Frequency of the MSTN Lys(K)-153Arg(R) polymorphism among track & field athletes and swimmers

Association between ACTN3 (R577X), ACE (I/D), BDKRB2 (-9/+9), and AGT (M268T) polymorphisms and performance phenotypes in Brazilian swimmers

BACKGROUND

The influence of genetic polymorphisms on athletic performance has been widely explored. This study investigated the interactions between the polymorphisms ACTN3 (R577X), ACE (I/D), BDKRB2 (-9/+9), and AGT (M/T) and their association with endurance and strength phenotypes in Brazilian swimmers.

METHODS

123 athletes (aged 20-30 years) and 718 controls participated in the study. The athletes were divided into elite and sub-elite (N = 19 and 104, respectively) and strength and endurance experts (N = 98 and 25, respectively). Hardy-Weinberg equilibrium was observed in all groups.

RESULTS

Considering the ACE polymorphism, it was observed a higher frequency of the DD genotype than expected in the strength experts of the elite group, whereas the strength experts sub-elite athletes had a higher frequency of the ID genotype (χ2 = 8.17; p = 0.01). Subjects with XX genotypes of ACTN3 are more likely to belong to the athlete group when compared to the control group (OR = 1.79, p = 0.04). The DD homozygotes of the ACE are more likely to belong to the elite group with strength phenotypes than the group of sub-elite (OR = 7.96, p = 0.01) and elite strength experts compared to elite endurance (OR = 18.0, p = 0.03). However, no significant differences were observed in the allelic distribution of the polymorphisms evaluated when comparing Elite, sub-elite athletes and controls.

CONCLUSION

ACE and ACTN3 allele frequencies should be considered with regard to performance influencing factors in Brazilian swimmers.

Association of Myostatin Gene Polymorphisms with Strength and Muscle Mass in Athletes: A Systematic Review and Meta-Analysis of the MSTN rs1805086 Mutation

Polymorphism (rs1805086), c.458A>G, p.Lys(K)153Arg(R), (K153R) of the myostatin gene (MSTN) has been associated with a skeletal muscle phenotype (hypertrophic response in muscles due to strength training). However, there are not enough reliable data to demonstrate whether MSTN rs1805086 K and R allelic variants are valid genetic factors that can affect the strength phenotype of athletes' skeletal muscles. The aim is to conduct a systematic review and meta-analysis of the association of MSTN rs1805086 polymorphism with the strength phenotype of athletes. This study analyzed 71 research articles on MSTN and performed a meta-analysis of MSTN K153R rs1805086 polymorphism in strength-oriented athletes and a control (non-athletes) group. It was found that athletes in the strength-oriented athlete group had a higher frequency of the R minor variant than that in the control group (OR = 2.02, P = 0.05). Thus, the obtained results convincingly demonstrate that there is an association between the studied polymorphism and strength phenotype of athletes; therefore, further studies on this association are scientifically warranted.

Genetics of long-distance runners and road cyclists-A systematic review with meta-analysis

The aim of this systematic review and meta-analysis was to identify the genetic variants of (inter)national competing long-distance runners and road cyclists compared with controls. The Medline and Embase databases were searched until 15 November 2021. Eligible articles included genetic epidemiological studies published in English. A homogenous group of endurance athletes competing at (inter)national level and sedentary controls were included. Pooled odds ratios based on the genotype frequency with corresponding 95% confidence intervals (95%CI) were calculated using random effects models. Heterogeneity was addressed by Q-statistics, and I² . Sources of heterogeneity were examined by meta-regression and risk of bias was assessed with the Clark Baudouin scale. This systematic review comprised of 43 studies including a total of 3938 athletes and 10 752 controls in the pooled analysis. Of the 42 identified genetic variants, 13 were investigated in independent studies. Significant associations were found for five polymorphisms. Pooled odds ratio [95%CI] favoring athletes compared with controls was 1.42 [1.12-1.81] for ACE II (I/D), 1.66 [1.26-2.19] for ACTN3 TT (rs1815739), 1.75 [1.34-2.29] for PPARGC1A GG (rs8192678), 2.23 [1.42-3.51] for AMPD1 CC (rs17602729), and 2.85 [1.27-6.39] for HFE GG + CG (rs1799945). Risk of bias was low in 25 (58%) and unclear in 18 (42%) articles. Heterogeneity of the results was low (0%-20%) except for HFE (71%), GNB3 (80%), and NOS3 (76%). (Inter)national competing runners and cyclists have a higher probability to carry specific genetic variants compared with controls. This study confirms that (inter)national competing endurance athletes constitute a unique genetic make-up, which likely contributes to their performance level.

Genetics and sports performance: the present and future in the identification of talent for sports based on DNA testing

The impact of genetics on physiology and sports performance is one of the most debated research aspects in sports sciences. Nearly 200 genetic polymorphisms have been found to influence sports performance traits, and over 20 polymorphisms may condition the status of the elite athlete. However, with the current evidence, it is certainly too early a stage to determine how to use genotyping as a tool for predicting exercise/sports performance or improving current methods of training. Research on this topic presents methodological limitations such as the lack of measurement of valid exercise performance phenotypes that make the study results difficult to interpret. Additionally, many studies present an insufficient cohort of athletes, or their classification as elite is dubious, which may introduce expectancy effects. Finally, the assessment of a progressively higher number of polymorphisms in the studies and the introduction of new analysis tools, such as the total genotype score (TGS) and genome-wide association studies (GWAS), have produced a considerable advance in the power of the analyses and a change from the study of single variants to determine pathways and systems associated with performance. The purpose of the present study was to comprehensively review evidence on the impact of genetics on endurance- and power-based exercise performance to clearly determine the potential utility of genotyping for detecting sports talent, enhancing training, or preventing exercise-related injuries, and to present an overview of recent research that has attempted to correct the methodological issues found in previous investigations.

Insulin-like Growth Factor Axis Genetic Score and Sports Excellence

ABSTRACT

Ben-Zaken, S, Meckel, Y, Nemet, D, and Eliakim, A. Insulin-like growth factor axis genetic score and sports excellence. J Strength Cond Res 35(9): 2421-2426, 2021-It has been suggested that IGF1 polymorphisms associated with circulating IGF1 levels may be linked to elite short-distance running performance. This study assessed genetic score based on 6 polymorphisms related to the Insulin-like growth factor axis (rs7136446, rs35767, rs6220, rs680, rs2854744, and rs1805086) among elite Israeli runners and swimmers. One hundred sixty-one track and field athletes (123 men and 38 women, age 17-50 years) and 94 swimmers (61 men and 33 women, age 16-49 years) participated in the study. Athletes were divided into short-distance runners (SDRs, major event: 100-200-m sprints and jumps, n = 63) and long-distance runners (LDRs, major event: 5,000 m and marathon, n = 98). Swimmers were divided into short-distance swimmers (SDSs, major event: 50-100 m, n = 44) and long-distance swimmers (LDSs, major event: 400-1,500 m, n = 50). Groups were subdivided into top-level and national-level athletes. We calculated the IGF genetic score (IGF-GS) of all the subjects on a 0-100 scale. Top-level SDRs' mean IGF-GS (30.8 ± 11.7) was significantly higher (p < 0.006) compared with national-level SDRs' (20.5 ± 11.3) and top-level SDSs' (19.9 ± 8.5). Subjects with IGF-GS >25 had an increased odds ratio (OR) of being elite-level SDRs (OR: 4.2; 95% confidence interval: 0.68-26.09; p < 0.001). In summary, a combined assessment of 6 single-nucleotide polymorphisms, all known to modulate circulation IGF1 levels, was associated with a higher genetic score among SDRs, emphasizing the importance of the IGF system to land speed sports events but not to swimming events. Whether the IGF-GS may be used for selection of elite-level sprinters in early stages of their athletic career needs to be further investigated.

Variants in the Myostatin Gene and Physical Performance Phenotype of Elite Athletes

The MSTN gene is a negative regulator of muscle growth that is attracting attention as a candidate gene for physical performance traits. We hypothesised that variants of MSTN might be associated with the status of elite athlete. We therefore sought to study the potential role of MSTN in the physical performance of athletes by analysing the whole coding sequence of the MSTN gene in a cohort of Lithuanian elite athletes (n = 103) and non-athletes (n = 127). Consequently, two genetic variants were identified: the deletion of one of three adenines in the first intron (c.373+90delA, rs11333758) and a non-synonymous variant in the second exon (c.458A>G, p.Lys(K)153Arg(R), rs1805086). Among all samples, the MSTN rs1805086 Lys(K) allele was the most common form in both groups. Homozygous genotype for the less common Arg(R) allele was identified in only one elite canoe rower, and we could find no direct association between rs1805086 and successful results in elite athletes. Surprisingly, the intronic variant (rs11333758) was abundant among all samples. The main finding was that endurance-oriented athletes had 2.1 greater odds of being MSTN deletion genotype than non-athletes (13.6% vs. 0.8%). The present study confirms the association of the polymorphism rs11333758 with endurance performance status in Lithuanian elite athletes.

Genomic profile in association with sport-type, sex, ethnicity, psychological traits and sport injuries of elite athletes: review and future perspectives

In the last few years, some inherited determinants have been associated with elite athletic performance, but its polygenic trait character has limited the correct definition of elite athlete's genomic profile. This qualitative descriptive study aims to summarise the current understanding about genetic and epigenetic factors in elite athletes, as well as their genomic profile in association with sport-type, sex, ethnicity, psychological traits and sport injuries. A narrative review of the literature across a broad cross-section of the elite athletes' genomic profile was undertaken. Elite performance relies on rare gene variants within a great interface between molecular, cellular and behavioural sport-related phenotypes and the environment, which is still poorly understood. ACTN3 rs1815739 and ACE I/D polymorphisms appear to be associated to specific sprint phenotypes and influence the athletic status, i.e., the rs1815739 variant is more influential to 200-m performance and the ACE ID polymorphism is more involved in the longer, 400-m sprint performance. Generally, athletes show endurance-based sports characteristics or power-based sports characteristics, but some studies have reported some genes associations to both sports-based characteristics. Furthermore, genetic studies with larger cohorts of single-sport athletes might be preferable than studies combining athletes of different sports, given the existence of distinct athlete profiles and sport demands. Athletic performance may be influenced by the serotonergic pathway and the potential injury risk (namely stress fracture) might be associated to a genetic predisposition associated to the mechanical loading from the intense physical exercise. The study of gene variants associated to sex and ethnicity-related to athletic performance needs further investigation. The combination of genome-wide association studies addressing the genetic architecture of athletes and the subsequent replication and validation studies might for additional genetic data is mandatory.

High prevalence of the IGF2 rs680 GG polymorphism among top-level sprinters and jumpers

Previous studies have shown that the IGF1 polymorphism is associated with greater muscle mass and improved power athletic ability, but very little is known about the IGF2 polymorphism and athletic performance.

PURPOSE

The aim of the present study was to assess the frequency distribution of the IGF2 rs680 polymorphism among Israeli athletes.

METHODS

185 short- (n=72) and long-distance (n=113) runners, 94 short- (n=44) and long-distance (n=50) swimmers, 54 weight lifters and 111 controls participated in the study. Genomic DNA was extracted from peripheral EDTA treated anti-coagulated blood using a standard protocol. Genotyping of the IGF2 A/G polymorphism (rs680) was performed using allelic discrimination assay.

RESULTS

The frequency of IGF2 (rs680) G allele carriers was significantly greater among top compared to national-level track and field sprinters and jumpers (p<0.05). The IGF2 (rs680) GG genotype frequency was significantly greater among track and field sprinters and jumpers compared to weight lifters p<0.02), and among top-level sprinters and jumpers compared to top-level weight lifters p<0.01). There were no statistically significant differences in the IGF2 (rs680) GG genotype frequency among endurance athletes and between the swimmers and the other sports disciplines and the controls.

CONCLUSIONS

While a single polymorphism cannot determine athletic success or failure, the findings of the present study suggest a potential importance of the IGF2 polymorphism, mainly regarding speed sport performance.

Potential effect of exercise in ameliorating insulin resistance at transcriptome level

BACKGROUND

Insulin resistance can lead to the pathogenesis of type 2 diabetes and exercise can increase insulin sensitivity. And different exercises may have different influences on the mitigation of insulin resistance. It is still unclear how exercise affects inherited insulin resistance at transcriptome level. The purpose of our study was to analyze the potential effects of exercise in ameliorating insulin resistance at transcriptome level.

METHODS

Herein, we analyzed two skeletal muscle transcriptome profiles, including gene profiles between inherited insulin resistant patients and matched healthy controls, and between trained and sedentary subjects (young and old subjects, respectively).

RESULTS

Analysis of differentially expressed genes revealed that 12 genes (SGK1, LOC101929876, MYL5, COL6A3, MLF1, LUM, MSTN, COL1A2, COL3A1, IL32, IRS2, and ID1) associated with insulin resistance were reversed by exercise in young subjects, while six genes (MSTN, CFHR1, PFKFB3, IL32, RGCC, and NMRK2) were identified in old subjects, suggesting that those genes play potential roles in insulin resistance response to exercise. In addition, we observed that two insulin resistance-related genes, MSTN and IL32, were identified in muscle cells of both young and old subjects, indicating their important roles in the mechanisms behind the beneficial effects of exercise on humans with inherited insulin resistance. Several pathways were also identified, such as "collagen metabolic process," "focal adhesion," and "negative regulation of myoblast differentiation."

CONCLUSIONS

Taken together, our findings provide novel markers in insulin resistant patients and exercise, and some valuable information for future functional studies on how exercise ameliorating insulin resistance.

The combined frequency of IGF and myostatin polymorphism among track & field athletes and swimmers

OBJECTIVE

The IGF C-1245T (rs35767) and the myostatin (MSTN) Lys(K)-153Arg(R) genetic polymorphism may influence skeletal muscle phenotypes and athletic performance. Carrying the minor IGF T allele and the myostatin rare R allele was associated with higher circulating IGF-I levels, greater muscle mass and improved performance. The aim of the present study was to assess the combined frequency of the IGF 1245T (rs35767) and MSTN 153Arg(R) polymorphism among Israeli track and field athletes (n=111) and swimmers (n=80).

DESIGN

Track & field athletes were divided to long distance runners (major event 5000m-marathon, n=63) and power athletes (major event 100-200m sprints and long jump, n=48). Swimmers were divided into long-distance swimmers (major event: 400-1500m, n=38), and short-distance swimmers (major event: 50-100m, n=42).

RESULTS

Carrying both mutations was significantly higher (p<0.05) among long distance runners (LDR, 17%) compared to short distance runners (SDR, 10%), long distance swimmers (LDS, 8%), short distance swimmers (SDS, 2%) and controls (n=111, 7%). Carrying both mutations was significantly higher (p<0.05) among LDS compared to SDS (8% versus 2%, p<0.05). Among LDR and LDS carriers of both mutations, 40% and 25% were of elite level, respectively. Despite the fact that carrying both mutations among SDR and SDS was not greater than controls, all SDR and SDS carriers were elite athletes.

CONCLUSION

Our finding suggests that carrying both IGF 1245T and MSTN 153Arg(R) polymorphisms may contribute for long distance running success but not necessarily to elite performance. In contrast, although the frequency was not higher than the general population, all carriers of both mutations among short distance runners and swimmers were of elite competitive caliber. Whether evaluation of the IGF 1245T and MSTN 153R polymorphism can be used for sports selection in young athletes needs to be further studied.

Biochemistry and Biology of GDF11 and Myostatin: Similarities, Differences, and Questions for Future Investigation

Growth differentiation factor 11 (GDF11) and myostatin (or GDF8) are closely related members of the transforming growth factor β superfamily and are often perceived to serve similar or overlapping roles. Yet, despite commonalities in protein sequence, receptor utilization and signaling, accumulating evidence suggests that these 2 ligands can have distinct functions in many situations. GDF11 is essential for mammalian development and has been suggested to regulate aging of multiple tissues, whereas myostatin is a well-described negative regulator of postnatal skeletal and cardiac muscle mass and modulates metabolic processes. In this review, we discuss the biochemical regulation of GDF11 and myostatin and their functions in the heart, skeletal muscle, and brain. We also highlight recent clinical findings with respect to a potential role for GDF11 and/or myostatin in humans with heart disease. Finally, we address key outstanding questions related to GDF11 and myostatin dynamics and signaling during development, growth, and aging.

Advanced Running Performance by Genetic Predisposition in Male Dummerstorf Marathon Mice (DUhTP) Reveals Higher Sterol Regulatory Element-Binding Protein (SREBP) Related mRNA Expression in the Liver and Higher Serum Levels of Progesterone

Long-term-selected DUhTP mice represent a non-inbred model for inborn physical high-performance without previous training. Abundance of hepatic mRNA in 70-day male DUhTP and control mice was analyzed using the Affymetrix mouse array 430A 2.0. Differential expression analysis with PLIER corrected data was performed using AltAnalyze. Searching for over-representation in biochemical pathways revealed cholesterol metabolism being most prominently affected in DUhTP compared to unselected control mice. Furthermore, pathway analysis by AltAnalyze plus PathVisio indicated significant induction of glycolysis, fatty acid synthesis and cholesterol biosynthesis in the liver of DUhTP mice versus unselected control mice. In contrast, gluconeogenesis was partially inactivated as judged from the analysis of hepatic mRNA transcript abundance in DUhTP mice. Analysis of mRNA transcripts related to steroid hormone metabolism inferred elevated synthesis of progesterone and reduced levels of sex steroids. Abundance of steroid delta isomerase-5 mRNA (Hsd3b5, FC 4.97) was increased and steroid 17-alpha-monooxygenase mRNA (Cyp17a1, FC -11.6) was massively diminished in the liver of DUhTP mice. Assessment of steroid profiles by LC-MS revealed increased levels of progesterone and decreased levels of sex steroids in serum from DUhTP mice versus controls. Analysis of hepatic mRNA transcript abundance indicates that sterol regulatory element-binding protein-1 (SREBP-1) may play a major role in metabolic pathway activation in the marathon mouse model DUhTP. Thus, results from bioinformatics modeling of hepatic mRNA transcript abundance correlated with direct steroid analysis by mass spectrometry and further indicated functions of SREBP-1 and steroid hormones for endurance performance in DUhTP mice.