NIHR Leicester Biomedical Research Centre (BRC), Leicester Diabetes Centre, University of Leicester, UK; Leicester Kidney Lifestyle Team, Department of Health Sciences, University of Leicester, UK.
NIHR Leicester Biomedical Research Centre (BRC), Leicester Diabetes Centre, University of Leicester, UK; Department of Respiratory Sciences, University of Leicester, UK.
Clin Nutr ESPEN. 2024 Oct;63:207-213. doi: 10.1016/j.clnesp.2024.06.041. Epub 2024 Jun 28.
BACKGROUND & AIMS: There is an emerging and urgent need to identify biomarkers of sarcopenia. A novel sarcopenia index (SI), based on serum creatinine and cystatin C, has emerged as a potential biomarker for use. The SI can predict clinical outcomes and discriminate between the presence of sarcopenia in a range of chronic and acute conditions. However, the SI has not yet been tested in a large real-world general population dataset. This study aimed to investigate the accuracy of the SI in the identification of sarcopenia in a large prospective general population cohort.
Data were taken from UK Biobank, a large prospective epidemiological study in the United Kingdom (UK). Serum creatinine and cystatin C values were used to calculate the SI [creatinine (mg/dl)/cystatin C (mg/dl) × 100]. Probable sarcopenia was defined by maximum handgrip strength (HGS). Muscle mass was assessed using bioelectrical impedance analysis. Low muscle mass was defined as an appendicular lean mass (ALM) index below prespecified thresholds. Confirmed sarcopenia was defined as both low HGS and low muscle mass. Pearson correlation coefficients and logistic regression were used to explore the association between various sarcopenia traits (probable sarcopenia, low ALM index, and confirmed sarcopenia) and the SI. The diagnostic value of the SI was investigated using the area under the receiver operating characteristic curve (area under the curve, AUC).
458,702 participants were included in the analysis (46.4% males, mean age, males: 68.7 (±8.2) years; females: 68.2 (±8.0) years)). Probable sarcopenia was observed in 4.5% of males and 6.1% of females; low ALM index in 2.8% of males and 0.7% of females; confirmed sarcopenia in 0.3% of males and 0.1% of females. SI was significantly lower in individuals with confirmed sarcopenia (males: 86.3 ± 16.6 vs. 99.5 ± 15.3, p < .01; females: 73.6 ± 13.7 vs. 84.6 ± 14.0, p < .01). For every 1-unit increase in the SI, the odds of confirmed sarcopenia were reduced by 5% in males (odds ratio (OR): 0.95, p < 0.001) and 7% in females (OR: 0.923, p < 0.001). The AUC showed acceptable discriminative ability of confirmed sarcopenia (males: AUC = 0.731; females: AUC = 0.711).
Using a large real-world dataset of almost half a million people, our study indicated the SI has acceptable diagnostic accuracy when identifying those with sarcopenia and may be a useful biomarker to aid the stratification of those at risk and in need of intervention.
目前迫切需要识别肌少症的生物标志物。一种新的肌少症指数（SI），基于血清肌酐和胱抑素 C，已成为一种潜在的生物标志物。SI 可预测临床结局，并区分各种慢性和急性疾病中肌少症的存在。然而，SI 尚未在大型真实世界的一般人群数据集上进行测试。本研究旨在调查 SI 在识别大型前瞻性一般人群队列中肌少症的准确性。
数据来自英国生物银行（UK Biobank），这是英国一项大型前瞻性流行病学研究。使用血清肌酐和胱抑素 C 值计算 SI [肌酐（mg/dl）/胱抑素 C（mg/dl）×100]。通过最大握力（HGS）来定义可能的肌少症。肌肉量通过生物电阻抗分析进行评估。低肌肉量定义为四肢瘦体重（ALM）指数低于规定阈值。确诊肌少症定义为低 HGS 和低肌肉量。使用 Pearson 相关系数和逻辑回归来探索各种肌少症特征（可能的肌少症、低 ALM 指数和确诊的肌少症）与 SI 之间的关联。使用受试者工作特征曲线下的面积（曲线下面积，AUC）来研究 SI 的诊断价值。
共纳入 458702 名参与者（46.4%为男性，平均年龄，男性：68.7（±8.2）岁；女性：68.2（±8.0）岁））。男性中有 4.5%存在可能的肌少症，女性中有 6.1%存在可能的肌少症；男性中有 2.8%存在低 ALM 指数，女性中有 0.7%存在低 ALM 指数；男性中有 0.3%存在确诊的肌少症，女性中有 0.1%存在确诊的肌少症。确诊肌少症患者的 SI 明显较低（男性：86.3±16.6 vs. 99.5±15.3，p<0.01；女性：73.6±13.7 vs. 84.6±14.0，p<0.01）。SI 每增加 1 个单位，男性确诊肌少症的几率降低 5%（比值比（OR）：0.95，p<0.001），女性降低 7%（OR：0.923，p<0.001）。AUC 显示出对确诊肌少症的可接受的区分能力（男性：AUC=0.731；女性：AUC=0.711）。
使用近 50 万人的大型真实世界数据集，我们的研究表明 SI 在识别肌少症患者方面具有可接受的诊断准确性，并且可能是一种有用的生物标志物，有助于对处于风险中并需要干预的人群进行分层。
