scholarly journals Older Subjects With β-Cell Dysfunction Have an Accentuated Incretin Release

2018 ◽  
Vol 103 (7) ◽  
pp. 2613-2619 ◽  
Author(s):  
José de Jesús Garduno-Garcia ◽  
Amalia Gastaldelli ◽  
Ralph A DeFronzo ◽  
Raweewan Lertwattanarak ◽  
Jens J Holst ◽  
...  
Keyword(s):  
Older Adults ◽  
Glucose Tolerance ◽  
Normal Glucose Tolerance ◽  
Β Cell ◽  
Secretory Rate ◽  
C Peptide ◽  
Cell Dysfunction ◽  
Normal Glucose ◽  
Matsuda Index ◽  
Older Subjects

Abstract Objective Insulin secretion (IS) declines with age, which increases the risk of impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) in older adults. IS is regulated by the incretin hormones glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). Here we tested the hypotheses that incretin release is lower in older adults and that this decline is associated with β-cell dysfunction. Research Design A total of 40 young (25 ± 3 years) and 53 older (74 ± 7 years) lean nondiabetic subjects underwent a 2-hour oral glucose tolerance test (OGTT). Based on the OGTT, subjects were divided into three groups: young subjects with normal glucose tolerance (Y-NGT; n = 40), older subjects with normal glucose tolerance (O-NGT; n = 32), and older subjects with IGT (O-IGT; n = 21). Main Outcome Measures Plasma insulin, C-peptide, GLP-1, and GIP concentrations were measured every 15 to 30 minutes. We quantitated insulin sensitivity (Matsuda index) and insulin secretory rate (ISR) by deconvolution of C-peptide with the calculation of β-cell glucose sensitivity. Results Matsuda index, early phase ISR (0 to 30 minutes), and parameters of β-cell function were lower in O-IGT than in Y-NGT subjects but not in O-NGT subjects. GLP-1 concentrations were elevated in both older groups [GLP-1 area under the curve (AUC)0–120 was 2.8 ± 0.1 in Y-NGT, 3.8 ± 0.5 in O-NGT, and 3.7 ± 0.4 nmol/L∙120 minutes in O-IGT subjects; P < 0.05], whereas GIP secretion was higher in O-NGT than in Y-NGT subjects (GIP AUC0–120 was 4.7 ± 0.3 in Y-NGT, 6.0 ± 0.4 in O-NGT, and 4.8 ± 0.3 nmol/L∙120 minutes in O-IGT subjects; P < 0.05). Conclusions Aging is associated with an exaggerated GLP-1 secretory response. However, it was not sufficient to increase insulin first-phase release in O-IGT and overcome insulin resistance.

scholarly journals Impaired fasting glucose with or without impaired glucose tolerance: progressive or parallel states of prediabetes?

2008 ◽  
Vol 295 (2) ◽  
pp. E428-E435 ◽  
Author(s):  
Leigh Perreault ◽  
Bryan C. Bergman ◽  
Mary C. Playdon ◽  
Chiara Dalla Man ◽  
Claudio Cobelli ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Impaired Glucose Tolerance ◽  
Impaired Fasting Glucose ◽  
Insulin Action ◽  
Low Dose ◽  
Fasting Glucose ◽  
Normal Glucose Tolerance ◽  
Β Cell ◽  
Cell Dysfunction ◽  
Normal Glucose

Our objective was to determine whether defects underlying impaired fasting glucose (IFG) are maintained and additive when combined with impaired glucose tolerance (IGT) (representing a progressive form of prediabetes) or are distinct in IFG/IGT (reflecting a parallel form of prediabetes). Volunteers with IFG ( n = 10), IFG/IGT ( n = 14), or normal glucose tolerance (NGT; n = 15) were matched for demographics and anthropometry. Insulin secretion was assessed using the glucose step-up protocol and insulin action through the use of a two-stage hyperinsulinemic euglycemic clamp with infusion of [6,6-2H2]glucose. Modeling of insulin secretory parameters revealed similar basal (Φb) but diminished dynamic (Φd) components in both IFG and IFG/IGT ( P = 0.05 vs. NGT for both). Basal glucose rate of appearance (Ra) was higher in IFG compared with NGT ( P < 0.01) and also, surprisingly, with IFG/IGT ( P < 0.04). Moreover, glucose Ra suppressed more during the low-dose insulin clamp in IFG ( P < 0.01 vs. NGT, P = 0.08 vs. IFG/IGT). Insulin-stimulated glucose uptake [glucose rate of disappearance (Rd)] was similar in IFG, IFG/IGT, and NGT throughout the clamp. We conclude that nuances of β-cell dysfunction observed in IFG were also noted in IFG/IGT. A trend for additional insulin secretory defects was observed in IFG/IGT, possibly suggesting progression in β-cell failure in this group. In contrast, basal glucose Ra and its suppressability with insulin were higher in IFG, but not IFG/IGT, compared with NGT. Together, these data indicate that IFG/IGT may be a distinct prediabetic syndrome rather than progression from IFG.

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 PPARαAgonist Fenofibrate Reduced the Secreting Load ofβ-Cells in Hypertriglyceridemia Patients with Normal Glucose Tolerance

PPAR Research ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Jia Liu ◽  
Rui Lu ◽  
Ying Wang ◽  
Yanjin Hu ◽  
Yumei Jia ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Tolerance ◽  
Cell Function ◽  
Density Lipoprotein ◽  
Normal Glucose Tolerance ◽  
Model Assessment ◽  
Homeostasis Model Assessment ◽  
Cell Dysfunction ◽  
Fenofibrate Treatment ◽  
Normal Glucose

Hypertriglyceridemia is an important risk factor associated with insulin resistance andβ-cell dysfunction. This study investigated the effects of hypertriglyceridemia and fenofibrate treatment on insulin sensitivity andβ-cell function in subjects with normal glucose tolerance. A total of 1974 subjects with normal glucose tolerance were divided into the normal TG group (NTG group,n=1302) and hypertriglyceridemia group (HTG group,n=672). Next, 92 patients selected randomly from 672 patients with hypertriglyceridemia were assigned to a 24-week fenofibrate treatment. The HTG group had increased waist circumference (WC), body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR), and homeostasis model assessment ofβ-cell function (HOMA-β) and decreased high-density lipoprotein cholesterol (HDL-C) compared with the NTG group (allP<0.01). The 24-week fenofibrate treatment significantly decreased the WC, BMI, TG, HOMA-IR, and HOMA-βlevels and increased the HDL-C levels in the patients with hypertriglyceridemia (WC, BMI, and HOMA-IR:P<0.05; TG, HDL-C, and HOMA-β:P<0.01). The fenofibrate treatment significantly alleviated insulin resistance and reduced the secreting load ofβ-cells in the hypertriglyceridemia patients with normal glucose tolerance.

scholarly journals Plasma omentin-1 levels are reduced in non-obese women with normal glucose tolerance and polycystic ovary syndrome

2011 ◽  
Vol 165 (5) ◽  
pp. 789-796 ◽  
Author(s):  
Ji-Hun Choi ◽  
Eun-Jung Rhee ◽  
Kye-Hyun Kim ◽  
Hee-Yeon Woo ◽  
Won-Young Lee ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Polycystic Ovary Syndrome ◽  
Glucose Tolerance ◽  
Polycystic Ovary ◽  
Normal Glucose Tolerance ◽  
Obese Women ◽  
Ovary Syndrome ◽  
C Peptide ◽  
Normal Glucose ◽  
Androgen Levels

ObjectiveOmentin-1 is a novel adipokine that increases insulin sensitivity and is expressed in visceral adipose tissue. The aim of this study was to determine the metabolic parameters that influence plasma omentin-1 levels in women with polycystic ovary syndrome (PCOS).Design and methodsA cross-sectional study was performed in 87 women with PCOS and 53 body mass index (BMI)-matched healthy controls including 39 non-obese, normal-weight (NW) PCOS women with normal glucose tolerance (NGT) and 44 BMI- and homeostasis model assessment (HOMA)-matched controls. Indices of insulin sensitivity, metabolic variables, circulating androgen levels, serum adiponectin, and omentin-1 levels were measured. A 75 g oral glucose tolerance test was performed in all participants.ResultsPlasma omentin-1 levels were significantly lower in women with PCOS compared with those in BMI-matched controls (P<0.001). A significantly lower level of plasma omentin-1 was observed in non-obese women with PCOS and NGT compared with that in BMI- and HOMA-matched controls (P<0.001). Omentin-1 level was negatively correlated with BMI, indices of insulin sensitivity, and circulating androgens and was associated with greater 2 h postprandial glucose, C-peptide, and insulin levels compared with fasting values. Within the NW and NGT groups, omentin-1 levels remained negatively correlated with BMI, 2 h postprandial C-peptide, and circulating androgens and demonstrated a negative linear trend according to quartile of free testosterone (P=0.028).ConclusionsPlasma levels of omentin-1 were reduced in non-obese women with PCOS and NGT. Postprandial hyperinsulinemia and hyperglycemia contributed more to lower omentin-1 levels than did fasting values in the setting of PCOS. Increased androgen levels contributed to decreased omentin-1 levels in women with PCOS.

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