IGF-I receptor 275124A>C (rs1464430) polymorphism and athletic performance

ObjectivesTo examine the prevalence of the Insulin-Like Growth Factor-I receptor (IGF-IR) 275124A>C polymorphism, known to be associated with exercise-related cardiac hypertrophy, among elite endurance and power athletes.DesignOne hundred and fifty-nine athletes (118 men and 41 women, age: 35.9 ± 12.2 yrs) participated in the study.MethodsWe hypothesized that presence of the A allele will be significantly more common among endurance athletes (n = 77) compared to power athletes (n = 82) and non-physically active controls (n = 68). Athletes within each group were further divided according to their individual best performance into elite athletes (those who had represented the country in international track-and-field or triathlon competitions or in the Olympic Games) and national-level athletes.ResultsThe prevalence of the AA genotype was significantly higher (p < 0.05) in the endurance athletes group (49%) compared to the power athletes group (33%), but did not differ from the control group (46%). There was no significant difference in the prevalence of the AA genotype between elite and national level endurance athletes (44% versus 52%, respectively). In contrast, among power athletes, the prevalence of the AA genotype was significantly lower in the elite compared to national level athletes (17% versus 42%, respectively; p < 0.05).ConclusionsThe results of the present study may suggest that the IGF-IR AA polymorphism is beneficial for endurance-type sports, but is not associated with elite endurance performance. In contrast, the presence of the AA genotype may be a disadvantage in power sports. All together the results of the present study suggest that IGF-IR polymorphism may differentiate between the two edges of the endurance-power athletic performance spectrum.