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Hand grip strength is a widely used proxy of muscular fitness, a marker of frailty, and predictor of a range of morbidities and all-cause mortality. To investigate the genetic determinants of variation in grip strength, we perform a large-scale genetic discovery analysis in a combined sample of 195,180 individuals and identify 16 loci associated with grip strength (P

Purpose: To replicate previous genome-wide association study identified sprint-related polymorphisms in 3 different cohorts of top-level sprinters and to further validate the obtained results in functional studies. Methods: A total of 240 Japanese, 290 Russians, and 593 Brazilians were evaluated in a case-control approach. Of these, 267 were top-level sprint/power athletes. In addition, the relationship between selected polymorphisms and muscle fiber composition was evaluated in 203 Japanese and 287 Finnish individuals. Results: The G allele of the rs3213537 polymorphism was overrepresented in Japanese (odds ratio [OR]: 2.07, P =.024) and Russian (OR: 1.93, P =.027) sprinters compared with endurance athletes and was associated with an increased proportion of fast-twitch muscle fibers in Japanese (P =.02) and Finnish (P =.041) individuals. A meta-analysis of the data from 4 athlete cohorts confirmed that the presence of the G/G genotype rather than the G/A+A/A genotypes increased the OR of being a sprinter compared with controls (OR: 1.49, P =.01), endurance athletes (OR: 1.79, P =.001), or controls + endurance athletes (OR: 1.58, P =.002). Furthermore, male sprinters with the G/G genotype were found to have significantly faster personal times in the 100-m dash than those with G/A+A/A genotypes (10.50 [0.26] vs 10.76 [0.31], P =.014). Conclusion: The rs3213537 polymorphism found in the CPNE5 gene was identified as a highly replicable variant associated with sprinting ability and the increased proportion of fast-twitch muscle fibers, in which the homozygous genotype for the major allele (ie, the G/G genotype) is preferable for performance. [ABSTRACT FROM AUTHOR]

This study aimed to examine how genetic polymorphisms related to muscular strength and flexibility influence artistic gymnastic performance in an attempt to identify a novel polymorphism associated with flexibility. In study 1, the passive straight-leg-raise (PSLR) score and aromatase gene CYP19A1 rs936306 polymorphism, a key enzyme for estrogen biosynthesis, were assessed in 278 individuals. In study 2, athletes (281 gymnasts and 1908 other athletes) were asked about their competition level, and gymnasts were assessed using the difficulty score (D-score) for each event. Muscular strength- (ACTN3 R577X rs1815739 and ACE I/D rs4341) and flexibility-related (ESR1 rs2234693 T/C and CYP19A1 rs936306 C/T) genetic polymorphisms were analyzed. In study 1, males with the CYP19A1 CT + TT genotype showed significantly higher PSLR scores than those with the CC genotype. In study 2, male gymnasts with the R allele of ACTN3 R577X showed a correlation with the floor, rings, vault, and total D-scores. In addition, male gymnasts with the C allele of ESR1 T/C and T allele of CYP19A1 C/T polymorphisms were correlated with the pommel horse, parallel bars, horizontal bar, and total D-scores. Furthermore, genotype scores of these three polymorphisms correlated with the total D-scores and competition levels in male gymnasts. In contrast, no such associations were observed in female gymnasts. Our findings suggest that muscular strength- and flexibility-related polymorphisms play important roles in achieving high performance in male artistic gymnastics by specifically influencing the performance of events that require muscular strength and flexibility, respectively. Highlights Estrogen-related CYP19A1 polymorphism is a novel determinant of flexibility in males. Muscular strength- and flexibility-related polymorphisms play important roles in high performance in male artistic gymnastics. Genotypes of ACTN3 R577X, ESR1 rs2234693, and CYP19A1 rs936306 may contribute to training plan optimization and event selection in artistic gymnastics. [ABSTRACT FROM AUTHOR]

Previous small-scale studies have shown an association between the COL5A1 gene and anterior cruciate ligament (ACL) injury risk. In this larger study, the genotype and allele frequency distributions of the COL5A1 rs12722 C/T and rs10628678 AGGG/deletion (AGGG/-) indel variants were compared between participants: (i) with ACL injury in independent and combined cohorts from South-Africa (SA) and Australia (AUS) vs controls (CON), and (ii) with any ligament (ALL) or only ACL injury in a Japanese (JPN) cohort vs CON. Samples were collected from SA (235 cases; 232 controls), AUS (362 cases; 80 controls) and JPN (500 cases; 1,403 controls). Genomic DNA was extracted and genotyped. Distributions were compared, and inferred haplotype analyses performed. No independent associations were noted for rs12722 or rs10628678 when the combined SA + AUS cohort was analysed. However, the C-deletion (rs12722-rs10628678) inferred haplotype was under-represented (p = 0.040, OR = 0.15, CI = 0.04-0.56), while the T-deletion inferred haplotype was over-represented in the female SA + AUS ACL participants versus controls (p < 0.001, OR = 4.74, CI = 1.66-13.55). Additionally, the rs12722 C/C genotype was under-represented in JPN CON vs ACL (p = 0.039, OR = 0.52, 0.27-1.00), while the rs10628678 −/− genotype was associated with increased risk of any ligament injuries (p = 0.035, OR = 1.31, CI = 1.02-1.68) in the JPN cohort. Collectively, these results highlight that a region within the COL5A1 3'-UTR is associated with ligament injury risk. This must be evaluated in larger cohorts and its functional relevance to the structure and capacity of ligaments and joint biomechanics be explored. Highlights The COL5A1 T-deletion inferred haplotype (rs12722-rs10628678) was associated with an increased risk of ACL rupture in the combined SA and AUS female participants. The COL5A1 C-deletion inferred haplotype (rs12722-rs10628678) was associated with a decreased risk of ACL rupture in the combined SA and AUS female participants. The COL5A1 rs12722 C/C and rs10628678 −/− genotypes were associated with increased risk of ACL rupture and of ligament injuries in JPN, respectively. A region within the COL5A1 3'-UTR is associated with risk of ligament injury, including ACL rupture, and therefore the functional significance of this region on ligament capacity and joint biomechanics requires further exploration. [ABSTRACT FROM AUTHOR]

Kumagai, H, Miyamoto-Mikami, E, Kikuchi, N, Kamiya, N, Zempo, H, and Fuku, N. A rs936306 C/T polymorphism in the CYP19A1 is associated with stress fractures. J Strength Cond Res 36(8): 2322–2325, 2022—A stress fracture (SF) is an overuse injury, and low bone mineral density (BMD) is the risk factor for the SF. Estrogen is suggested to have a crucial role in bone metabolism, and estrogen-related genetic polymorphisms are associated with BMD. However, the possible association between SF and estrogen-related genetic polymorphisms has not been clarified yet. Therefore, we aimed to clarify whether estrogen-related genetic polymorphisms are associated with a history of SFs in Japanese athletes. A total of 1,311 (men: n = 868, women: n = 443) top-level Japanese athletes who participated in various sports and at different levels were analyzed. The history of SFs was assessed using a questionnaire, and the cytochrome P450 aromatase gene (CYP19A1) rs936306 C/T and estrogen receptor α gene (ESR1) rs2234693 T/C polymorphisms were analyzed using the TaqMan genotyping assay. The genotype frequency of the CYP19A1 C/T polymorphism was significantly different between the injured group and noninjured group under the C allele additive genetic model (odds ratio = 1.31, 95% confidence interval = 1.01–1.70), especially in men and in women with irregular menstruation. On the other hand, there were no significant differences with the ESR1 T/C polymorphism. This study demonstrated that the C allele in the CYP19A1 rs936306 polymorphism is a risk factor for SFs in top-level Japanese athletes. [ABSTRACT FROM AUTHOR]

This study aimed to assess (1) blood pressure between young, current athletes, and non‐athletes early in life; (2) hypertension prevalence between former athletes and the general population later in life; and (3) understand the mechanisms between exercise training and hypertension risks in the form of DNA methylation. Study 1: A total of 354 young male participants, including current athletes, underwent blood pressure assessment. Study 2: The prevalence of hypertension in 1269 male former athletes was compared with that in the Japanese general population. Current and former athletes were divided into three groups: endurance‐, mixed‐, and sprint/power‐group. Study 3: We analyzed the effect of aerobic‐ or resistance‐training on DNA methylation patterns using publicly available datasets to explore the possible underlying mechanisms. In young, current athletes, the mixed‐ and sprint/power‐group exhibited higher systolic blood pressure, and all groups exhibited higher pulse pressure than non‐athletes. In contrast, the prevalence of hypertension in former athletes was significantly lower in all groups than in the general population. Compared to endurance‐group (reference), adjusted‐hazard ratios for the incidence of hypertension among mixed‐ and sprint/power‐group were 1.24 (0.87–1.84) and 1.50 (1.04–2.23), respectively. Moreover, aerobic‐ and resistance‐training commonly modified over 3000 DNA methylation sites in skeletal muscle, and these were suggested to be associated with cardiovascular function‐related pathways. These findings suggest that the high blood pressure induced by exercise training at a young age does not influence the development of future hypertension. Furthermore, previous exercise training experiences at a young age could decrease the risk of future hypertension. [ABSTRACT FROM AUTHOR]

This study aimed to clarify 1) the influence of genetic polymorphisms in the cytochrome P450 aromatase gene (CYP19A1) on circulating estradiol levels in men and 2) whether estrogen-related genetic polymorphisms, such as the CYP19A1 rs936306 and estrogen receptor-a (ESR1) rs2234693 polymorphisms, predict exercise-induced serum creatine kinase (CK) activity, which is an index of skeletal muscle membrane disruption. Serum estradiol levels were examined in young men (n = 167). In a different cohort, serum CK activity was analyzed in a 2-day ultramarathon race: baseline, after the first day, and after the second day (114 males and 25 females). Genetic polymorphisms in CYP19A1 rs936306 C/T and ESR1 rs2234693 T/C were analyzed using the TaqMan SNP Genotyping Assay. Male subjects with the TT genotype of the CYP19A1 polymorphism exhibited significantly higher serum estradiol levels than the C allele carriers. Male runners had significantly higher postrace serum CK activity than female runners. The change in the CK activity during the ultramarathon race was significantly lower in male subjects with the CYP19A1 TT genotype than in those with the CC þ CT genotypes and was correlated with the number of C alleles in ESR1 rs2234693 in male subjects. Furthermore, the genotype scores of these two polymorphisms were significantly correlated with changes in serum CK activity during race (r = -0.279, P = 0.003). The results of this study suggest that genetic polymorphisms in CYP19A1 rs936306 influence serum estradiol levels in men, and genetic polymorphisms in CYP19A1 and ESR1 are associated with serum CK activity in men. NEW & NOTEWORTHY Men with the TT genotype of the CYP19A1 polymorphism exhibited higher circulating estradiol levels than the TC þ CC genotype. The TT genotype in the CYP19A1 polymorphism and the C allele of the ESR1 polymorphism, an allele increasing ESR1 expression, were associated with low serum CK activity after the ultramarathon. A combination of these polymorphisms was correlated with changes in the serum CK activity. Therefore, estrogen-related genetic polymorphisms partially predict exercise-induced muscle damage, that is, skeletal muscle membrane disruption. [ABSTRACT FROM AUTHOR]