Author:
Atila Cihan,Monnerat Sophie,Urwyler Sandrine Andrea,Refardt Julie,Winzeler Bettina,Christ-Crain Mirjam
Abstract
Abstract
Purpose
Non-osmotic stimulation tests using glucagon, arginine, or macimorelin were recently evaluated for their ability to assess posterior pituitary function. Glucagon and arginine, but not macimorelin, stimulated copeptin secretion (a surrogate marker of vasopressin) and, therefore, provide novel tests to assess the posterior pituitary. The exact underlying mechanism behind their stimulatory effect remains elusive.
Methods
This analysis combined data from three diagnostic studies conducted at the University Hospital Basel, Switzerland. In total, 80 healthy adults underwent the glucagon (n = 22), arginine (n = 30), or macimorelin (n = 28) stimulation tests. The primary objective was to investigate glucose course upon glucagon, arginine, and macimorelin stimulation tests and its effect on plasma copeptin release.
Results
Upon glucagon stimulation, the median [IQR] glucose level at baseline was 5.0 [4.6, 5.2] mmol/l, peaked at 8.1 [7.2, 9.4] mmol/l after 30 min and decreased to a minimum of 3.8 [3.5, 4.5] mmol/l after 120 min. The median copeptin increase upon glucagon stimulation was 7.7 [2.6, 28.0] pmol/l. Upon arginine, the glucose level at baseline was 4.9 [4.8, 5.5] mmol/l, peaked at 6.0 [5.2, 6.4] mmol/l after 30 min and decreased to a minimum of 4.3 [3.8, 4.8] mmol/l after 60 min. The median copeptin increase upon arginine stimulation was 4.5 [2.9, 7.5] pmol/l. Upon macimorelin, glucose levels showed no notable dynamics over the 120 min, and no major change in copeptin was observed.
In the pooled dataset, a decrease in glucose levels was significantly correlated with copeptin increase (ρ = 0.53, p < 0.01).
Conclusion
A similar course in plasma glucose was observed in the copeptin-stimulating test, i.e., after glucagon and arginine, while macimorelin had no effect on glucose and copeptin levels. We hypothesize that a drop in glucose levels observed upon glucagon and arginine might stimulate copeptin.
Funder
Swiss Academy of Medical Sciences and G.& J. Bangerter-Rhyner Foundation
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
Schweizerische Gesellschaft für Endokrinologie und Diabetologie
University of Basel
Publisher
Springer Science and Business Media LLC
Subject
Endocrinology,Endocrinology, Diabetes and Metabolism