Tabara Yasuharu, Okada Yoko, Ochi Masayuki, Ohyagi Yasumasa, Igase Michiya
Center for Genomic Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan; Graduate School of Public Health, Shizuoka Graduate University of Public Health, Aoi-ku, Shizuoka, Japan.
Department of Geriatric Medicine and Neurology, Ehime University Graduate School of Medicine, Toon City, Japan.
J Am Med Dir Assoc. 2021 Nov;22(11):2366-2372.e3. doi: 10.1016/j.jamda.2021.03.021. Epub 2021 Apr 27.
Sarcopenia is a risk factor for poor outcomes in older adults. Identification of plasma markers may facilitate screening of sarcopenia. We previously reported that creatinine-to-cystatin C ratio is a simple marker of muscle mass. To further assess the clinical relevance of the creatinine-to-cystatin C ratio, we investigated its association with myosteatosis and physical performance.
Observational study.
Cross-sectional analysis of the dataset obtained from a Japanese population consisting of 1468 older (≥60 years of age) community residents.
The mean attenuation values of the skeletal muscle calculated from computed tomography images of the midthigh were used as an index of myosteatosis, while the cross-sectional area of the muscle was used as a proxy for muscle mass. Physical performance was assessed by 1-leg standing time.
Creatinine-to-cystatin C ratio was positively associated with the cross-sectional area of muscle fiber-rich muscles, while it showed an inverse association with fat-rich muscle areas, resulting in the positive association between creatinine-to-cystatin C ratio and the mean attenuation value of the skeletal muscle [creatinine-to-cystatin C ratio quartiles (Q), Q1: 47.4 ± 4.8, Q2: 48.9 ± 4.4, Q3: 49.8 ± 4.1, Q4: 50.9 ± 3.7, P < .001]. The results of the linear regression analysis adjusted for major covariates (including muscle cross-sectional area) identified creatinine-to-cystatin C ratio as an independent determinant of the mean attenuation value (Q1: reference, Q2: β = 0.07, P = .019, Q3: β = 0.11, P < .001, Q4: β = 0.16, P < .001). Low creatinine-to-cystatin C ratio was independently associated with 1-leg standing time, although the association was attenuated substantially by adjusting for skeletal muscle cross-sectional area and mean attenuation value.
Creatinine-to-cystatin C ratio was associated with myosteatosis in older adults, independent of the muscle mass. Creatinine-to-cystatin C ratio may serve as a convenient marker of sarcopenia.
肌肉减少症是老年人预后不良的一个危险因素。识别血浆标志物可能有助于肌肉减少症的筛查。我们之前报道过，肌酐与胱抑素C的比值是肌肉量的一个简单标志物。为了进一步评估肌酐与胱抑素C比值的临床相关性，我们研究了它与肌少脂性和身体表现之间的关联。
观察性研究。
对从1468名年龄≥60岁的日本社区居民组成的人群中获得的数据集进行横断面分析。
从大腿中部的计算机断层扫描图像计算出的骨骼肌平均衰减值用作肌少脂性的指标，而肌肉的横截面积用作肌肉量的替代指标。通过单腿站立时间评估身体表现。
肌酐与胱抑素C比值与富含肌纤维的肌肉的横截面积呈正相关，而与富含脂肪的肌肉区域呈负相关，导致肌酐与胱抑素C比值与骨骼肌平均衰减值呈正相关[肌酐与胱抑素C比值四分位数（Q），Q1：47.4±4.8，Q2：48.9±4.4，Q3：49.8±4.1，Q4：50.9±3.7，P<.001]。在对主要协变量（包括肌肉横截面积）进行调整后的线性回归分析结果中，肌酐与胱抑素C比值被确定为平均衰减值的独立决定因素（Q1：参照组，Q2：β=0.07，P=.019，Q3：β=0.11，P<.001，Q4：β=0.16，P<.001）。低肌酐与胱抑素C比值与单腿站立时间独立相关，尽管通过调整骨骼肌横截面积和平均衰减值后，这种关联显著减弱。
肌酐与胱抑素C比值与老年人的肌少脂性相关，与肌肉量无关。肌酐与胱抑素C比值可能是肌肉减少症的一个便捷标志物。
