The bradykinin β2 receptor (BDKRB2) and endothelial nitric oxide synthase 3 (NOS3) genes and endurance performance during Ironman Triathlons

Abstract

We have previously shown that the insertion allele of the angiotensin-converting enzyme (ACE) gene was over-represented in the fastest South-African-born finishers of the South African Ironman Triathlons. As ACE is a component of the skeletal muscle kallikrein-kinin system (KKS), the aim of this study is to determine if there are any further associations between polymorphisms within the BDKRB2 and NOS3 genes, which encode for the KKS components, bradykinin beta(2) receptor and nitric oxide synthase, respectively, and ultra-endurance performance during the Ironman Triathlons. Four-hundred and forty-three male Caucasian triathletes who completed the 2000 and/or 2001 South African Ironman Triathlons and 203 healthy Caucasian male control subjects were genotyped for the functional -9/+9 polymorphism within exon 1 of the BDKRB2 gene and the G894T NOS3 gene polymorphisms. The BDKRB2 -9/-9 genotype occurred at a significantly higher frequency when the triathlete group (27.0%) was compared with the control group (19.3%, P=0.035). When divided into tertiles, there was also a significant linear trend for the NOS3 GG genotype distribution among the fastest (35.0%), middle (40.4%) and slowest (46.9%) finishers (P=0.039). The overall finishing times of the triathletes with an NOS3 GG genotype together with a BDKRB2 +9 allele were significantly slower than those with other genotype combinations (P=0.001). The NOS3/BDKRB2 genotype (beta=-0.150, B=-31.48, P=0.002), together with body mass index and age, accounted for 14.6% of the variance in the overall race time for the triathlon. In conclusion, both the NOS3 and BDKRB2 genes are associated with the actual performance during the Ironman Triathlons.

Endothelial nitric oxide synthase g894t (rs1799983) gene polymorphism in polish athletes

“…There were no significant differences in the frequencies of the genotype and allele distributions of the NOS3 gene G894T polymorphism between groups of triathletes classified according to finishing time into fastest (n=148), middle (n=147), slowest (n=148) and control subjects (n=203), however, the triathletes with a GG NOS3 genotype were significantly slower in the swimming and cycling phases than those possessing a 894T allele [30]. In contrast to Saunders et al [30], we did not find an association of G894T with athletic performance. There were no differences in the G894T allele frequencies in athletes stratified by the level of competitiveness (elite versus sub-elite) regardless of the athletes' status (power, "mixed" and endurance).…”

“…In contrast, Saunders et al found a significant association of this variant with endurance performance in triathletes [30]. There were no significant differences in the frequencies of the genotype and allele distributions of the NOS3 gene G894T polymorphism between groups of triathletes classified according to finishing time into fastest (n=148), middle (n=147), slowest (n=148) and control subjects (n=203), however, the triathletes with a GG NOS3 genotype were significantly slower in the swimming and cycling phases than those possessing a 894T allele [30]. In contrast to Saunders et al [30], we did not find an association of G894T with athletic performance.…”

“…Hence, the NOS3 gene, due to its central role in the production of NO in the vascular endothelium [6], became a candidate gene for association with athlete status or athletic performance. Indeed, NOS3 has been associated with endurance performance, endurance elite status [6,30], power elite athlete status [31,32] and elite soccer player's status [33], being an example of "mixed" exercise phenotype requiring both endurance and power abilities.…”

“…Saunders et al [30] reported an excess of the G894 allele (combined with a DKRB2 -9/-9 genotype) in the fastest finishing Caucasian Ironman triathletes when compared with control subjects. However, Wolfarth et al [6] in the Genathlete study found no difference in allele and genotype frequencies of the G894T between elite endurance athletes and controls.…”

The Endothelial Nitric Oxide Synthase Gene Variant rs2070744 in Turkish Elite Athletes

“…In in-vitro luciferasebased transcription analysis, it was shown that C allele of eNOS has a lower promoter activity than T allele [6]. In previous studies, it was reported that eNOS G894T variant was associated with physical performance [23] however in another study, it wasn't found difference three variants of eNOS compared with controls [24]. When distribution of alleles is investigated, there are studies reporting that T allele is more abundant in athletes [25][26][27].…”