Glucose Tolerance In Nondiabetic Subjects Research Articles

Clinical Study of Astaxanthin on Glucose Tolerance in Nondiabetic Subjects

Astaxanthin (ASTX) is a xanthophyll carotenoid produced by Haemococcus pluvialis, and is found in microalgae, plankton, krill and other seafood. ASTX has strong antioxidant activity, which is an attractive nutraceutical for further investigation in diabetes, lipid profile, and atherosclerotic cardiovascular disease where antioxidant cellular protection may be of clinical benefit. We already reported the effects of astaxanthin (randomized, double-blind, placebo-controlled study) on glucose metabolism and lipid profile in 44 healthy volunteers in the 10th Asia Pacific Conference on Clinical Nutrition 2017. Here we report the effects of ASTX on glucose metabolism in 29 subjects whose HbA1c was from 5.6 % to 6.4 % at baseline. Data of 75g OGTT and HbA1c in 29 subjects (16 in ASTX group and 13 in Placebo group) were analyzed. After ASTX (12mg/day) supplementation for 12 weeks, the glucose level at 30 min by 75g OGTT was significantly decreased compared to before. The level of HbA1c was also significantly decreased compared to before. Furthermore, we assessed indices of insulin resistance derived from OGTT. Both Matsuda index and hepatic insulin resistance were improved after ASTX (12mg/day) supplementation, although muscle insulin sensitivity index was unchanged. Our results suggest that ASTX might have beneficial effects on the prevention of diabetes in subjects whose HbA1c was from 5.6 % to 6.4 %, including subjects with prediabetes. Disclosure M. Urakaze: Research Support; Self; Fuji Chemical Industry Co., Ltd.. C. Kobashi: None. Y. Satou: None. M. Takagi: None. K. Shigeta: None. M. Toshima: Research Support; Self; Fuji Chemical Industry Co., Ltd. J. Takahashi: Employee; Self; Fuji Chemical Industry Co., Ltd. M. Nishida: Other Relationship; Self; Fuji Chemical Industry Co., Ltd..

Use of cannabinoid CB1 receptor antagonists for the treatment of metabolic disorders

Abdominal obesity is associated with numerous metabolic abnormalities, including insulin resistance, impaired glucose tolerance/type-2 diabetes, and atherogenic dyslipidaemia with low high-density lipoprotein (HDL) cholesterol, high triglycerides, and increased small dense low-density lipoprotein (LDL) cholesterol. A proportion of these metabolic disorders may be attributed to increased endocannabinoid activity. The selective cannabinoid 1 (CB1) receptor antagonist rimonabant has been shown to reduce body weight, waist circumference, insulin resistance, triglycerides, dense LDL, C-reactive protein (CRP), and blood pressure, and to increase HDL and adiponectin concentrations in both non-diabetic and diabetic overweight/obese patients. Besides an improvement in glucose tolerance in non-diabetic subjects, a reduction of 0.5-0.7% in haemoglobin A1C (HbA(1c)) levels was consistently observed in various groups of patients with type-2 diabetes. Almost half the metabolic changes could not be explained by weight loss, supporting direct peripheral effects of rimonabant. Ongoing studies should demonstrate whether improved metabolic disorders with CB1 receptor antagonists (rimonabant, taranabant, etc.) would translate into fewer cardiovascular complications among high-risk individuals.

Islet dysfunction in insulin resistance involves impaired insulin secretion and increased glucagon secretion in postmenopausal women with impaired glucose tolerance.

To characterize in detail the association between insulin sensitivity and islet function in relation to glucose tolerance in nondiabetic subjects. The study included 108 postmenopausal women, aged 57-59 years, with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) and measured glucose tolerance (World Health Organization, 75 g glucose), insulin sensitivity (euglycemic-hyperinsulinemic clamp), and islet function (the 2-5 min insulin responses [AIR] and glucagon [AGR] responses to 5 g intravenous arginine at fasting, 14 and >25 mmol/l glucose levels). The product of insulin sensitivity and secretion was calculated (disposition index [DI]) and used to study the relationship between the two parameters. Insulin sensitivity and insulin secretion were highly inversely correlated in a hyperbolic manner (r > 0.64, P < 0.001) in women with NGT (n = 71). Women with IGT (n = 37) had reduced insulin sensitivity compared with women with NGT (P = 0.011). The AIRs were not appropriately increased in relation to the reduced insulin sensitivity in the IGT women, demonstrated as reduced DI in IGT compared with NGT (P < 0.001). Further, women with IGT had an increased AGR (P < 0.001) and a reduced glucose inhibition of glucagon secretion (slopeAGR, P = 0.014) compared with women with NGT. In a multivariate regression model including all of the 108 women, 2-h glucose was independently determined by the DI, the AGR, and the slopeAGR (r = 0.63, P < 0.001). We have shown that both the individual ability to adapt insulin secretion to the ambient insulin sensitivity and the level of glucagon secretion are important parameters for maintenance of NGT. Therefore, islet dysfunction in IGT involves low insulin and high glucagon secretion, which present potential targets for correcting impaired glycemia.

Effect of Tea Prepared From Leaves of Syzygium jambos on Glucose Tolerance in Nondiabetic Subjects

Effect of Tea Prepared From Leaves of <i>Syzygium jambos</i> on Glucose Tolerance in Nondiabetic Subjects

Insulin Receptors in Acute Infection: A Study of Factors Conferring Insulin Resistance*

Acute infections are accompanied by tissue insulin resistance, as manifested by worsening of metabolic control in diabetic patients and decreased glucose tolerance in non-diabetic subjects. To clarify the potential role of altered insulin receptor status in this phenomenon, we studied [125I]insulin binding to monocytes in 7 otherwise healthy subjects during acute bacterial and viral infections of moderate severity. The values were compared to those obtained after convalescence (five patients) and those of 24 normal subjects. Insulin binding during infection, at a time when insulin resistance was demonstrable, was indistinguishable from convalescent or normal values. Plasma glucose and insulin levels, the insulin to glucose ratio, as well as plasma GH, cortisol, and FFA were significantly elevated during infection, while plasma glucagon, epinephrine, and norepinephrine levels were normal. We conclude that insofar as monocyte receptors are representative of other tissues, insulin resistance in infection is mediated at the postreceptor level.

Diagnostic evaluation of oral glucose tolerance tests in nondiabetic subjects after various levels of carbohydrate intake.

IT is routine for most clinicians to instruct patients to take a high-carbohydrate diet for three days before a glucose tolerance test. Even with careful dietary instructions many patients find the suggested level of 250 to 300 gm. of carbohydrate in excess of their usual intake and have difficulty in consuming the amount of food required. In this study, an attempt is made to determine the effect of lower levels of carbohydrate intake on glucose tolerance in nondiabetic subjects, particularly regarding diagnostic evaluation.Since the time of Claude Bernard1 the concept of decreased glucose tolerance after starvation has been accepted. . . .