In this study the plasma, erythrocyte, and platelet myo-inositol levels in 24 type I, 24 type II diabetics, and in 15 healthy controls were determined. The diabetics were devided into two groups with microangiopathy (n = 26) and without microangiopathy (n = 22). The plasma, erythrocyte, and platelet myo-inositol levels in the whole diabetic group and control subjects were as follows. Diabetic group: 46.5 +/- 39.8 mumol.l-1 23.3 +/- 19.8 nmol.ml-1, 2.6 +/- 2.8 nmol.ml-1 (10(5) cells)-1.
Control group: 17.4 +/- 3.7 mumol.l-1, 12.2 +/- 5.2 nmol.ml-1, 1.5 +/- 0.9 nmol.ml-1 (10(5) cells)-1. The values of the diabetic group were significantly higher than the values of the control group (p < 0.01). In patients with HbA1c levels more than 9% plasma, erythrocyte, and platelet myo-inositol values were significantly higher than the values of the group with HbA1C levels less than 9% (p < 0.05, p < 0.05 and p < 0.01). In diabetics without complications plasma and erythrocyte myo-inositol levels were higher than the values of the control group (p < 0.01), whereas there was no significant difference between the platelet myo-inositol values. In diabetics with complication all these three values were higher than those of the control group (p < 0.01, p < 0.01, p < 0.01). The most profound increase in the plasma, erythrocyte, and platelet myo-inositol levels were seen in complicated diabetics with a diabetes duration of 6-10 years (p < 0.01). After 10 years duration the values declined. In the group without complication there was no difference according to the duration of diabetes.