way to traditional association studies with single nucleotide polymorphisms (SNPs), the use of population distance genetics including SNP data from human genomics databases can provide important information for a better understanding of heritability in exercise science. Methods Subjects The study
Gustavo Monnerat, Alex S. Maior, Marcio Tannure, Lia K.F.C. Back and Caleb G.M. Santos
Thomas Yvert, Catalina Santiago, Elena Santana-Sosa, Zoraida Verde, Felix Gómez-Gallego, Luis Lopez-Mojares, Margarita Pérez, Nuria Garatachea and Alejandro Lucia
In patients with cystic fibrosis (CF), physical capacity (PC) has been correlated with mortality risk. In turn, PC is dependent on genetic factors. This study examines several polymorphisms associated with PC and healthrelated phenotype traits (VO2peak, FEV1, FVC, PImax and muscular strength) in a group of children with CF (n = 66, primary purpose). The same analyses were also performed in a control group of healthy children (n = 113, secondary purpose). The polymorphisms determined were classified as muscle function polymorphisms (ACE rs1799752; AGT rs699; ACTN3 rs1815739; PTK2 rs7843014 and rs7460; MSTN rs1805086; TRHR rs7832552; NOS3 rs2070744) or energy metabolism polymorphisms (PPARGC1A rs8192678; NRF1 rs6949152; NRF2 rs12594956; TFAM rs1937; PPARD rs2267668; ACSL1 rs6552828). No significant polymorphism/phenotype correlations were detected in children with CF, with marginal associations being observed between NOS3 rs2070744 and VO2peak and FEV1, as well as between PPARGC1A rs8192678 and FEV1. Overall, similar findings were observed in the control group, i.e., no major associations. The PC-related polymorphisms examined seem to have no effects on the PC or health of children with CF.
Sigal Ben-Zaken, Yoav Meckel, Nitzan Dror, Dan Nemet and Alon Eliakim
In recent years several genetic polymorphisms related to the GH-IGF-I axis were suggested to promote athletic excellence in endurance and power sports. We studied the presence of the C-1245T SNP (rs35767), a nucleotide substitution in the promoter region of the IGF-I gene, and the presence of the 275124A > C SNP (rs1464430), a common nucleotide substitution in the intron region of the IGF-I receptor (IGF-IR) gene in elite long and short-distance swimmers compared with nonphysically active controls. The rare T/T IGF-I polymorphism was found only in 5.3% of the long-distance swimmers, and was not found at all in the short-distance swimmers or among the control group participants. The prevalence of the IGF-I receptor AA genotype was significantly lower in the swimming group as a whole (35%) compared with the control group (46%), in particularly due to reduced frequency of the AA genotype among short-distance swimmers (26%). In contrast to previous reports in elite endurance and power track and field athletes, single nucleotide polymorphisms of the IGF-I and the IGF-IR were not frequent among elite Israeli short- and long-distance swimmers emphasizing the importance of other factors for excellence in swimming. The results also suggest that despite seemingly similar metabolic characteristics different sports disciplines may have different genetic polymorphisms. Thus, combining different disciplines for sports genetic research purposes should be done with extreme caution.
Ildus I. Ahmetov, Olga L. Vinogradova and Alun G. Williams
The ability to perform aerobic or anaerobic exercise varies widely among individuals, partially depending on their muscle-fiber composition. Variability in the proportion of skeletal-muscle fiber types may also explain marked differences in aspects of certain chronic disease states including obesity, insulin resistance, and hypertension. In untrained individuals, the proportion of slow-twitch (Type I) fibers in the vastus lateralis muscle is typically around 50% (range 5–90%), and it is unusual for them to undergo conversion to fast-twitch fibers. It has been suggested that the genetic component for the observed variability in the proportion of Type I fibers in human muscles is on the order of 40–50%, indicating that muscle fiber-type composition is determined by both genotype and environment. This article briefly reviews current progress in the understanding of genetic determinism of fiber-type proportion in human skeletal muscle. Several polymorphisms of genes involved in the calcineurin–NFAT pathway, mitochondrial biogenesis, glucose and lipid metabolism, cytoskeletal function, hypoxia and angiogenesis, and circulatory homeostasis have been associated with fiber-type composition. As muscle is a major contributor to metabolism and physical strength and can readily adapt, it is not surprising that many of these gene variants have been associated with physical performance and athlete status, as well as metabolic and cardiovascular diseases. Genetic variants associated with fiber-type proportions have important implications for our understanding of muscle function in both health and disease.
Olga N. Fedotovskaya, Leysan J. Mustafina, Daniil V. Popov, Olga L. Vinogradova and Ildus I. Ahmetov
In red skeletal muscle, monocarboxylate transporter 1 (MCT1) is required for lactate to enter the myocytes for oxidation. The A1470T polymorphism (rs1049434) in the MCT1 gene was shown to be associated with lactate transport rates in human skeletal muscles. The aim of the study was to compare genotype and allele frequencies of the MCT1 gene polymorphism in 323 Russian athletes and 467 nonathletic controls and to investigate the association of the MCT1 gene A1470T polymorphism with maximal oxygen consumption and maximal lactate concentration in rowers (n = 79).
Genotyping for the A1470T MCT1 polymorphism was performed by PCR-RFLP method. Physiological measurements of 79 Russian rowers of national competitive standard were determined during an incremental test to exhaustion on a rowing ergometer.
Frequencies of the A allele (71.8% vs 62.5%, P < .0001) and AA genotype (59.8% vs 39.4%, P < .0001) were significantly higher in endurance-oriented athletes (n = 142) than in the control group. Mean blood lactate concentration was higher in male rowers with the T allele (AT+TT 10.26 ± 1.89 mmol/L, AA 8.75 ± 1.69 mmol/L, P = .005).
MCT1 gene A1470T polymorphism is associated with endurance athlete status and blood lactate level after intensive exercise.
Wai Pong Wong, Yi Zhao and Woon-Puay Koh
The angiotensin-I-converting enzyme (ACE) I/D gene polymorphism has been studied for its role in determining habitual physical activity level, but there is no information from Asian populations. The objective of this study was to determine whether this ACE gene polymorphism was associated with physical activity level among Chinese in Singapore. In this cross-sectional study, 110 normotensive Chinese in Singapore, age 21–61 yr, completed the short-form version of the International Physical Activity Questionnaire and contributed buccal cell samples for genotyping of the ACE I/D gene polymorphism using polymerase chain-reaction amplification. They also provided demographic information and underwent anthropometric measurements. Physical activity level was expressed as continuous (in kcal/wk) and categorical (low, moderate, or high) data. The 3 genotypes of ACE were DD (homozygous for the deletion allele), II (homozygous for the insertion allele), and ID. Among the participants, 28.2% reported low, 49.1% moderate, and 22.7% high physical activity level. Frequencies of the genotypes were 11.8% for DD, 42.7% for ID, and 45.5% for II. ACE genotype was independently associated with physical activity level. After age, gender, and body-mass index were adjusted for, individuals with DD or ID genotypes were more likely to report insufficient or low physical activity level than those with II genotypes (odds ratio = 6.88; 95% confidence interval: 2.26, 20.94). In conclusion, the I/D polymorphism of the ACE gene is significantly associated with self-reported physical activity level in normotensive Chinese Singaporeans.
Marta Stepien-Slodkowska, Krzysztof Ficek, Pawel Zietek, Mariusz Kaczmarczyk, Wioletta Lubkowska, Miroslawa Szark-Eckardt and Pawel Cieszczyk
The most commonly injured body part for skiing has been found to be the knee. The rupture of the anterior cruciate ligament (ACL) was the most frequent diagnosis. ACL ruptures are determined by several extrinsic and intrinsic risk factors including those that are hormonal, neuromuscular, anatomical, or genetic.
To examine the association of both COL1A1 rs1800012 (+1245G/T) and COL1A1 rs1107946 (–1997G/T) polymorphisms, individually and as haplotypes, with ACL ruptures in recreational Polish skiers.
Genomic DNA was extracted from buccal cells donated by the subjects, and genotyping was carried out using real-time polymerase chain reaction.
138 male recreational skiers with surgically diagnosed primary ruptures and 183 apparently healthy male recreational skiers not differing markedly in age or level of exposure to ACL injury.
Main Outcome Measures:
COL1A1 rs1800012 and COL1A1 rs1107946 polymorphisms.
There were significant differences in genotype distribution of the COL1A1 rs1800012 polymorphism between the ACL rupture group and the control group. The GG homozygotes were underrepresented in the ACL rupture group compared with the control group. There were no significant differences in genotype distribution or allele frequency of COL1A1 rs1107946 polymorphisms between the ACL rupture group and the control group. The G-G (COL1A1 rs1800012G and COL1A1 rs1107946G) haplotype was the most common. There were no significant differences in haplotype distribution between the ACL-rupture and control groups.
The study showed that GG homozygotes were underrepresented in the ACL-rupture group compared with the control group, which suggests an association with reduced risk of ACL injury.
Yandiswa Y. Yako, Mogamat S. Hassan, Rajiv T. Erasmus, Lize van der Merwe, Susan Janse van Rensburg and Tandi Edith Matsha
There is evidence demonstrating that the contribution of sedentary behavior and effect of physical activity on metabolic phenotypes is mediated by polymorphisms in genes.
The type and frequency of physical activity was assessed by means of structured questionnaires in 1555 South African school learners. Anthropometric measurements, blood pressure, fasting blood glucose and lipids were measured using standard procedures. The effect of different types and frequency of physical activity on obesity-related traits was assessed in relation to MC3R T6K and V81I genotypes in 430 of the learners.
Levels of total cholesterol were significantly lower in learners carrying the MC3R T6K and V81I minor alleles, after adjusting for age, race, gender, and each specific physical activity category. An activity-by-genotype interaction was also detected: learners heterozygous for the V81I polymorphism and performed house chores often had reduced total cholesterol. Though no association was observed between frequency of physical activity and BMI, television viewing was significantly associated with an increase in height, weight and marginally with waist circumference.
Our findings suggest that physical activity even in the form of house chores has a positive effect on metabolic traits and this effect is further enhanced in the presence of MC3R polymorphisms.
Nuria Garatachea, Zoraida Verde, Alejandro Santos-Lozano, Thomas Yvert, Gabriel Rodriguez-Romo, Francisco J. Sarasa, Sonsoles Hernández-Sánchez, Catalina Santiago and Alejandro Lucia
To determine the association of the ACTN3 R577X polymorphism with leg-muscle explosive power in Spanish (white) elite basketball players and controls.
100 (60 men) elite basketball players (cases) and 283 nonathletic controls.
The authors assessed power performance by means of the vertical-squat and countermovement-jump tests.
Genotype distributions did not differ between groups (cases: 37.0% [RR], 42.0% [RX], and 21.0% [XX]; controls: 31.8% [RR], 49.8% [RX], and 18.4% [XX]; P = .353). The authors did not observe any effect of the ACTN3 R577X polymorphism on study phenotypes in either group, including when they performed the analyses separately in men and women. They found no association between the ACTN3 R577X polymorphism and the likelihood of being an elite basketball player using the dominant or the recessive model, and the results remained unaltered when the analyses were adjusted for sex, weight, height, and age or when performed for men and women separately.
Although the ACTN3 R577X is associated with explosive muscle performance and this phenotype is important in the sport of basketball (ie, during jumps), the authors found no association with leg explosive power in elite basket players or with the status of being this type of athlete.
Gabriel Rodríguez-Romo, Thomas Yvert, Alfonso de Diego, Catalina Santiago, Alfonso L. Díaz de Durana, Vicente Carratalá, Nuria Garatachea and Alejandro Lucia
The authors compared ACTN3 R577X genotype and allele frequencies in the majority of all-time-best Spanish judo male athletes (n = 108) and 343 ethnically matched nonathletic men. No between-groups differences were found in allele (P = .077) or genotype distributions (P = .178). Thus, the R577X polymorphism was not significantly associated with the status of being an elite judo athlete, at least in the Spanish population. The contribution of genetics to sports-related phenotype traits is undeniable with some genotypes, of which ACTN3 R577X is currently the leading candidate, partly distinguishing individuals predisposed to either endurance or power sports. However, few athletic events can be categorized as purely power or endurance based. Although genetic testing (ie, for ACTN3 R577X) is already being marketed to predict sports talent and potential of young children, its usefulness is still questionable, at least in competitive judo.