Register for Low GH, high ATCH responses to glucagon found in obese patients
EndocrinologySeptember 23, 2002
by Maria G. Essig, MS, ELS, senior medical writer - Obesity disturbs the responses of growth hormone (GH) and adrenocorticotropic hormone (ATCH) to glucagon, causing abnormally low GH release and high ATCH release, according to a report in the Journal of Endocrinological Investigation.
"Reduction in both spontaneous and stimulated GH secretion in obesity has been clearly demonstrated," commented F. Tassone and colleagues at the University of Turin, Italy. "Glucagon, at least after im administration, induces clear increase in either GH or ACTH and F levels but its effect on somatotroph and corticotroph secretion in obesity has never been studied."
The investigators measured GH, ACTH, and F levels after glucagon administration in seven obese adults, 24-42 years old, with a body mass index (BMI) of 29.1-43.9 kg/m2 and a waist-to-hip ratio (WHR) ranging from 0.86-1.00, and in six lean adults, 26-32 years old, with a BMI of 19.7-22.5 kg/m2.
Significant increases from baseline levels in GH (3.3 to 11.6 microgram/L; p<0.02) and ACTH (19.0 to 52.9 pg/mL; p<0.02) concentrations occurred in the lean control subjects after glucagon administration (Glucagon administration elicits blunted GH but exaggerated ACTH response in obesity. J Endocrinol Invest, 2002;25(6):551-556).
Obese subjects experienced a lower GH response to glucagon administration (0.8 to 7.4 microgram/L; p<0.05). For GH, covariant analysis revealed that only peak values differed significantly between obese and lean subjects. However, ACTH response was significantly greater in obese subjects than in the normal weight subjects (11,452.6 vs. 4,892.2 pg/mL.min; p<0.05 ).
Lean subjects experienced a significant increase in F levels from baseline (158.3 to 222.3 ng/mL; p<0.05) in response to glucagon. However, F response to glucagon was similar in obese and normal weight subjects (24057.9 vs. 29835.9 ng/mL.min, respectively).
"In conclusion, this study demonstrates that in obese patients the im administration of glucagon elicits blunted GH response but exaggerated ACTH increase which is uncoupled with the adrenal response," commented Tassone and collaborators. "These findings agree with the existence of concomitant GH insufficiency and altered corticotroph function in obesity."
The corresponding author for this study is M. Maccario, Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Turin, Turin, Italy.
A search at www.NewsRx.net using the search term "endocrinology" yielded 381 articles in 30 specialized reports.
Key points reported in this study include:
* Patients with abdominal obesity experienced a significantly greater increase in ACTH response to glucagon administration compared with lean subjects
* Peak GH response to glucagon administration was significantly lower in obese subjects than in normal weight subjects
* No significant difference in F response to glucagon administration was found between obese and lean subjects This article was prepared by Obesity, Fitness & Wellness Week editors from staff and other reports.
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