Department of Anaesthesia, Intensive Care Medicine and Pain Medicine, Division of Cardiothoracic and Vascular Anaesthesia and Intensive Care Medicine, Medical University of Vienna, 1090 Vienna, Austria.
Department of Health Economics, Center for Public Health, Medical University of Vienna, 1090 Vienna, Austria.
Nutrients. 2022 Aug 22;14(16):3446. doi: 10.3390/nu14163446.
Measuring skeletal muscle area (SMA) at the third lumbar vertebra level (L3) using computed tomography (CT) is increasingly popular for diagnosing low muscle mass. The aim was to describe the effect of the CT L3 cut-off choice on the prevalence of low muscle mass in medical and surgical patients. Two hundred inpatients, who underwent an abdominal CT scan for any reason, were included. Skeletal muscle area (SMA) was measured according to Hounsfield units on a single CT scan at the L3 level. First, we calculated sex-specific cut-offs, adjusted for height or BMI and set at mean or mean-2 SD in our population. Second, we applied published cut-offs, which differed in statistical calculation and adjustment for body stature and age. Statistical calculation of the cut-off led to a prevalence of approximately 50 vs. 1% when cut-offs were set at mean vs. mean-2 SD in our population. Prevalence varied between 5 and 86% when published cut-offs were applied (p < 0.001). The adjustment of the cut-off for the same body stature variable led to similar prevalence distribution patterns across age and BMI classes. The cut-off choice highly influenced prevalence of low muscle mass and prevalence distribution across age and BMI classes.
使用计算机断层扫描（CT）测量第三腰椎水平（L3）的骨骼肌面积（SMA）越来越常用于诊断肌肉减少症。目的是描述 CT L3 截止值选择对医学和外科患者低肌肉量患病率的影响。我们纳入了 200 名因任何原因接受腹部 CT 扫描的住院患者。根据 L3 水平的 CT 扫描，按照亨氏单位测量骨骼肌面积（SMA）。首先，我们根据身高或 BMI 调整了性别特异性截止值，并将其设置为我们人群中的平均值或平均值-2 SD。其次，我们应用了已发表的截止值，这些截止值在统计计算和对身体体型和年龄的调整方面存在差异。在我们的人群中，将截止值设置为平均值与平均值-2 SD 时，截止值的统计计算导致患病率约为 50%与 1%。当应用已发表的截止值时，患病率在 5%至 86%之间变化（p<0.001）。对于相同的体型变量，截止值的调整导致了不同年龄和 BMI 类别之间的患病率分布模式相似。截止值的选择极大地影响了低肌肉量的患病率和在年龄和 BMI 类别中的分布。
