Division of Nephrology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97004, Taiwan; School of Medicine, Tzu Chi University, Hualien 97004, Taiwan.
Division of Nephrology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97004, Taiwan; School of Post-baccalaureate Chinese Medicine, Tzu Chi University, Hualien 97004, Taiwan.
Clin Nutr. 2024 Mar;43(3):765-772. doi: 10.1016/j.clnu.2024.01.029. Epub 2024 Feb 1.
BACKGROUND & AIMS: Skeletal muscle mass measurements are important for customizing nutritional strategies for patients with chronic kidney disease (CKD). The serum creatinine-to-cystatin C ratio (Cr/CysC) is a potential indicator of sarcopenia. We developed simple equations to predict the appendicular skeletal muscle mass (ASM) of patients with CKD using readily available parameters and Cr/CysC.
Overall, 573 patients with nondialysis CKD stages 3-5 were included for developing and validating the equations. The participants were randomly divided into development and validation groups in a 2:1 ratio. ASM was measured using the Body Composition Monitor (BCM), a multifrequency bioelectrical impedance spectroscopy device. The height, weight, anthropometric data, and handgrip strength (HGS) of the participants were obtained. Equations were generated using stepwise multiple linear regression models. The prognostic significance of the predicted ASM was evaluated in a CKD registry comprising 1043 patients.
The optimal equation without anthropometric data and HGS (Equation 1) was as follows: ASM (kg) = -7.949 - 0.049 × Age (years) - 2.213 × Woman + 0.090 × Height (cm) + 0.210 × Weight (kg) + 1.141 × Cr/CysC. The modified equation (Equation 2) with anthropometric data and HGS was as follows: ASM (kg) = -4.468 - 0.050 × Age (years) - 2.285 × Woman+ 0.079 × Height (cm) + 0.228 × Weight (kg) - 0.127 × Mid-arm muscular circumference (cm) + 1.127 × Cr/CysC. Both equations exhibited strong correlations with the ASM measured via BCM in the validation cohort (r = 0.944 and 0.943 for Equations 1 and 2, respectively) with minimal bias. When Equation 1 was applied to the CKD registry, the estimated ASM index (ASM/Height) significantly predicted overall mortality over a median of 54 months.
Novel ASM equations offer a simple method for predicting skeletal muscle mass and can provide valuable prognostic information regarding patients with nondialysis CKD.
骨骼肌质量测量对于为慢性肾脏病（CKD）患者定制营养策略非常重要。血清肌酐与半胱氨酸蛋白酶抑制剂 C 的比值（Cr/CysC）是肌少症的潜在指标。我们开发了简单的方程，使用现成的参数和 Cr/CysC 来预测 CKD 患者的四肢骨骼肌质量（ASM）。
共有 573 名非透析 CKD 3-5 期患者纳入该研究以开发和验证方程。参与者以 2:1 的比例随机分为开发组和验证组。ASM 使用身体成分监测仪（BCM），一种多频生物电阻抗谱仪进行测量。记录参与者的身高、体重、人体测量数据和握力（HGS）。使用逐步多元线性回归模型生成方程。在包含 1043 名患者的 CKD 登记处评估预测 ASM 的预后意义。
没有人体测量数据和 HGS 的最佳方程（方程 1）如下：ASM（kg）=-7.949-0.049×年龄（岁）-2.213×女性+0.090×身高（cm）+0.210×体重（kg）+1.141×Cr/CysC。带有人体测量数据和 HGS 的改良方程（方程 2）如下：ASM（kg）=-4.468-0.050×年龄（岁）-2.285×女性+0.079×身高（cm）+0.228×体重（kg）-0.127×上臂肌围（cm）+1.127×Cr/CysC。两个方程在验证队列中与 BCM 测量的 ASM 均具有很强的相关性（方程 1 和 2 的 r 值分别为 0.944 和 0.943），且偏差最小。当方程 1 应用于 CKD 登记处时，估计的 ASM 指数（ASM/身高）在中位数为 54 个月的时间内显著预测了全因死亡率。
新的 ASM 方程提供了一种预测骨骼肌质量的简单方法，并可提供有关非透析 CKD 患者的有价值的预后信息。
