Increased platelet activity in diabetic macroangiopathy

In order to investigate the relationship between the in vivo platelet activity and diabetic macroangiopathy we have measured plasma beta-thromboglobulin (beta-TG) concentrations by means of a very sensitive radioimmunoassay in 55 diabetics, aged 47-80 years, and in 27 non-diabetic healthy controls (group A) of respective age and sex. Among diabetics 17 were free of vascular complications (group B) in terms of diabetic micro- or macroangiopathy, while the remaining 38 (group C) suffered from peripheral occlusive arterial disease (POAD) of the lower limbs. All subjects underwent a thorough clinical and laboratory investigation. The diagnosis of POAD was based upon the findings of Doppler ultrasound examination and was confirmed by selective arteriography. The mean plasma beta-TG concentrations were significantly higher in the two groups of diabetics compared to the non-diabetic controls (p < 0.001), whereas the highest beta-TG levels were found in diabetics with POAD (py 0.001), (beta-TG: mean +/- 1 SD ng/ml; group A: 26.50 +/- 13.14; group B: 55.88 +/- 26.56; group C: 106.50 +/- 52.65). These findings reveal an increased release reaction of platelets in diabetics and an enhanced in vivo platelet activity especially in POAD subjects. However, this may occur not only in cases with prominent macroangiopathy but also in the early stages of diabetic angiopathy when the vascular lesions cannot be traced clinically.