Association between ACTN3 R577X Polymorphism and Trunk Flexibility in 2 Different Cohorts

Abstract

α-Actinin-3 (ACTN3) R577X polymorphism is associated with muscular strength and power. This study was performed to investigate the association between ACTN3 R577X polymorphisms and flexibility as another component of fitness in 2 cohorts. Cohort 1 consisted of 208 men and 568 women (ages 23-88), while Cohort 2 consisted of 529 men and 728 women (ages 23-87). All participants were recruited from the Tokyo metropolitan area and underwent a battery of tests to assess their grip strength and sit-and-reach flexibility. Genotyping results were analyzed for ACTN3 (rs1815739) polymorphism using the TaqMan approach. In Cohort 1, sit-and-reach in the RR genotype (35.3±0.7 cm) was significantly lower than those in the RX and XX genotypes (37.2±0.3 cm) even after adjusting for sex, age, and exercise habit as covariates (P<0.01). In Cohort 2, sit-and-reach tended to be lower in RR (38.1±0.6 cm) than in RX and XX (39.1±0.3 cm), but the differences were not significant (P=0.114). Analysis in pooled subjects indicated that RR was associated with significantly lower flexibility than RX and XX (P=0.009). The RR genotype of ACTN3 R577X in the general Japanese population showed lower flexibility compared to the RX and XX genotypes.

Effects of the ACTN3 R577X Genotype on the Muscular Strength and Range of Motion Before and After Eccentric Contractions of the Elbow Flexors

“…Broos et al [3] reported that individuals with the RR genotype of the ACTN3 R577X polymorphism have higher hysteresis and Young's modulus of single fibers than individuals with RX and XX genotypes among subjects with a spinal cord injury. Recently, we also showed that RR exhibits lower trunk flexibility than RX and XX genotypes in the Asian general population (n = 2,033), particularly women [18]. These studies suggest that the recessive model of the ACTN3 R577X genotype has the potential to affect joint flexibility, including muscle hardness.…”

“…One-way analysis of variance was performed to compare the values between the ACTN3 genotypes. Student's ttests were used to compare the RR and RX + XX alleles in the MVC torque and ROM as previously [18]. In addition, changes in the dependent variables (MVC, ROM, and VAS) over time were compared between the RR and RX + XX alleles by a two-way repeated meas-ure analysis of variance (ANOVA).…”

“…α-actinin-3, normally expressed in type II muscle fibers, is important for anchoring actin and plays a regulatory role in coordinating muscle fiber contraction [26]. Homozygosity (XX genotype) for the common nonsense polymorphism R577X in the ACTN3 gene results in a complete deficiency of α-actinin-3 protein in type II muscle fibers, and 18 % of Caucasian and 25 % of Japanese populations have the XX genotype [18].…”

Greater Progression of Age-Related Aortic Stiffening in Adults with Poor Trunk Flexibility: A 5-Year Longitudinal Study

“…Thus, flexibility might be an independent factor of age-related arterial stiffening. Our recent study indicated that ACTN3 R577X genotype could be an independent genetic factor of trunk flexibility (Kikuchi et al, 2017). This study indicated that RR genotype was associated with significantly lower flexibility than XX.…”

Treinamento combinado versus multicomponente em parâmetros de saúde de mulheres de 50 a 75 anos: associação com variantes genéticas

“…Tais resultados evidenciam a importância da análise genética da ECA antes do uso de um medicamento, que pode não demonstrar resultados positivos para indivíduos com determinadas características genéticas 7 .Em relação ao polimorfismo da ACTN3 para o grupo treinamento multicomponente foram encontradas diminuição da circunferência da cintura em mulheres com genótipo CC e melhora no teste flexão e extensão de cotovelo, sentar e levantar e domínio mental da qualidade de vida em mulheres com genótipos TT+TC.Delmonico et al (2007), assim como no presente estudo, não encontraram diferença para índice de massa corporal após dez semanas de treinamento de força em idosos (homens e mulheres) fisicamente inativos36 . Para o polimorfismo ACTN3 não encontramos diferenças estatisticamente significantes nos valores de flexibilidade, o que difere dos achados deKikushi et al (2016), que pesquisaram a associação do polimorfismo da ACTN3 com a flexibilidade em mulheres e homens de 23 a 87 anos em duas coortes e demonstraram que o genótipo TT foi associado a menores valores quando comparado com os genótipos TC e CC37 . Nosso estudo não observou efeito para capacidade cardiorrespiratória com o treinamento multicomponente, porém, em estudo com adultos saudáveis, demonstraram que 18 semanas de e encontraram que mulheres homozigotas TT tiveram menor resistência muscular isométrica e demonstraram maiores ganhos absolutos e relativos de força no teste de uma repetição máxima pós treinamento comparadas com aquelas com o tipo selvagem homozigótico (TT) e o genótipo heterozigoto (TC)43 .…”