Kunio Yamanouchi

Prevalence of diabetes mellitus in Japanese patients infected chronically with hepatitis C virus.

Background: To examine the relationship between hepatitis C virus (HCV) infection and diabetes mellitus (DM) in Japanese populations, a retrospective study was done in 866 patients with chronic viral disease. Methods: The present study included 707 HCV-infected and 159 hepatitis B virus (HBV)-infected patients. The prevalences of HBV- and HCV-related cirrhosis were 32% and 33%, respectively. A case-control study was also conducted to determine the seroprevalence of HCV infection in a cohort of 459 diabetics. Results: The prevalence of DM was higher in HCV-infected patients (20.9%; P < 0.02) than in HBV-infected subjects (11.9%). In the cirrhotic patients, DM was observed in 30.8% of the subjects with HCV compared with 11.8% of those with HBV (P < 0.01). Multivariate analysis revealed that the major independent variables associated with type II DM were male sex (odds ratio, 1.54; p = 0.020) and cirrhosis (odds ratio, 1.97; P = 0.0007). The relative odds of the development of DM were calculated to be 3.2 times higher in HCV-infected cirrhotic patients than in HBV-infected ones. In the case-control study of the diabetic cohort, 10.5% of patients were infected with HCV compared with 1.1% with HBV (P < 0.0001). The results indicate that HCV infection is closely associated with DM, compared with HBV infection. Cirrhosis was an independent risk factor for DM. Conclusions: Taken together, the findings indicate that cirrhosis appears to be a more important predictor of glucose intolerance than HCV infection, and the combination of both factors increases the risk of DM in our populations.

Rat C peptide I and II stimulate glucose utilization in STZ-induced diabetic rats

Aims. To study the effects of physiological concentrations of rat proinsulin C peptide I and II, respectively, on whole body glucose utilization in streptozotocin diabetic and healthy rats. Methods. A sequential insulin clamp procedure was used (insulin infusion rates 3.0 and 30.0 mU · kg–1· min–1) in awake animals. C-peptide infusion rates were 0.05 and 0.5 nmol · kg–1· min–1. Blood glucose was clamped at 7.7 ± 0.3 mmol/l in the diabetic rats and at 3.9 ± 0.1 mmol/l in the healthy rats. Results. In diabetic rats infused at lower rates of C peptide and insulin, glucose utilization increased by 79–90 % (p < 0.001) compared with diabetic animals infused with saline and insulin. Increasing the rate of C-peptide infusion tenfold did not elicit a statistically significant further increase in glucose utilization. C peptide I and II exerted similar effects. The metabolic clearance rate for glucose in the diabetic animals infused with C peptide was not different from that of the healthy rats. During high-dose insulin infusion (30.0 mU · kg–1· min–1) glucose utilization increased considerably and no statistically significant C-peptide effects were observed. About 85 % of the increase in glucose utilization induced by C peptide could be blocked by treatment with N-monomethyl-l-arginine. Conclusions/interpretation. Physiological concentrations of homologous C peptide stimulate whole body glucose utilization in diabetic but not in healthy rats. C peptide I and II elicit similar effects. The influence of C peptide on glucose utilization may be mediated by nitric oxide. [Diabetologia (1999) 42: 958–964]

The effect of low intensity bicycle exercise on the insulin-induced glucose uptake in obese patients with Type 2 diabetes

OBJECTIVE The present study was undertaken to reveal the effect of low intensity bicycle exercise on the insulin-induced glucose uptake in obese patients. SUBJECTS AND METHODS Seven obese men with Type 2 diabetes (OBDM) and seven healthy young men (HY) participated in this study. The glucose infusion rate (GIR) was determined by glucose clamp procedure at an insulin infusion rate of 40 mU m-2 min-1 (plasma insulin concentrations: 700-800 pmol l-1). Confirming stabilized GIR, a 30-min bicycle exercise was performed during the glucose clamp which was continued for 120 min after exercise. RESULTS Average GIR in OBDM for last 30 min prior to exercise were significantly lower than HY (28.3 +/- 1.7, 47.4 +/- 1.8 mumol kg-1 min-1 respectively, P < 0.05). GIR abruptly increased during exercise and gradually decreased after exercise to the nadir almost at the time from 30 to 60 min in recovery period in both groups. GIR in OBDM, however, gradually increased significantly over pre-exercise levels (P < 0.05), following exercise and reached the same levels compared to HY after 80 min of recovery period. CONCLUSION These results indicated that in obese Type 2 diabetes, 30 min of low intensity bicycle exercise significantly enhances the lower level of insulin-induced glucose uptake shortly after exercise and might be useful for the treatment of post-prandial hyperglycemia.

Effects of aerobic and resistance exercise training on insulin action in the elderly

Background:  Aging is associated with a declining glucose tolerance, which is primarily caused by peripheral insulin resistance, and with a decline in physical activity. The aim of this study was to assess the effect of aerobic and resistance exercise training on insulin action in the elderly.

The effect of walking before and after breakfast on blood glucose levels in patients with type 1 diabetes treated with intensive insulin therapy

OBJECTIVE We examined the effect of walking at different timing on carbohydrate metabolism in patients with type 1 diabetes. SUBJECTS AND METHODS Subjects included six non-obese patients treated with intensive insulin therapy. The blood glucose profile was determined with and without walking for 30 min before (ExBM) or after (ExAM) breakfast. RESULTS Mean blood glucose values at 07:00 h in the control, ExBM, and ExAM were 9.0, 8.0, 8.8 mM, respectively. Glucose levels gradually increased after meals up to 13.6, 15.0, and 15.3 mM, respectively, at 09:00 h (0.5 h after meals). At 09:30 h, glucose levels significantly fell to 11.0 mM during walking in the ExAM (P=0.039 vs 09:00 h values). The area under blood glucose response curve was significantly lower only in the ExAM when compared with that in the control (P=0.043) (11.8, 17.8. and 3.8 h mM in the control, ExBM and ExAM, respectively). CONCLUSION These results might suggest that walking after meals improves glycemic control in patients with type 1 diabetes being treated with intensive insulin therapy consisting of the basal-bolus (NPH-human regular) insulin regimen.

Association between insulin resistance and cognitive function in elderly diabetic patients

Background:  Recently, cognitive impairment in elder diabetic subjects has sparked considerable interest. Insulin resistance (IR) is one of the central pathologies in diabetes mellitus, and several studies have shown that IR is associated with cognitive impairment in non‐diabetic elderly subjects. However, the involvement of IR in cognitive dysfunction in the diabetic elderly has remained to be elucidated.

Association between improvements in insulin resistance and changes in cognitive function in elderly diabetic patients with normal cognitive function.

Aim:  The number of elderly with cognitive dysfunction has been increasing in developed countries. Several studies have shown that diabetes is a risk factor for declines in cognitive function and, recently, numerous studies have demonstrated that exercise improves insulin resistance (IR). However, no studies have been undertaken to examine the relationship between IR and cognitive dysfunction.

Octreotide-induced suppression of the hyperglycemic response to neostigmine or bombesin: relationship to hypothalamic noradrenergic drive

Neostigmine (cholinesterase inhibitor) or bombesin, when injected into the third cerebral ventricle of awake rat, dose-dependently increased serum glucose with the simultaneous rise in hypothalamic noradrenergic neuronal activity (NAA). Co-administration of octreotide with neostigmine or bombesin suppressed the hypothalamic NNA response with the simultaneous inhibition of the hyperglycemic response. There was a close relationship between hypothalamic NNA and serum glucose in these studies. On the basis of the concept that hypothalamic noradrenergic drive plays an important role in mediating the hyperglycemic response to stressful stimuli, the present findings suggest that the hyperglycemic response to neostigmine or bombesin is mediated via the interaction with hypothalamic noradrenergic neurons.