Department of Health and Exercise Science, University of Oklahoma, Norman, OK 73019, USA.
J Nutr Health Aging. 2012;16(6):534-8. doi: 10.1007/s12603-012-0015-2.
Asians seem to have less skeletal muscle mass (SMM) than other ethnic groups, but it is not clear whether relative SMM, i.e., SMM / height square or SMM to fat-free mass (FFM) ratio, differs among different ethnic groups at the same level of body mass index (BMI).
To compare the SMM to fat-free mass (FFM) ratio as well as anthropometric variables and body composition among 3 ethnic groups.
DESIGN, SETTING, AND PARTICIPANTS: Three hundred thirty-nine Japanese, 343 Brazilian, and 183 German men and women were recruited for this cross-sectional study.
Muscle thickness (MTH) and subcutaneous fat thickness (FTH) were measured by ultrasound at nine sites on the anterior and posterior aspects of the body. FTH was used to estimate the body density, from which fat mass and fat-free mass (FFM) was calculated by using Brozek equation. Total SMM was estimated from ultrasound-derived prediction equations.
Percentage body fat was similar among the ethnic groups in men, while Brazilians were higher than Japanese in women. In German men and women, absolute SMM and FFM were higher than in their Japanese and Brazilians counterparts. SMM index and SMM:FFM ratios were similar among the ethnic groups in women, excluding SMM:FFM ratio in Brazilian. In men, however, these relative values (SMM index and SMM:FFM ratio) were still higher in Germans. After adjusting for age and BMI, the SMM index and SMM:FFM ratios were lower in Brazilian men and women compared with the other two ethnic groups, while the SMM index and SMM:FFM ratios were similar in Japanese and German men and women, excluding SMM:FFM ratio in women.
Our results suggest that relative SMM is not lower in Asian populations compared with European populations after adjusted by age and BMI.
亚洲人的骨骼肌质量（SMM）似乎比其他种族少，但目前尚不清楚在相同的体重指数（BMI）水平下，不同种族之间的相对 SMM，即 SMM/身高平方或 SMM 与去脂体重（FFM）的比值是否存在差异。
比较 3 个种族的 SMM 与去脂体重（FFM）的比值以及人体测量学变量和身体成分。
设计、地点和参与者：本横断面研究共招募了 339 名日本男性、343 名巴西男性和 183 名德国男性和女性，以及 339 名日本女性、343 名巴西女性和 183 名德国女性。
使用超声在身体前后侧的 9 个部位测量肌肉厚度（MTH）和皮下脂肪厚度（FTH）。使用 FTH 估计体密度，根据 Brozek 方程计算体脂肪量和去脂体重（FFM）。使用超声衍生的预测方程估算总 SMM。
在男性中，各种族的体脂百分比相似，而女性的巴西人比日本人高。在德国男性和女性中，绝对 SMM 和 FFM 均高于其日本和巴西同行。在女性中，各种族的 SMM 指数和 SMM:FFM 比值相似，但巴西除外。然而，在男性中，这些相对值（SMM 指数和 SMM:FFM 比值）在德国人中仍然较高。调整年龄和 BMI 后，与其他两个种族相比，巴西男性和女性的 SMM 指数和 SMM:FFM 比值较低，而日本和德国男性和女性的 SMM 指数和 SMM:FFM 比值相似，除了女性的 SMM:FFM 比值。
我们的结果表明，在调整年龄和 BMI 后，亚洲人群的相对 SMM 并不低于欧洲人群。
