[Levels of skeletal muscle mass and handgrip strength in adults from 10 regions of China].

Objective: To describe the regional and population-related differences in skeletal muscle mass and handgrip strength across the 10 regions of China. Methods: 24 533 participants aged 38-88 years from the second resurvey of China Kadoorie Biobank were included in our analyses. Appendicular and trunk skeletal muscle mass were assessed using the bioelectrical impedance analysis (TANITA). Handgrip strength was measured using Jamar hand-held dynamometer. Low muscle mass and low muscle strength were defined as the lowest quintile of height-adjusted appendicular muscle mass or handgrip strength according to the Consensus Report of the Asian Working Group for Sarcopenia. We analyzed the mean value of absolute muscle mass, height-adjusted muscle mass, weight-adjusted muscle mass and handgrip strength. We also reported the prevalence of low muscle mass and low muscle strength. Results: The average appendicular and total skeletal muscle mass were (22.0±0.02) kg and (49.7±0.05) kg in men, which were higher than in women [(15.9±0.02) kg and (37.2±0.04) kg, respectively]. The handgrip strength was (32.6±0.06) kg in men, which was higher than (19.9±0.05) kg in women. The absolute muscle mass was higher in north area and urban region (P<0.001). The weight-adjusted muscle mass showed reverse patterns of regional difference compared with height-adjusted muscle mass. Both muscle mass and handgrip strength decreased by age (trend P<0.001), with a larger decline observed in handgrip strength. According to AWGS criteria, the proportions of low muscle mass and strength increased by age. Among participants over 80 years old, the prevalence of low muscle mass and strength were 56.2% and 74.5% in men, and 35.7% and 66.0% in women. Conclusions: Levels of skeletal muscle mass and strength varied greatly among people from 10 regions and among participants with different demographic characteristics. The prevalence of low muscle mass and strength was extremely high in elderly.目的： 描述中国10个地区成年人骨骼肌质量和手握力的地区和人群分布特征。 方法： 对来自中国慢性病前瞻性研究项目第2次重复调查的24 533名研究对象进行分析。采用生物电阻抗分析法测量四肢和躯干的肌肉质量，通过Jamar手持握力计测量手握力来衡量肌肉力量水平，并根据亚洲肌少症工作组（AWGS）推荐的标准判断人群低肌肉质量和力量的比例。分地区和人群特征，报告肌肉质量和手握力的均值及标准误，以及低肌肉质量和力量的百分比。 结果： 男性的四肢和全身肌肉质量分别为（22.0±0.02）kg和（49.7±0.05）kg，高于女性的（15.9±0.02）kg和（37.2±0.04）kg；男性手握力为（32.6±0.06）kg，高于女性的（19.9±0.05）kg。绝对肌肉质量和手握力均呈现北方高于南方、城市高于农村的地区差异（P<0.001）。而身高和体重调整的肌肉质量的地区差异规律相反。随着年龄的增加，肌肉质量各项指标和手握力均呈线性下降趋势（线性趋势P<0.001），且手握力下降幅度更大。进一步按照AWGS判断，低肌肉质量和力量的比例随年龄增加而不断上升，≥80岁的老年男性低肌肉质量和力量的比例分别达到56.2%和74.5%，女性分别达到35.7%和66.0%。 结论： 中国成年人肌肉质量和手握力的分布存在明显的地区和人群差异，尤其以老年人低肌肉质量和手握力的比例最高。.