Tiainen Kristina, Sipilä Sarianna, Alen Markku, Heikkinen Eino, Kaprio Jaakko, Koskenvuo Markku, Tolvanen Asko, Pajala Satu, Rantanen Taina
Dept. of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
J Appl Physiol (1985). 2004 Jan;96(1):173-80. doi: 10.1152/japplphysiol.00200.2003. Epub 2003 Sep 5.
The purpose of the present study was to examine genetic and environmental effects on maximal isometric handgrip, knee extension, and ankle plantar flexion strength. In addition, we wanted to investigate whether the strength of these three muscle groups shares a genetic component or whether the genetic effect is specific for each muscle group. Muscle strength was measured as part of the Finnish Twin Study on Aging in 97 monozygotic (MZ) and 102 dizygotic (DZ) female twin pairs, aged 63-76 yr. The MZ and DZ individuals did not differ from each other in age, body height, weight, or self-related health. The age-adjusted pairwise (intraclass) correlations of the MZ and DZ twins were, respectively, 0.462 and 0.242 in knee extension, 0.435 and 0.345 in handgrip, and 0.512 and 0.435 in ankle plantar flexion strength. The multivariate genetic analysis showed that handgrip and knee extension strength shared a genetic component, which accounted for 14% (95% confidence interval: 4-28%) of the variance in handgrip strength and 31% (95% confidence interval: 18-45%) in knee extension strength. The influence of genetic effects on ankle plantar flexion strength was minor and not significant. Furthermore, these three muscle groups had a nongenetic familial effect in common and nonshared environmental effects in common. The results suggested that muscle strength is under a genetic regulation, but also environmental effects have a significant role in explaining the variability in the muscle strength.
本研究的目的是检验遗传和环境因素对最大等长握力、膝关节伸展力和踝关节跖屈力的影响。此外，我们还想研究这三组肌肉力量是否共享一个遗传成分，或者遗传效应是否对每组肌肉是特定的。作为芬兰衰老双胞胎研究的一部分，对97对单卵（MZ）和102对双卵（DZ）女性双胞胎进行了肌肉力量测量，年龄在63 - 76岁之间。MZ和DZ个体在年龄、身高、体重或自我相关健康方面没有差异。MZ和DZ双胞胎的年龄调整后成对（组内）相关性在膝关节伸展力方面分别为0.462和0.242，握力方面分别为0.435和0.345，踝关节跖屈力方面分别为0.512和0.435。多变量遗传分析表明，握力和膝关节伸展力共享一个遗传成分，该成分分别占握力方差的14%（95%置信区间：4 - 28%）和膝关节伸展力方差的31%（95%置信区间：18 - 45%）。遗传效应对踝关节跖屈力的影响较小且不显著。此外，这三组肌肉具有共同的非遗传家族效应和共同的非共享环境效应。结果表明，肌肉力量受遗传调控，但环境因素在解释肌肉力量变异性方面也起着重要作用。
