no difference between the platelet variables measured in the two groups. We would therefore suggest that improvement of glycaemic control, rather than any specific effect of the oral hypoglycaemic agent employed, is the most important factor in returning these parameters towards normality.