Anderson David B, Beach Aaron J, Chen Lingxiao, Feng Henry J, McKay Marnee J, Smith Zachary A, Weber Kenneth A, Wesselink Evert Onno, Elliott James M
School of Health Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia.
Department of Health Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia.
Geroscience. 2025 Feb;47(1):1175-1185. doi: 10.1007/s11357-024-01304-y. Epub 2024 Aug 12.
A loss of skeletal muscle mass and an increase in intramuscular fat are known to occur as we enter middle and older age, but the expected changes or normative values have remained unknown. The primary reason for this is that imaging studies are difficult and expensive to conduct, and consequently, the sample sizes have remained small. The development of the UK Biobank which provides access to a large magnetic resonance imaging (MRI) data set of more than 50,000 participants provides an opportunity to finally address this question of normative values for each age group. The study's primary aim was to determine the age-related changes in thigh muscle composition (e.g., thigh fat-free muscle volume and intramuscular fat) between the ages of 45 and 84 years. The second aim was to analyse associations between thigh fat-free muscle volume and intramuscular fat with lifestyle behaviours (smoking, alcohol consumption, and physical activity), leg pain, and bone mineral density. Fifty thousand three hundred thirty-two participants were included in the study. Total fat-free thigh muscle declined between the ages of 45 and 84 years, while intramuscular fat of the thigh continued to increase. The changes were stable between these age groups. The mean volume of fat-free muscle ranged from 11.16 (SD: 1.40) to 13.26 L (SD: 1.85) in adult males and 7.60 (SD: 0.97) to 8.80 L (SD 1.29) in females between the ages of 45 and 84 years. For intramuscular fat, the change among women was from 6.94% (SD: 1.59) in the 45 to 54 years age bracket to 8.83% (SD: 1.92) in the 75 to 84 age bracket, while for men, it was 5.83% (SD: 1.30) in the 45 to 54 age bracket to 7.85% (SD 1.89) in the 75 to 84 age bracket. The total fat-free muscle volume and intramuscular fat percentage provided can be used for the purpose of reference standards or normative values for adults in the age groups provided. Fat-free muscle and intramuscular fat were found to be associated with a range of health, activity, and leg pain outcomes, and these should be investigated in a follow-up longitudinal imaging study.
众所周知，随着步入中老年，骨骼肌质量会减少，肌肉内脂肪会增加，但预期变化或标准值仍不清楚。主要原因是进行影像学研究困难且昂贵，因此样本量一直较小。英国生物银行的发展提供了一个包含5万多名参与者的大型磁共振成像（MRI）数据集，终于有机会解决每个年龄组标准值的问题。该研究的主要目的是确定45至84岁之间大腿肌肉成分（如大腿无脂肪肌肉体积和肌肉内脂肪）与年龄相关的变化。第二个目的是分析大腿无脂肪肌肉体积和肌肉内脂肪与生活方式行为（吸烟、饮酒和体育活动）、腿部疼痛和骨密度之间的关联。该研究纳入了5332名参与者。45至84岁之间，大腿无脂肪肌肉总量下降，而大腿肌肉内脂肪持续增加。这些变化在这些年龄组之间是稳定的。45至84岁的成年男性中，无脂肪肌肉的平均体积在11.16（标准差：1.40）至13.26升（标准差：1.85）之间，女性在7.60（标准差：0.97）至8.80升（标准差1.29）之间。对于肌肉内脂肪，女性在45至54岁年龄组的变化是从6.94%（标准差：1.59）到75至84岁年龄组的8.83%（标准差：1.92），而男性在45至54岁年龄组是5.83%（标准差：1.30）到75至84岁年龄组的7.85%（标准差1.89）。所提供 的无脂肪肌肉总体积和肌肉内脂肪百分比可用于所提供年龄组成年人的参考标准或标准值。发现无脂肪肌肉和肌肉内脂肪与一系列健康、活动和腿部疼痛结果相关，这些应在后续纵向影像学研究中进行调查。
