The combination of IMT and stiffness parameter beta is highly associated with concurrent coronary artery disease in type 2 diabetes.

AIMS: The clinical implications of stiffness of the carotid artery (CA) have not been fully clarified in the prediction of coronary artery disease (CAD), although intima-media thickness (IMT) has been established as a surrogate marker. We examined the associations of stiffness parameter beta (ST) and IMT with concurrent CAD. METHODS: IMT and ST were measured by ultrasound in 439 nondiabetic subjects as a control and 1528 type 2 diabetic subjects (T2DM) with or without CAD in a cross-sectional study. RESULTS: Both IMT and ST significantly increased with age and group category, in the order of control, T2DM without CAD, and T2DM with CAD (p<0.001). The area under the curve on ROC analysis of ST for concurrent CAD was comparable to that for IMT. On multivariate logistic regression analysis, High IMT (>or=1.30 mm) and High stiffness (>or=20.0) had significant odds ratios for concurrent CAD (2.205, p<0.001 and 1.548, p<0.05, respectively). The group with High IMT and High Stiffness exhibited a stronger multivariate odds ratio (3.115, p=0.0001). CONCLUSIONS: ST and IMT are associated with CAD and exhibited significant odds ratios for CAD. Our findings suggest that the combination of IMT and ST is a useful marker of atherosclerosis.

Glimepiride increases high-density lipoprotein cholesterol via increasing adiponectin levels in type 2 diabetes mellitus.

The aims of the present study are to investigate the effect of glimepiride 1 mg/d on plasma adiponectin and to assess the contribution of adiponectin in changing high-density lipoprotein cholesterol (HDL-c) levels after glimepiride treatment. Forty patients with type 2 diabetes mellitus were included. Plasma adiponectin, fasting plasma glucose, insulin, hemoglobin A(1c), and cholesterol were measured at study entry and after 3 months of treatment with glimepiride. Both plasma adiponectin level (7.5 +/- 4.5 vs 8.3 +/- 4.5 microg/mL, P = .040) and HDL-c level increased significantly (50 +/- 11 vs 53 +/- 10 mg/dL, P = .041) in the all-subjects group. In the low-adiponectin group (initial plasma adiponectin level <6 microg/mL), both plasma adiponectin level (4.5 +/- 0.9 vs 5.9 +/- 2.0 microg/mL, P = .004) and HDL-c level increased significantly (44 +/- 8 vs 49 +/- 9 mg/dL, P = .011). There was no significant change in the high-adiponectin group (initial plasma adiponectin level >or=6 microg/mL). Change in plasma adiponectin level was an independent factor for change in HDL-c level after adjustment for other factors (beta = .574, P = .009, R(2) = 0.524, P = .036). In conclusion, glimepiride improved plasma adiponectin level, especially in the subjects with type 2 diabetes mellitus with low adiponectin level before treatment, and may directly contribute to improving HDL-c level.

Effects of pioglitazone on serum fetuin-A levels in patients with type 2 diabetes mellitus.

Fetuin-A (alpha2-Heremans-Schmid glycoprotein), a circulating glycoprotein, can inhibit insulin signaling both in vivo and in vitro. Recently, we and another independent group have shown that fetuin-A is positively associated with insulin resistance in humans. Furthermore, it has been reported that higher fetuin-A levels are associated with metabolic syndrome and atherogenic lipid profiles. These data suggest that fetuin-A might be a regulator of insulin resistance and/or metabolic syndrome. However, it is not clear how fetuin-A levels are regulated. To address this, we investigated the effects of representative insulin-sensitizing therapies such as pioglitazone, metformin, and aerobic exercise on fetuin-A levels. Twenty-seven patients with type 2 diabetes mellitus were divided into pioglitazone-treated (Pio), metformin-treated (Met), and exercise-treated (Ex) groups. Ten patients in the Pio group and 9 patients in the Met group took 15 or 30 mg/d pioglitazone or 500 or 750 mg/d metformin, respectively, for 6 months. Eight patients in the Ex group underwent a 3-month aerobic exercise program. Serum fetuin-A levels were measured before and after each intervention. Intervention significantly decreased hemoglobin A(1c) in all groups. After treatment, serum fetuin-A levels significantly decreased in the Pio group (291.2 +/- 57.7 to 253.1 +/- 43.9 microg/mL, P = .006), whereas there were no changes in serum fetuin-A after intervention in either the Met or the Ex groups. We hypothesize that pioglitazone could partially ameliorate insulin resistance via modulating fetuin-A levels.

Clinical impact of metabolic syndrome by modified NCEP-ATPIII criteria on carotid atherosclerosis in Japanese adults.

AIM: The present study aimed to clarify the clinical impact of modified NCEP-ATP III criteria for metabolic syndrome (MS) and Framingham Risk Score (FRS) on carotid atherosclerosis in 615 Japanese adults (319 men and 296 women) including 307 with type 2 diabetes. METHODS: Waist circumference was the only component from the original NCEP-ATP III criteria based on Japanese criteria. The intima-medial thickness (IMT) and stiffness parameter beta of the carotid artery were measured by ultrasound. RESULTS: Both IMT and stiffness parameter beta were significantly increased with the number of coexisting components of MS, and higher in subjects with MS than in those without MS (all Ps < 0.0001). In a logistic regression analysis with each component of MS as independent factors, hyperglycemia and hypertension had the highest odds ratio for progressors of IMT and stiffness parameter beta , respectively. Univariate odds ratios of MS for both IMT and stiffness parameter beta were comparable with that of an increase of 10% in 10-year coronary heart disease (CHD) risk by FRS (CHD risk/ 10%) but inferior to CHD risk by FRS >/= 20%. CONCLUSION: The modified NCEP-ATP III criteria for MS revealed an additive predictive impact on carotid atherosclerosis but no superiority to FRS.

Association of serum fetuin-A with carotid arterial stiffness.

OBJECTIVE: Fetuin-A is a circulating glycoprotein which is well characterized as an inhibitor of ectopic calcification. Vascular calcification commonly found in chronic kidney disease (CKD) patients is a predictor of cardiovascular death. Recently, several groups have demonstrated that low fetuin-A levels are associated with mortality in uraemic patients, possibly through regulation of vascular calcification. However, the physiological significance of fetuin-A in atherosclerosis remains unknown, except in specific conditions, such as vascular calcification in CKD patients. The objective of this study was to investigate the association between serum fetuin-A levels and arterial stiffness, a functional property of atherosclerosis, in healthy subjects. PATIENTS AND MEASUREMENTS: The study subjects comprised 141 healthy subjects. We measured serum fetuin-A levels and stiffness parameter beta for the common carotid artery, which was assessed by ultrasound using a phase-locked echo-tracking system. RESULTS: Simple regression analyses indicated that serum fetuin-A levels were significantly correlated with stiffness parameter beta (r = 0.200, P = 0.018). Multiple regression analyses showed that, besides age, fetuin-A (beta = 0.166, P = 0.033) independently contribute to the stiffness parameter beta (R(2) = 0.310, P < 0.0001). CONCLUSIONS: Serum fetuin-A level is associated with carotid arterial stiffness, independent of known atherogenic factors in healthy subjects.

Effect of adiponectin on carotid arterial stiffness in type 2 diabetic patients treated with pioglitazone and metformin.

Adiponectin, an adipocyte-specific plasma protein, has been reported to exhibit protective effects against atherosclerosis as well as an insulin-sensitizing effect. This study was designed to investigate the effect of adiponectin on carotid arterial stiffness in type 2 diabetic patients treated with pioglitazone and metformin. Twenty type 2 diabetic patients were enrolled and divided into 2 groups, a pioglitazone-treated group (n = 10) and a metformin-treated group (n = 10). Before and after intervention, plasma adiponectin levels were measured by enzyme-linked immunosorbent assay and carotid arterial stiffness was evaluated by the stiffness parameter beta, measured by ultrasound equipped with a phase-locked echo-tracking system. In the pioglitazone group, plasma adiponectin level significantly increased and stiffness parameter beta significantly decreased, whereas in the metformin group neither of these parameters changed significantly. The changes in stiffness parameter beta were significantly and inversely correlated with change in plasma adiponectin level after treatment with pioglitazone or metformin in the group of all subjects (r = -0.472, P = .036). In conclusion, the present study is the first to demonstrate that increase in adiponectin level after treatment with the insulin sensitizers pioglitazone and metformin may improve arterial stiffness in patients with type 2 diabetes mellitus.

Plasma adiponectin level is associated with insulin-stimulated nonoxidative glucose disposal.

CONTEXT: Impaired nonoxidative glucose disposal and decrease in mitochondrial glucose oxidation both contribute to insulin resistance in diabetic subjects. OBJECTIVE: In the present study, we investigated whether plasma adiponectin is associated with glucose oxidation and nonoxidative glucose disposal in subjects with and without type 2 diabetes. DESIGN: Euglycemic-hyperinsulinemic clamp was performed in 42 type 2 diabetic (T2DM) and 13 nondiabetic (non-DM) subjects. The whole-body glucose disposal rate (GDR) was evaluated as the mean of the glucose infusion rate during steady state of the clamp. Glucose and fat oxidation rates were assessed by indirect calorimetry, and nonoxidative glucose disposal rate was calculated by subtracting glucose oxidation rate from GDR. RESULTS: Plasma adiponectin level was significantly lower in T2DM than non-DM (2.87 +/- 1.40 vs. 3.96 +/- 2.39 microg/ml, P = 0.045). GDR (3.39 +/- 1.53 vs. 4.83 +/- 1.70 mg/kg x min, P = 0.006) and nonoxidative glucose disposal rate (1.89 +/- 1.39 vs. 3.11 +/- 1.76 mg/kg x min, P = 0.012) were significantly lower in T2DM, compared with non-DM, although no difference was found in glucose oxidation rate between the two groups. In all subjects, plasma adiponectin level was positively correlated with GDR (r = 0.351, P = 0.009) and nonoxidative glucose disposal rate (r = 0.324, P = 0.016) but not glucose oxidation rate. There was no significant correlation between plasma adiponectin level and fat oxidation, either before or during the clamp. CONCLUSIONS: In conclusion, plasma adiponectin level is associated with nonoxidative glucose disposal, which is reduced in type 2 diabetic subjects. Our results suggest that adiponectin controls insulin sensitivity by modulating the glycogen synthetic process in human skeletal muscle.