Glucagon-Like Peptide 1 (GLP-1)

• ISI Order Code:

  GLP1

• CPT Code:

  83519

Clinical Significance:
Glucagon-Like peptide 1 (GLP-1) has two forms of 31 and 37 amino acids produced in the small intestine and in the pancreas in humans. GLP-1 is processed from its precursor, proglucagon, in the pancreatic cells and is a stimulator for insulin secretion in vitro and in vivo. GLP-1 amide is present in many brain regions and may paly a role in the physiological control of feeding implicated in satiation and food intake regulation. Exogenous GLP-1 lowers postprandial glycaemia by slowing gastric emptying, glucagon secretion and food intake. The use of exogenous GLP-1 as an agonist for the GLP-s receptors has been widely used in the management of type 2 diabetes and obesity.

Test validated for clinical use.

• Reference Range:

  Fasting: up to 50 pmol/L

• Procedure:

  GLP-1 is measured by radioimmunoassay

• Expected Turnaround Time:

  3-5 Business Days

Turnaround time is defined as the usual number of days from the date of receipt of a specimen for testing to when the result is released to the ordering facility.

• Report:

  Sample Report

Patient Preparation:

Patient should be fasting 10 – 12 hours prior to collection. Patient should not be on any medications that influence insulin secretion or intestinal motility if possible.

Specimen Collection:

Collect using EDTA plasma collection tube OR 10mL blood directly into ISI’s G.I Preservative, and separate as soon as possible. Freeze plasma immediately after separation. Special G.I Preservative tubes are available from ISI. Minimum specimen size is 1 ml.

Please contact ISI for separation using a non refrigerated centrifuge. Contact ISI for details.

The Inter Science Institute GI Preservative collection and preservative tube is intended for use with Inter Science Institute’s Cholecystokinin (CCK), Ghrelin, GLP-1, Peptide YY (PYY), Secretin, Somatostatin, and VIP assays only. It has not been validated for use with other in vitro assays. Effects of using this device other than as intended are unknown, and is not recommended.

• Rejection Criteria:

  Gross hemolysis/lipemia/icteric

Shipping Instructions:

Ship specimens strictly frozen in dry ice. 

References:

1. Whalley NM, Pritchard LE, Smith DM, White A. Processing of proglucagon to GLP-1 in pancreatic α-cells: is this a paracrine mechanism enabling GLP-1 to act on β-cells?. J Endocrinol. 2011;211(1):99-106. doi:10.1530/JOE-11-0094

2. Meloni AR, DeYoung MB, Lowe C, Parkes DG. GLP-1 receptor activated insulin secretion from pancreatic β-cells: mechanism and glucose dependence. Diabetes Obes Metab. 2013;15(1):15-27. doi:10.1111/j.1463-1326.2012.01663.x

3. Maselli DB, Camilleri M. Effects of GLP-1 and Its Analogs on Gastric Physiology in Diabetes Mellitus and Obesity. Adv Exp Med Biol. 2021;1307:171-192. doi:10.1007/5584_2020_496

4. Prasad-Reddy L, Isaacs D. A clinical review of GLP-1 receptor agonists: efficacy and safety in diabetes and beyond. Drugs Context. 2015;4:212283. Published 2015 Jul 9. doi:10.7573/dic.212283