Pharmacodynamics of growth hormone abuse biomarkers and the influence of gender and testosterone: a randomized double-blind placebo-controlled study in young recreational athletes.

Context: IGF axis proteins and collagen peptides are promising markers of GH abuse. Objective: Our objective was to investigate whether responses of serum IGF axis and collagen markers to GH differ between men and women, and are influenced by testosterone (T). Design: This was a randomized, double-blind, placebo-controlled study of 8-wk treatment followed by 6-wk washout. Setting: The study was performed at a clinical research facility. Participants: A total of 96 recreationally trained healthy athletes (63 men, 33 women), aged 18–40 yr, were studied. Intervention: All subjects received GH (2 mg/d sc) or placebo for 8 wk; men also received T (250 mg/wk im) or placebo for 5 wk. Main Outcome Measures: Serum IGF axis proteins (IGF-I, IGF binding protein-3, and acid labile subunit) and collagen peptides (N-terminal propeptide of type I procollagen, C-terminal telopeptide of type I collagen, and N-terminal propeptide of type III procollagen) were measured. Results: GH induced significant increases in IGF axis ...