Abstract
Context: The GH-2000 and GH-2004 research groups developed a method for detecting GH misuse in athletes based on the measurement of serum IGF-I and P-III-NP. There are reports that IGF-I is also misused by athletes but currently there is no internationally recognised test designed to detect recombinant human IGF-I misuse.
Objective: To examine the response of serum IGF-I, P-III-NP and the GH-2000 score to rhIGF-I/rhIGFBP-3 administration in recreational athletes.
Design and Setting: Randomised, double-blind, placebo-controlled rhIGF-I/rhIGFBP-3 administration study at Southampton General Hospital, UK.
Participants: 56 recreational athletes (26 women, 30 men).
Intervention: Participants were randomised to treatment with low dose (30mg/day), high dose (60mg/day) rhIGF-I/rhIGFBP-3 complex or placebo for 28 days. Blood was collected throughout the drug administration and washout periods. Serum IGF-I and P-III-NP were measured using commercial immunoassays and GH-2000 scores were calculated.
Results: IGF-I, P-III-NP and GH-2000 score rose in response to both low and high dose rhIGF-I/rhIGFBP-3 administration. The relative maximum response of IGF-I (approximately four-fold increase in women and men) was greater than that of P-III-NP (40-50% increase in women, 35-50% increase in men). The GH-2000 formulae, which incorporate IGF-I and P-III-NP results, detected up to 61% of women and 80% of men in the rhIGF-I/rhIGFBP-3 groups but using IGF-I concentrations alone, the sensitivity increased to 94% in both women and men during the administration period.
Conclusions: The rise in P-III-NP after rhIGF-I/rhIGFBP-3 administration is small compared with that after rhGH administration. Although rhIGF-I/rhIGFBP-3 administration can be detected using the GH-2000 score method, a test based on serum IGF-I alone provides better sensitivity.
Objective: To examine the response of serum IGF-I, P-III-NP and the GH-2000 score to rhIGF-I/rhIGFBP-3 administration in recreational athletes.
Design and Setting: Randomised, double-blind, placebo-controlled rhIGF-I/rhIGFBP-3 administration study at Southampton General Hospital, UK.
Participants: 56 recreational athletes (26 women, 30 men).
Intervention: Participants were randomised to treatment with low dose (30mg/day), high dose (60mg/day) rhIGF-I/rhIGFBP-3 complex or placebo for 28 days. Blood was collected throughout the drug administration and washout periods. Serum IGF-I and P-III-NP were measured using commercial immunoassays and GH-2000 scores were calculated.
Results: IGF-I, P-III-NP and GH-2000 score rose in response to both low and high dose rhIGF-I/rhIGFBP-3 administration. The relative maximum response of IGF-I (approximately four-fold increase in women and men) was greater than that of P-III-NP (40-50% increase in women, 35-50% increase in men). The GH-2000 formulae, which incorporate IGF-I and P-III-NP results, detected up to 61% of women and 80% of men in the rhIGF-I/rhIGFBP-3 groups but using IGF-I concentrations alone, the sensitivity increased to 94% in both women and men during the administration period.
Conclusions: The rise in P-III-NP after rhIGF-I/rhIGFBP-3 administration is small compared with that after rhGH administration. Although rhIGF-I/rhIGFBP-3 administration can be detected using the GH-2000 score method, a test based on serum IGF-I alone provides better sensitivity.
Original language | English |
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Number of pages | 10 |
Journal | The Journal of clinical endocrinology and metabolism |
DOIs | |
Publication status | E-pub ahead of print - 2014 |