Amaya Buxens

World-class performance in lightweight rowing: is it genetically influenced? A comparison with cyclists, runners and non-athletes

In this study, genotype frequencies of several polymorphisms that are candidates to influence sports performance (ie, ACTN3 R577X, ACE ID, PPARGC1A Gly482Ser, AMPD1 C34T, CKMM 985bp/1170bp and GDF8 (myostatin) K153R) were compared in 123 nonathletic controls, 50 professional cyclists, 52 Olympicclass runners and 39 world-class rowers (medallists in world championships, lightweight category). Significant differences in genotype distributions among the groups were not found except for the ACE gene, that is, lower (p<0.05) proportion of II in rowers (10.3%) than in the total subject population (22.3%). In summary, sports performance is likely polygenic with the combined effect of hundreds of genetic variants, one possibly being the ACE ID polymorphism (at least in the sports studied here), but many others remain to be identified.

Can we predict top‐level sports performance in power vs endurance events? A genetic approach

The goal of our study was to discriminate potential genetic differences between humans who are in both endpoints of the sports performance continuum (i.e. world‐class endurance vs power athletes). We used DNA‐microarray technology that included 36 genetic variants (within 20 different genes) to compare the genetic profile obtained in two cohorts of world‐class endurance (N=100) and power male athletes (N=53) of the same ethnic origin. Stepwise multivariate logistic regression showed that the rs1800795 (IL6−174 G/C), rs1208 (NAT2 K268R) and rs2070744 (NOS3−786 T/C) polymorphisms significantly predicted sport performance (model χ2=25.3, df=3, P‐value <0.001). Receiver–operating characteristic (ROC) curve analysis showed a significant discriminating accuracy of the model, with an area under the ROC curve of 0.72 (95% confidence interval: 0.66–0.81). The contribution of the studied genetic factors to sports performance was 21.4%. In summary, although an individuals potential for excelling in endurance or power sports can be partly predicted based on specific genetic variants (many of which remain to be identified), the contribution of complex gene–gene interactions, environmental factors and epigenetic mechanisms are also important contributors to the “complex trait” of being an athletic champion. Such trait is likely not reducible to defined genetic polymorphisms.

The-174 G/C polymorphism of the IL6 gene is associated with elite power performance

The -174 G/C polymorphism [rs1800795] of the IL6 gene is a candidate to explain individual variations in health and exercise related phenotypes. We compared -174 G/C genotypic and allelic frequencies in three groups of men of the same Caucasian (Spanish) descent: elite endurance athletes (cyclists, runners; n=100); elite power athletes (jumpers, throwers, sprinters; n=53) and non-athletic controls (n=100). The frequency of the GG genotype (P=0.030) and G allele (P=0.026) was higher in the power athletes group compared with the control group. The frequency of the GG genotype (P=0.033) and G allele (P=0.013) was also higher in the power athletes group compared with the endurance athletes group. The odds ratio of being a power athlete if the subject had the GG genotype (dominant model) was 2.471 (95% confidence interval: 1.242-4.915) compared to the control group or the endurance athlete group. We did not find differences between the control and endurance athlete groups. In summary, our findings suggest that the G allele of the IL6 -174 G/C polymorphism might favour sprint/power sports performance.

Are elite endurance athletes genetically predisposed to lower disease risk

We compared a polygenic profile that combined 33 disease risk-related mutations and polymorphisms among nonathletic healthy control subjects and elite endurance athletes. The study sample comprised 100 healthy Spanish male nonathletic (sedentary) control subjects and 100 male elite endurance athletes. We analyzed 33 disease risk-related mutations and polymorphisms. We computed a health-related total genotype score (TGS, 0-100) from the accumulated combination of the 33 variants. We did not observe significant differences in genotype or allele distributions among groups, except for the rs4994 polymorphism (P < 0.001). The computed health-related TGS was similar among groups (23.8 +/- 1.0 vs. 24.2 +/- 0.8 in control subjects and athletes, respectively; P = 0.553). Similar results were obtained when computing specific TGSs for each main disease category (cardiovascular disease and cancer). We observed no evidence that male elite endurance athletes are genetically predisposed to have lower disease risk than matched nonathletic control subjects.