Influence of ethnicity on IGF-I and procollagen III peptide (P-III-P) in elite athletes and its effect on the ability to detect GH abuse

Summary Context A method based on the two GH dependent markers, IGF‐I and procollagen III peptide (P‐III‐P) has been proposed to detect exogenously administered GH. As previous studies involved predominantly white European elite athletes, it is necessary to validate the method in other ethnic groups. Objective To examine serum IGF‐I and P‐III‐P in elite athletes of different ethnicities within 2 h of competing at national or international events. Design Cross‐sectional observational study. Setting National and International sporting events. Subjects 1085 elite athletes of different ethnicities. Intervention Serum IGF‐I and P‐III‐P were measured and GH‐2000 discriminant function score was calculated. Effect of ethnicity was assessed. Results In men, IGF‐I was 21·7 ± 2·6% lower in Afro‐Caribbeans than white Europeans (P