Impact of Oral Glucose Tolerance Test on Extent of Hemoglobin Glycation (HbA1c)

Impact d'Une Surcharge Glycemique Sur le Taux HbA1c

The glycation extent of human hemoglobin is under control of the Maillard reaction, a chemical interaction between an amino acide and a reducing sugar. About 5% ( 31.1 mmol/mol) of hemoglobin molecules secluded in a red blood cell are glycated; excessive values > 6.5% point to prediabetes or overt diabetes mellitus. To ascertain the diagnosis doctors prescribe oral glucose tolerance upon which glucose concentrations in blood increase - how much HbA1c reacts under these circumstances is ill known.

Study Overview

• Status: Unknown
• Conditions: Blood Glucose, High; Oral Hypoglycaemic Overdose

Detailed Description

Medical laboratory assays for delineation of impaired glucose metabolism and overt diabetes mellitus, beyond measurement of (fasting) blood serum or plasma glucose levels, include extent of hemoglobin A1c glycation, concentration of fructosamines, insulin concentrations to calculate the homeostasis model assessment (HOMA) index and other clinically putative biomarkers of glucose homoeostasis. HbA1c levels form now part of routine elucidation of metabolic disorders and are used for therapy monitoring. Initially used to monitor glucose levels in follow-up care of diabetics it is considered as a track marker of ups and downs of blood glucose concentrations. Its behavior under the 2 h period of oral glucose tolerance tests (OGTT) is ill known - most clinicians believe the glycation extent will not change. Since the dynamics of glycation is temperature dependent,non-febrile patients under OGTT likely keep their glycation extent between time zero and 120 min after glucose charge constant but this has not been investigated and with the sensitive lab assays for HbA1c now in use we postulate a significant increase in glycation. The Patient Registry includes recruited children and adults sick from diabetes, overweight or metabolic syndrome as a whole. Three medical offices will address their patients to the VidyMed lab to perform the OGTT framed by lab assays on venous blood samples

• Study Type: Observational
• Enrollment (Anticipated): 100

Contacts and Locations

• Study Contact: Name: Nathalie Gilliéron, CT; Phone Number: +41(0)21 622.87.32; Email: nathalie.gillieron@vidymed.ch
• Study Contact Backup: Name: Urs Nydegger, MD; Phone Number: +41(0)58 523.34.66; Email: urs.nydegger@risch.ch

Study Locations

• Switzerland
  • Kanton Bern
    • Bern, Kanton Bern, Switzerland, 3000
      • University of Bern

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 5 years to 40 years (Child, Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

(i) Those suspected to suffer from the metabolic syndrome including high blood pressure, high blood sugar, excess of body fat and increased cholesterol levels (ii) patients with overt impaired carbohydrate metabolisms, under treatment and tested for follow up

Description

Inclusion Criteria:

• apparently healthy subjects or subjects supposedly experiencing a metabolic disease (e.g. prediabetes) Subjects with asked for fasting blood glucose

Exclusion Criteria:

• current steroid use thyroid dysfunction (free-thyroxin levels < 9 or > 19 pmol/L, hsCRP > 10 mg/L hospitalized

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
HbA1c concentration upon oral glucose tolerance testing	HbA1c significantly increases upon oral glucose tolerance testing	48 hours

Collaborators and Investigators

• Sponsor: Urs E. Nydegger
• Collaborators: Labormedizinisches Zentrum Dr. Risch
• Investigators: Study Chair: Urs Nydegger, MD, Labormedizinisches Zentrum Dr. Risch

Publications and helpful links

General Publications

• Medina Escobar P, Moser M, Risch L, Risch M, Nydegger UE, Stanga Z. Impaired glucose metabolism and type 2 diabetes in apparently healthy senior citizens. Swiss Med Wkly. 2015 Nov 23;145:w14209. doi: 10.4414/smw.2015.14209. eCollection 2015.
• Rabbani N, Ashour A, Thornalley PJ. Mass spectrometric determination of early and advanced glycation in biology. Glycoconj J. 2016 Aug;33(4):553-68. doi: 10.1007/s10719-016-9709-8. Epub 2016 Jul 20.

Study record dates

Study Major Dates

• Study Start (Anticipated): September 1, 2019
• Primary Completion (Anticipated): September 30, 2020
• Study Completion (Anticipated): September 30, 2021

Study Registration Dates

• First Submitted: July 10, 2019
• First Submitted That Met QC Criteria: July 10, 2019
• First Posted (Actual): July 12, 2019

Study Record Updates

• Last Update Posted (Actual): July 12, 2019
• Last Update Submitted That Met QC Criteria: July 10, 2019
• Last Verified: July 1, 2019

More Information

Terms related to this study

• Keywords: glucose, insulin, HbA1c
• Additional Relevant MeSH Terms: Chemically-Induced Disorders; Substance-Related Disorders; Drug Overdose
• Other Study ID Numbers: Lmzrisch

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: peer reviewed publication in an anglophone scientific journal. No IPD sharing

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No