Skeletal muscle size is a major predictor of intramuscular fat content regardless of age
Skeletal muscle size is a major predictor of intramuscular fat content regardless of age
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DOI：
10.1007/s00421-015-3148-2
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发表时间：
2015-08-01
影响因子：
3
通讯作者：
Oshida, Yoshiharu
中科院分区：
文献类型：
--
作者：
Akima, Hiroshi;Yoshiko, Akito;Oshida, Yoshiharu
老年人的骨骼肌比年轻人有更多的肌肉内脂肪组织(IntraMAT)。目前尚不清楚衰老如何影响大腿个别肌肉的肌内MAT含量。15名老年(70.7+/-A3.8岁)和15名年轻(20.9+/-A0.3岁)的男性和女性参与了这项研究。于右侧大腿进行磁共振成像，测量股四头肌(QF)、股四头肌(HM)、内收肌(AD)肌群和大腿皮下脂肪组织CSA的肌内MAT含量和骨骼肌CSA。采集空腹血样，测定血脂、脂联素和糖化血红蛋白水平。老年组QF、HM和AD的血浆MAT含量显著高于青年组。然而，在QF(P<；0.001)和大腿全长(P<；0.01)中，按体重归一化的骨骼肌CSA(骨骼肌CSA/BW)显著低于青年组，而HM和AD则无显著差异。以IntraMAT含量为因变量的逐步回归分析表明，大腿骨骼肌CSA/BW是预测IntraMAT含量的唯一变量。这些结果表明，无论年龄大小，骨骼肌大小都可能是IntraMAT含量的主要决定因素。
Skeletal muscles of older individuals have a larger amount of intramuscular adipose tissue (IntraMAT) than those of younger individuals. It is not understood how aging affects the IntraMAT content of individual muscles of the thigh. We assessed the relationship between IntraMAT content and skeletal muscle cross-sectional area (CSA), subcutaneous adipose tissue CSA, biochemical blood profiles, and physical activity.Fifteen older (70.7 +/- A 3.8 years) and 15 younger (20.9 +/- A 0.3 years) men and women participated in this study. Magnetic resonance imaging of the right thigh was taken to measure IntraMAT content and skeletal muscle CSA for the quadriceps femoris (QF), hamstrings (HM), adductor (AD) muscle groups and subcutaneous adipose tissue CSA of the thigh. Fasting blood samples were collected to measure plasma lipids, adiponectin, and HbA1c levels.IntraMAT content in QF, HM, and AD for the Older group was significantly higher than in the Younger group. However, skeletal muscle CSA normalized by body weight (skeletal muscle CSA/bw) in the QF (P < 0.001) and total thigh (P < 0.01) were significantly lower in the Older group compared with the Younger group.There were no significant differences in HM and AD. Stepwise regression analysis with IntraMAT content as a dependent variable revealed that skeletal muscle CSA/bw of the thigh was the only predictive variable for IntraMAT content in Older and Younger groups.These results suggest that skeletal muscle size could be a major determinant of IntraMAT content regardless of age.