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.
BACKGROUND
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.


METHODS
Cross-sectional observational study.


METHODS
National and International sporting events.


METHODS
1085 elite athletes of different ethnicities.


METHODS
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 < 0.0001) but there were no differences between other ethnic groups. In women, IGF-I was 14.2 +/- 5.1% lower in Afro-Caribbeans (P = 0.005) and 15.6 +/- 7.0% higher in Orientals (P = 0.02) compared with white Europeans. P-III-P was 15.2 +/- 3.5%, 26.6 +/- 6.6% and 19.3 +/- 5.8% lower in Afro-Caribbean (P < 0.0001), Indo-Asian (P < 0.0001) and Oriental men (P = 0.001), respectively, compared with white European men. In women, P-III-P was 15.7 +/- 4.7% lower in Afro-Caribbeans compared to white Europeans (P =0.0009) but there were no differences between other ethnicities. Despite these differences, most observations were below the upper 99% prediction limits derived from white European athletes. All GH-2000 scores lay below the cut-off limit proposed for doping.


CONCLUSIONS
The GH-2000 detection method based on IGF-I and P-III-P would be valid in all ethnic groups.
Erotokritou-Mulligan
Ioulietta
I
Endocrinology and Metabolism Unit, Developmental Origins of Health and Disease Division, School of Medicine, University of Southampton, Southampton, UK.
Bassett
E Eryl
EE
Cowan
David A
DA
Bartlett
Christiaan
C
McHugh
Cathy
C
Sönksen
Peter H
PH
Holt
Richard I G
RI
D000293:Adolescent; D000328:Adult; D000375:Aging; D044466:Asian People / Q000235:genetics; D044383:Black People / Q000235:genetics; D004300:Doping in Sports; D005006:Ethnicity; D005260:Female; D019382:Human Growth Hormone / Q000032:analysis*; D006801:Humans; D007334:Insulin-Like Growth Factor I; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D011347:Procollagen / Q000097:blood; D013177:Sports; D015813:Substance Abuse Detection / Q000379:methods*; D044465:White People / Q000235:genetics
D010446:Peptide Fragments; D011347:Procollagen; C041876:procollagen Type III-N-terminal peptide; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I