Clinical trial NCT04018430: Impact of Oral Glucose Tolerance Test on Extent of Hemoglobin Glycation
Official title: Impact d'Une Surcharge Glycemique Sur le Taux HbA1c
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Blood Glucose, High
Oral Hypoglycaemic Overdose
Keywords: glucose, insulin, HbA1c
Lead sponsor: Labormedizinisches Zentrum Dr. Risch
Sponsor class: INDUSTRY
Collaborators: name: Labormedizinisches Zentrum Dr. Risch
First posted: 2019-07-12
Enrollment: 100
Sex: ALL
Minimum age (years): 5
Maximum age (years): 40
Standard ages: CHILD
ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
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

Brief summary: 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.

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

Eligibility criteria: 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

Primary outcomes:
measure: HbA1c concentration upon oral glucose tolerance testing
timeFrame: 48 hours
Secondary outcomes:
Other outcomes:
Locations:
city: Bern
country: Switzerland
facility: University of Bern
state: Kanton Bern
Study officials:
affiliation: Labormedizinisches Zentrum Dr. Risch
name: Urs Nydegger, MD
role: STUDY_CHAIR
References:
citation: 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.
citation: 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.