Inability of Some Commercial Assays to Measure Suppression of Glucagon Secretion

Area of Science:

• Endocrinology
• Clinical Chemistry
• Assay Development

Background:

• Glucagon levels are increasingly important clinical trial endpoints, particularly in diabetes research.
• Over 400 clinical trials currently use glucagon as an outcome measure.
• Reliability of immunoassays for measuring endogenous glucagon is critical.

Purpose of the Study:

• To evaluate the ability of four different immunoassay technologies to detect suppressed glucagon levels.
• To compare the performance of advanced (electrochemiluminescence, HTRF) and traditional (radioimmunoassay, ELISA) methods.

Main Methods:

• Assessed four immunoassay technologies for measuring glucagon.
• Studied assay performance under conditions of glucagon suppression induced by a glucose clamp (6 mmol/L) in healthy males.
• Included atropine as a potential modulator of glucagon suppression.

Main Results:

• Electrochemiluminescence and HTRF assays failed to detect glucagon suppression during glucose clamp.
• Radioimmunoassay and spectrophotometry-based ELISA successfully detected glucagon suppression.
• The study involved five healthy male participants.

Conclusions:

• Measurement of low-abundant peptides like human glucagon presents significant challenges, even with advanced technologies.
• Clinical researchers should carefully validate their chosen glucagon assay, as the most technologically advanced method is not always superior.
• The findings suggest a need to reconsider the validity of certain glucagon assays used in clinical studies.