Associations of the Alpha-Actinin Three Genotype with Bone and Muscle Mass Loss among Middle-Aged and Older Adults

Abstract

Bone and muscle mass loss are known to occur simultaneously. The alpha-actinin three (ACTN3) genotype has been shown to potentially affect bone and muscle mass. In this study, we investigated the association between the ACTN3 genotype and bone and muscle mass loss in community-dwelling adults aged ≥ 60 years. This study was a cross-sectional analysis of data from 295 participants who participated in a community health checkup. The ACTN3 genotypes were classified as RR, RX, or XX types. Bone mass loss was defined as a calcaneal speed of sound T-score of <−1.32 and <−1.37, and muscle mass loss was defined as an appendicular skeletal muscle index of <7.0 kg/m2 and <5.7 kg/m2 in men and women, respectively. The percentages of XX, RX, and RR in the combined bone and muscle mass loss group were 33.8%, 30.8%, and 16.7%, respectively, with a significantly higher trend for XX. Multinomial logistic regression analysis showed that XX had an odds ratio of 3.00 (95% confidence interval 1.05–8.54) of being in the combined bone and muscle mass loss group compared to the RR group (covariates: age, sex, grip strength, and medications). The ACTN3 genotype of XX is associated with a higher rate of comorbid bone and muscle mass loss. Therefore, ACTN3 genotyping should be considered for preventing combined bone and muscle mass loss.

Independent Association between Cognitive Frailty and Cardio-Ankle Vascular Index in Community-Dwelling Older Adults

“…Physical function was assessed in terms of maximum grip strength and normal walking speed. Grip strength was measured using a digital grip strength meter (GRIP-D; Takei Scientific Instruments Co., Ltd., Niigata, Japan) to determine the maximum grip strength of the dominant hand [20]. Normal walking speed was measured using an infrared sensor (YW; YAGAMI Inc., Aichi, Japan).…”

Fiber-Type Shifting in Sarcopenia of Old Age: Proteomic Profiling of the Contractile Apparatus of Skeletal Muscles

“…The major ACTN proteins found in the Z-disc are the alpha-actinin-2 isoform ACTN-2 (ACTN2 gene) and the alpha-actinin-3 isoform ACTN-3 (ACTN3 gene) [317]. Interestingly, the ACTN3 genotype appears to be linked to the maintenance of bone and skeletal muscle mass during aging [318]. MYOZ isoforms that are present in skeletal muscles are MYOZ-1 (myozenin-1; previously named FATZ-1; MYOZ1 gene), MYOZ-2 (myozenin-2; MYOZ2 gene) and MYOZ-3 (myozenin-3; MYOZ3 gene) [319,320].…”

Slow or fast: Implications of myofibre type and associated differences for manifestation of neuromuscular disorders

“…The loss of α‐actinin‐3 changes the overall protein composition and elastic properties of fast myofibre Z‐bands, resulting in loss of force generation and increased susceptibility to eccentric damage in α‐actinin‐3‐deficient individuals 170,171 . Other effects of the ACTN3 XX genotype related to altered muscle function and adaptation to physical demands and atrophy are observed and have been widely investigated in various human populations, with the ACTN3 XX genotype associated with age‐related loss of human muscle and bone 172 and considered a disease modifier for inherited myopathies such as McArdle disease and DMD 173 …”