Impaired growth hormone secretion in obese subjects is partially reversed by acipimox-mediated plasma free fatty acid depression.

GH secretion in response to provocative stimuli is blunted in obese patients. On the other hand, increases in plasma free fatty acids (FFA) inhibit the GH response to a variety of stimuli, and FFA levels in plasma are increased with obesity. To ascertain whether FFA might be responsible for the GH secretory alterations of obesity, we studied spontaneous and stimulated GH secretion in 31 obese patients after FFA reduction by acipimox, a lipid-lowering drug devoid of serious side-effects. Each subject underwent two paired tests. In one, acipimox was administered orally at a dose of 250 mg at -270 min and at a dose of 250 mg at -60 min; in the matched test, placebo was given at similar intervals. To induce GH release, three stimuli acting through different mechanisms were used: pyridostigmine (60 mg, orally, at -60 min), GHRH (100 micrograms, iv, at 0 min), and GHRH plus GH-releasing peptide (GHRP-6; His-D-Trp-Ala-Trp-D-Phe-Lys-NH2; both at a dose of 100 micrograms, iv, at 0 min). GH secretion was analyzed a...