Association between a β2-adrenergic receptor polymorphism and elite endurance performance

The Arg16Gly single nucleotide polymorphism of the human β 2-adrenoceptor (ADRB2) gene was evaluated in a case-control study that included 313 white male elite endurance athletes and 297 white male sedentary controls (SCs) recruited in a multicenter project from North America, Finland, and Germany. The groups were matched by country of origin. The elite endurance athletes were required to have a maximum oxygen uptake ≥75 mL·kg−1·min−1 (mean [SD], 79.0 [3.5]), whereas SC subjects had to be sedentary with a measured maximum oxygen uptake ≤50 mL·kg−1·min−1 (40.1 [7.0]). Polymerase chain reaction technique was used to amplify the single nucleotide polymorphism–containing region in codon 16 of the ADRB2 gene. ADRB2 genotypes were in Hardy-Weinberg equilibrium in both groups. Genotypes did not differ between countries or sports of the athletes. The χ 2 analysis for the genotype distribution showed a significant difference between the 2 cohorts (P = .030), suggesting a positive association between the tested Arg16Gly polymorphism and endurance performance. Comparing carriers vs non-carriers for the 2 alleles, an excess of Gly allele carriers was seen in the SC group (P = .009), indicating an unfavorable effect of the Gly allele with respect to the performance status. In conclusion, we found suggestive evidence that the Arg16Gly polymorphism in the gene encoding for the β 2-adrenergic receptor may associate with endurance performance status in white men.