ACTN3 genotypes and its relationship with muscle mass and function of Kosovan adults

Autor(en)
Arben Boshnjaku, Ermira Krasniqi, Harald Tschan, Barbara Wessner
Abstrakt

INTRODUCTION:

The ACTN3 gene in humans encodes the muscle protein 훼-actinin 3, whereby a common null polymorphism (rs1815739) results in the replacement of an arginine (R) with a premature stop codon (X) at the amino acid at position 577 [1]. It has been shown that humans homozygotic for the XX genotype were at a significantly higher risk of sarcopenia and osteoporosis than RR homozygotes [2]. Therefore, the aim of this study was to determine the relationship between ACTN3 genotypes, muscle mass and function in Kosovan men and women.

METHODS:

In this cross sectional study, genomic DNA was extracted from saliva samples of 300 participants living in Prishtina (Kosovo) (M: 47.2%, F: 52.8%) aged 66.1 ± 9.8 years. ACTN3 genotypes were assessed on a QuantStudio 7 Flex Real-Time PCR System using commercially available primers and probes. Anthropometric data (weight, BMI, body composition), physical performance (handgrip strength, 30-s chair stand test and gait speed) and isokinetic peak torque of knee extensors were determined at 60°/s (Biodex). Differences between genotype groups (RR, RX, XX) were analyzed by one-way ANOVA.

RESULTS:

The study population was characterized by a BMI of 29.3±4.7 kg/m² (f: 30.6±4.7 kg/m², m: 27.9±4.3 kg/m², p<0.001), muscle mass of 26.9±5.4 kg (f: 23.5±3.2 kg, m: 30.8±5.4 kg, p<0.001), a handgrip strength of 30.8±9.6 kg (f: 25.4±5.9 kg, m: 36.9±9.2 kg, p<0.001), a 30-s chairstand test of 11.7±3.1 reps (f: 11.3±3.2 reps, m: 12.0±3.0 reps, p=0.049), a gait speed of 1.52±0.34 m/s (f: 1.45±0.30 m/s, m: 1.60±0.37 m/s, p<0.001), and a isokinetic peak torque (knee extensors) of 74.6±39.2 Nm (f: 58.9±27.6 Nm, m: 92.2±42.7 Nm, p<0.008). The quality of 282 samples (94.0%) was high enough to perform genotyping. The ACTN3 genotype distribution in the remaining samples was RR=41.5%, RX=53.9%, XX=4.6% which was in Hardy-Weinberg equilibrium. However, no significant differences were found between the genotype groups in all measured parameters when tested in the whole population or separated by gender (p>0.05).

CONCLUSION:

Our data suggest that muscle mass, strength and function are not related to ACTN3 genotype in Kosovan older adults. Interestingly, the percentage of participants carrying the XX genotype (4.2%) was considerably lower compared to the worldwide average (18%) [1]. As the level of overweight and obesity in this population was high (M: 76.7%, F: 87.2%), this could have masked the outcome measures [3]. However, we hypothesize that during ageing environmental factors might become more important than genetics to determine physical fitness.

Organisation(en)
Institut für Sport- und Bewegungswissenschaft, Forschungsplattform Active Ageing
Seiten
270
Publikationsdatum
07-2019
Peer-reviewed
Ja
ÖFOS 2012
303028 Sportwissenschaft, 106023 Molekularbiologie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/e168d46f-64a3-44ce-91d0-5008abfb8da5