Abdominal adiposity rather than age and sex predicts mass and regularity of GH secretion in healthy adults

Abstract

We tested the hypothesis that body composition is the major predictor of growth hormone (GH) secretion in nonobese adults. We measured lean and fat tissue distribution (computerized tomography and dual-energy X-ray absorptiometry scan) and physical fitness [maximal oxygen consumption (Vo2max)] in 42 healthy nonobese adults (22 women and 20 men, age range 27-59 yr, 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 with younger subjects. 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 waist-to-hip ratio and positively with Vo2max. Multiple linear regression analysis revealed intra-abdominal fat as the dominant determinant of estimates of GH secretion. Vo2max 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 nonobese adults. Although the underlying mechanisms remain elusive, our findings extend the clinical implications of visceral adiposity to include hyposomatotropism.

Conventional and novel biomarkers of treatment outcome in patients with acromegaly: discordant results after somatostatin analog treatment compared with surgery

“…Several lines of evidence suggest that the elevated GH levels in females represent an increase in GH secretion to compensate for a suppressive effect of estrogen on hepatic IGF1 production (44,45), but the genderspecific difference in patients with acromegaly is also reported in elderly subjects and is not fully accounted for by estrogen status (9). The observation made from that study, which did not include patients on medical treatment, was replicated in our population, and both dataset suggest that additional factors such as abdominal adiposity may contribute to the relative increase in GH levels in females as compared with males (46). It is generally appreciated that health-related quality of life is impaired in acromegaly, and that this impairment is only partially restored following treatment (47)(48)(49).…”

Prevalence of Pituitary Hormone Dysfunction, Metabolic Syndrome, and Impaired Quality of Life in Retired Professional Football Players: A Prospective Study

“…[28][29][30] Consequently, BMI-adjusted cut points for GH stimulation testing test have been proposed and are currently recommended by several consensus guidelines. 31,32 Because of this known inverse relationship with BMI and peak GH after stimulation testing with glucagon, GHRH/arginine, and insulin tolerance testing, GHD was defined at 3 cut points, adjusted for BMI using a normal non-head-injured control cohort referred to the Dynamic Endocrine Testing Unit at the Oregon Health & Science University (Portland, OR) for assessment of possible GHD with low normal to low serum IGF-1 levels.…”

Aspectos neuroendócrinos da síndrome metabólica

“…As alterações no eixo somatotrófico, relacionadas à obesidade, parecem ser ocasionadas mais por fatores associados à SM do que ao simples aumento do tecido adiposo. Interessante é que a inibição da secreção de GH aos estímulos farmacológicos, como arginina e clonidina, relaciona-se inversa e independentemente com o teor de gordura visceral, medida por tomografia computadorizada (51). Além do mais, o pool de GH em 24 horas também se mostrou inversamente relacionado com a gordura visceral (52).…”