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

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.