Impact of the GH-cortisol ratio on the age-dependent changes in body composition.
Aging is associated with a decrease in GH levels and this is paralleled by changes in body composition, i.e., increased visceral fat, and decreased lean body mass and bone mineral density. Similar changes in body composition are seen in the state of hypercortisolism. Increasing age has been shown to be associated with elevated evening cortisol levels in men. An increased exposure of several tissues to glucocorticoids with aging, i.e., visceral fat cells, in combination with the reduction of the lipolytic effects of declining GH levels, may contribute to the age-dependent increase of visceral fat accumulation. We hypothesize that the age-dependent changes in body fat are the result of an age-dependent decrease of the GH/cortisol ratio at the level of the adipocyte. This is caused by the decline in GH concentrations and the increase in cortisol levels and/or metabolism at the adipocyte.
Nass
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Department of Medicine, University of Virginia Health System, Charlottesville, Virginia 22908, USA.
Thorner
M O
MO
D017667:Adipocytes / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D000818:Animals; D001823:Body Composition; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D019382:Human Growth Hormone / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D009765:Obesity / Q000209:etiology / Q000378:metabolism; D010913:Pituitary-Adrenal System / Q000378:metabolism
D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D006854:Hydrocortisone