scholarly journals METABOLIC PHENOTYPING GUIDELINES: Assessing glucose homeostasis in rodent models

2014 ◽  
Vol 222 (3) ◽  
pp. G13-G25 ◽  
Author(s):  
James E Bowe ◽  
Zara J Franklin ◽  
Astrid C Hauge-Evans ◽  
Aileen J King ◽  
Shanta J Persaud ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Glucose Tolerance ◽  
Glucose Homeostasis ◽  
Β Cells ◽  
Advantages And Disadvantages ◽  
Autoimmune Destruction ◽  
Normal Glucose

The pathophysiology of diabetes as a disease is characterised by an inability to maintain normal glucose homeostasis. In type 1 diabetes, this is due to autoimmune destruction of the pancreatic β-cells and subsequent lack of insulin production, and in type 2 diabetes it is due to a combination of both insulin resistance and an inability of the β-cells to compensate adequately with increased insulin release. Animal models, in particular genetically modified mice, are increasingly being used to elucidate the mechanisms underlying both type 1 and type 2 diabetes, and as such the ability to study glucose homeostasisin vivohas become an essential tool. Several techniques exist for measuring different aspects of glucose tolerance and each of these methods has distinct advantages and disadvantages. Thus the appropriate methodology may vary from study to study depending on the desired end-points, the animal model, and other practical considerations. This review outlines the most commonly used techniques for assessing glucose tolerance in rodents and details the factors that should be taken into account in their use. Representative scenarios illustrating some of the practical considerations of designingin vivoexperiments for the measurement of glucose homeostasis are also discussed.

scholarly journals Evidence That Hypothalamic Gliosis Is Related to Impaired Glucose Homeostasis in Adults With Obesity

2021 ◽  
Author(s):  
Jennifer L. Rosenbaum ◽  
Susan J. Melhorn ◽  
Stefan Schoen ◽  
Mary F. Webb ◽  
Mary Rosalynn B. De Leon ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Cohort Study ◽  
Glucose Tolerance ◽  
Glucose Homeostasis ◽  
Relaxation Times ◽  
Normal Glucose Tolerance ◽  
T2 Relaxation ◽  
Β Cell ◽  
Normal Glucose

Objective: Preclinical research implicates hypothalamic glial cell responses in the pathogenesis of obesity and type 2 diabetes. The current study sought to translate such findings into humans by testing if radiologic markers of gliosis in the mediobasal hypothalamus (MBH) were greater in persons with obesity and impaired glucose homeostasis or type 2 diabetes. <p>Research Design and Methods: Using cross-sectional and prospective cohort study designs, we applied a validated, quantitative magnetic resonance imaging (MRI) approach to assess gliosis in 67 adults with obesity and normal glucose tolerance, impaired glucose tolerance, or type 2 diabetes. Assessments of glucose homeostasis were conducted via oral glucose tolerance tests (OGTT) and β-cell modeling. </p> <p> Results: We found significantly greater T2 relaxation times (a marker of gliosis by MRI), that were independent of adiposity, in the impaired glucose tolerance and type 2 diabetes groups as compared to the normal glucose tolerance group. Findings were present in the MBH, but not control regions. Moreover, positive linear associations were present in the MBH but not control regions between T2 relaxation time and glucose area under the curve during an OGTT, fasting glucose concentrations, hemoglobin A1c, and visceral adipose tissue mass, whereas negative linear relationships were present in the MBH for markers of insulin sensitivity and β-cell function. In a prospective cohort study, greater MBH T2 relaxation times predicted declining insulin sensitivity over one year. </p> Conclusions: Findings support a role for hypothalamic gliosis in the progression of insulin resistance in obesity and, thus, type 2 diabetes pathogenesis in humans.

scholarly journals Evidence That Hypothalamic Gliosis Is Related to Impaired Glucose Homeostasis in Adults With Obesity

2021 ◽  
Author(s):  
Jennifer L. Rosenbaum ◽  
Susan J. Melhorn ◽  
Stefan Schoen ◽  
Mary F. Webb ◽  
Mary Rosalynn B. De Leon ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Cohort Study ◽  
Glucose Tolerance ◽  
Glucose Homeostasis ◽  
Relaxation Times ◽  
Normal Glucose Tolerance ◽  
T2 Relaxation ◽  
Β Cell ◽  
Normal Glucose

Objective: Preclinical research implicates hypothalamic glial cell responses in the pathogenesis of obesity and type 2 diabetes. The current study sought to translate such findings into humans by testing if radiologic markers of gliosis in the mediobasal hypothalamus (MBH) were greater in persons with obesity and impaired glucose homeostasis or type 2 diabetes. <p>Research Design and Methods: Using cross-sectional and prospective cohort study designs, we applied a validated, quantitative magnetic resonance imaging (MRI) approach to assess gliosis in 67 adults with obesity and normal glucose tolerance, impaired glucose tolerance, or type 2 diabetes. Assessments of glucose homeostasis were conducted via oral glucose tolerance tests (OGTT) and β-cell modeling. </p> <p> Results: We found significantly greater T2 relaxation times (a marker of gliosis by MRI), that were independent of adiposity, in the impaired glucose tolerance and type 2 diabetes groups as compared to the normal glucose tolerance group. Findings were present in the MBH, but not control regions. Moreover, positive linear associations were present in the MBH but not control regions between T2 relaxation time and glucose area under the curve during an OGTT, fasting glucose concentrations, hemoglobin A1c, and visceral adipose tissue mass, whereas negative linear relationships were present in the MBH for markers of insulin sensitivity and β-cell function. In a prospective cohort study, greater MBH T2 relaxation times predicted declining insulin sensitivity over one year. </p> Conclusions: Findings support a role for hypothalamic gliosis in the progression of insulin resistance in obesity and, thus, type 2 diabetes pathogenesis in humans.

Effect of High ß-Glucan Barley on Postprandial Plasma Glucose Levels in Subjects with Normal Glucose Tolerance and Patients with Type 2 Diabetes

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 772-P
Author(s):  
MARIKO HIGA ◽  
AYANA HASHIMOTO ◽  
MOE HAYASAKA ◽  
MAI HIJIKATA ◽  
AYAMI UEDA ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Glucose Tolerance ◽  
Plasma Glucose ◽  
Normal Glucose Tolerance ◽  
Postprandial Plasma Glucose ◽  
Glucose Levels ◽  
Normal Glucose

Liraglutide Therapy in a Prediabetic State: Rethinking the Evidence

2020 ◽  
Vol 16 (7) ◽  
pp. 699-715 ◽  
Author(s):  
Georgios S. Papaetis
Keyword(s):  
Type 2 Diabetes ◽  
Glucose Tolerance ◽  
Cell Function ◽  
Normal Glucose Tolerance ◽  
Current Evidence ◽  
Β Cell ◽  
Prediabetic State ◽  
New Therapeutic Approaches ◽  
Normal Glucose

Background: Prediabetes is defined as a state of glucose metabolism between normal glucose tolerance and type 2 diabetes. Continuous β-cell failure and death are the reasons for the evolution from normal glucose tolerance to prediabetes and finally type 2 diabetes. Introduction: The necessity of new therapeutic approaches in order to prevent or delay the development of type 2 diabetes is obligatory. Liraglutide, a long-acting GLP-1 receptor agonist, has 97% homology for native GLP-1. Identification of the trophic and antiapoptotic properties of liraglutide in preclinical studies, together with evidence of sustained β-cell function longevity during its administration in type 2 diabetes individuals, indicated its earliest possible administration during this disease, or even before its development, so as to postpone or delay its onset. Methods: Pubmed and Google databases have been thoroughly searched and relevant studies were selected. Results: This paper explores the current evidence of liraglutide administration both in humans and animal models with prediabetes. Also, it investigates the safety profile of liraglutide treatment and its future role to postpone or delay the evolution of type 2 diabetes. Conclusion: Liralgutide remains a valuable tool in our therapeutic armamentarium for individuals who are overweight or obese and have prediabetes. Future well designed studies will give valuable information that will help clinicians to stratify individuals who will derive the most benefit from this agent, achieving targeted therapeutic strategies.

scholarly journals PAR-4/Ca2+-calpain pathway activation stimulates platelet-derived microparticles in hyperglycemic type 2 diabetes

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Alessandra Giannella ◽  
Giulio Ceolotto ◽  
Claudia Maria Radu ◽  
Arianna Cattelan ◽  
Elisabetta Iori ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Normal Glucose Tolerance ◽  
Calpain Inhibitor ◽  
Pathway Activation ◽  
Normal Glucose ◽  
Circulating Levels ◽  
Dependent Mechanism

Abstract Background Patients with type 2 diabetes (T2DM) have a prothrombotic state that needs to be fully clarified; microparticles (MPs) have emerged as mediators and markers of this condition. Thus, we investigate, in vivo, in T2DM either with good (HbA1c ≤ 7.0%; GGC) or poor (HbA1c > 7.0%; PGC) glycemic control, the circulating levels of MPs, and in vitro, the molecular pathways involved in the release of MPs from platelets (PMP) and tested their pro-inflammatory effects on THP-1 transformed macrophages. Methods In 59 T2DM, and 23 control subjects with normal glucose tolerance (NGT), circulating levels of CD62E+, CD62P+, CD142+, CD45+ MPs were determined by flow cytometry, while plasma levels of ICAM-1, VCAM-1, IL-6 by ELISA. In vitro, PMP release and activation of isolated platelets from GGC and PGC were investigated, along with their effect on IL-6 secretion in THP-1 transformed macrophages. Results We found that MPs CD62P+ (PMP) and CD142+ (tissue factor-bearing MP) were significantly higher in PGC T2DM than GGC T2DM and NGT. Among MPs, PMP were also correlated with HbA1c and IL-6. In vitro, we showed that acute thrombin exposure stimulated a significantly higher PMP release in PGC T2DM than GGC T2DM through a more robust activation of PAR-4 receptor than PAR-1 receptor. Treatment with PAR-4 agonist induced an increased release of PMP in PGC with a Ca2+-calpain dependent mechanism since this effect was blunted by calpain inhibitor. Finally, the uptake of PMP derived from PAR-4 treated PGC platelets into THP-1 transformed macrophages promoted a marked increase of IL-6 release compared to PMP derived from GGC through the activation of the NF-kB pathway. Conclusions These results identify PAR-4 as a mediator of platelet activation, microparticle release, and inflammation, in poorly controlled T2DM.

Plasma Folate Levels in Men with Type 2 Diabetes

2005 ◽  
Vol 75 (5) ◽  
pp. 307-311
Author(s):  
Sakuta ◽  
Suzuki ◽  
Yasuda ◽  
Ito
Keyword(s):  
Type 2 Diabetes ◽  
Glucose Tolerance ◽  
Vegetable Intake ◽  
Normal Glucose Tolerance ◽  
Diabetic Patients ◽  
Newly Diagnosed ◽  
Plasma Folate ◽  
Normal Glucose ◽  
Diagnosed Diabetes

Limited data suggest that folate levels are higher in patients with type 2 diabetes than in subjects with normal glucose tolerance (NGT). We compared the fasting plasma folate, glucose (FPG), body mass index (BMI), and supplementary vitamin use among male subjects with NGT, those with impaired glucose tolerance (IGT), those with newly diagnosed type 2 diabetes, and those with previously diagnosed type 2 diabetes. Plasma folate of patients with newly diagnosed diabetes and that of patients with previously diagnosed diabetes was significantly higher than that of NGT subjects (p < 0.001). Prevalence of vitamin use was lower in newly diagnosed or previously diagnosed diabetic patients compared with non-diabetic subjects. Self-rated vegetable intake was similar among the four groups. FPG, BMI, triglycerides, and systolic blood pressure correlated with plasma folate levels independently of lifestyle factors studied. These results suggest that plasma folate levels are elevated in male diabetic patients independently of health-conscious behavior that is recommended for diabetic people.

scholarly journals Increased vimentin in human α- and β-cells in type 2 diabetes

2017 ◽  
Vol 233 (3) ◽  
pp. 217-227 ◽  
Author(s):  
Maaike M Roefs ◽  
Françoise Carlotti ◽  
Katherine Jones ◽  
Hannah Wills ◽  
Alexander Hamilton ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Epithelial To Mesenchymal Transition ◽  
Islet Cells ◽  
Cell Types ◽  
Β Cells ◽  
Β Cell ◽  
Mesenchymal Transition ◽  
Cell Expression

Type 2 diabetes (T2DM) is associated with pancreatic islet dysfunction. Loss of β-cell identity has been implicated via dedifferentiation or conversion to other pancreatic endocrine cell types. How these transitions contribute to the onset and progression of T2DM in vivo is unknown. The aims of this study were to determine the degree of epithelial-to-mesenchymal transition occurring in α and β cells in vivo and to relate this to diabetes-associated (patho)physiological conditions. The proportion of islet cells expressing the mesenchymal marker vimentin was determined by immunohistochemistry and quantitative morphometry in specimens of pancreas from human donors with T2DM (n = 28) and without diabetes (ND, n = 38) and in non-human primates at different stages of the diabetic syndrome: normoglycaemic (ND, n = 4), obese, hyperinsulinaemic (HI, n = 4) and hyperglycaemic (DM, n = 8). Vimentin co-localised more frequently with glucagon (α-cells) than with insulin (β-cells) in the human ND group (1.43% total α-cells, 0.98% total β-cells, median; P < 0.05); these proportions were higher in T2DM than ND (median 4.53% α-, 2.53% β-cells; P < 0.05). Vimentin-positive β-cells were not apoptotic, had reduced expression of Nkx6.1 and Pdx1, and were not associated with islet amyloidosis or with bihormonal expression (insulin + glucagon). In non-human primates, vimentin-positive β-cell proportion was larger in the diabetic than the ND group (6.85 vs 0.50%, medians respectively, P < 0.05), but was similar in ND and HI groups. In conclusion, islet cell expression of vimentin indicates a degree of plasticity and dedifferentiation with potential loss of cellular identity in diabetes. This could contribute to α- and β-cell dysfunction in T2DM.

scholarly journals Changes in Glucose Tolerance over Time in Women with Polycystic Ovary Syndrome: A Controlled Study

2005 ◽  
Vol 90 (6) ◽  
pp. 3236-3242 ◽  
Author(s):  
Richard S. Legro ◽  
Carol L. Gnatuk ◽  
Allen R. Kunselman ◽  
Andrea Dunaif
Keyword(s):  
Type 2 Diabetes ◽  
Glucose Tolerance ◽  
Polycystic Ovary ◽  
Normal Glucose Tolerance ◽  
Ovary Syndrome ◽  
Normal Glucose ◽  
Pcos Group ◽  
Over Time

We performed this study to access the changes in glucose tolerance over time in a group of women with polycystic ovary syndrome (PCOS) (n = 71) and control women (n = 23) with regular menstrual cycles and baseline normal glucose tolerance. Mean follow-up was between 2 and 3 yr for both groups (PCOS 2.5 ± 1.7 yr; controls 2.9 ± 2.1 yr). Based on World Health Organization glucose tolerance categories, there was no significant difference in the prevalence of glucose intolerance at follow-up in the PCOS group. In the PCOS group, 25 (37%) had impaired glucose tolerance (IGT) and seven (10%) had type 2 diabetes mellitus at baseline, compared with 30 (45%) and 10 (15%), respectively, at follow-up. There were also no differences within groups (PCOS or control) or between groups (PCOS vs. control) in the oral glucose tolerance test-derived measure of insulin sensitivity, but in the women with PCOS who converted to either IGT or type 2 diabetes mellitus, there was a significant decrease (P &lt; 0.0001). At the follow-up visit, the mean glycohemoglobin level was 6.1 ± 0.9% in women with PCOS vs. 5.3 ± 0.7% in the control women (P &lt; 0.001). Women with PCOS and baseline IGT had a low conversion risk of 6% to type 2 diabetes over approximately 3 yr, or 2% per year. The effect of PCOS, given normal glucose tolerance (NGT) at baseline, is more pronounced with 16% conversion to IGT per year. Our study supports that women with PCOS (especially with NGT) should be periodically rescreened for diabetes due to worsening glucose intolerance over time, but this interval may be over several years and not annually.

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