The -9/+9 polymorphism of the bradykinin receptor Beta 2 gene and athlete status: a study involving two European cohorts.

Previous studies concerning the relevance of BDKRB2 gene polymorphisms revealed that the absence (-9 allele) of a nine-base-pair sequence in exon 1 of the BDKRB2 gene is correlated with higher skeletal muscle metabolic efficiency, glucose uptake during exercise, and endurance athletic performance. The aim of the study was to investigate the association between the BDKRB2 -9/+9 polymorphism and elite athletic status in two cohorts of eastern European athletes. We examined the genotype distribution of the BDKRB2 9/+9 polymorphic site in a group of Polish athletes and confirmed the results obtained in a replication study of Russian athletes. Three hundred and two Polish athletes and 684 unrelated sedentary controls, as well as 822 Russian athletes and 507 unrelated sedentary volunteers, were recruited for this study. All samples were genotyped for the -9/+9 polymorphism within exon 1 of the BDKRB2 gene using polymerase chain reaction. Significance was assessed by chi square analysis with Bonferroni's correction for multiple testing. We found no statistical difference in the -9/+9 genotype and allele frequencies in two groups of athletes divided into four subgroups: endurance, sprint-endurance, sprint-strength, and strength athletes, compared with controls. There were no significant differences in allele frequencies (p = 0.477) and genotype distribution (p = 0.278) in the initial and replication studies. Thus, no association was found between the BDKRB2 -9/+9 polymorphism and elite athletic status in two cohorts of eastern European athletes.