Lin Yu-Li, Wang Chih-Hsien, Chang I-Chen, Hsu Bang-Gee
Division of Nephrology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.
School of Medicine, Tzu Chi University, Hualien, Taiwan.
Front Nutr. 2022 Feb 25;9:828880. doi: 10.3389/fnut.2022.828880. eCollection 2022.
Sarcopenia is highly prevalent in patients with advanced chronic kidney disease (CKD), yet a reliable serum index has not been established. The product of serum creatinine and the estimated glomerular filtration rate based on cystatin C (Cr×eGFRcys) was recently proposed as a sarcopenia index (SI), approximately to 24-h filtered creatinine through the glomerulus. We aimed to evaluate the diagnostic validity of the novel SI in advanced CKD. In 297 patients with non-dialysis stage 3b-5 CKD, aged 68.8 ± 12.9 years, the total skeletal muscle mass (SMM), handgrip strength (HGS), and usual gait speed were assessed. Sarcopenia was defined based on the Asian Working Group for Sarcopenia 2019 consensus update. The prevalence of sarcopenia in this cohort was 20.2%. The SI correlated moderately with SMM ( = 0.503, < 0.001), HGS ( = 0.508, < 0.001), and gait speed ( = 0.381, < 0.001); the independency of the SI with three muscle metrics was confirmed after extensive adjustment. For sarcopenia prediction, the SI had acceptable discriminative powers in males [area under the receiver operating characteristic curve (AUC) 0.646, 95% confidence interval (CI) 0.569-0.718] and females (AUC 0.754, 95% CI 0.670-0.826). In males, the best cut-off was 53.9, which provided 71.1% sensitivity, 58.0% specificity, 32.9% positive predictive value (PPV), and 87.4% negative predictive value (NPV); in females, the best cut-off was 45.8, which provided 81.8% sensitivity, 62.3% specificity, 31.0% PPV, and 94.3% NPV. In conclusion, Cr×eGFRcys could be served as a surrogate marker for sarcopenia and may be helpful for sarcopenia screening in advanced CKD. Further studies are needed to expand our investigation.
肌肉减少症在晚期慢性肾脏病（CKD）患者中非常普遍，但尚未建立可靠的血清指标。血清肌酐与基于胱抑素C的估计肾小球滤过率的乘积（Cr×eGFRcys）最近被提议作为肌肉减少症指数（SI），近似于24小时经肾小球滤过的肌酐量。我们旨在评估这种新型SI在晚期CKD中的诊断有效性。在297例年龄为68.8±12.9岁的非透析3b - 5期CKD患者中，评估了总体骨骼肌质量（SMM）、握力（HGS）和日常步速。根据2019年亚洲肌肉减少症工作组共识更新来定义肌肉减少症。该队列中肌肉减少症的患病率为20.2%。SI与SMM（r = 0.503，P < 0.001）、HGS（r = 0.508，P < 0.001）和步速（r = 0.381，P < 0.001）呈中度相关；在进行广泛调整后，证实了SI与三项肌肉指标的独立性。对于肌肉减少症的预测，SI在男性中具有可接受的判别能力[受试者操作特征曲线下面积（AUC）为0.646，95%置信区间（CI）为0.569 - 0.718]，在女性中（AUC为0.754，95%CI为0.670 - 0.826）。在男性中，最佳截断值为53.9，其灵敏度为71.1%，特异度为58.0%，阳性预测值（PPV）为32.9%，阴性预测值（NPV）为87.4%；在女性中，最佳截断值为45.8，其灵敏度为81.8%，特异度为62.3%，PPV为31.0%，NPV为94.3%。总之，Cr×eGFRcys可作为肌肉减少症的替代标志物，可能有助于晚期CKD患者肌肉减少症的筛查。需要进一步研究来扩大我们的调查。
