ENDOCRINE ABNORMALITIES IN OBESITY

There are a multitude of endocrine abnormalities in human obesity In t his review, those of steroid hormones, growth hormone (GH), end insuli n are considered, Characteristic of all these abnormalities is that th ey are more pronounced in obesity with central visceral preponderance than with peripheral gluteofemoral enlargement of adipose tissue depot s, Cortisol secretion is frequently increased as a result of a hyperse nsitive hypothalamopituitary adrenal (HPA) axis, This may also be foll owed by increased adrenal androgen secretion in women, The HPA axis di sturbance might be due to excess traffic over the axis and/or a downre gulation of the feedback inhibition by central glucocorticoid receptor s, with or without a genetic susceptibility, Probably secondarily the hypothalamopituitary-gonadal and GH axes are inhibited, The net result is increased cortisol, and, in women, androgen secretions, and inhibi ted gender-specific sex steroid hormones as well as GH, These hormonal abnormalities; in concert with elevated free fatty acid concentration s, probably contribute significantly to peripheral insulin resistance, Cortisol and insulin facilitate triglyceride accumulation, whereas se x steroids and GH both inhibit triglyceride accumulation as well as ac tivate lipid mobilization pathways The endocrine abnormalities in cent ral, visceral obesity therefore seem to create a milieu for Lipid accu mulation in adipose tissue in general, This is probably more pronounce d in visceral than in other adipose tissue depots because of the highe r density of active cytoplasmic mass, elevated blood flow, and dense i nnervation as well as the higher density of specific steroid hormone r eceptors; Therefore, excess triglycerides probably tend to accumulate preferentially in visceral adipose tissue because of the combined endo crine abnormalities in central, visceral obesity. This conclusion is b ased on consistent data regarding cellular and molecular levels from i a Five studies of lipid uptake and mobilization in humans, as,yell. as from clinical and intervention studies with in vitro measurements of metabolic pathways and the net effects on visceral adipose tissue mass , The effect of steroid hormones in women remains nuclear.