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Sarcopenia is associated with progressive generalized skeletal muscle weakness, persistent decline in muscle strength, function, and quality of life in the elderly population. The presence of sarcopenia worsens the prognosis of older patients. In this regard, the study of the etiology and pathogenesis of sarcopenia, the identification of early markers for the diagnosis of this disease are relevant areas today. Myokines are secreted by skeletal muscle and play a important role in the regulation of muscle mass and function, metabolic homeostasis. Myokine synthesis disruption may contribute to the development of sarcopenia. In addition, we can see the polymorphism association of various genes with the development of the disease. This review brings together current knowledge about myokines and genetic factors as potential biomarkers for the early diagnosis of sarcopenia.

The alpha actinin-3 gene (ACTN3) is a significant candidate gene among genetic markers that determine athletic ability. The ACTN3 gene is responsible for the creation of the actin protein in fast-twitch muscle fibers, which is associated with muscle power and speed. The objective of this study was to analyze the changes in performance of the arrowhead agility drill test and the distribution of genotype variants in the ACTN3 rs1815739 gene polymorphism in physically active adult males after a 6- week training period. The research will focus on a cohort of 58 male students, aged 19-24, who are enrolled in the Faculty of Sports Sciences and participate in swimming activities. Genomic DNA was extracted from swab samples obtained from participants using the Buccalyse DNA Extraction Kit from Isohelix, following the manufacturer's supplied technique. The study findings revealed that there was no statistically significant difference between all three genotypes when comparing the pre-test and post-test values of the sample group in terms of left and right foot characteristics. Within this framework, it is acknowledged that the outcomes derived from our investigation could potentially influence the research findings. These aspects include the restricted sample size and the incapacity to regulate individual variances such as concentration and motivation during the pre-test and post-test sessions. Nevertheless, it is believed that the results obtained from our study could potentially enhance future research and literary works in the same field.

Roles of genes in heat acclimation (HA, repeated exercise-heat exposures) had not been explored. ACE I/D and ACTN3 R577X genetic polymorphisms are closely associated with outstanding exercise performances. This study investigated whether the two polymorphisms influenced the response to HA. Fifty young Han nationality male subjects were selected and conducted HA for 2 weeks. Exercise indicators (5-km run, push-up and 100-m run) were tested and rest aural thermometry (RTau) was measured before and after HA. ACE gene was grouped by I homozygote and D carrier, and ACTN3 gene was grouped by R homozygote and X carrier. Results showed that there were no differences between groups in age, body mass index, exercise indicators and RTau before HA. After HA, RTau of ACE I homozygote was lower than that of D carrier [F (1, 48) = 9.12, p = 0.004, η = 0.40]. Compared with RTau before HA, that of I homozygote decreased after HA (Δ = −0.26 °C, 95 % CI -0.34–0.18, p

مقاله پژوهشیمقدمه: امروزه علم ژنتیک با تعیین ژنوتیپ، بررسی می‌کند که یک فرد در چه ورزشی ممکن است موفقیت‌آمیزتر عمل کند. در این مطالعه، به بررسی دو پلی‎مورفیسم مهم از ژن‎های ACTN3 ( rs1815739)که نقش اساسی در شکل‌گیری تنوع تارهای عضلانی دارد و VDR(rs2228570) (رسپتور جذب ویتامین D) که نقش حیاتی در رشد تارهای عضلانی و استخوان‎ها را دارد؛ پرداختیم.روش‌ها: در این مطالعه، ۲۰۰ نفر زن و مرد ورزشکار حرفه‌ای، با (Body mass index) BMI نرمال و حداقل پنج سال سابقه‌ی ورزش حرفه‌ای، در بازه‌ی سنی ۳۵-۲۰ سال با نمره‌ی W ۱۱۰۰-۱۰۰۰ Peak power:در جمعیت مردان و W 700-750Peak power: در جمعیت زنان با بررسی تست Wingate و درصد عضلات حداقلی 30%:SMM با توجه‌ به آنالیزهای دستگاه بادی‎کامپوزیشن انتخاب شدند و با گروه شاهد ۲۰۰ نفری مقایسه گردیدند. پس از نمونه‌گیری و استخراج DNA، با استفاده از تکنیک RFLP-PCR پلی‌مورفیسم‌ها بررسی شدند.یافته‌ها: نتایج پژوهش حاضر نشان داد که در بین شاخص‌های توده‌ی عضلانی و نمره‌ی تست Wingate در بین جمعیت مرد و زن ورزشکار، نسبت به نمونه‌های کنترل تفاوت معنی‌داری وجود دارد، همچنین برای پلی‌مورفیسم rs1815739 در حالت هتروزیگوت و پلی‌مورفیسم rs2228570 در فرم هموزیگوت غالب تفاوت‌های معنی‌داری مشاهده شد.نتیجه‌گیری: به نظر می‌رسد در پلی‌مورفیسم rs1815739، ورزشکاران نیازمند هر دو نوع تارهای عضلانی تند و کند انقباض برای موفقیت خود هستند و وجود بیشتر هموزیگوت GG در پلی‌مورفیسم rs2228570 به ورزشکاران در جذب بهتر ویتامین D کمک کرده است.

This study aimed to investigate the longitudinal evolution of vertical jump height in soccer players and its association with their genotypic profiles. The genotypes of 37 soccer players were characterized and the countermovement jump (CMJ) height, concentric mean power, force, and jump strategy were assessed at two time points: at the onset of the regular season (Pre) and at the conclusion of the first half (Mid). AMPD1 (rs17602729), ACE (rs4646994), ACTN3 (rs1815739), CKM (rs8111989), and MLCK (rs2849757 and rs2700352) polymorphisms were genotyped. No significant differences were found between Pre and Mid in concentric power (p = 0.068; d = 0.08) or force (p = 0.258; d = 0.04), while jump height displayed trivial increases (p = 0.046; d = 0.15). Individual analysis revealed that 38% of participants increased the vertical jump height and mean concentric power over the smallest worthwhile change (SWC), while 27% experienced an increased mean concentric force. The positive responders were characterized by a decreased frequency of the AA genotype and an increased frequency of the CA genotype for the c.37885C>A polymorphism of MLCK (p = 0.035), as well as a decreased frequency of the TT genotype of ACTN3 (p = 0.042) and the CC genotype of AMPD1 (p = 0.022). Our findings suggest that genetic analysis could explain some variability in neuromuscular adaptations during the in-season.

Objective:A functional polymorphism on the 16th exon of the alpha-actinin-3 gene has an effect on the protein structure and cellular signaling and therefore on muscle contraction. In this study, we aimed to analyze the alpha-actinin-3 rs1815739 polymorphism in 3-dimensional malocclusions and different craniofacial skeletal patterns.Methods: Forty-nine volunteering subjects enrolled for the study. Genotyping of alpha-actinin-3 rs1815739 polymorphism was performed using real-time polymerase chain reaction. Pre-orthodontic cephalometric radiographs were traced using NemoTech cephalometric tracing software. IBM SPSS Statistics for Windows was utilized to carry out statistical analysis. P < .05 was considered to be statistically significant.Results: The respective numbers and the percentages of alpha-actinin-3 rs1815739 polymorphisms for RR, RX, and XX genotypes were 39 (79.6%), 4 (8.2%), and 6 (12.2%), respectively. Twenty-one patients had low angle vertical patterns and 17 patients had Class I and the same number of the patients had Class III facial patterns. But none of these had statistically significant difference in terms of alpha-actinin-3 rs1815739 polymorphism and in vertical or sagittal facial patterns, and mandibular incisor inclination. When we examined the maxillary anteroposterior position, we found a significant difference between rs1815739 polymorphisms (P < .05). Also, we detected a significant difference between rs1815739 polymorphism and maxillary incisor inclination (P < .05).Conclusion: Maxillary incisor inclination and maxillary anteroposterior position are associated with alpha-actinin-3 rs1815739 polymorphism in a Turkish cohort.

This study aimed to investigate the ACTN3 R577X, ACE I/D, CKM rs8111989, and TRHR rs7832552 genotypes in climbers and controls in three ethnicities. The study consisted of 258 climbers (Japanese, n = 100; Polish, n = 128; Russian, n = 30) and 1151 controls (Japanese: n = 332, Polish: n = 635, Russian: n = 184). Genotyping results were analyzed using the TaqMan approach in Japanese and Polish subjects and HumanOmni1-Quad Bead Chips in Russian subjects. There were no significant differences in ACTN3 R577X and ACE I/D polymorphism distribution between climbers and controls in any ethnic cohort or model. The frequencies of the C allele in the CKM polymorphism and the T allele in the TRHR polymorphism were higher in climbers than in controls only in the Russian cohort (p = 0.045 and p = 0.039, respectively). The results of the meta analysis on three cohorts showed that the frequency of XX+RX genotypes in the ACTN3 R577X polymorphism was significantly higher in climbers than that in the controls (p = 0.01). The X allele of the ACTN3 R577X polymorphism was associated with sport climbing status, as assessed using a meta-analysis of climbers across three different ethnicities.

Abstract Objects We investigated the association of ACE I/D and ACTN3 R577X polymorphisms with the performance of Chinese elite female soccer athletes for the first time. Material and methods The genotype distributions of ACE I/D and ACTN3 R577X in the athlete group and the control group of Chinese females were evaluated via PCR and compared. VO2max value was tested as per standard protocol. Results Regarding the distribution of ACE polymorphisms, the genotype frequency was indifferent between the athletes (II 40 %, ID 46.7 %, DD 13.3 %) and the controls (II 42 %, ID 48 %, DD 10 %). No difference in the I/D allele frequency was observed between the athlete group and the control group. Regarding the distribution of ACTN3 polymorphisms, the genotype frequency was significantly different between the athletes (XX 0 %, XR 53.3 %, RR 46.7 %) and the controls (XX 16 %, XR 44 %, RR 40 %). The allele frequency was observed no different between the athlete and the control group. The ACE ID and ACTN3 RR genotype combination was associated with higher VO2max values among defenders than among other players. According to VO2max values,The ACE and ACTN3 genotype combinations (II/ID/DD + RR/XR) significantly differed between the athletes and the controls (p

Abstract Aim: This study analyzed the influences of ACE and ACTN3 gene variants in sprinters, jumpers, and endurance young athletes of track and field. Methods: 36 school-level competitors of both sex (15 girls and 21 boys; aged 16.4 ± 1.2 years; training experience 4 ± 1.2 years) practitioners of different sport disciplines (i.e., sprint, jump, and endurance athletes) participated in the study. The deoxyribonucleic acid (DNA) was extracted from peripheral blood using a standard protocol. Anthropometric measurements, 30 m sprint, squat jump (SJ), and maximal oxygen uptake (VO2max) tests were measured. Results: Genotype distribution of the ACE and ACTN3 genes did not differ between groups. In ACE DD and ACTN3 RX genotypes, the SJ test was bigger in sprinters and jumpers than in the endurance runners. In contrast, when analyzing the ACE ID genotype, sprinters had higher SJ than endurance athletes. Moreover, in the ACE DD genotype, the sprinters and jumpers’ athletes had lower time in 30 m tests compared to endurance runners. However, the ACE ID and ACTN3 RX genotypes was greater aerobic fitness in endurance runners than in jumpers’ athletes. Conclusion: Although the genetic profile is not a unique factor for determining athletic performance, the ACE DD and ACTN3 RX genotypes seem to favor athletic performance in power and sprint versus endurance sports. Thus, this study evidenced that assessing genetic variants could be used as an auxiliary way to predict a favorable profile for the identification of young talents of track and field.

This study aimed to investigate if ACTN3 gene polymorphism impacts the susceptibility to exercise-induced muscle damage (EIMD) and changes in running economy (RE) following downhill running. Thirty-five healthy men were allocated to the two groups based on their ACTN3 gene variants: RR and X allele carriers. Neuromuscular function [knee extensor isometric peak torque (IPT), rate of torque development (RTD), and countermovement, and squat jump height], indirect markers of EIMD [muscle soreness, mid-thigh circumference, knee joint range of motion, and serum creatine kinase (CK) activity], and RE (oxygen uptake, minute ventilation, blood lactate concentration, and perceived exertion) for 5-min of running at a speed equivalent to 80% of individual maximal oxygen uptake speed were assessed before, immediately after, and 1–4 days after a 30-min downhill run (−15%). Neuromuscular function was compromised (P < 0.05) following downhill running with no differences between the groups, except for IPT, which was more affected in the RR individuals compared with the X allele carriers immediately (−24.9 ± 6.9% vs. −16.3 ± 6.5%, respectively) and 4 days (−16.6 ± 14.9% vs. −4.2 ± 9.5%, respectively) post-downhill running. EIMD manifested similarly for both the groups except for serum CK activity, which was greater for RR (398 ± 120 and 452 ± 126 U L–1 at 2 and 4 days following downhill running, respectively) compared with the X allele carriers (273 ± 121 and 352 ± 114 U L–1 at the same time points). RE was compromised following downhill running (16.7 ± 8.3% and 11 ± 7.5% increases in oxygen uptake immediately following downhill running for the RR and X allele carriers, respectively) with no difference between the groups. We conclude that although RR individuals appear to be more susceptible to EIMD following downhill running, this does not extend to the changes in RE.

Abstract Background There are large individual differences in physical activity (PA) behavior as well as trainability of physical capacity. Heritability studies have shown that genes may have as much impact on exercise participation behavior as environmental factors. Genes that favor both trainability and participation may increase the levels of PA. The present study aimed to assess the allele frequencies in genes associated with PA and/or physical capacity, and to see if there is any association between these polymorphisms and self-reported PA levels in a cohort of middle-aged Norwegians of Scandinavian descent (n = 831; mean age mean age (± SD) 55.5 ± 3.8 years). Results The genotype distributions of the ACTN3 R577X, ACE I/D and MAOA uVNTR polymorphisms were similar to other populations of European descent. When comparing the genotype distribution between the low/medium level PA group (LMPA) and high level PA groups (HPA), a significant difference in ACTN3 577X allele distribution was found. The X allele frequency was 10% lower in the HPA level group (P = 0.006). There were no differences in the genotype distribution of the ACE I/D or MAOA uVNTR polymorphism. Education and previous participation in sports or outdoor activities was positively associated with the self-reported PA levels (P ≤ 0.001). Conclusions To the best of our knowledge, this is the first study to report association between ACTN3 R577X genotype and PA level in middle-aged Scandinavians. Nevertheless, the contribution of a single polymorphism to a complex trait, like PA level, is likely small. Socioeconomic variables, as education and previous participation in sports or outdoor activities, are positively associated with the self-reported PA levels.

Abstract Background During the process of acclimatization, when our organism needs to adjust several metabolic processes in the attempt of establishing a better oxygenation, it is normal that individuals present some symptoms that can lead to the disease of the mountain. However, not everyone presents such symptoms and individuals native of high altitudes regions present genetic differences compared to natives of low altitudes which can generate a better acute adaptation. One of these differences is the higher proportion of type I muscle fibers, which may originate from the R577X polymorphism of the ACTN3 gene. The aim of this study was to compare the response of individuals with different ACTN3 genotypes at simulated 4500 m altitude on the presence of Acute Mountain Sickness (AMS) symptoms. Twenty-three volunteers (RR = 7, RX = 8, XX = 8) spent 4 hours exposed to a simulated altitude of 4500 m inside a normobaric hypoxia chamber. Lactate and glucose concentrations, SpO2, heart rate and the symptoms of AMS were analyzed immediately before entering the chamber and at each hour of exposure. Statistical analysis was performed using IBM SPSS Statistics 21 software. Results Our results point to an association between AMS symptoms and the presence of R allele from R577X polymorphism. Conclusion We conclude that individuals with at least one R allele of the R577X polymorphism seems to be more susceptible to the effects of hypoxia during the acclimatization process and may develop AMS symptoms.

Background. Soccer, combat sports and motorcycling have all been classified as mixed in terms of their metabolism predominance thus showing a common multifaceted nature of physical requirements, which include aerobic capacity, strength, endurance, power and agility. Objectives. The aim of the current study was to compare allelic and genotype frequencies of four well-known polymorphisms among athletes from different mixed sport disciplines in order to investigate genetic markers suitable for distinguishing the predominant components of these sports. Methods. Genotyping for the angiotensin-converting enzyme (ACE) insertion/deletion (I/D), α-actinin-3 (ACTN3) R577X, muscle‐specific creatine kinase (CK-MM) A/G and peroxisome proliferator-activated receptor alpha (PPARα) G/C polymorphisms among 113 professional athletes from motorcycling, soccer and combat sports was performed by PCR-RFLP method. Results. We found that the G allele of the PPARα polymorphism was significantly (p

BackgroundSpondyloarthritis (SpA) are the most common group of chronic inflammatory rheumatic diseases affecting about 1.5% of the adult Caucasian population. Low back pain is the most common symptom. The aetiopathogenesis of SpA is multifactorial, with well-known genetic and environmental contributions. Furthermore, muscle properties might also be involved in the pathophysiological process and these could be modulated by the genetic background. Alpha-actinin-3 (ACTN3) and Vitamin D receptor (VDR) genes are well-known genes related with muscle performance. Our aim was to analyze four SNPs of these genes and to evaluate their influence in axial SpA (axSpA) susceptibility, phenotype and muscle properties.MethodsWe performed a pilot study based on case-control approach involving 56 participants: 28 axSpA patients and 28 healthy controls matched by age, gender and levels of physical activity. Clinical, epidemiological and muscle characterization data—muscle physical properties (stiffness, tone, and elasticity), strength, mass, and performance, were collected. Two different muscles were considered for analysis, the Multifidus and Gastrocnemius. Four SNPs of ACTN3 (rs1815739) and VDR (rs2228570, rs731236, and rs7975232), were selected, analyzed and correlated with clinical, epidemiological and muscle characterization data.ResultsIn total, 51 individuals (27 axSpA patients and 24 matched controls) were eligible for further genetic analysis, 66.7% being male and with a mean age of 36 years. Muscle physical properties, muscle strength and muscle mass were similar in both groups; however, axSpA patients showed a decrease in muscle performance. None of the studied SNPs were associated with disease susceptibility/phenotype, muscle physical properties, muscle strength or muscle mass. However, ACTN3 rs1815739 and VDR rs2228570 were shown to be associated with muscle performance.ConclusionOur results suggest an association between ACTN3 and VDR polymorphisms and muscle performance in axSpA.

Introducción. El estudio de variables antropométricas y genéticas son fundamentales como determinantes del rendimiento deportivo. Objetivo. El objetivo del estudio fue determinar el somatotipo y la frecuencia de genotipo y alelo de 𝜶-actinina 3 (ACTN3) R577X y enzima convertidora de angiotensina (ECA) I/D polimorfismo de jugadores de tenis de mesa chilenos. Método. Se estudiaron 24 tenimesistas varones (edad 22,1 ± 5,4) del ranking nacional de Chile. La obtención de ACTN3 y ECA se recogió por muestra la saliva y se analizaron mediante reacción cadena de la polimerasa convencional. La estructura corporal se caracterizó a través del método del somatotipo propuesto por Carter. A partir de estadísticas descriptiva, se analizaron los valores medios de somatotipo, frecuencia de clasificación y ubicación de somato carta, además, de valores de frecuencia de genotipo y alelo de ACTN3 R/X y ECA I/D polimorfismo de acuerdo con número de aparición y porcentaje.Resultados. Se evidenció un predominio de clasificación mesoendomórfica y endomesomórfica, una mayor frecuencia fenotípica XX con predominio de alelo X para el gen ACTN3 y mayor frecuencia DI con predominio de alelo D para ECA. Conclusión. El somatotipo de tenimesistas chilenos tiene una orientación hacia mesoendomorfía y un predominio XX y alelo X del gen ACTN3 y, predominio del genotipo DI y alelo D del gen ECA, estas características podrían ofrecer una ventaja genética en cuanto a niveles de fuerza y potencia muscular, posiblemente facilitando la práctica y el éxito competitivo en estos tenimesistas chilenos. Abstract. Introduction. The study of anthropometric and genetic variables are essential as determinants of sports performance. Objective. The objective of the study was to determine the somatotype and the frequency of genotype and allele of 𝜶-actinin 3 (ACTN3) R577X and angiotensin converting enzyme (RCT) I / D polymorphism of Chilean table tennis players. Method. 24 male table tennis players (age 22.1 x 5.4) of Chile's national rankings were studied. Obtaining ACTN3 and ACE was collected by sample of saliva and analyzed by polymerase chain in real time. The body structure was characterized through the somatotype method proposed by Carter. From descriptive statistics, the mean values of somatotype, frequency of classification and location of somato letter were analyzed, in addition, of genotype frequency values and allele of ACTN3 R/X and ECA I/D polymorphism according to number of occurrence and percentage. Results. It demonstrated a predominance of mesoendomorphy and endomorphy classification, a higher phenotypic frequency XX with predominance of allele X for the ACTN3 gene and higher frequency of DI allele with predomina D for ACE. Conclusion. The somatotype of Chilean tenimestists has an orientation towards mesoendomorphy and a predominance of the genotype XX and allele X of the ACTN3 gene and, predominance of the DI genotype and allele D of the ACE gene, these characteristics could offer a genetic advantage in terms of strength levels and muscle potency, possibly facilitating practice and competitive success in these Chilean tenimists.

Despite strong evidence of an inheritable component of muscle phenotypes, little progress has been made in identifying the specific genetic factors involved in the development of sarcopenia. Even rarer are studies that focus on predicting the risk of sarcopenia based on a genetic risk score. In the present study, we tested the single and combined effect of seven candidate gene variants on the risk of sarcopenia. Single nucleotide polymorphisms in candidate genes were genotyped using the KASP assay. We examined 190 older adults that were classified as non-sarcopenic or sarcopenic according to the diagnostic criteria of the European Working Group on Sarcopenia in Older People. Sarcopenia was associated with Methylenetetrahydrofolate reductase, Alpha-actinin-3, and Nuclear respiratory factor 2 genotypes. The combined effect of all three polymorphisms explained 39% of the interindividual variation in sarcopenia risk. Our results suggest that the single and combined effect of Methylenetetrahydrofolate reductase, Alpha-actinin-3, and Nuclear respiratory factor 2 polymorphism is associated with sarcopenia risk in older adults. Nowadays, as the population is getting older and older, great efforts are being made to research the etiology, diagnosis and treatment of sarcopenia. At the same time, small progress has been made in understanding the genetic etiology of sarcopenia. Given the importance of research on this disease, further genetic studies are needed to better understand the genetic risk underlying sarcopenia. We believe that this small-scale study will help to demonstrate that there is still much to be discovered in this field.

The aim of this study was to determine the distribution of ACTN3 R577X gene polymorphism in soccer players and sedentary individuals, and to investigate the relationship of this distribution with performance tests. A total of 100 soccer players and 101 sedentary individuals were enrolled in the study. Standing long jump and countermovement jump (with arm swing, without arm swing and repeated) scores were recorded, using a jump meter. Maximum VO 2 levels were measured using a treadmill-connected cardiopulmonary exercise device, Masterscreen CPX. ACTN3 R577X polymorphism was evaluated by real-time PCR. ACTN3 R577X genotype distribution was found to be similar in soccer players and controls (p>0.05). The only statistically significant finding was a shorter countermovement jump with arm swing scores in the RR-genotyped soccer players, compared with their RX genotyped counterparts (p

Abstract 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.

Objectives: Polymorphisms in α-actinin-3 (ACTN3) gene are considered to be important in the genetic predisposition to human athletic performance. Most of the activities in soccer such as jumping, striking the ball, and running are considered plyometric and explosive. Performance power during such activities depends on the strength of the muscles involved. Therefore, high muscle strength is considered crucial for soccer players. The primary objective of this study was to ascertain the association between ACTN3 R577X (rs1815739) polymorphism and sports athletism in Iranian elite male soccer players. Methods: In total, 90 top-level professional Iranian male soccer players and 200 nonathletic Iranian men from the general population participated in this case–control study. Exon 16 of ACTN3 was genotyped throughout polymerase chain reaction (PCR) followed by Restriction Fragment Length Polymorphism (RFLP) using the restriction enzyme DdeI and direct sequencing. The genotypic and allelic frequencies of R577X polymorphism in athletes were compared to the frequencies in the general population (nonathletes). Results: According to the results, the percentage distributions of 577RR and 577RX genotypes (41% and 37%, respectively) were significantly higher and lower, respectively, than that of controls (25% and 57%, respectively) (P

Abstract Background Gorkhas, a sub-mountainous population of the Himalayan region, are known for strength and bravery. In the present study when “Gorkha” is used without brackets, we are mentioning Gorkhas of Tibeto-Burman origin. Physical capability, strength and endurance are important components of fitness associated with genetic traits. The aim of this study was to examine the endurance potential of male Gorkha soldiers, based on endurance-related genetic markers ACE I/D, ACTN3 Arg (R)577Ter(X), CKMM A/G NcoI and eNOS Glu(G)298Asp(T). Methods Genotypic and allelic frequencies were determined in 374 male Gorkha soldiers (Tibeto-Burman). These frequencies were compared with frequencies obtained from Gorkha (Indo-Aryan), high-altitude natives (Tibeto-Burman) and Indian lowlanders (Indo-Aryan). “Total genotype score” (TGS) was calculated from accumulated combination of polymorphisms with maximum value “100” for theoretically “optimal” polygenic score. Probability of occurrence of “optimal” endurance profile was also determined. Results ACE II genotypic frequency was highest in Tamangs followed by Gurungs, Rais, Limbus and Magars. No statistical difference in genotypic and allelic frequency of ACTN3 Arg(R)577Ter(X) was noted within the groups. Rais showed the highest CKMM A allele frequency (0.908) compared to other Gorkha (Tibeto-Burman) groups. Limbus and Tamangs showed the highest eNOS G allele frequency (0.938 and 0.915, respectively) compared to that of other groups. Probability of male Gorkha soldiers possessing a theoretically optimal polygenic endurance profile for four candidate polymorphisms was ~3.35% (1 in 30). Four percent of the population of male Gorkha soldiers (15 in 374) exhibited an optimal TGS 100, and 16% exhibited TGS 87 for endurance compared to male Indian soldiers belonging to the lowland (Indo-Aryan) and Gorkha (Indo-Aryan) populations suggesting an overall more “favourable” polygenic profile in the male Gorkha soldier (Tibeto-Burman) population. Conclusions This study presents evidence of higher frequency of endurance-associated genes in the Gorkhas implying thereby that such genetically endowed individuals from the population may be selected and trained for achieving excellence in endurance-related elite sports activities.

In this study, we aimed to investigate the influence of ACTN3 R577X gene polymorphism on muscle damage responses in athletes competing in an ultra-endurance race. Twenty moderate to well-trained ultra-runners who had entered in an official 37.1 km adventure race (22.1 km mountain biking, 10.9 km trek¬king, 4.1 km water trekking, 30 m rope course, and orienteering) volunteered for the study. Blood samples were collected for genotyping and analysis of muscle protein levels before and after the race. Percentage changes (pre- to post-race) of serum myoglobin [XX = 5,377% vs. RX/RR = 1,666%; P = 0.005, effect size (ES) = 1.73], creatine kinase (XX = 836.5% vs. RX/RR = 455%; P = 0.04, ES = 1.29), lactate dehydrogenase (XX = 82% vs. RX/RR = 65%; P = 0.002, ES = 1.61), and aspartate aminotransferase (XX = 148% vs. RX/RR = 75%; P = 0.02, ES = 1.77) were significantly greater for XX than RX/RR genotypes. ES analysis confirmed a large magnitude of muscle damage in XX genotype ultra-runners. Therefore, athletes with the ACTN3 577XX genotype experienced more muscle damage after an adventure race. This suggests that ultra-runners with alpha-actinin-3 deficiency may be more susceptible to rhabdomyolysis and associated health complications during ultra-endurance com¬petitions.

As human longevity increases, recent research has focused on the maintenance of optimal health during old age. One such area of focus is that of muscle function in the elderly, with a loss of muscle mass increasing the risk of negative outcomes such as sarcopenia and a decrease in bone mineral density. In this mini-review, we focus on the impact of a single nucleotide polymorphism in ACTN3, shown to impact muscle phenotype in elite athletes, on loss of muscle function, maintenance of bone mineral density, and metabolic disorder risk in an elderly population. From the surveyed research, this polymorphism has a clear and demonstrable impact on muscle phenotype and bone mineral density in this population, and acts as a potential modulator for metabolic disorders. As such, knowledge of an individual’s ACTN3 genotype may better inform the management of risk factors in the elderly, as well as driving innovations in exercise program design. Subsequently, such insights may contribute to the prolonged maintenance of health and function long into old age.

Over the last couple of decades, research has focused on attempting to understand the genetic influence on sports performance. This has led to the identification of a number of candidate genes which may help differentiate between elite and non-elite athletes. One of the most promising genes in that regard is ACTN3, which has commonly been referred to as “a gene for speed”. Recent research has examined the influence of this gene on other performance phenotypes, including exercise adaptation, exercise recovery, and sporting injury risk. In this review, we identified 19 studies exploring these phenotypes. Whilst there was large variation in the results of these studies, as well as extremely heterogeneous cohorts, there is overall a tentative consensus that ACTN3 genotype can impact the phenotypes of interest. In particular, the R allele of a common polymorphism (R577X) is associated with enhanced improvements in strength, protection from eccentric training-induced muscle damage, and sports injury. This illustrates that ACTN3 is more than just a gene for speed, with potentially wide-ranging influence on muscle function, knowledge of which may aid in the future personalization of exercise training programmes.

α-Actinin-3 (ACTN3) has been proposed to regulate skeletal muscle differentiation and hypertrophy through its interaction with the signalling protein calcineurin. Since the inhibition of calcineurin potentiates the production of testosterone, we hypothesized that α-actinin-3 deficiency (predicted from the ACTN3 XX genotype) may influence serum levels of testosterone of athletes. Objective: To investigate the association of ACTN3 gene R577X polymorphism with resting testosterone levels in athletes. Methods: A total of 209 elite Russian athletes from different sports (119 males, 90 females) were genotyped for ACTN3 gene R577X polymorphism by real-time PCR. Resting testosterone was examined in serum of athletes using enzyme immunoassay. Results: The mean testosterone levels were significantly higher in both males and females with the ACTN3 R allele than in XX homozygotes (males: RR: 24.9 (5.7), RX: 21.8 (5.5), XX: 18.6 (4.9) ng · mL-1, P = 0.0071; females: RR: 1.43 (0.6), RX: 1.21 (0.71), XX: 0.79 (0.66) ng · mL-1, P = 0.0167). Conclusions: We found that the ACTN3 R allele was associated with high levels of testosterone in athletes, and this may explain, in part, the association between the ACTN3 RR genotype, skeletal muscle hypertrophy and power athlete status.

O objetivo deste estudo foi analisar os efeitos dos polimorfismos genéticos I/D da enzima conversora de angiotensina (ECA) e R/X da proteína alfa-actinina 3 (ACTN3) na capacidade funcional e na incidência de quedas em idosas. Foram genotipadas 66 idosas e com base nestas características genéticas foram divididas em grupos e submetidas a medidas de estatura, massa corporal, testes de força de preensão manual, sentar e levantar, coordenação, alcance funcional e alcance lateral, além de responderem alguns questionários. Os resultados mostraram que idosas com o genótipo ID no gene da ECA apresentaram melhores resultados de alcance funcional. Em relação aos polimorfismos da ACTN3, a incidência de quedas no grupo XX foi em termos descritivos consideravelmente maior do que a do grupo RR/RX (0,69 versus 0,29 queda em um ano).

The aim of the present study was to review the evidence on the relationship between the R577X polymorphism of the ACTN3 gene and sports performance. The Pubmed database was searched using ACTN3 gene AND sports performance as keywords. The ACTN3 gene encodes a muscle-specific protein, called α-actinin-3, which is only present in type II fibers. Most studies have demonstrated a relationship between the presence of α-actinin-3 and the ability of muscle to generate force. However, recent studies suggest that the absence of the functional form of this protein may regulate substrate utilization during exercise, giving priority to oxidative metabolism, sparing muscle glycogen, and improving performance in long-duration events. Nevertheless, further studies involving humans are needed to better understand the metabolic role of this protein.

The aim of the present study was to review the evidence on the relationship between the R577X polymorphism of the ACTN3 gene and sports performance. The Pubmed database was searched using ACTN3 gene AND sports performance as keywords. The ACTN3 gene encodes a muscle-specific protein, called α-actinin-3, which is only present in type II fibers. Most studies have demonstrated a relationship between the presence of α-actinin-3 and the ability of muscle to generate force. However, recent studies suggest that the absence of the functional form of this protein may regulate substrate utilization during exercise, giving priority to oxidative metabolism, sparing muscle glycogen, and improving performance in long-duration events. Nevertheless, further studies involving humans are needed to better understand the metabolic role of this protein.

In elite sporting codes, the identification and promotion of future athletes into specialised talent pathways is heavily reliant upon objective physical, technical, and tactical characteristics, in addition to subjective coach assessments. Despite the availability of a plethora of assessments, the dependence on subjective forms of identification remain commonplace in most sporting codes. More recently, genetic markers, including several single nucleotide polymorphisms (SNPs), have been correlated with enhanced aerobic capacity, strength, and an overall increase in athletic ability. In this review, we discuss the effects of a number of candidate genes on athletic performance, across single-skilled and multifaceted sporting codes, and propose additional markers for the identification of motor skill acquisition and learning. While displaying some inconsistencies, both the ACE and ACTN3 polymorphisms appear to be more prevalent in strength and endurance sporting teams, and have been found to correlate to physical assessments. More recently, a number of polymorphisms reportedly correlating to athlete performance have gained attention, however inconsistent research design and varying sports make it difficult to ascertain the relevance to the wider sporting population. In elucidating the role of genetic markers in athleticism, existing talent identification protocols may significantly improve—and ultimately enable—targeted resourcing in junior talent pathways.