scholarly journals Impaired Suppression of Glucagon in Obese Subjects Parallels Decline in Insulin Sensitivity and Beta-Cell Function

Author(s):  
Xi Chen ◽  
Enrique Maldonado ◽  
Ralph A DeFronzo ◽  
Devjit Tripathy

Abstract Aim To examine the relationship between plasma glucagon levels and insulin sensitivity and insulin secretion in obese subjects. Methods Suppression of plasma glucagon was examined in 275 obese Hispanic Americans with varying glucose tolerance. All subjects received a 2-hour oral glucose tolerance test (OGTT) and a subset (n = 90) had euglycemic hyperinsulinemic clamp. During OGTT, we quantitated suppression of plasma glucagon concentration, Matsuda index of insulin sensitivity, and insulin secretion/insulin resistance (disposition) index. Plasma glucagon suppression was compared between quartiles of insulin sensitivity and beta-cell function. Results Fasting plasma glucagon levels were similar in obese subjects with normal glucose tolerance (NGT), prediabetes, and type 2 diabetes (T2D), but the fasting glucagon/insulin ratio decreased progressively from NGT to prediabetes to T2D (9.28 ± 0.66 vs 6.84 ± 0.44 vs 5.84 ± 0.43; P < 0.001). Fasting and 2-hour plasma glucagon levels during OGTT progressively increased and correlated positively with severity of insulin resistance (both Matsuda index and euglycemic hyperinsulinemic clamp). The fasting glucagon/insulin ratio declined with worsening insulin sensitivity and beta-cell function, and correlated with whole-body insulin sensitivity (Matsuda index, r = 0.81; P < 0.001) and beta-cell function (r = 0.35; P < 0.001). The glucagon/insulin ratio also correlated and with beta-cell function during OGTT at 60 and 120 minutes (r = −0.47; P < 0.001 and r = −0.32; P < 0.001). Conclusion Insulin-mediated suppression of glucagon secretion in obese subjects is impaired with increasing severity of glucose intolerance and parallels the severity of insulin resistance and beta-cell dysfunction.

2004 ◽  
pp. 97-104 ◽  
Author(s):  
B Ahren ◽  
G Pacini

Insulin sensitivity and insulin secretion are mutually related such that insulin resistance is compensated by increased insulin secretion. A correct judgement of insulin secretion therefore requires validation in relation to the insulin sensitivity in the same subject. Mathematical analyses of the relationship between insulin sensitivity and insulin secretion has revealed a hyperbolic function, such that the product of the two variables is constant. This product is usually called the disposition index. Several techniques may be used for its estimation such as data derived from the frequently sampled i.v. glucose tolerance test, the oral glucose tolerance test or the glucose-dependent arginine stimulation test or the euglycemic hyperinsulinemic clamp technique in combination with a test on insulin secretion. Using these techniques the compensatory increase in beta cell function in insulin resistance has been verified in obesity, in pregnancy and after glucocorticoid administration as has the defective beta cell function as the underlying cause of impaired glucose tolerance and type 2 diabetes. Similarly, combined analysis of insulin sensitivity and insulin secretion has shown a down-regulation of beta cell function in increased insulin sensitivity accompanying weight reduction in obesity and following exercise. Acknowledging this inverse relationship between insulin secretion and insulin sensitivity therefore requires estimation of both variables for correct assessment in any individual.


2019 ◽  
Vol 105 (3) ◽  
pp. e651-e659
Author(s):  
Alessandro Volpe ◽  
Chang Ye ◽  
Anthony J Hanley ◽  
Philip W Connelly ◽  
Bernard Zinman ◽  
...  

Abstract Context Serum uric acid has been linked to risk of type 2 diabetes (T2DM), but debate persists as to whether it plays a causal role. Indeed, it is unclear if changes in uric acid relate to the pathophysiologic determinants of T2DM (insulin resistance, beta-cell dysfunction), as would be expected if causal. Objective To evaluate the impact of changes in uric acid over 2 years on changes in insulin sensitivity, beta-cell function, and glycemia in women with and without recent gestational diabetes (GDM), a model of the early natural history of T2DM. Design/Setting/Participants At both 1 and 3 years postpartum, 299 women (96 with recent GDM) underwent uric acid measurement and oral glucose tolerance tests that enabled assessment of insulin sensitivity/resistance (Matsuda index, homeostasis model assessment of insulin resistance [HOMA-IR]), beta-cell function (insulin secretion-sensitivity index-2 [ISSI-2], insulinogenic index/HOMA-IR [IGI/HOMA-IR]), and glucose tolerance. Results Women with recent GDM had higher serum uric acid than their peers at both 1 year (281 ± 69 vs 262 ± 58 µmol/L, P = 0.01) and 3 years postpartum (271 ± 59 vs 256 ± 55 µmol/L, P = 0.03), coupled with lower insulin sensitivity, poorer beta-cell function, and greater glycemia (all P < 0.05). However, on fully adjusted analyses, neither uric acid at 1 year nor its change from 1 to 3 years was independently associated with any of the following metabolic outcomes at 3 years postpartum: Matsuda index, HOMA-IR, ISSI-2, IGI/HOMA-IR, fasting glucose, 2-hour glucose, or glucose intolerance. Conclusion Serum uric acid does not track with changes over time in insulin sensitivity, beta-cell function, or glycemia in women with recent GDM, providing evidence against causality in its association with diabetes.


Author(s):  
Thi To Nhu Phan ◽  
Trung Vinh Hoang

Aims: Our aim was to evaluate the uptake of postpartum screening, the prevalence and the risk factors for glucose intolerance in women with a recent history of gestational diabetes mellitus (GDM). Methods: All women with a history of GDM are advised to undergo a 75g oral glucose tolerance test (OGTT) around 6 - 12 weeks postpartum. Indices of insulin sensitivity (the Matsuda index and the reciprocal of the homeostasis model assessment of insulin resistance, HOMA-IR) and an index of beta-cell function, the Insulin Secretion-Sensitivity Index-2 (ISSI-2) were calculated based on the OGTT postpartum. Multivariable logistic regression was used to some factors. Results: Of all women (135) who received an OGTT postpartum, 42.2% (57) had glucose intolerance (11.8% impaired fasting glucose, 24.4% impaired glucose tolerance and 6.0% both impaired fasting and impaired glucose tolerance) and 1.5% (2) had overt diabetes. Compared to women with a normal OGTT postpartum, women with glucose intolerance and diabetes were older (32.5 ± 4.3 vs. 30.8 ± 4.8 years, p = 0.049), were more often obese (34.5% vs. 17.3%, p = 0.023). In the multivariable logistic regression, an EM background [OR = 2.76 (1.15 - 6.62), p = 0.023] and the HbA1c level at the time of the OGTT in pregnancy [OR = 4.78 (1.19 - 19.20), p = 0.028] remained significant predictors for glucose intolerance postpartum. Women with glucose intolerance and diabetes postpartum had a similar insulin sensitivity [Matsuda index 0.656 (0.386 - 1.224) vs. 0.778 (0.532 - 1.067), p = 0.709; HOMA-IR 0.004 (0.002 - 0.009) vs. 0.064 (0.003 - 0.007), p = 0.384] but a lower beta-cell function compared to women with a normal OGTT postpartum, remaining significant after adjustment for confounders [ISSI-2 1.6 (1.2 - 2.1) vs. 1.9 (1.7 - 2.4), p = 0.002]. Conclusions: Glucose intolerance is very frequent in early postpartum in women with GDM these women have an impaired beta-cell function. Nearly one third of women did not attend the scheduled OGTT postpartum and these women have an adverse risk profile. More efforts are needed to engage and stimulate women with GDM to attend the postpartum OGTT.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A319-A320
Author(s):  
Vishwanath Pattan ◽  
Maria Chang Villacreses ◽  
Rudruidee Karnchanasorn ◽  
Wei Feng ◽  
Raynald Samoa ◽  
...  

Abstract Trace element is essential for the proper growth, development, and physiology of the organism and the primary source of trace element is dietary intake. Among trace elements, the role of copper (Cu), selenium (Se), and zinc (Zn) in the pathogenesis of diabetes have been widely recognized. However, there is little information available about these 3 trace elements across the different states of glucose tolerance. We examined associations between serum levels of trace elements - Cu, Zn, and Se with various stages of glucose tolerance in a representative, cross-sectional sample of US adults. Our sample included 5,087 adults (≥20 years) with available serum concentrations of Cu, Zn and Se as well as states of glucose tolerance, defined by history, HbA1c, fasting, and 2-hour plasma glucose concentrations. Serum concentrations of trace elements were compared with glucose tolerance status with the consideration of covariates. Regression analyses was used to examine the relationship of trace elements with HOMA-IR, HOMA-B, and BMI in non-diabetic subjects with the consideration of appropriate covariates. Serum Se (P<0.0001) and Zn (P<0.0001) concentrations differed significantly among 3 groups based on the states of glucose tolerance, while no difference was noted in serum Cu concentration. In non-diabetic subjects, serum Cu concentration was positively correlated with BMI (P<0.0001) with a possible compensatory increased beta cell function (P=0.018). Serum Se concentration was negatively correlated with insulin resistance (P=0.016) but not with beta cell function or BMI. Serum Zn concertation was negatively correlated with beta cell function (P=0.0023) and BMI (P=0.018), but not with insulin resistance. We found that a higher serum concentration of trace elements was associated with negative glucose and fuel homeostasis in a non-deficiency population possibly through different mechanisms. Although the casual relationship remains to be elucidated, we recommend against trace element supplementation in a non-deficiency population.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 585-585
Author(s):  
Hassan Dashti ◽  
Jesus Lopez ◽  
Céline Vetter ◽  
Millán Pérez-Ayala ◽  
Juan Carlos Baraza ◽  
...  

Abstract Objectives Eating at times that conflict with our physiology and coincide with the biological evening has been associated with increased disease risk. In free-living adults from the ONTIME-MT study (#NCT03036592) study, we tested the hypothesis that advancing the timing of dinner relative to bedtime, simulated by advancing an evening oral glucose tolerance test (OGTT), will result in improved glucose control. Methods In a randomized, cross-over study design, following an 8h fast, each participant underwent two evening 2-hour 75-gram oral OGTT: early and late (4h vs. 1h prior to habitual bedtime), simulating early and late dinner timing. Habitual bedtime was determined using one-week of electronic sleep logs via smartphone application. The OGTT order was randomized and separated by 1-week washout period. Light intensity was kept bright (≥450 lux) and dim (0–25 lux) in the early and late conditions, respectively. Melatonin was assessed at the start and end of each OGTT by radioimmunoassay. Postprandial glucose and insulin were determined using incremental area under the curve (AUC). Insulin sensitivity and beta-cell function were evaluated using standard metrices: insulin sensitivity index (ISI), corrected insulin response (CIR), and disposition index (DI). Values were compared using paired t-tests and differences were considered significant at P < 0.05. Results A total of 750 participants (mean age = 37 ± 14; 70% female; mean BMI = 26.12 ± 5.66) underwent OGTTs in two evening timing conditions. As expected, melatonin levels were higher in the late vs. early condition (4.49 ± 4.15-fold lower in the early vs. late meal condition. In the early condition, there was an 8.68% lower AUC for glucose (P = .0001) and 4.4% higher insulin AUC (P = 0.059), relative to the late condition. In addition, the CIR was 16% (P = .0001) higher and the DI was higher by 20% (P = .014) in the early compared to the late condition. The ISI was similar in both conditions (P = 0.66). Conclusions In this large study, glucose tolerance was better during early vs. late evening OGTT. Better glucose tolerance was primarily attributed to improved insulin secretion and beta-cell function. These results indicate that for the general population, advancing dinner relative to bedtime may be a novel and an effective strategy to improve glucose tolerance. Funding Sources ONTIME-MT was funded by the NIH R01 grant R01DK105072.


2016 ◽  
Vol 175 (5) ◽  
pp. 367-377 ◽  
Author(s):  
Christian Herder ◽  
Kristine Færch ◽  
Maren Carstensen-Kirberg ◽  
Gordon D Lowe ◽  
Rita Haapakoski ◽  
...  

Objective Higher systemic levels of pro-inflammatory biomarkers and low adiponectin are associated with increased risk of type 2 diabetes, but their associations with changes in glycaemic deterioration before onset of diabetes are poorly understood. We aimed to study whether inflammation-related biomarkers are associated with 5-year changes in glucose and insulin, HbA1c, insulin sensitivity and beta-cell function before the diagnosis of type 2 diabetes and whether these associations may be bidirectional. Design and methods We used multiple repeat measures (17 891 person-examinations from 7683 non-diabetic participants) from the Whitehall II study to assess whether circulating high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL6), IL1 receptor antagonist (IL1Ra) and adiponectin are associated with subsequent changes in glycaemia, insulin, insulin resistance and beta-cell function (based on oral glucose tolerance tests). We examined bidirectionality by testing if parameters of glucose metabolism at baseline are associated with changes in inflammation-related biomarkers. Results Higher hsCRP and IL6 were associated with increases in fasting insulin, insulin resistance and, for IL6, with beta-cell function after adjustment for confounders. Higher adiponectin was associated with decreases in fasting glucose, HbA1c, fasting insulin, insulin resistance and beta-cell function. The reverse approach showed that 2-h glucose and insulin sensitivity were associated with changes in IL1Ra. Fasting insulin and insulin resistance showed inverse associations with changes in adiponectin. Conclusions Subclinical inflammation is associated with development of increased glycaemia, insulin resistance and beta-cell function in non-diabetic individuals. These findings are consistent with the hypothesis that inflammation-related processes may increase insulin resistance and lead to a compensatory upregulation of beta-cell function.


Sign in / Sign up

Export Citation Format

Share Document