| Popis: |
Growth hormone (GH) treatment decreases total body fat while this effect has not yet been documented for the oral GH secretagogue MK-677. In the present study, the effects of MK-677 treatment on serum levels of leptin, thyroid hormones and testosterone were determined.This was a randomized, double-blind, and parallel study. Twenty-four healthy obese males, 19-49 years of age, with body mass index (BMI)30 kg/m2 and a waist:hip ratio0.95, were treated with MK-677 (25 mg/day; n = 12) or placebo (n = 12) for 8 weeks.MK-677 treatment increased serum leptin levels and leptin/body fat ratio at 2 weeks of treatment (P0.05 vs. placebo) but no significant change was observed at 8 weeks. An increase in serum free 3, 5, 3'-triiodothyronine (free T3) was not detected until 8 weeks of MK-677 treatment (P0.05 vs. placebo). Peak serum thyroid stimulating hormone (TSH) concentration after MK-677 administration was similar to that after placebo administration at initiation of treatment and at 2 weeks. At 8 weeks of MK-677 treatment, mean peak serum TSH concentration was increased (P0.05 vs. placebo) although it remained within the normal range. Serum peak values of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were similar after MK-677 and placebo administration. MK-677 treatment reduced serum total testosterone (P0.05 vs. placebo) although total testosterone/sex hormone-binding globulin (SHBG) ratio (an index of free testosterone) was not changed.Treatment with the oral GH secretagogue MK-677 transiently increased serum leptin levels and leptin/body fat ratio at 2 weeks of treatment, and increased serum free T3 after 8 weeks. These results indicate that MK-677 treatment is able to affect circulating factors of importance for adipose tissue mass and fuel metabolism. |
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