The Association between HbA1c, Fasting Glucose, 1-Hour Glucose and 2-Hour Glucose during an Oral Glucose Tolerance Test and Cardiovascular Disease in Individuals with Elevated Risk for Diabetes

Context: Prediabetes is a heterogeneous disorder classified on the basis of fasting glucose concentrations and 2-hour glucose tolerance. Objective: We sought to determine the relative contributions of insulin secretion and action to the pathogenesis of isolated impaired glucose tolerance (IGT). Design: The study consisted of an oral glucose tolerance test and a euglycemic clamp performed in two cohorts matched for anthropometric characteristics and fasting glucose but discordant for glucose tolerance. Setting: An inpatient clinical research unit at an academic medical center. Patients or Other Participants: Twenty-five subjects who had normal fasting glucose (NFG) and normal glucose tolerance (NGT) and 19 NFG/IGT subjects participated in this study. Intervention(s): Subjects underwent a seven-sample oral glucose tolerance test and a 4-hour euglycemic, hyperinsulinemic clamp on separate occasions. Glucose turnover during the clamp was measured using tracers, and endogenous hormone secretion was inhibited by somatostatin. Main Outcome Measures: We sought to determine whether hepatic glucose metabolism, specifically the contribution of gluconeogenesis to endogenous glucose production, differed between subjects with NFG/NGT and those with NFG/IGT. Results: Endogenous glucose production did not differ between groups before or during the clamp. Insulin-stimulated glucose disappearance was lower in NFG/IGT (24.6 ± 2.2 vs 35.0 ± 3.6 μmol/kg/min; P = .03). The disposition index was decreased in NFG/IGT (681 ± 102 vs 2231 ± 413 × 10−14 dL/kg/min2 per pmol/L; P < .001). Conclusions: We conclude that innate defects in the regulation of glycogenolysis and gluconeogenesis do not contribute to NFG/IGT. However, insulin-stimulated glucose disposal is impaired, exacerbating defects in β-cell function.

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A CROSS-SECTIONAL STUDY OF THE ASSOCIATION BETWEEN THE 1-HOUR ORAL GLUCOSE TOLERANCE TEST AND THE METABOLIC SYNDROME IN A HIGH-RISK SAMPLE WITH IMPAIRED FASTING GLUCOSE

Endocrine Practice ◽

10.4158/ep-2019-0387 ◽

2020 ◽

Vol 26 (5) ◽

pp. 529-534

Author(s):

Juan Carlos Lizarzaburu-Robles ◽

Lizardo Torres-Aparcana ◽

Raúl Mansilla ◽

José Valera ◽

Gabriela Vargas ◽

...

Keyword(s):

Metabolic Syndrome ◽

Glucose Tolerance ◽

Oral Glucose Tolerance Test ◽

Impaired Fasting Glucose ◽

Glucose Tolerance Test ◽

Fasting Glucose ◽

Tolerance Test ◽

Oral Glucose ◽

Oral Glucose Tolerance ◽

Glucose Levels

Objective: The aim of this study was to evaluate the association between the 1-hour oral glucose tolerance test (OGTT) (≥155 mg/dL) and metabolic syndrome (MS) in a sample with previous impaired fasting glucose (IFG). Methods: Three hundred and twenty four Peruvian subjects with a history of IFG ≥100 mg/dL were selected for a cross-sectional study. They underwent a 75 g OGTT and were assigned to different groups according to the result. We evaluated the association between 1-hour OGTT and MS. Results: The mean age was 56.5 ± 12.6 years and 191 (61.5%) were female. During the OGTT, we found 28 (8.6%) subjects with diabetes, 74 (22.8%) with IGT, and 222 (68.5%) with a normal glucose tolerance test with a 2-hour glucose <140 mg/dL (NGT). In the NGT group, 124 (38.3%) had 1-hour glucose levels <155 mg/dL, while 98 (30.2%) had 1-hour glucose levels ≥155 mg/dL. Evaluating the association between the 1-hour value in the OGTT and MS, we found that subjects with a 1-hour glucose ≥155 mg/dL were more than twice as likely to have MS as those with a 1-hour glucose <155 mg/dL (odds ratio = 2.64, 95% confidence interval: 1.52 to 4.57). In addition, body mass index, fasting glycemia, triglycerides, and waist circumferences were significantly higher in subjects with 1-hour glucose levels ≥155 mg/dL compared to those with 1-hour glucose levels <155 mg/dL ( P<.05). Conclusion: Among subjects with IFG, performing an OGTT was helpful to identify subjects with 1-hour glucose levels ≥155 mg/dL and NGT who were significantly more likely to have MS and a worse cardiometabolic risk profile. Abbreviations: AST = aspartate aminotransferase; BMI = body mass index; CI = confidence interval; IFG = impaired fasting glucose; IGT = impaired glucose tolerance; LDL = low-density lipoprotein; MS = metabolic syndrome; NGT = normal glucose tolerance; OGTT = oral glucose tolerance test; OR = odds ratio; T2DM = type 2 diabetes; TG = triglycerides

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Oral glucose tolerance test-based calculation identifies different glucose intolerance phenotypes within the impaired fasting glucose range

Journal of Diabetes Investigation ◽

10.1111/jdi.12185 ◽

2014 ◽

Vol 5 (5) ◽

pp. 533-538 ◽

Cited By ~ 1

Author(s):

Gian Piero Carnevale Schianca ◽

Gian Paolo Fra ◽

Marcello Bigliocca ◽

Roberto Mella ◽

Luca Rossi ◽

...

Keyword(s):

Glucose Tolerance ◽

Oral Glucose Tolerance Test ◽

Glucose Intolerance ◽

Impaired Fasting Glucose ◽

Glucose Tolerance Test ◽

Fasting Glucose ◽

Tolerance Test ◽

Oral Glucose ◽

Oral Glucose Tolerance

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Does multiple sclerosis affect glucose tolerance?

Multiple Sclerosis Journal ◽

10.1177/1352458513515957 ◽

2013 ◽

Vol 20 (9) ◽

pp. 1273-1276 ◽

Cited By ~ 18

Author(s):

I Wens ◽

U Dalgas ◽

N Deckx ◽

N Cools ◽

BO Eijnde

Keyword(s):

Multiple Sclerosis ◽

Glucose Tolerance ◽

Oral Glucose Tolerance Test ◽

Glucose Tolerance Test ◽

Fasting Glucose ◽

Tolerance Test ◽

Oral Glucose ◽

Healthy Controls ◽

Oral Glucose Tolerance ◽

Increased Risk

Based on current literature, it is not clear if multiple sclerosis (MS) patients are at increased risk to develop impaired glucose tolerance (IGT). Eighty-one MS patients and 45 healthy controls (HC) performed an oral glucose tolerance test. IGT was defined as a fasting glucose concentration of 6.1–6.9 mmol/l and two-hour post-load glucose of 7.8–11.1 mmol/l. The prevalence of impaired fasting glucose concentrations (17% vs 2%) and IGT (11% vs 0%) was higher in MS patients than HC. Accordingly, the areas under the glucose and insulin curves were higher in MS patients. The current study demonstrates an elevated IGT-prevalence in MS.

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