TTN genotype is associated with fascicle length and marathon running performance

The PPARGC1A Gly482Ser polymorphism is associated with elite long-distance running performance

Success in long-distance running relies on multiple factors including oxygen utilisation and lactate metabolism, and genetic associations with athlete status suggest elite competitors are heritably predisposed to superior performance. The Gly allele of the PPARGC1A Gly482Ser rs8192678 polymorphism has been associated with endurance athlete status and favourable aerobic training adaptations. However, the association of this polymorphism with performance amongst long-distance runners remains unclear. Accordingly, this study investigated whether rs8192678 was associated with elite status and competitive performance of long-distance runners. Genomic DNA from 656 Caucasian participants including 288 long-distance runners (201 men, 87 women) and 368 non-athletes (285 men, 83 women) was analysed. Medians of the 10 best UK times (Top10) for 10 km, half-marathon and marathon races were calculated, with all included athletes having personal best (PB) performances within 20% of Top10 (this study's definition of "elite"). Genotype and allele frequencies were compared between athletes and non-athletes, and athlete PB compared between genotypes. There were no differences in genotype frequency between athletes and non-athletes, but athlete Ser allele carriers were 2.5% faster than Gly/Gly homozygotes (p = 0.030). This study demonstrates that performance differences between elite long-distance runners are associated with rs8192678 genotype, with the Ser allele appearing to enhance performance.

Collagen Gene Polymorphisms Previously Associated with Resistance to Soft-Tissue Injury Are More Common in Competitive Runners Than Nonathletes

ABSTRACT

Dines, HR, Nixon, J, Lockey, SJ, Herbert, AJ, Kipps, C, Pedlar, CR, Day, SH, Heffernan, SM, Antrobus, MR, Brazier, J, Erskine, RM, Stebbings, GK, Hall, ECR, and Williams, AG. Collagen gene polymorphisms previously associated with resistance to soft-tissue injury are more common in competitive runners than nonathletes. J Strength Cond Res 37(4): 799-805, 2023-Single-nucleotide polymorphisms (SNPs) of collagen genes have been associated with soft-tissue injury and running performance. However, their combined contribution to running performance is unknown. We investigated the association of 2 collagen gene SNPs with athlete status and performance in 1,429 Caucasian subjects, including 597 competitive runners (354 men and 243 women) and 832 nonathletes (490 men and 342 women). Genotyping for COL1A1 rs1800012 (C > A) and COL5A1 rs12722 (C > T) SNPs was performed by a real-time polymerase chain reaction. The numbers of "injury-resistant" alleles from each SNP, based on previous literature (rs1800012 A allele and rs12722 C allele), were combined as an injury-resistance score (RScore, 0-4; higher scores indicate injury resistance). Genotype frequencies, individually and combined as an RScore, were compared between cohorts and investigated for associations with performance using official race times. Runners had 1.34 times greater odds of being rs12722 CC homozygotes than nonathletes (19.7% vs. 15.5%, p = 0.020) with no difference in the rs1800012 genotype distribution ( p = 0.659). Fewer runners had an RScore 0 of (18.5% vs. 24.7%) and more had an RScore of 4 (0.6% vs. 0.3%) than nonathletes ( p < 0.001). Competitive performance was not associated with the COL1A1 genotype ( p = 0.933), COL5A1 genotype ( p = 0.613), or RScore ( p = 0.477). Although not associated directly with running performance among competitive runners, a higher combined frequency of injury-resistant COL1A1 rs1800012 A and COL5A1 rs12722 C alleles in competitive runners than nonathletes suggests these SNPs may be advantageous through a mechanism that supports, but does not directly enhance, running performance.

TTN Variants Are Associated with Physical Performance and Provide Potential Markers for Sport-Related Phenotypes

TTN encodes the third myofilament, titin, which plays structural, mechanical, regulatory, and developmental roles in sarcomeres. The aim of this research was to determine the interaction between novel and previously described TTN variants and athletic performance, as well as competition level, in Caucasians. Firstly, 100 athletes and 47 controls were recruited, and whole-genome sequencing was performed. Secondly, 348 athletes (108 endurance, 100 sprint/power, 140 mixed-sport athletes) and 403 volunteers were included, and real-time PCR was performed. We found a significant overrepresentation of the rs10497520 CT and TT genotypes in the sprint/power athlete group (95% CI, 1.41-3.66, p = 0.0013). The rs10497520 T carriers were 2.17 times more likely to become sprint/power athletes (95% CI 1.35-3.49, p = 0.0021). We also found that the likelihood of having the TT genotype was higher for the highly elite and sub-elite sprint/power athletes. Possessing at least one TAA (rs10497520, rs55837610, rs72648256) haplotype resulted in an increase in the log-odds ratio by 0.80 (p = 0.0015), 1.42 (p = 0.003), and 0.77 (p = 0.044) for all, highly elite, and sub-elite sprint/power athletes, respectively. We demonstrated that harbouring the rs10497520 T allele, individually and in a haplotype combination, increased the chance of being an elite sprint/power athlete, indicating that this allele may be favourable for sprint/power performance.

Polygenic Models Partially Predict Muscle Size and Strength but Not Low Muscle Mass in Older Women

Background: Heritability explains 45-82% of muscle mass and strength variation, yet polygenic models for muscle phenotypes in older women are scarce. Therefore, the objective of the present study was to (1) assess if total genotype predisposition score (GPSTOTAL) for a set of polymorphisms differed between older women with low and high muscle mass, and (2) utilise a data-driven GPS (GPSDD) to predict the variance in muscle size and strength-related phenotypes. Methods: In three-hundred 60- to 91-year-old Caucasian women (70.7 ± 5.7 years), skeletal muscle mass, biceps brachii thickness, vastus lateralis anatomical cross-sectional area (VLACSA), hand grip strength (HGS), and elbow flexion (MVCEF) and knee extension (MVCKE) maximum voluntary contraction were measured. Participants were classified as having low muscle mass if the skeletal muscle index (SMI) < 6.76 kg/m2 or relative skeletal muscle mass (%SMMr) < 22.1%. Genotyping was completed for 24 single-nucleotide polymorphisms (SNPs). GPSTOTAL was calculated from 23 SNPs and compared between the low and high muscle mass groups. A GPSDD was performed to identify the association of SNPs with other skeletal muscle phenotypes. Results: There was no significant difference in GPSTOTAL between low and high muscle mass groups, irrespective of classification based on SMI or %SMMr. The GPSDD model, using 23 selected SNPs, revealed that 13 SNPs were associated with at least one skeletal muscle phenotype: HIF1A rs11549465 was associated with four phenotypes and, in descending number of phenotype associations, ACE rs4341 with three; PTK2 rs7460 and CNTFR rs2070802 with two; and MTHFR rs17421511, ACVR1B rs10783485, CNTF rs1800169, MTHFR rs1801131, MTHFR rs1537516, TRHR rs7832552, MSTN rs1805086, COL1A1 rs1800012, and FTO rs9939609 with one phenotype. The GPSDD with age included as a predictor variable explained 1.7% variance of biceps brachii thickness, 12.5% of VLACSA, 19.0% of HGS, 8.2% of MVCEF, and 9.6% of MVCKE. Conclusions: In older women, GPSTOTAL did not differ between low and high muscle mass groups. However, GPSDD was associated with muscle size and strength phenotypes. Further advancement of polygenic models to understand skeletal muscle function during ageing might become useful in targeting interventions towards older adults most likely to lose physical independence.

Advances in sports genomics

Sports genomics is the scientific discipline that focuses on the organization and function of the genome in elite athletes, and aims to develop molecular methods for talent identification, personalized exercise training, nutritional need and prevention of exercise-related diseases. It postulates that both genetic and environmental factors play a key role in athletic performance and related phenotypes. This update on the panel of genetic markers (DNA polymorphisms) associated with athlete status and soft-tissue injuries covers advances in research reported in recent years, including one whole genome sequencing (WGS) and four genome-wide association (GWAS) studies, as well as findings from collaborative projects and meta-analyses. At end of 2020, the total number of DNA polymorphisms associated with athlete status was 220, of which 97 markers have been found significant in at least two studies (35 endurance-related, 24 power-related, and 38 strength-related). Furthermore, 29 genetic markers have been linked to soft-tissue injuries in at least two studies. The most promising genetic markers include HFE rs1799945, MYBPC3 rs1052373, NFIA-AS2 rs1572312, PPARA rs4253778, and PPARGC1A rs8192678 for endurance; ACTN3 rs1815739, AMPD1 rs17602729, CPNE5 rs3213537, CKM rs8111989, and NOS3 rs2070744 for power; LRPPRC rs10186876, MMS22L rs9320823, PHACTR1 rs6905419, and PPARG rs1801282 for strength; and COL1A1 rs1800012, COL5A1 rs12722, COL12A1 rs970547, MMP1 rs1799750, MMP3 rs679620, and TIMP2 rs4789932 for soft-tissue injuries. It should be appreciated, however, that hundreds and even thousands of DNA polymorphisms are needed for the prediction of athletic performance and injury risk.

Beneficial Effects of Cardiomyopathy-Associated Genetic Variants on Physical Performance: A Hypothesis-Generating Scoping Review

BACKGROUND

Genetic variants associated with cardiomyopathies (CMPs) are prevalent in the general population. In young athletes, CMPs account for roughly a quarter of sudden cardiac death, with further unexplained clustering in specific sports. Consequently, most CMPs form a contraindication for competitive sports. We hypothesized that genetic variants might (paradoxically) improve physical performance early in life while impairing cardiac function later in life.

METHODS

Systematic PubMed search was done to investigate whether genetic variants in genes associated with CMPs could be related to beneficial performance phenotypes.

SUMMARY

In a limited number of studies (n = 6), 2,860 individuals/subjects with genetic variants were able to outperform those without said variants, as measured by running speed (∼38 m/min in heterozygous [HET] mice, n = 6, vs. ∼32 m/min in wild type [WT] mice, n = 7, p = 0.004) and distance (966 ± 169 km HET mice vs. 561 ± 144 km WT mice, p = 0.0035, n = 10), elite athlete status in endurance athletes (n = 1,672, p = 1.43 × 10-8), maximal oxygen uptake in elite athletes (absolute difference not provided, n = 32, p = 0.005), maximal oxygen uptake in unrelated individuals (n = 473, p = 0.0025), personal records in highly trained marathon runners (2:26:28 ± 0:06:23 min HET, n = 32, vs. 2:28:53 ± 0:05:50 min without polymorphism, n = 108, p = 0.020), and peripheral muscle force contraction in patients following a cardiac rehabilitation program (absolute values not provided, n = 260). Key Message: Beneficial effects in genetic variants associated with CMPs could hypothetically play a role in the selection of young athletes, consequently explaining the prevalence of such genetic variants in athletes and the general population.

Genetic Polymorphisms Related to VO2max Adaptation Are Associated With Elite Rugby Union Status and Competitive Marathon Performance

PURPOSE

Genetic polymorphisms have been associated with the adaptation to training in maximal oxygen uptake (V˙O2max). However, the genotype distribution of selected polymorphisms in athletic cohorts is unknown, with their influence on performance characteristics also undetermined. This study investigated whether the genotype distributions of 3 polymorphisms previously associated with V˙O2max training adaptation are associated with elite athlete status and performance characteristics in runners and rugby athletes, competitors for whom aerobic metabolism is important.

METHODS

Genomic DNA was collected from 732 men including 165 long-distance runners, 212 elite rugby union athletes, and 355 nonathletes. Genotype and allele frequencies of PRDM1 rs10499043 C/T, GRIN3A rs1535628 G/A, and KCNH8 rs4973706 T/C were compared between athletes and nonathletes. Personal-best marathon times in runners, as well as in-game performance variables and playing position, of rugby athletes were analyzed according to genotype.

RESULTS

Runners with PRDM1 T alleles recorded marathon times ∼3 minutes faster than CC homozygotes (02:27:55 [00:07:32] h vs 02:31:03 [00:08:24] h, P = .023). Rugby athletes had 1.57 times greater odds of possessing the KCNH8 TT genotype than nonathletes (65.5% vs 54.7%, χ2 = 6.494, P = .013). No other associations were identified.

CONCLUSIONS

This study is the first to demonstrate that polymorphisms previously associated with V˙O2max training adaptations in nonathletes are also associated with marathon performance (PRDM1) and elite rugby union status (KCNH8). The genotypes and alleles previously associated with superior endurance-training adaptation appear to be advantageous in long-distance running and achieving elite status in rugby union.

Can Genetic Testing Predict Talent? A Case Study of 5 Elite Athletes

PURPOSE

The genetic influence on the attainment of elite athlete status is well established, with a number of polymorphisms found to be more common in elite athletes than in the general population. As such, there is considerable interest in understanding whether this information can be utilized to identify future elite athletes. Accordingly, the aim of this study was to compare the total genotype scores of 5 elite athletes to those of nonathletic controls, to subsequently determine whether genetic information could discriminate between these groups, and, finally, to suggest how these findings may inform debates relating to the potential for genotyping to be used as a talent-identification tool.

METHODS

The authors compared the total genotype scores for both endurance (68 genetic variants) and speed-power (48 genetic variants) elite athlete status of 5 elite track-and-field athletes, including an Olympic champion, to those of 503 White European nonathletic controls.

RESULTS

Using the speed-power total genotype score, the elite speed-power athletes scored higher than the elite endurance athletes; however, using this speed-power score, 68 nonathletic controls registered higher scores than the elite power athletes. Surprisingly, using the endurance total genotype score, the elite speed-power athletes again scored higher than the elite endurance athletes.

CONCLUSIONS

These results suggest that genetic information is not capable of accurately discriminating between elite athletes and nonathletic controls, illustrating that the use of such information as a talent-identification tool is currently unwarranted and ineffective.

Impact of angiotension I converting enzyme gene I/D polymorphism on running performance, lipid, and biochemical parameters in ultra-marathoners

The insertion (I) or deletion (D) polymorphism in the angiotension I converting enzyme gene, (ACE I/D, rs1799752) is associated with human exercise endurance and performance. However, most of the aforementioned studies focus on marathons, swimming, and triathlons, while the ACE polymorphism in ultra-marathoners has not yet been reported. We studied the impact of ACE I/D polymorphism in ultra-marathoners and investigated its relationship with lipid profiles, interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hs-CRP) levels in runners before and after ultra-marathon racing.This observational study used data from a 100-km ultra-marathon in Taipei, Taiwan. Twenty-four male participants were analyzed for their ACE insertion/deletion polymorphism, lipid profiles, hs-CRP, IL-6 in serum immediately before and after ultra-marathon running.In our 24 subjects analyzed, 7, 14, and 3 subjects were of I/I, I/D, and D/D genotypes, respectively. Runners with the D polymorphism (I/D and D/D) showed a trend of better performance in the 100-km ultra-marathon (measured by completion time in minutes, P = .036). In this group, the previous best marathon performance was also significantly better than the I/I group (P = .047). After adjusting for body mass index (BMI), the difference in performance was not significant. Ketone levels, IL-6, and hs-CRP levels were highly increased at immediately and 24-hour post-race. No correlation was found between different ACE polymorphisms and common biochemical parameters examined.We report the first study in the impact of the ACE I/D (rs1799752) on ultra-marathoners. Presence of the D polymorphism in ACE gene is associated with better performance, although the BMI of the runners contribute as a major factor. There was no difference in the biochemical or lipid parameters measured among different ACE polymorphisms.

American Society of Biomechanics Journal of Biomechanics Award 2017: High-acceleration training during growth increases optimal muscle fascicle lengths in an avian bipedal model

Sprinters have been found to possess longer muscle fascicles than non-sprinters, which is thought to be beneficial for high-acceleration movements based on muscle force-length-velocity properties. However, it is unknown if their morphology is a result of genetics or training during growth. To explore the influence of training during growth, thirty guinea fowl (Numida meleagris) were split into exercise and sedentary groups. Exercise birds were housed in a large pen and underwent high-acceleration training during their growth period (age 4-14 weeks), while sedentary birds were housed in small pens to restrict movement. Morphological analyses (muscle mass, PCSA, optimal fascicle length, pennation angle) of a hip extensor muscle (ILPO) and plantarflexor muscle (LG), which differ in architecture and function during running, were performed post-mortem. Muscle mass for both ILPO and LG was not different between the two groups. Exercise birds were found to have ∼12% and ∼14% longer optimal fascicle lengths in ILPO and LG, respectively, than the sedentary group despite having ∼3% shorter limbs. From this study we can conclude that optimal fascicle lengths can increase as a result of high-acceleration training during growth. This increase in optimal fascicle length appears to occur irrespective of muscle architecture and in the absence of a change in muscle mass. Our findings suggest high-acceleration training during growth results in muscles that prioritize adaptations for lower strain and shortening velocity over isometric strength. Thus, the adaptations observed suggest these muscles produce higher force during dynamic contractions, which is beneficial for movements requiring large power outputs.

No association between ACTN3 R577X and ACE I/D polymorphisms and endurance running times in 698 Caucasian athletes

BACKGROUND

Studies investigating associations between ACTN3 R577X and ACE I/D genotypes and endurance athletic status have been limited by small sample sizes from mixed sport disciplines and lack quantitative measures of performance.

AIM

To examine the association between ACTN3 R577X and ACE I/D genotypes and best personal running times in a large homogeneous cohort of endurance runners.

METHODS

We collected a total of 1064 personal best 1500, 3000, 5000 m and marathon running times of 698 male and female Caucasian endurance athletes from six countries (Australia, Greece, Italy, Poland, Russia and UK). Athletes were genotyped for ACTN3 R577X and ACE ID variants.

RESULTS

There was no association between ACTN3 R577X or ACE I/D genotype and running performance at any distance in men or women. Mean (SD) marathon times (in s) were for men: ACTN3 RR 9149 (593), RX 9221 (582), XX 9129 (582) p = 0.94; ACE DD 9182 (665), ID 9214 (549), II 9155 (492) p = 0.85; for women: ACTN3 RR 10796 (818), RX 10667 (695), XX 10675 (553) p = 0.36; ACE DD 10604 (561), ID 10766 (740), II 10771 (708) p = 0.21. Furthermore, there were no associations between these variants and running time for any distance in a sub-analysis of athletes with personal records within 20% of world records.

CONCLUSIONS

Thus, consistent with most case-control studies, this multi-cohort quantitative analysis demonstrates it is unlikely that ACTN3 XX genotype provides an advantage in competitive endurance running performance. For ACE II genotype, some prior studies show an association but others do not. Our data indicate it is also unlikely that ACE II genotype provides an advantage in endurance running.