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

Area of Science:

• Genetics and Sports Science
• Exercise Physiology
• Molecular Biology

Background:

• The Insulin-Like Growth Factor-I receptor (IGF-IR) plays a role in cellular growth and adaptation.
• Specific polymorphisms in the IGF-IR gene, such as the 275124A>C variant, have been linked to exercise-induced cardiac hypertrophy.
• Understanding the prevalence of such genetic variants in different athletic populations can provide insights into performance specializations.

Purpose of the Study:

• To investigate the frequency of the IGF-IR 275124A>C polymorphism (specifically the AA genotype) in elite endurance and power athletes.
• To compare the prevalence of this polymorphism between endurance athletes, power athletes, and non-physically active controls.
• To explore potential associations between the IGF-IR AA genotype and athletic performance levels (elite vs. national).

Main Methods:

• A cohort of 159 athletes (118 men, 41 women) and 68 controls were genotyped for the IGF-IR 275124A>C polymorphism.
• Athletes were categorized into endurance (n=77) and power (n=82) groups based on their sport specialization.
• Participants were further classified as elite or national-level athletes based on competitive achievements.

Main Results:

• The AA genotype was significantly more prevalent in endurance athletes (49%) compared to power athletes (33%), but not different from controls (46%).
• Among endurance athletes, there was no significant difference in AA genotype prevalence between elite and national levels.
• Conversely, elite power athletes showed a significantly lower prevalence of the AA genotype (17%) compared to national-level power athletes (42%).

Conclusions:

• The IGF-IR AA polymorphism may be advantageous for endurance sports, though not directly linked to elite endurance performance.
• The presence of the AA genotype appears to be a potential disadvantage for power athletes, particularly at the elite level.
• IGF-IR polymorphism may help distinguish between athletes at the endurance and power ends of the performance spectrum.