The Effect of Fractionating the Caloric Intake on Weight, Serum Lipids, Post-Prandial Blood Sugar, Serum Insulin and the Oral Glucose Tolerance Test in the Normal Adult

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.

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Obestatin Is Not Elevated or Correlated with Insulin in Children with Prader-Willi Syndrome

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2006-0754 ◽

2007 ◽

Vol 92 (1) ◽

pp. 229-234 ◽

Cited By ~ 25

Author(s):

Won Hah Park ◽

Yoo Joung Oh ◽

Gae Young Kim ◽

Sang Eun Kim ◽

Kyung-Hoon Paik ◽

...

Keyword(s):

Glucose Tolerance ◽

Oral Glucose Tolerance Test ◽

Glucose Tolerance Test ◽

Medical Center ◽

Serum Insulin ◽

Tolerance Test ◽

Oral Glucose ◽

Prader Willi Syndrome ◽

Oral Glucose Tolerance ◽

Significant Difference

Abstract Context: Obestatin is a peptide hormone derived from the proteolytic cleavage of ghrelin preprohormone. In Prader-Willi syndrome (PWS), the levels of total ghrelin (TG) and acylated ghrelin (AG) are increased, and these hormones are regulated by insulin. Objective: Our objective was to analyze the changes in the obestatin levels after glucose loading and to characterize the correlations of obestatin with TG, AG, and insulin. Design: Plasma obestatin, TG, AG, and insulin levels were measured in PWS children (n = 15) and controls (n = 18) during an oral glucose tolerance test. Setting: All subjects were admitted to the Samsung Medical Center. Interventions: An oral glucose tolerance test was performed after an overnight fast. Main Outcome Measures: The plasma levels of obestatin, TG, AG, and serum insulin were measured at 0, 30, 60, 90, and 120 min after glucose challenge, and areas under the curves (AUCs) were calculated. Results: No significant difference in AUC of the plasma obestatin was found between the PWS children and normal obese controls (P = 0.885), although AUC of AG (P = 0.002) and TG (P = 0.003) were increased in the PWS children. Moreover, There was a negative correlation between the AUC of AG and AUC of insulin both in PWS (r = −0.432; P = 0.049) and in controls (r = −0.507; P = 0.016). However, AUC of obestatin was not significantly correlated with AUC of insulin (in PWS, r = 0.168 and P = 0.275; in controls, r = −0.331 and P = 0.09). Conclusions: Our results indicate that plasma obestatin is not elevated in PWS children and is not regulated by insulin both in PWS children and in obese controls.

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Thyroidectomy and combined thyroxine-cortisol therapy. Their effects on blood sugar, serum immunoreactive insulin and free fatty acids during an oral glucose tolerance test

Acta Diabetologica Latina ◽

10.1007/bf02581309 ◽

1974 ◽

Vol 11 (2) ◽

pp. 96-105

Author(s):

Aurora Renauld ◽

Rita C. Sverdlik

Keyword(s):

Fatty Acids ◽

Glucose Tolerance ◽

Oral Glucose Tolerance Test ◽

Free Fatty Acids ◽

Blood Sugar ◽

Glucose Tolerance Test ◽

Tolerance Test ◽

Immunoreactive Insulin ◽

Oral Glucose ◽

Oral Glucose Tolerance

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Caffeine ingestion elevates plasma insulin response in humans during an oral glucose tolerance test

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y01-026 ◽

2001 ◽

Vol 79 (7) ◽

pp. 559-565 ◽

Cited By ~ 81

Author(s):

Terry E Graham ◽

Premila Sathasivam ◽

Mary Rowland ◽

Natasha Marko ◽

Felicia Greer ◽

...

Keyword(s):

Blood Glucose ◽

Glucose Tolerance ◽

Oral Glucose Tolerance Test ◽

Glucose Tolerance Test ◽

Serum Insulin ◽

Tolerance Test ◽

Oral Glucose ◽

Oral Glucose Tolerance ◽

Caffeine Ingestion ◽

C Peptide

We tested the hypothesis that caffeine ingestion results in an exaggerated response in blood glucose and (or) insulin during an oral glucose tolerance test (OGTT). Young, fit adult males (n = 18) underwent 2 OGTT. The subjects ingested caffeine (5 mg/kg) or placebo (double blind) and 1 h later ingested 75 g of dextrose. There were no differences between the fasted levels of serum insulin, C peptide, blood glucose, or lactate and there were no differences within or between trials in these measures prior to the OGTT. Following the OGTT, all of these parameters increased (P [Formula: see text] 0.05) for the duration of the OGTT. Caffeine ingestion resulted in an increase (P [Formula: see text] 0.05) in serum fatty acids, glycerol, and plasma epinephrine prior to the OGTT. During the OGTT, these parameters decreased to match those of the placebo trial. In the caffeine trial the serum insulin and C peptide concentrations were significantly greater (P [Formula: see text] 0.001) than for placebo for the last 90 min of the OGTT and the area under the curve (AUC) for both measures were 60 and 37% greater (P [Formula: see text] 0.001), respectively. This prolonged, increased elevation in insulin did not result in a lower blood glucose level; in fact, the AUC for blood glucose was 24% greater (P = 0.20) in the caffeine treatment group. The data support our hypothesis that caffeine ingestion results in a greater increase in insulin concentration during an OGTT. This, together with a trend towards a greater rather than a more modest response in blood glucose, suggests that caffeine ingestion may have resulted in insulin resistance.Key words: adenosine, skeletal muscle, methylxanthines, glucose uptake, diabetes.

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