Session: SAT 338-357-Steroid Hormone Actions
Poster Board SAT-349
Objective: To determine whether liver-targeted androgen supplementation induces protein anabolism in GH-replete normal women.
Design: An open-label study.
Patients and intervention: Eight healthy postmenopausal women received 2-weeks treatment with oral T 40 mg/day (crystalline testosterone USP). This dose increases portal T concentrations exerting androgenic effects on the liver without spill-over into the systemic circulation (2).
Main Outcome Measures: Whole body leucine turnover, from which leucine rate of appearance (LRa; an index of protein breakdown) and leucine oxidation (Lox; a measure of irreversible protein loss) were estimated. We measured liver transaminases, as well as testosterone, SHBG and IGF-I in peripheral blood, together with energy expenditure and substrate utilization.
Results: T treatment significantly reduced LRa by 7.1 ± 2.5 % and Lox by 14.6 ± 4.5 % (p<0.05). Liver transaminases did not change significantly, while serum SHBG fell within the normal range by 16.8 ± 4.0 % and IGF-I increased by 18.4 ± 7.7 % (p<0.05). Peripheral T rose from 0.4 ± 0.1 nmol/l at baseline to a mean level of 1.1 ± 0.2 nmol/l, with none exceeding the upper normal limit (3 nmol/l). There was no change in energy expenditure, fat and carbohydrate utilization.
Conclusions: Solely hepatic exposure to unesterified T by oral delivery stimulates protein anabolism by reducing protein breakdown and protein oxidation without inducing systemic androgen excess in women. We conclude that a small oral dose of unesterified T holds promise as a simple novel treatment of protein catabolism and muscle wasting.
1) Birzniece et al., J Clin Endocrinol Metab. 2011 Apr;96(4):1060-7.
2) Birzniece et al., Clin Endocrinol (Oxf). 2009 Nov;71(5):715-21.
Nothing to Disclose: VB, MU, AP, DJH, KH
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