Assessment of β-cell function during the oral glucose tolerance test by a minimal model of insulin secretion

2001 ◽  
Vol 31 (5) ◽  
pp. 405-416 ◽  
Author(s):  
A. Cretti ◽  
M. Lehtovirta ◽  
E. Bonora ◽  
B. Brunato ◽  
M. G. Zenti ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Glucose Tolerance ◽  
Oral Glucose Tolerance Test ◽  
Glucose Tolerance Test ◽  
Cell Function ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Β Cell ◽  
Β Cell Function

Detection of Glycemic Abnormalities in Young Adult Patients with Beta Thalassemia Major Using Continuous Glucose Monitoring System (CGMS) and Oral Glucose Tolerance Test (OGTT)

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2158-2158
Author(s):  
Mohamed A. Yassin ◽  
Ahmed M Elawa ◽  
Ashraf T Soliman
Keyword(s):  
Glucose Tolerance ◽  
Oral Glucose Tolerance Test ◽  
Glucose Tolerance Test ◽  
Cell Function ◽  
Serum Insulin ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Β Cell ◽  
Β Cell Function

Abstract Abstract 2158 Introduction: Both insulin deficiency and insulin resistance are reported in patients with β thalassemia major (BTM). The use of continuous blood glucose monitoring system (CGMS) among the different methods for early detection of glycaemic abnormalities has not been studied thoroughly in these patients. Aims: The aims of this study were: 1. to detect glycaemic abnormalities, if any, in young adults with BTM using fasting blood glucose (FBG), oral glucose tolerance test (OGTT), 72-h continuous glucose concentration by CGMS system, and serum insulin and C-peptide concentrations 2. To compare the results of these two methods in detecting glycaemic abnormalities in these patients and 3. To calculate homeostatic model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI) in these patients. In order to evaluate whether glycaemic abnormalities are due to insulin deficiency and/or resistance. Materials and methods: Randomly selected young adults (n = 14) with BTM were the subjects of this study. All patients were investigated using a standard oral glucose tolerance test (OGTT) (using 75 gram of glucose) and 72-h continuous glucose concentration by CGM system (Medtronic system). Fasting serum insulin and C-peptide concentrations were measured and HOMA-B, HOMA-IR were calculated accordingly. Results: Using OGTT, 5 patients had impaired fasting glucose (IFG) (Fasting BG from 5.6 to 6.9 mmol/L). Two of them had impaired glucose tolerance IGT (BG from 7.8 and < 11.1 mmol/L) and one had BG = 16.2 mmol/L after 2-hrs (diabetic). Using CGMS in addition to the glucose data measured by glucometer (3–5 times/ day), 6 patients had IFG. The maximum (postprandial) BG recorded exceeded 11.1 mmol/L in 4 patients (28.5%) (Diabetics) and was > 7.8 but < 11.1 mmol/L in 8 patients (57%) (IGT). The mean values of HOMA and QUICKI in patients with BTM were < 2.6 (1.6± 0.8) and > 0.33 (0.36±0.03) respectively ruling out significant insulin resistance in these adolescents. There was a significant negative correlation between the β-cell function (B %) on the one hand and the fasting and the 2-h BG (r= −0.6, and − 0.48, P< 0.01 respectively) on the other hand. Serum insulin concentrations were not correlated with fasting BG or ferritin levels. The average and maximum BG levels recorded by CGMS were significantly correlated with the fasting BG (r= 0.69 and 0.6 respectively with P < 0.01) and with the BG at 2-hour after oral glucose intake (r= 0.87and 0.86 respectively with P < 0.01). Ferritin concentrations were positively correlated with the fasting BG and the 2-h BG levels in the OGTT (r= 0.69, 0.43 respectively, P < 0.001) as well as with the average and the maximum BG recorded by CGM (r =0.75, and 0.64 respectively with P < 0.01). Ferritin concentrations were negatively correlated with the β-cell function (r= −0.41, P< 0.01). Conclusion: CGMS has proved to be superior to OGTT for the diagnosis of glycaemic abnormalities in young adult patients with BTM. In our patients, defective β-cell function rather than insulin resistance appeared to be the cause for these abnormalities. The significant correlations between serum ferritin concentrations and the beta cell functions suggested the importance of adequate chelation to prevent β-cell dysfunction Disclosures: No relevant conflicts of interest to declare.

scholarly journals Evaluation of Fasting State-/Oral Glucose Tolerance Test-Derived Measures of Insulin Release for the Detection of Genetically Impaired β-Cell Function

PLoS ONE ◽  
2010 ◽  
Vol 5 (12) ◽  
pp. e14194 ◽  
Author(s):  
Silke A. Herzberg-Schäfer ◽  
Harald Staiger ◽  
Martin Heni ◽  
Caroline Ketterer ◽  
Martina Guthoff ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Oral Glucose Tolerance Test ◽  
Glucose Tolerance Test ◽  
Cell Function ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Fasting State ◽  
Oral Glucose Tolerance ◽  
Β Cell ◽  
Β Cell Function

scholarly journals Evaluation of oral glucose tolerance test, β-cell function and adverse obstetric outcomes

2013 ◽  
Vol 1 (5) ◽  
pp. 807-811 ◽  
Author(s):  
HONGXIU ZHANG ◽  
DONGMEI ZHAO ◽  
JIE SHEN ◽  
XIAOPING ZHOU ◽  
WENWEI CHEN ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Oral Glucose Tolerance Test ◽  
Glucose Tolerance Test ◽  
Cell Function ◽  
Tolerance Test ◽  
Obstetric Outcomes ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Β Cell ◽  
Β Cell Function

scholarly journals Identification of insulin secretory defects and insulin resistance during oral glucose tolerance test in a cohort of cystic fibrosis patients

2011 ◽  
Vol 165 (1) ◽  
pp. 69-76 ◽  
Author(s):  
A Battezzati ◽  
A Mari ◽  
L Zazzeron ◽  
G Alicandro ◽  
L Claut ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Cell Function ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Β Cell ◽  
Β Cell Function

BackgroundCystic fibrosis (CF)-related diabetes is a leading complication of CF and is associated with pulmonary and nutritional deterioration, years before an evident hyperglycemia, possibly because of insulin deficiency and resistance.AimTo evaluate glucose tolerance, insulin secretion, and insulin sensitivity by a widely applicable method suitable for accurate and prospective measurements in a CF population.MethodsA total of 165 CF subjects (80 females) aged 17±5 years and 18 age- and sex-matched healthy controls (CON) received an oral glucose tolerance test with glucose, insulin and C-peptide determinations. Insulin sensitivity was defined on the basis of glucose and insulin concentrations using the oral glucose insulin sensitivity index, whereas β-cell function was determined on the basis of a model relating insulin secretion (C-peptide profile) to glucose concentration.ResultsFifteen percent of CF patients had glucose intolerance and 6% had diabetes without fasting hyperglycemia and 3% had diabetes with fasting hyperglycemia. β-cell function was reduced in CF patients compared with CON (70.0±4.1 vs 117.9±11.6 pmol/min per m2 per mM, P<0.001) and decreased significantly with age by −2.7 pmol/min per m2 per mM per year (confidence interval (CI) −4.5 to −0.82), i.e. almost 4% yearly. The early insulin secretion index was also reduced. Insulin sensitivity was similar to CON. CF patients who attained glucose tolerance comparable to CON had lower β-cell function and higher insulin sensitivity.ConclusionThe major alteration in insulin secretion and insulin sensitivity of CF patients is slowly declining β-cell function, consisting of delayed and reduced responsiveness to hyperglycemia, that in CF patients with normal glucose tolerance may be compensated by an increased insulin sensitivity.

Shape of glucose, insulin, C-peptide curves during a 3-h oral glucose tolerance test: any relationship with the degree of glucose tolerance?

2011 ◽  
Vol 300 (4) ◽  
pp. R941-R948 ◽  
Author(s):  
Andrea Tura ◽  
Umberto Morbiducci ◽  
Stefano Sbrignadello ◽  
Yvonne Winhofer ◽  
Giovanni Pacini ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Cell Function ◽  
Shape Index ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Β Cell ◽  
C Peptide ◽  
Β Cell Function

We aimed to analyze the shape of the glucose, insulin, and C-peptide curves during a 3-h oral glucose tolerance test (OGTT). Another aim was defining an index of shape taking into account the whole OGTT pattern. Five-hundred ninety-two OGTT curves were analyzed, mainly from women with former gestational diabetes, with glycemic concentrations characterized by normal glucose tolerance ( n = 411), impaired glucose metabolism ( n = 134), and Type 2 diabetes ( n = 47). Glucose curves were classified according to their shape (monophasic, biphasic, triphasic, and 4/5-phases), and the metabolic condition of the subjects, divided according to the glucose shape stratification, was analyzed. Indices of shape based on the discrete second-order derivative of the curve patterns were also defined. We found that the majority of the glucose curves were monophasic ( n = 262). Complex shapes were less frequent but not rare ( n = 37 for the 4/5-phases shape, i.e., three peaks). There was a tendency toward the amelioration of the metabolic condition for increasing complexity of the shape, as indicated by lower glucose concentrations, improved insulin sensitivity and β-cell function. The shape index computed on C-peptide, WHOSHCP (WHole-Ogtt-SHape-index–C-peptide), showed a progressive increase [monophasic: 0.93 ± 0.04 (dimensionless); 4/5-phases: 1.35 ± 0.14], and it showed properties typical of β-cell function indices. We also found that the type of glucose shape is often associated to similar insulin and C-peptide shape. In conclusion, OGTT curves can be characterized by high variability, and complex OGTT shape is associated with better glucose tolerance. WHOSHCP (WHole-Ogtt-SHape-index) may be a powerful index of β-cell function much simpler than model-based indices.

Sign in / Sign up

Export Citation Format

Share Document