Abdominal adiposity rather than age and sex predicts the mass and
regularity of growth hormone secretion in healthy adults.
Vahl, Nina, Jens O. L. J[stod]orgensen, Christian Skjaerbaek, Johannes
D. Veldhuis, Hans Rskov, and Jens S. Christiansen.
Medical Department M (Endocrinology and Diabetes), and Center for
Clinical Pharmacology, Aarhus Kommunehospital (N.V., J.O.L.J.,
J.S.C.), and Institute of Experimental Clinical Research (C.S, H.),
Aarhus University, Aarhus, Denmark; Endocrinology Division, NSF
Center for Biological Timing, and University of Virginia, Health
Sciences Center, Charlottesville, VA 22908 (J.D.V)
APStracts 4:0045E, 1997.
We tested the hypothesis that body composition is the major predictor
of growth hormone (GH) secretion in non-obese adults. We measured
lean and fat tissue distribution (CT and DXA scan), and physical
fitness (VO2-max) in 42 healthy, non-obese adults [22 women and 20
men, age range 27-59 years, mean+/-SE body mass index=24+/-0.5
kg/m2]. Deconvolution analysis was used to estimate specific features
of 24-h GH secretion and clearance. Approximate entropy was used to
quantify the regularity of GH release. Older subjects exhibited
decreased estimates of GH secretion compared to younger. Females had
higher estimates of GH secretion, a longer GH half-life, and
displayed more irregularity in GH release than males. Mean 24-h serum
GH concentrations correlated inversely with intra-abdominal fat and
W/H-ratio and positively with VO2-max. Multiple linear regression
analysis revealed intra-abdominal fat as the dominant determinant of
estimates of GH secretion. VO2-max was more important than sex and
age in predicting GH secretion. We conclude that abdominal fat is the
major determinant of GH secretion in healthy non-obese adults.
Although the underlying mechanisms remain elusive, our findings
extend the clinical implications of visceral adiposity to include
hyposomatotropism.
Received 15 July 1996; accepted in final form 4 February 1997.
APS Manuscript Number E336-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 20 February 1997