scholarly journals Short-Term Exercise Improves β-Cell Function and Insulin Resistance in Older People with Impaired Glucose Tolerance

2008 ◽  
Vol 93 (2) ◽  
pp. 387-392 ◽  
Author(s):  
Cathie J. Bloem ◽  
Annette M. Chang
Keyword(s):  
Insulin Resistance ◽  
Glucose Tolerance ◽  
Older People ◽  
Impaired Glucose Tolerance ◽  
Cell Function ◽  
Β Cell ◽  
Short Term ◽  
Β Cell Function

scholarly journals Novel canine models of obese prediabetes and mild type 2 diabetes

2010 ◽  
Vol 298 (1) ◽  
pp. E38-E48 ◽  
Author(s):  
Viorica Ionut ◽  
Huiwen Liu ◽  
Vahe Mooradian ◽  
Ana Valeria B. Castro ◽  
Morvarid Kabir ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Glucose Tolerance ◽  
Impaired Glucose Tolerance ◽  
Low Dose ◽  
Cell Function ◽  
High Fat ◽  
Β Cell ◽  
Β Cell Function

Human type 2 diabetes mellitus (T2DM) is often characterized by obesity-associated insulin resistance (IR) and β-cell function deficiency. Development of relevant large animal models to study T2DM is important and timely, because most existing models have dramatic reductions in pancreatic function and no associated obesity and IR, features that resemble more T1DM than T2DM. Our goal was to create a canine model of T2DM in which obesity-associated IR occurs first, followed by moderate reduction in β-cell function, leading to mild diabetes or impaired glucose tolerance. Lean dogs ( n = 12) received a high-fat diet that increased visceral (52%, P < 0.001) and subcutaneous (130%, P < 0.001) fat and resulted in a 31% reduction in insulin sensitivity (SI) (5.8 ± 0.7 × 10−4 to 4.1 ± 0.5 × 10−4 μU·ml−1·min−1, P < 0.05). Animals then received a single low dose of streptozotocin (STZ; range 30–15 mg/kg). The decrease in β-cell function was dose dependent and resulted in three diabetes models: 1) frank hyperglycemia (high STZ dose); 2) mild T2DM with normal or impaired fasting glucose (FG), 2-h glucose >200 mg/dl during OGTT and 77–93% AIRg reduction (intermediate dose); and 3) prediabetes with normal FG, normal 2-h glucose during OGTT and 17–74% AIRg reduction (low dose). Twelve weeks after STZ, animals without frank diabetes had 58% more body fat, decreased β-cell function (17–93%), and 40% lower SI. We conclude that high-fat feeding and variable-dose STZ in dog result in stable models of obesity, insulin resistance, and 1) overt diabetes, 2) mild T2DM, or 3) impaired glucose tolerance. These models open new avenues for studying the mechanism of compensatory changes that occur in T2DM and for evaluating new therapeutic strategies to prevent progression or to treat overt diabetes.

Pancreatic β-cell function and fetal growth in gestational impaired glucose tolerance

2010 ◽  
Vol 89 (6) ◽  
pp. 769-775 ◽  
Author(s):  
Kei Miyakoshi ◽  
Mamoru Tanaka ◽  
Yoshifumi Saisho ◽  
Akira Shimada ◽  
Kazuhiro Minegishi ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Impaired Glucose Tolerance ◽  
Fetal Growth ◽  
Cell Function ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Β Cell Function

Association between Genetic Polymorphisms of β-Cell Differentiation Genes and Insulin Resistance (β-Cell Dysfunction) in Childhood Acute Lymphoblastic Leukemia (ALL) Survivors.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4281-4281
Author(s):  
Pacharapan Surapolchai ◽  
Suradej Hongeng ◽  
Samart Pakakasama ◽  
Pat Mahachoklertwattana ◽  
Angkana Winaichatsak ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Cell Function ◽  
Sensitivity Index ◽  
Insulin Sensitivity Index ◽  
Β Cell ◽  
Childhood All ◽  
Cell Dysfunction ◽  
Β Cell Function

Abstract Background: The purposes of the study were to determine β-cell function and insulin sensitivity after ALL therapy cessation and the association between genetic polymorphisms of β-cell differentiation genes, TCF7L2 and PAX4, with insulin resistance (β-cell dysfunction) in childhood ALL survivors. Methods: Childhood ALL patients diagnosed during 1997–2004 finished the treatment for at least 6 months. The oral glucose tolerance test and lipid screening were performed. Impaired glucose tolerance and diabetes mellitus (DM) were defined according to WHO criteria. β-cell function was estimated by homeostasis model assessment β-cell (HOMA β-cell) and insulinogenic index (IGI) and insulin sensitivity was estimated by whole body insulin sensitivity index (WBISI). The polymorphisms of TCF7L2 (rs12255372 and rs7903146) and PAX4 (A1186C) were genotyped and assessed for the association between these polymorphisms and the β-cell function and the insulin sensitivity. Results: 126 patients were studied (52 females, 74 males and age at the time of study; 4–20 yrs). 116 patients (92%) had normal glucose tolerance (NGT) while the others 10 patients (8%) had impaired glucose tolerance (IGT). Comparing between IGT and NGT groups respectively, we found statistically significant differences in age at the diagnosis (7.5 and 5.2 yrs, p=0.041), age at the study (14 and 10.3 yrs, p=0.001), the duration of post ALL therapy cessation (43 and 26 months, p=0.015), and insulin sensitivity index (WBISI) (5.75 and 9.52, p<0.001). HOMA β-cell and IGI were not different between NGT and IGT group (190.8 and 139.5, p=0.332; 23.6 and 15.8, p=0.310, respectively). Moreover, 32 of 126 patients (25%) had insulin resistance (modified from the criteria of WBISI in obese children and adolescents). These 32 patients who had insulin resistance demonstrated significant pictures of metabolic syndrome i.e. hypertriglyceridemia (116.6 and 85.4 mg/dL, p=0.036), low HDL-C (43.0 and 48.3 mg/dL, p=0.015), obesity (BMI SDS 1.03 and 0.38, p=0.044) and were also older age at the study (12.8 and 9.9 yrs, p<0.001). The genotype frequencies and allele frequencies of polymorphisms of TCF7L2 and PAX4 genes between IGT and NGT groups and between insulin resistance and nonresistance were not difference (p>0.05). Conclusion: The childhood ALL survivors who had IGT were associated with the longer duration of ALL therapy cessation, the older age at diagnosis and at the time of study, and insulin resistance while β-cell function was still relatively preserved. Long-term childhood ALL survivors have potential risks of IGT, insulin resistance and metabolic syndrome. Our findings with such small representatives are not yet applicable to associate TCF7L2 and PAX4 polymorphisms with the insulin resistance (β-cell dysfunction) in the childhood ALL survivors.

Impact of incretin hormones on β-cell function in subjects with normal or impaired glucose tolerance

2006 ◽  
Vol 291 (6) ◽  
pp. E1144-E1150 ◽  
Author(s):  
Elza Muscelli ◽  
Andrea Mari ◽  
Andrea Natali ◽  
Brenno D. Astiarraga ◽  
Stefania Camastra ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Glucose Tolerance ◽  
Impaired Glucose Tolerance ◽  
Cell Function ◽  
Oral Glucose ◽  
Incretin Effect ◽  
Β Cell ◽  
Β Cell Function ◽  
Glucose Sensitivity ◽  
Cell Glucose

The mechanisms by which the enteroinsular axis influences β-cell function have not been investigated in detail. We performed oral and isoglycemic intravenous (IV) glucose administration in subjects with normal (NGT; n = 11) or impaired glucose tolerance (IGT; n = 10), using C-peptide deconvolution to calculate insulin secretion rates and mathematical modeling to quantitate β-cell function. The incretin effect was taken to be the ratio of oral to IV responses. In NGT, incretin-mediated insulin release [oral glucose tolerance test (OGTT)/IV ratio = 1.59 ± 0.18, P = 0.004] amounted to 18 ± 2 nmol/m2 (32 ± 4% of oral response), and its time course matched that of total insulin secretion. The β-cell glucose sensitivity (OGTT/IV ratio = 1.52 ± 0.26, P = 0.02), rate sensitivity (response to glucose rate of change, OGTT/IV ratio = 2.22 ± 0.37, P = 0.06), and glucose-independent potentiation were markedly higher with oral than IV glucose. In IGT, β-cell glucose sensitivity (75 ± 14 vs. 156 ± 28 pmol·min−1·m−2·mM−1 of NGT, P = 0.01) and potentiation were impaired on the OGTT. The incretin effect was not significantly different from NGT in terms of plasma glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide responses, total insulin secretion, and enhancement of β-cell glucose sensitivity (OGTT/IV ratio = 1.73 ± 0.24, P = NS vs. NGT). However, the time courses of incretin-mediated insulin secretion and potentiation were altered, with a predominance of glucose-induced vs. incretin-mediated stimulation. We conclude that, under physiological circumstances, incretin-mediated stimulation of insulin secretion results from an enhancement of all dynamic aspects of β-cell function, particularly β-cell glucose sensitivity. In IGT, β-cell function is inherently impaired, whereas the incretin effect is only partially affected.

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