The effect of sports injury on insulin-like growth factor-I and type 3 procollagen: implications for detection of growth hormone abuse in athletes.

ABSTRACT

CONTEXT A method to detect exogenously administered growth hormone (GH) based on the measurement of two GH-dependent markers, IGF-I and type 3 procollagen (P-III-P) has been proposed. Skeletal or soft tissue injury may alter these markers. Elevations in either of these proteins after injury might lead to a false accusation of doping with GH. OBJECTIVE: The objective of the study was to assess the effect of musculoskeletal or soft tissue injury on IGF-I and P-III-P concentrations in amateur and elite athletes and assess the effect of injury on the proposed GH detection method. DESIGN: This was a longitudinal observational study after sporting injury. SETTING: The study was conducted at Southampton General Hospital and British Olympic Medical Centre. SUBJECTS: Subjects included elite and amateur athletes after an injury. INTERVENTION Interventions included measurement of IGF-I and P-III-P and application of the GH-2000 discriminant function score up to 84 d after an injury as well as classification of injury by type and severity. OUTCOME MEASURES: IGF-I and P-III-P concentration and ability to detect GH abuse in athletes without the risk of false accusation because of an injury were measured. RESULTS: There was no change in IGF-I concentration after an injury. By contrast, P-III-P concentrations rose by 41.1 +/- 16.6%, reaching a peak around 14 d after an injury. The rise in P-III-P varied according to injury type and severity. This rise had a trivial effect on the GH-2000 discriminant function score, and no subject reached the threshold needed for a doping offense. CONCLUSIONS: Although there was a rise in P-III-P after injury, this was insufficient to invalidate the GH-2000 detection method based on IGF-I and P-III-P concentrations.