Metabolic syndrome, insulin resistance, and atherosclerosis in Japanese type 2 diabetic patients

The aim of the present study was to investigate the relationships between metabolic syndrome and atherosclerosis in 57 Japanese type 2 diabetic patients. Metabolic syndrome was diagnosed based on the criteria raised by the Japan Internal Medicine Society. Insulin resistance was estimated by the insulin resistance index of homeostasis model assessment. Ultrasonographically measured carotid atherosclerosis, brachial-ankle pulse wave velocity (ba-PWV), and ankle brachial index (ABI) were used to assess the degree of atherosclerosis. Of 57 patients, 25 were diagnosed as having metabolic syndrome. The patients with metabolic syndrome had significantly higher levels of waist circumference, insulin, insulin resistance index of homeostasis model assessment, systolic and diastolic blood pressures, and serum triglycerides, and lower concentrations of adiponectin. However, there was no significant difference in age, sex, glycosylated hemoglobin (hemoglobin A1c), fasting glucose, leptin, and tumor necrosis factor system activities including tumor necrosis factor α between the 2 groups. Furthermore, no significant difference was observed in the degree of carotid atherosclerosis (intimal-medial thickness in plaque-free segments: 0.72 ± 0.03 vs 0.72 ± 0.02 mm, P = .435; carotid stenosis in plaque segments: 6.6% ± 3.0% vs 6.6% ± 1.7%, P = .497), ba-PWV (1676 ± 56 vs 1654 ± 44, P = .380), and ABI (1.16 ± 0.01 vs 1.15 ± 0.01, P = .245) between the 2 groups. From these results, it can be suggested that metabolic syndrome, an insulin-resistant state, is not associated with carotid atherosclerosis, ba-PWV, or ABI in Japanese type 2 diabetic patients.