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Glucose Challenge (glucose + challenge)

Distribution by Scientific Domains

Medical Sciences	87%
Life Sciences	12%

Terms modified by Glucose Challenge

glucose challenge test

Selected Abstracts

Moxonidine improves glycaemic control in mildly hypertensive, overweight patients: a comparison with metformin

DIABETES OBESITY & METABOLISM, Issue 4 2006
Irina Chazova
Aim:, To compare the effects of moxonidine and metformin on glycaemic control in patients with impaired glucose tolerance and signs of the metabolic syndrome. Methods:, A multicentre, prospective, randomized, open-label study design was adopted with blinded endpoint evaluation. Patients ,40 years old, with impaired glucose tolerance (or diabetes mellitus treated with diet alone) and a body mass index (BMI) of at least 27 kg/m2 were treated twice daily with moxonidine 0.2 mg or metformin 500 mg for 16 weeks. Oral glucose tolerance test (OGTT) was performed at baseline and end-of-study; plasma insulin and plasma glucose levels were measured at 0, 60, 120 and 180 min after administration. Results:, With regard to effects on insulin [mean area under the curve (AUC) for insulin], the primary efficacy endpoint of the study, both drugs did not show equivalence. On the contrary, in the per protocol (PP) population, moxonidine statistically significantly (p = 0.025) decreased the AUC for insulin from baseline in the PP population; for metformin, the treatment effect on insulin was a small, net increase resulting in a statistically significant between-group difference of 16.2% (95% CI = 0.1,35.0). The change in mean insulin AUC was most marked in the subgroup of patients with higher sympathetic activity (heart rate >80 bpm). Mean fasting plasma glucose (FPG) levels and HbA1c levels were largely unchanged by moxonidine treatment but significantly decreased by metformin treatment. The difference between the groups was 14.7% (p = 0.0523) in the intent-to-treat (ITT) sample. By study end, both treatments had significantly increased the Matsuda Insulin Sensitivity Index (ISI) from baseline to a comparable extent: moxonidine by reducing plasma insulin after a glucose challenge, metformin by reducing FPG. BMI fell significantly in both groups and blood pressure normalized; both drugs were well tolerated. Conclusions:, Moxonidine improved insulin sensitivity in response to glucose challenge in patients with evidence of metabolic syndrome. This improvement resulted from a reduction in plasma insulin levels and was most marked in patients with high sympathetic drive at baseline. By enhancing insulin sensitivity, moxonidine treatment may help prevent the development of diabetes and thereby ameliorate the risk for cardiovascular disease. [source]

Targeting of the central histaminergic system for treatment of obesity and associated metabolic disorders

DRUG DEVELOPMENT RESEARCH, Issue 8 2006
Kjell Malmlöf
Abstract There is currently a need for effective pharmacological therapies for treatment of obesity. In this communication, the involvement of the neurotransmitter histamine in the regulation of food intake is reviewed, together with results obtained in animals with pharmacologically increased brain histamine levels. A survey of the literature reveals that histaminergic circuits, arising from nerve cell bodies in the tuberomammillary nucleus and projecting into the paraventricular nucleus, the arcuate nucleus, and the ventromedial hypothalamus, are strongly involved in regulation of food intake and possibly also energy expenditure. Current literature also suggests the histaminergic circuits connect to other neuronal pathways involved in the regulation of energy balance and body weight. Studies performed in rodents demonstrate that H3 receptor antagonists increase hypothalamic histamine and decrease food intake, which result in decreased body weight. Lipid oxidation is increased and, at higher doses, body fat is also decreased. These changes are associated with lower circulating levels of insulin during an oral glucose challenge suggesting an increase in insulin sensitivity. The effects on food intake have also been confirmed in pigs and rhesus monkeys. It can thus be concluded that results obtained with H3 antagonist in animals warrant future clinical studies to evaluate whether this principle is effective in the treatment of human obesity. Drug Dev. Res. 67:651,665, 2006. © 2006 Wiley-Liss, Inc. [source]

Dyskeratosis congenita with isolated neutropenia and granulocyte colony-stimulating factor treatment

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 3 2002
Kutluhan Yilmaz
A 3-year-old Turkish boy with a history of chronic cough, recurrent bronchopneumonia, and a borderline sweat chloride test (40 mEq/L) was referred for further evaluation to our department. He was born at term (2100 g) to a marriage with no consanguinity. His mother and father were 40 and 46 years old, respectively. Physical examination (Fig. 1) revealed hypopigmented, atrophic, and hyperkeratotic skin lesions surrounded by reticulate hyperpigmentation on the entire body, predominantly on the face, neck, arms, shoulders, and legs, which had been noticed initially at the age of 18 months. Dystrophic toenails, sparse and thin hair, and phimosis were also observed. Laboratory tests disclosed an isolated neutropenia (white blood cell count, 1800/mm3). Bone marrow (BM) aspiration showed a decreased myelopoiesis without myelodysplastic changes, but normal erythropoiesis, megakaryopoiesis, and normal stroma. Lymphocyte subgroups containing CD4, CD5, CD6, CD8, CD19, CD23, and CD25, and immunoglobulin G (IgG), IgM, IgA, and IgE, were in the normal range; hemoglobin F (HbF), 2.8%. Spontaneous and clastogen-induced chromosome breaks were not increased. A skin biopsy showed increased pigmentation at the basal layer, dyskeratotic epidermal cells, and marked IgM deposition and cytoid bodies and mild IgA and IgG deposits at the dermo-epidermal junction. Lactate response to glucose challenge, amino acid chromatography, and urine organic acid analysis were normal. Figure 1. Hypopigmented, atrophic, and hyperkeratotic skin lesions surrounded by reticulate hyperpigmentation involving predominantly the face, neck, arms, shoulders, and legs, dystrophic toenails, and sparse and thin hair A diagnosis of dyskeratosis congenita (DC) was made with typical skin lesions, dystrophic toenails, thin and sparse hair, and neutropenia with decreased myelopoiesis in BM. Treatment with granulocyte colony-stimulating factor (G-CSF) was considered for the neutropenia. As the increase in neutrophil count at a dose of 5 µg/kg was not adequate, 10 µg/kg G-CSF was tried (Fig. 2). With 10 µg/kg once to three times a week, a 1.8,4.8-fold increase in the absolute neutrophil count (ANC) was achieved with no side-effects. Treatment was more frequent during infection (days 22,28). Figure 2. Response of absolute neutrophil count (ANC) to granulocyte colony-stimulating factor (G-CSF) administration (5 µg/kg on days 1 and 3; 10 µg/kg on days 5, 10, 16, 23, 26, 28, 34, 40, 48, 54) [source]

Repeatability of measurements of the initial distribution volume of glucose in haemodynamically stable patients

JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 4 2004
B. O. Rose MD
Summary Aims:, The initial distribution volume of glucose (IDVG) has been proposed to provide a useful tool to estimate the central extracellular fluid volume. The purpose of this study was to determine the repetition interval of two consecutive measurements in haemodynamically stable patients without presence of recent changes in fluid status. Methods:, Twenty-nine patients admitted to the general intensive care unit of the University of Hirosaki Hospital were entered into this study. After achieving a haemodynamically stable state in each patient regardless of an infusion of vasoactive drugs, two glucose challenges at an interval of either 30 or 60 min, were carried out to calculate the IDVG. The IDVG was calculated using a one-compartment model after intravenous administration of glucose (5 g) followed by serial arterial blood sampling. Results:, Although plasma glucose levels immediately before the second glucose challenge in either group were increased compared with those of the first challenge (P < 0·001, respectively), the bias of the IDVG measurements was 0·08 ± 0·32 L (SD) for the 30-min group and ,0·19 ± 0·28 L for the 60-min group. Conclusions:, Our results indicate that IDVG determinations can be reliably repeated within a minimum interval of 30 min. [source]

Multiple-bolus dynamic contrast-enhanced MRI in the pancreas during a glucose challenge

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2010
J.H. Naish PhD
Abstract Purpose: To assess the feasibility of multiple-bolus dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in the pancreas; to optimize the analysis; and to investigate application of the method to a glucose challenge in type 2 diabetes. Materials and Methods: A 4-bolus DCE-MRI protocol was performed on five patients with type 2 diabetes and 11 healthy volunteers during free-breathing. Motion during the dynamic time series was corrected for using a model-driven nonlinear registration. A glucose challenge was administered intravenously between the first and second DCE-MRI acquisition in all patients and in seven of the healthy controls. Results: Image registration improved the reproducibility of the DCE-MRI model parameters across the repeated bolus-acquisitions in the healthy controls with no glucose challenge (eg, coefficient of variation for Ktrans improved from 38% to 28%). Native tissue T1 was significantly lower in patients (374 ± 68 msec) compared with volunteers (519 ± 41 msec) but there was no significant difference in any of the baseline DCE-MRI parameters. No effect of glucose challenge was observed in either the patients or healthy volunteers. Conclusion: Multiple bolus DCE-MRI is feasible in the pancreas and is improved by nonlinear image registration but is not sensitive to the effects of an intravenous glucose challenge. J. Magn. Reson. Imaging 2010;32:622,628. © 2010 Wiley-Liss, Inc. [source]

Impaired Glucose Tolerance in the R6/1 Transgenic Mouse Model of Huntington's Disease

JOURNAL OF NEUROENDOCRINOLOGY, Issue 2 2008
K. Josefsen
Previous reports have highlighted a possible link between Huntington's disease (HD) and diabetes mellitus (DM), but the association has not been characterised in detail. A transgenic mouse model for HD, the R6/2 mouse, also develops diabetes. In the present study, we examined the R6/1 mouse, which carries a shorter CAG repeat than the R6/2 mouse, and found that, although not diabetic, the mice showed several signs of impaired glucose tolerance. First, following i.p. glucose injection, the blood glucose concentration was approximately 30% higher in young R6/1 mice (10 weeks) compared to wild-type mice (P = 0.004). In older mice (38 weeks), glucose tolerance was further impaired in both R6/1 and wild-type animals. Second, during glucose challenge, the R6/1 mice reached higher plasma insulin levels than wild-type mice, but the peripheral insulin sensitivity was normal as measured by injection of human or mouse insulin or when evaluated by the quantitative insulin sensitivity check index (QUICKI). Third, the beta cell volume was 17% and 39% smaller at 10 and 38 weeks of age, respectively, compared to age-matched wild-type littermates and the reduction was not caused by apoptosis at either age. Finally, we demonstrated the presence of the HD gene product, huntingtin (htt), in both alpha- and beta-cells in R6/1 islets of Langerhans. Since pancreatic beta cells and neurons share several common traits, clarification of the mechanism associating neurodegenerative diseases with diabetes might improve our understanding of the pathogenic events leading to both groups of diseases. [source]

Effects of soy vs. casein protein on body weight and glycemic control in female monkeys and their offspring

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 9 2009
Janice D. Wagner
Abstract Nutritional interventions are important for reducing obesity and related conditions. Soy is a good source of protein and also contains isoflavones that may affect plasma lipids, body weight, and insulin action. Described here are data from a monkey breeding colony in which monkeys were initially fed a standard chow diet that is low fat with protein derived from soy. Monkeys were then randomized to a defined diet with a fat content similar to the typical American diet (TAD) containing either protein derived from soy (TAD soy) or casein,lactalbumin (TAD casein). The colony was followed for over two years to assess body weight, and carbohydrate and lipid measures in adult females (n=19) and their offspring (n=25). Serum isoflavone concentrations were higher with TAD soy than TAD casein, but not as high as when monkey chow was fed. Offspring consuming TAD soy had higher serum isoflavone concentrations than adults consuming TAD soy. Female monkeys consuming TAD soy had better glycemic control, as determined by fructosamine concentrations, but no differences in lipids or body weight compared with those consuming diets with TAD casein. Offspring born to dams consuming TAD soy had similar body weights at birth but over a two-year period weighed significantly less, had significantly lower triglyceride concentrations, and like adult females, had significantly lower fructosamine concentrations compared to TAD casein. Glucose tolerance tests in adult females were not significantly different with diet, but offspring eating TAD soy had increased glucose disappearance with overall lower glucose and insulin responses to the glucose challenge compared with TAD casein. Potential reasons for the additional benefits of TAD soy observed in offspring but not in adults may be related to higher serum isoflavone concentrations in offspring, presence of the diet differences throughout more of their lifespan (including gestation), or different tissue susceptibilities in younger animals. Am. J. Primatol. 71:802,811, 2009. © 2009 Wiley-Liss, Inc. [source]

Effects of twin pregnancy and periconceptional undernutrition on maternal metabolism, fetal growth and glucose,insulin axis function in ovine pregnancy

THE JOURNAL OF PHYSIOLOGY, Issue 5 2008
C. W. H. Rumball
Although twins have lower birthweights than singletons, they may not experience the increased disease risk in adulthood reportedly associated with low birthweight. In contrast, another periconceptional event, maternal undernutrition, does not reduce birthweight but does affect fetal and postnatal physiology in sheep. We therefore studied maternal and fetal metabolism, growth and glucose,insulin axis function in late gestation in twin and singleton sheep pregnancies, either undernourished from 60 days before until 30 days after conception or fed ad libitum. We found that twin-bearing ewes had decreased maternal food intake in late gestation and lower maternal and fetal plasma glucose and insulin levels. Twin fetuses had fewer everted placentomes, grew slower in late gestation, and had a greater insulin response to a glucose challenge, but lesser response to arginine. In contrast, periconceptional undernutrition led to increased maternal food intake and a more rapid fall in maternal glucose levels in response to fasting. Periconceptional undernutrition increased the number of everted placentomes, and abolished the difference in insulin responses to glucose between twins and singletons. Thus, the physiology of twin pregnancy is quite different from that of singleton pregnancy, and is probably determined by a combination of factors acting in both early and late gestation. The inconsistency of the relationships between low birthweight and postnatal disease risk of twins may lie in their very different fetal development. These data suggest that twin pregnancy may be another paradigm of developmental programming, and indicate that twins and singletons must be examined separately in any study of fetal or postnatal physiology. [source]

Diet in late pregnancy and glucose-insulin metabolism of the offspring 40 years later

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 7 2000
A. W. Shiell Statistician
Objective To determine how diets of women in pregnancy influence the glucose-insulin metabolism of their offspring in adult life. Design A follow up study of men and women born during 1948,1954 whose mothers had taken part in a survey of diet in late pregnancy. Setting Aberdeen, Scotland. Population One hundred and sixty-eight men and women born in the Aberdeen Maternity Hospital. Main outcome measure Plasma glucose and insulin concentrations, fasting and after a standard oral glucose challenge. Results The offspring of women who had high intakes of fat and protein in late pregnancy had a reduced plasma insulin increment between fasting and 30 min with a 7.0% decrease in increment (P= 0.007) per 10 g increase in protein intake and a 4.9% decrease (P= 0.002) per 10 g increase in fat intake. This was independent of the mother's body mass index or weight gain in pregnancy. A low maternal body mass index in early or late pregnancy was associated with a raised fasting plasma insulin concentration with a decrease of 2.4% (P= 0.05) per 1 kg/m2 increase of maternal body mass. Conclusion High intakes of protein and fat during pregnancy may impair development of the fetal pancreatic beta cells and lead to insulin deficiency in the offspring. The offspring of thin mothers tend to be insulin resistant. [source]

Is Prenatal Glucocorticoid Administration Another Origin Of Adult Disease?

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 11 2001
John P Newnham
SUMMARY 1. The intra-uterine environment is now believed to play a major role in the origin of many adult diseases. Illnesses in which there is significant ,programming' before the time of birth include hypertension, diabetes, coronary heart disease and stroke. Acting on a genetic predisposition, intra-uterine triggers appear to programme the individual's metabolism and endocrine milieu and, after birth, these risk factors are then either amplified or minimized by environmental influences. The triggers operative during fetal life that have been studied most extensively are undernutrition and glucocorticoid exposure. 2. Over the past decade, a series of studies in sheep have focused on the perinatal and life-long consequences of glucocorticoid exposure in mid- to late-pregnancy. These studies in the sheep model have shown that maternal injections with glucocorticoids, in a manner similar to clinical treatment for women at risk of preterm birth, enhance fetal lung maturation, but were also associated with developmental and other functional alterations that are of concern. With weekly doses to the mother, there is restricted fetal growth, delayed myelination of the central nervous system, altered blood pressure soon after birth and increased insulin response to glucose challenge in early adulthood. If the glucocorticoids are given to the fetus by ultrasound-guided intramuscular injection, rather than to the mother, the effects on lung maturation are similar, but growth is spared and blood pressure after birth is unaltered. Increased insulin response to glucose challenge occurs in early adulthood with glucocorticoid by either route and is independent of growth restriction. 3. The findings in experimental animals are supported by studies of children in the Western Australian Preterm Infant Follow-up Study. Multivariate analyses have shown that increasing the number of glucocorticoid exposures, for the purpose of enhancing lung maturation prior to preterm birth, is associated with reduced birthweight and behavioural disorders at 3 years of age. 4. The results of these animal and clinical studies provide further support for a role of prenatal glucocorticoid exposure in triggering predisposition to adult disease. Further exploration of these models is expected to uncover the mechanisms and lead to effective strategies that may underpin clinical interventions. [source]

Effects of T4 replacement therapy on glucose metabolism in subjects with subclinical (SH) and overt hypothyroidism (OH)

CLINICAL ENDOCRINOLOGY, Issue 6 2008
Ammon Handisurya
Summary Objective To evaluate ,-cell function and insulin sensitivity in subjects with overt (OH) and subclinical hypothyroidism (SH) before and after T4 replacement therapy. Background Disturbances in glucose metabolism have been observed in hypothyroid states. However, the clinical significance and potential reversibility of these alterations by T4 replacement therapy remain to be elucidated especially in patients with SH. Design and patients Parameters of glucose metabolism have been investigated in subjects with OH (n = 12) and SH (n = 11). Insulin sensitivity has been assessed by the euglycaemic,hyperinsulinaemic clamp technique and ,-cell function by mathematical modelling of data derived from an oral glucose tolerance test. Results Fasting and dynamic glycaemia as assessed by the AUCGlucose remained unaltered following substitution therapy (P > 0·05). Insulin sensitivity significantly improved only in subjects with OH (P < 0·05). Fasting insulin and proinsulin concentrations increased proportionally in both groups (P < 0·05) with the proinsulin : insulin ratio remaining unchanged (P > 0·05). Total insulin secretion was higher in OH before initiation of therapy (P < 0·05). In both groups, dynamic parameters including total insulin secretion, hepatic insulin extraction and the adaptation index were significantly attenuated (P < 0·05) after restoration of thyroid function, whereas the disposition index and the basal insulin secretion rate remained unaltered (P > 0·05). Conclusion In summary, SH and OH are characterized by attenuated basal plasma insulin levels and increased glucose-induced insulin secretion. T4 replacement therapy partially ameliorates the insulin secretion profile and reduces the demand on pancreatic ,-cells after glucose challenge to an extent that exceeds any effect attributable to the improvement in insulin sensitivity. [source]

Rosiglitazone improves insulin sensitivity and glucose tolerance in subjects with impaired glucose tolerance

CLINICAL ENDOCRINOLOGY, Issue 1 2005
Yi-Jen Hung
Summary Objective, This study was designed to evaluate the effects of rosiglitazone (ROS) on insulin sensitivity, ,-cell function, and glycaemic response to glucose challenge and meal in subjects with impaired glucose tolerance (IGT). Methods, Thirty patients with IGT (ages between 30 and 75 years and BMI (body mass index) , 27 kg/m2) were randomly assigned to receive either placebo (n = 15) or ROS (4 mg/day) (n = 15). All participants underwent a 75-g oral glucose tolerance test (OGTT), meal test, and frequently sampled intravenous glucose tolerance test (FSIGT) before and after the 12-week treatment. Results, After 12 weeks of ROS treatment, there were significant increases in total cholesterol (TC) (4·25 ± 0·22 vs 4·80 ± 0·17 mmol/l, P < 0·001), high-density lipoprotein cholesterol (HDL-C) (1·25 ± 0·07 vs 1·43 ± 0·06 mmol/l, P < 0·05), and low-density lipoprotein cholesterol (LDL-C) (2·70 ± 0·15 vs 3·37 ± 0·17 mmol/l, P < 0·05) without changes in triglyceride concentration, TC/HDL-C and LDL-C/HDL-C ratio. Although the acute insulin response (AIR) to intravenous glucose and disposition index (measured as the ability of pancreatic ,-cell compensation in the presence of insulin resistance) remained unchanged, the insulin sensitivity (SI) and glucose effectiveness (SG) were remarkably elevated (0·38 ± 0·06 vs 0·54 ± 0·09 × 10,5 min,1/pmol, P < 0·05; 0·017 ± 0·002 vs 0·021 ± 0·001 min,1, P < 0·05, respectively) in the ROS group. The glucose, insulin, and c-peptide areas under curve (AUC) in response to OGTT and the glucose and insulin AUC during meal were significantly ameliorated in the ROS group. Five out of 15 (33%) and two out of 15 (13%) subjects treated with ROS and placebo, respectively, reversed to normal response during OGTT (P < 0·05). Conclusion, Rosiglitazone treatment significantly improved insulin resistance and reduced postchallenge glucose and insulin concentrations in patients with impaired glucose tolerance without remarkable effects on ,-cell secretory function. [source]

Three-yr follow-up of a type 1 diabetes mellitus patient with an islet xenotransplant

CLINICAL TRANSPLANTATION, Issue 3 2007
R.A. Valdés-González
Abstract:, In order to alleviate the shortage of human donors, the use of porcine islets of Langerhans for xenotransplantation in diabetic patients has been proposed as a solution. To overcome rejection, we have developed a procedure for protecting the islets by combining them with Sertoli cells and placing them in a novel subcutaneous device, that generates an autologous collagen covering. A type 1 diabetic woman was closely monitored for 10 months, and then transplanted in two devices with two months of difference and a third time after 22 months. Here we present a three-yr follow-up. The close monitoring induced a rapid decrease in exogenous insulin requirements, which stabilized between 19 and 28 IU/d for nine months. After transplantation, the requirements reduced further to below 6 IU/d and for some weeks she was insulin free. Glycosylated hemoglobin levels decreased concomitantly. Porcine insulin could be detected in the serum after a glucose challenge and insulin positive cells inside a removed device after two yr. No complications have arisen and no porcine endogenous retrovirus infection has been detected through PCR and RT-PCR. This case demonstrates the feasibility of using the xenotransplantation of porcine cells to alleviate metabolic complications and insulin requirements in type 1 diabetic patients. [source]