Coexistence of insulin resistance and inflammation effectively predicts cardiac disease but not stroke in Japanese patients with type 2 diabetes mellitus.

It is well known that insulin resistance (IR) and inflammation (IF) are associated with macroangiopathy. However, whether IR and IF are related to cardiac disease (myocardial infarction, angina pectoris, and heart failure), stroke or both remains elusive. The present hospital-based prospective study was designed to investigate this issue. The study subjects were 300 Japanese patients with type 2 diabetes mellitus and negative history of cardiac disease and stroke. IR (K index of insulin tolerance test; K(ITT)) and IF (high-sensitivity C-reactive protein [hs-CRP]) were measured in each patient at baseline. Patients were followed-up for a mean period of 5.5 years. The time of first evidenced cardiac disease or stroke was monitored. During the follow-up, 35 patients developed cardiac disease and 26 patients developed stroke. Age, smoking, K(ITT), and hs-CRP were independently related to cardiac disease, while age, systolic blood pressure, low HDL, and anti-platelet drug use were independently related to stroke. When patients were subdivided into IR(-) and IR(+), and IF(-) and IF(+), Kaplan-Meier survival analysis showed that the rate of cardiac disease, but not of stroke, was significantly higher in IR(+)IF(+) than IR(-)IF(-) patients (p < 0.01). In conclusion, coexistence of IR and IF effectively predicted cardiac disease but not stroke in Japanese patients with type 2 diabetes mellitus.

Genome-wide linkage analysis of type 2 diabetes mellitus reconfirms the susceptibility locus on 11p13-p12 in Japanese.

Type 2 diabetes mellitus is a heterogeneous disorder, and the development of type 2 diabetes mellitus is associated with both insulin secretion defect and insulin resistance. The primary metabolic defect leading to type 2 diabetes mellitus has been thought to be varied among populations, especially in Japanese and Caucasians. Here, we have done the genome-wide scan for type 2 diabetes mellitus using 102 affected Japanese sib-pairs to identify the genetic factors predisposing to type 2 diabetes mellitus. Nonparametric linkage analysis showed one suggestive evidence for linkage to 11p13-p12 [D11S905: two-point maximum LOD score (MLS) of 2.89 and multipoint MLS of 2.32] and one nominally significant evidence for linkage to 6q15-q16 (D6S462: two-point MLS of 2.02). Interestingly, the 11p13-p12 region was reported to be a susceptibility locus for Japanese type 2 diabetes mellitus with suggestive evidence of linkage, and D11S905 was within 5 cM to D11S935 with the highest MLS in the previous linkage analysis reported. The only overlapped susceptibility region with suggestive evidence of linkage for Japanese type 2 diabetes mellitus was D11S935-D11S905 among the three reports including this study. These results taken together suggest that a susceptibility gene for type 2 diabetes mellitus in Japanese will reside in 11p13-p12.

Metformin attenuates progression of carotid arterial wall thickness in patients with type 2 diabetes.

To investigate the anti-atherogenic effect of metformin, we prospectively evaluated the effect of metformin treatment on common carotid intima-media thickness (CCA-IMT) in patients with type 2 diabetes. A 2-year open prospective study was performed. Thirty-six patients were treated with metformin (500-750 mg per day). CCA-IMT was measured after 1- and 2-year treatment. Changes in CCA-IMT were compared with control patients. After 2-year metformin therapy, the progression of CCA-IMT was significantly less than 56 control patients (0.02+/-0.08 mm versus 0.07+/-0.08 mm, P<0.01). Metformin therapy did not alter body weight, blood pressure, HbA1c, and serum lipids relative to the control. Thus, metformin attenuates the progression of CCA-IMT. This anti-atherogenic effect is not mediated through changes in classical cardiovascular risk factors.

Inflammation and insulin resistance are independently related to all-cause of death and cardiovascular events in Japanese patients with type 2 diabetes mellitus.

Insulin resistance (IR)/hyperinsulinemia and low-grade inflammation (high-sensitivity C-reactive protein [hs-CRP]) can predict cardiovascular disease. However, because IR and inflammation (IF) have not been evaluated simultaneously, it is not known whether IR and IF are independently related to cardiovascular disease. Furthermore, the combined effect of IR and IF on the prediction of cardiovascular disease is presently unknown. Thus, we measured insulin sensitivity (K index of the insulin tolerance test; KITT) and hs-CRP in 350 Japanese patients with type 2 diabetes, and followed them for 1-7 years (mean, 4.5 years). During the follow-up, 33 patients died and 53 patients developed non-fatal coronary artery disease or stroke (endpoint). Age, systolic blood pressure, current smoking, past history of cardiovascular disease, KITT, and hs-CRP independently and significantly correlated with endpoint. One-S.D. difference was associated with a significant increase of relative risk in KITT (1.45; 95% CI 1.09-1.91) and hs-CRP (1.30; 1.04-1.67). When patients were subdivided to tertile, the relative risk in the highest tertile of KITT was 1.76 (95% CI 1.01-3.11) and hs-CRP was 2.00 (1.03-3.85) compared with the patients with lowest tertile. The relative risk in the highest tertile of both KITT and hs-CRP was 5.32 (1.18-24.0) compared with the lowest tertile of both values. In conclusion, low-grade IF and IR are independently related to all-cause of death and cardiovascular disease in Japanese patients with type 2 diabetes. Coexistence of low-grade IF and IR amplify this effect.

Combination therapy of alpha-glucosidase inhibitor and a sulfonylurea compound prolongs the duration of good glycemic control.

The aim of this study was to investigate whether combination therapy of alpha-glucosidase inhibitor and a sulfonylurea (SU) drug can prolong the duration of good glycemic control compared with SU alone in patients with type 2 diabetes. The open prospective study included 124 Japanese patients with type 2 diabetes and inadequate glycemic control (hemoglobin A(1c) [HbA(1c)] gt; 7.0%). Patients were given either voglibose plus a SU compound (glibenclamide or gliclazide, n = 61) or SU drug alone (n = 63). The first 6-month run-in period (targeted to HbA(1c) /= 8.0%). Fifty patients on combination therapy and 48 patients on SU alone completed the trial. During the follow-up, 21 patients on combination therapy and 30 patients on SU alone showed deterioration of glycemic control and reached the endpoint (P =.04). The combination therapy significantly prolonged the duration of good glycemic control (HbA(1c) < 8.0%) compared with SU alone by Kaplan-Meier estimated survival analysis using a log-rank test (P =.02). Thus, combination therapy with voglibose and a SU agent prolongs the duration of good glycemic control compared with SU alone in patients with type 2 diabetes.

High serum concentrations of soluble E-selectin correlate with obesity but not fat distribution in patients with type 2 diabetes mellitus.

Serum concentrations of soluble adhesion molecules, eg, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin are elevated in patients with type 2 diabetes. However, little is known about the role of obesity or abnormal fat distribution in inducing upregulation of adhesion molecules. To investigate this issue, soluble ICAM-1, VCAM-1, and E-selectin levels were evaluated in 40 obese and 30 nonobese patients with type 2 diabetes. Both groups were matched for age, sex, and glycosylated hemoglobin (HbA(1c)) levels. Computed tomography (CT) was used to measure the abdominal subcutaneous and visceral fat areas. Soluble ICAM-1 and VCAM-1 levels did not differ significantly between obese and nonobese patients. However, serum concentrations of soluble E-selectin were significantly higher in obese than in nonobese patients (90 +/- 7 v 56 +/- 4 ng/mL, P <.01). Soluble E-selectin levels significantly correlated with body mass index, subcutaneous fat area, and visceral fat area (Rho = 0.48, 0.37, and 0.30, respectively). Stepwise multiple regression analysis showed that body mass index (F = 16.7), but not subcutaneous and visceral fat areas (F = 0.29 and 0.01, respectively), significantly and independently correlated with soluble E-selectin levels. Our results suggest that obesity may induce endothelial activation or increased shedding of cell surface E-selectin that leads to subsequent increase in soluble E-selectin levels. The high serum concentrations of E-selectin closely correlated with increased total fat volume, but not with regional fat distribution.

Effect of filtration leukocytapheresis therapy: modulation of white blood cell enzyme activities in patients with rheumatoid arthritis.

We treated 12 patients with rheumatoid arthritis by filtration leukocytapheresis (FLCP) and evaluated its effect on leukocyte enzyme activities. We calculated the number of leukocytes removed and assessed the clinical response. We also evaluated the cellular enzyme activities of elastase and dipeptidylpeptidase IV (DPP IV). Out of 12 patients, 7 patients achieved 20% improvement for 4 weeks following FLCP. The FLCP treatment resulted in removal of 96% of granulocytes, 98% of monocytes, and 61% of lymphocytes. Granulocytes and monocytes with high elastase activity were effectively removed by FLCP. The elastase activity of granulocytes was increased 4 weeks after the last FLCP only in responders. On the other hand, the DPP IV activity of lymphocytes was low at 4 weeks after the last FLCP in responders. Modulation of leukocyte enzyme activities is one of the main effects of FLCP therapy and alteration of granulocytes, monocytes, and lymphocytes.

Correlation between common carotid arterial wall thickness and ischemic stroke in patients with type 2 diabetes mellitus.

If a strong association between intima-media thickness of the common carotid artery (CCA-IMT) and ischemic stroke can be determined in diabetic subjects, it may be a useful predictor to help identify patients at high risk of ischemic stroke. To investigate the relative contribution of CCA-IMT to ischemic stroke in patients with type 2 diabetes, we measured CCA-IMT and other conventional risk factors in 438 Japanese patients with type 2 diabetes, including 45 with ischemic stroke and 393 controls. Stroke patients were characteristically and significantly older with higher body mass index, longer duration of diabetes, likely to be smokers, higher blood pressure, and higher total cholesterol compared with the controls. CCA-IMT in stroke patients (1.23 +/- 0.04 mm) was significantly greater than in control patients (0.95 +/- 0.01 mm, P <.01). CCA-IMT in stroke patients was still significantly greater than controls after adjustment for age, sex, body mass index, and smoking status (P <.05). A 0.1-mm increase in CCA-IMT was associated with 1.80-fold increase in the odds ratio of stroke in diabetic patients (95%confidence interval [CI], 1.49 to 2.17; P <.01). Four independent factors were found to correlate significantly with CCA-IMT: age, systolic blood pressure, HbA(1c), and high-density lipoprotein (HDL) cholesterol. Thus, thickening of the intima-media of common carotid arteries is associated with ischemic stroke in type 2 diabetic patients. To prevent ischemic stroke, strict control of diabetes, hypertension, and dyslipidemia and monitoring of CCA-IMT may be important.

Serum concentrations of soluble adhesion molecules are related to degree of hyperglycemia and insulin resistance in patients with type 2 diabetes mellitus.

To investigate the relationships between serum concentrations of soluble adhesion molecules and hyperglycemia, insulin resistance, or other conventional risk factors in type 2 diabetes, we measured soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), E-selectin (sE-selectin), insulin sensitivity, and conventional risk factors in 150 Japanese type 2 diabetic patients without apparent diabetic macroangiopathy. High serum concentrations of sVCAM-1 and sE-selectin were observed in patients with type 2 diabetes. Serum concentrations of soluble adhesion molecules were not significantly influenced by sex, hypertension, dyslipidemia, or microangiopathy. Spearman correlation showed that sVCAM-1 concentrations correlated significantly with fasting plasma glucose (FPG), fasting C-peptide, and insulin sensitivity [K index of the insulin tolerance test (K(ITT))] (rho=0.19,0.23, and -0.23, respectively). Soluble E-selectin concentrations correlated significantly with body mass index (BMI), FPG, fasting C-peptide, insulin sensitivity, and triglyceride (rho=0.33,0.42,0.26,-0.48, and 0.29, respectively). Multiple regression analysis showed that FPG, fasting C-peptide, and total cholesterol were independent factors that correlated with sVCAM-1 levels. BMI, FPG, and insulin sensitivity were independent factors that correlated with sE-selectin levels. Serum concentrations of sE-selectin significantly increased associated with clustering of conventional risk factors those obesity, hypertension, dyslipidemia, and current smoking (P<0.01). Thus, sVCAM-1 and sE-selectin levels are related to both hyperglycemia and insulin resistance. Soluble E-selectin levels may be related to obesity, hyperglycemia, and insulin resistance and may reflect the presence of a multiple risk factor clustering syndrome.