Department of Ophthalmology, The Johns Hopkins University School of Medicine, Smith Building, M015, 400 N. Broadway, Baltimore, MD 21287, USA.
Eur J Appl Physiol. 2012 Apr;112(4):1215-20. doi: 10.1007/s00421-011-2072-3. Epub 2011 Jul 17.
Handgrip strength is a strong indicator of total body muscle strength and is a predictor of poor outcomes in older adults. The aging suppressor gene klotho encodes a single-pass transmembrane protein that is secreted as a circulating hormone. In mice, disruption of klotho expression results in a syndrome that includes sarcopenia, atherosclerosis, osteoporosis, and shortened lifespan, and conversely, overexpression of klotho leads to a greater longevity. The objective was to determine whether plasma klotho levels are related to skeletal muscle strength in humans. We measured plasma klotho in 804 adults, ≥65 years, in the InCHIANTI study, a longitudinal population-based study of aging in Tuscany, Italy. Grip strength was positively correlated with plasma klotho at threshold <681 pg/mL. After adjusting for age, sex, education, smoking, physical activity, cognition, and chronic diseases, plasma klotho (per 1 standard deviation increase) was associated with grip strength (beta = 1.20, standard error = 0.35, P = 0.0009) in adults with plasma klotho <681 pg/mL. These results suggest that older adults with lower plasma klotho have poor skeletal muscle strength.
握力是全身肌肉力量的有力指标，也是老年人预后不良的预测指标。衰老抑制基因 klotho 编码一种单次跨膜蛋白，作为一种循环激素分泌。在小鼠中，klotho 表达的破坏导致包括肌肉减少症、动脉粥样硬化、骨质疏松症和寿命缩短在内的综合征，相反，klotho 的过表达导致寿命延长。目的是确定血浆 klotho 水平与人类骨骼肌力量是否相关。我们在意大利托斯卡纳老龄化的纵向人群基础研究 InCHIANTI 研究中测量了 804 名≥65 岁的成年人的血浆 klotho。握力与血浆 klotho 在阈值<681pg/mL 时呈正相关。在调整年龄、性别、教育、吸烟、体力活动、认知和慢性疾病后，血浆 klotho（每增加 1 个标准差）与血浆 klotho<681pg/mL 的成年人的握力相关（β=1.20，标准误差=0.35，P=0.0009）。这些结果表明，血浆 klotho 水平较低的老年人骨骼肌力量较差。
