Royal National Orthopaedic Hospital, Stanmore, HA7 4LP, UK.
Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital (RNOH), University College London, Brockley Hill, Stanmore, Middlesex, HA7 4LP, UK.
Sci Rep. 2021 Nov 1;11(1):21401. doi: 10.1038/s41598-021-00790-w.
We aimed to determine if gluteus maximus (GMAX) fat infiltration is associated with different levels of physical activity. Identifying and quantifying differences in the intramuscular fat content of GMAX in subjects with different levels of physical activity can provide a new tool to evaluate hip muscles health. This was a cross-sectional study involving seventy subjects that underwent Dixon MRI of the pelvis. The individuals were divided into four groups by levels of physical activity, from low to high: inactive patients due to hip pain; and low, medium and high physical activity groups of healthy subjects (HS) based on hours of exercise per week. We estimated the GMAX intramuscular fat content for each subject using automated measurements of fat fraction (FF) from Dixon images. The GMAX volume and lean volume were also measured and normalized by lean body mass. The effects of body mass index (BMI) and age were included in the statistical analysis. The patient group had a significantly higher FF than the three groups of HS (median values of 26.2%, 17.8%, 16.7% and 13.7% respectively, p < 0.001). The normalized lean volume was significantly larger in the high activity group compared to all the other groups (p < 0.001, p = 0.002 and p = 0.02). Employing a hierarchical linear regression analysis, we found that hip pain, low physical activity, female gender and high BMI were statistically significant predictors of increased GMAX fat infiltration.
我们旨在确定臀大肌 (GMAX) 脂肪浸润是否与不同水平的身体活动有关。确定和量化不同身体活动水平的 GMAX 肌肉内脂肪含量的差异，可以为评估髋关节肌肉健康提供一种新的工具。这是一项涉及 70 名受试者的横断面研究，他们接受了骨盆 Dixon MRI 检查。根据每周锻炼的小时数，将个体分为低、中、高四个活动水平组：因髋痛而不活动的患者；以及健康受试者（HS）的低、中、高体力活动组。我们使用 Dixon 图像的脂肪分数 (FF) 自动测量来估计每个受试者的 GMAX 肌肉内脂肪含量。还测量并按瘦体重标准化了 GMAX 体积和瘦体积。在统计分析中包括了体重指数 (BMI) 和年龄的影响。患者组的 FF 明显高于三组 HS（中位数分别为 26.2%、17.8%、16.7%和 13.7%，p<0.001）。与所有其他组相比，高活动组的标准化瘦体积明显更大（p<0.001，p=0.002 和 p=0.02）。采用分层线性回归分析，我们发现髋痛、低体力活动、女性和高 BMI 是 GMAX 脂肪浸润增加的统计学显著预测因素。
