Ciliary neurotrophic factor and strength

肌肉力量和肌肉质量随年龄的损失（肌肉减少症）和增益与老年人的力量训练是有据可查的，但这些反应在个体之间差异很大。这种巨大的个体间变异性以及双胞胎研究表明力量变异的主要部分是由遗传引起的这一事实表明，遗传因素可能解释了对衰老和力量训练的力量反应的很大一部分变异。在最近的一项试点研究中，我们观察到睫状神经营养因子（CNTF）基因座的一种常见多态性，这是一个重要的预测年龄相关的力量水平在19-95岁的男性和女性的横断面研究，并提示证据表明，这种变化与个体间的差异在10年内的力量下降。本研究拟验证以下假设：1）CNTF基因座的“无效”等位基因与50-80岁男性的更高水平的力量相关，2）“无效”等位基因与7年随访期间力量的较小下降相关。这些研究将在STORM队列中进行，该队列提供了大样本量和年龄分布的优势，应最大限度地提高观察到的强度下降，这在50岁及以上时变得显着。最后，在大学年龄的男性和女性的干预试验中，我们将测试的假设，CNTF“空”等位基因是与较大的增益在肌肉力量响应于中等强度的力量训练干预相比，共同的等位基因。运动干预将联合收割机1998-1999年进行的干预研究的结果，并将再招募60名受试者。这些研究可能会发现一种遗传变异，可用于预测谁有患肌肉减少症的风险，以及谁将从预防肌肉减少症的力量训练干预中受益最多。

Losses of muscular strength and muscle mass with age (sarcopenia) and gains with strength training in the elderly are well documented, but these responses vary substantially among individuals. This large inter-individual variability and the fact that Twin studies show that a major portion of the variance in strength is accounted for by heredity, suggest that genetic factors may explain a large portion of the variation in strength responses to aging and strength training. In a recent pilot study, we observed a common polymorphism at the ciliary neurotrophic factor (CNTF) locus that was a significant predictor of age-associated strength levels in a cross-sectional study of 19-95 year old men and women, and suggestive evidence that this variation was associated with inter-individual variation in declines in strength over a 10 year period. This study proposes to test the hypothesis: 1) that the "null" allele at the CNTF locus is associated with greater levels of strength in 50-80 year old men and 2) that the "null" allele is associated with smaller declines in strength over a 7 year follow-up period. The studies, to be carried out in the STORM cohort, which offers the advantages of a large sample size and an age distribution that should maximize the observed declines in strength, which become significant around 50 years of age and older. Finally, in a intervention trial of college aged males and females, we will test the hypothesis that the CNTF "null" allele is associated with larger gains in muscle strength in response to a moderate intensity strength training intervention compared to the common allele. The exercise intervention will combine results from an intervention study carried out in 1998-1999 and will enroll an additional 60 subjects. These studies may identify a genetic variant which can be used to predict who is at risk of sarcopenia, and who will benefit most from strength training intervention to prevent sarcopenia.