Plasma Antithrombin III and Thrombin Generation Time: Correlation with Hemoglobin A₁ and Fasting Serum Glucose in Young Diabetic Women

Three parameters of coagulability – thrombin generation time (TGT), antithrombin III (AT III), and activated partial thromboplastin time (ATPP) – and two parameters of diabetic control – serial measurements of fasting serum glucose (FG) and hemoglobin A₁(HbA₁) – were used to study the relationship between diabetic control and hypercoagulability. Four groups of females were studied consisting of 10 young normal, 10 young insulin-dependent diabetic, 10 pregnant nondiabetic, and 8 first-trimester, insulin-dependent, pregnant diabetic subjects. Fasting serum glucose values and HbA₁ were higher (P < 0.005) in nonpregnant diabetic subjects (193.1 ± 29.1 mg/dl, 12.9 ± 1.1%) and pregnant diabetic subjects (111.0 ± 13.6 mg/dl, 8.2 ± 1.7%) than in controls (64.8 ± 4.4 mg/dl, 5.9 ± 0.1%) and the nondiabetic pregnant females (71.6 ± 3.8 mg/dl, 6.1 ± 0.2%). Young diabetic females, pregnant females, and pregnant diabetic subjects had a shorter (P < 0.01) TGT than did the controls. AT III was greater (P < 0.01) for controls (99.7 ± 2.7%) than for pregnant nondiabetic (83.2 ± 3.8%), diabetic (79.5 ± 2.5%), and pregnant diabetic subjects (76.2 ± 4–4%). There was a positive correlation (r = 0.88, P < 0.005) between HbA₁ and FG in the 10 young diabetic and in the 8 pregnant diabetic subjects (r = 0.74, P < < 0.05). In the 10 diabetic females there was a negative correlation between AT III andFG(r = -0.76, P < 0.01) and between AT III and HbA₁ (r = -0.79, P < 0.01). Thus, AT III is depressed in both diabetes and pregnancy, with pregnant diabetic subjects displaying the lowest AT III levels. Our observation that depression of AT III levels in young diabetic females was closely correlated with elevations of fasting serum glucose and HbA₁ suggests that strict diabetic control may help prevent hypercoagulability in diabetes.