Insulin-resistance and triglycerides as independent predictors of the early macrovascular involvement in type 2 diabetic patients

In Type Il Diabetes, microvascular complications are related mainly to hyperglycemia, while macrovascular disease seems to depend on lipids abnormalities. Insulin-resistance (IR) provides a unifying hypothesis accounting for the spectrum of metabolic fingerprints. Aim of the study: to assess the role of lR in the early large artery involvement in Type Il Diabetes. Methods: 18 Type Il diabetics under hypoglycemic therapy without clinical cardiovascular or cerebrovascular disease were studied (age 61\ub12, disease duration 7\ub11 years, body mass index 27.4\ub10.5 kg/m2, HbA1c 6.9\ub10.3%, blood pressure 132\ub13/74\ub12 mmHg). lnsulin sensitivity (IS) was assessed by 2-hr euglycemic hyperinsulinemic (40 mU/min/m2) clamp. Intima-media thickness (IMT) and diameter of the common carotid artery (CCA) were measured by 2D echo. CCA compliance was determined from simultaneously recorded CCA diameter (Wall Tracking System) and finger arterial pressure, and expressed as area under the compliance/pressure curve [CCA(AUC)) over a given pressure range (70-130 mmHg). Results: lnsulin stimulated glucose uptake (M) was 33\ub13 mmol/min/ per kg of free fatty mass. With reference to our control population, 9 patients were insulin-sensitive (IS) (M=45\ub1 7 mmol/min/kg), and 9 lR (M=22\ub14 mmol/min/kg). Compared to the 18 group, lR patients had lower CCA(AUC) (0.354\ub10.036 vs 0.491\ub10.044 (mm2/mmHg*10-3)*mmHg, p=0.02) and higher fasting insulin (19.5\ub12.8 vs 8.8\ub1 1.1 mU/ml, p<0.002) and triglycerides (161\ub117 vs 102\ub18 mg%, p <0.05). Fasting glucose, HbA1c, body mass index, serum cholesterol, age, blood pressure, CCA IMT and diameter were similar between groups. In univariate analysis, CCA(AUC) correlated directly with M (r=0.61, p<0.02) and inversely with triglycerides and insulin (r=-0.55 and -0.51 ; p<0.05 for both), whereas IMT correlated inversely with HDL cholesterol (r=-0.51, p