Development and validation of a diagnostic nomogram for sarcopenia in Chinese hemodialysis patients

Background Sarcopenia is a clinical condition that is common in patients with chronic kidney disease (CKD), especially in those on dialysis. However, the relatively complicated diagnostic procedure limits its use in clinical situations. In this study we aimed to establish a simplified tool for the diagnosis of sarcopenia in patients on hemodialysis (HD). Methods Overall, 757 eligible patients from seven HD centers in Shanghai and Suzhou, China, were recruited from 2020 to 2021. The cross-sectional data were analyzed. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019 criteria. Among them, 511 consecutive patients (77 with and 434 without sarcopenia) from five centers were included in the training set for the establishment of a diagnostic nomogram. Ten investigative parameters including clinical characteristics, body measurements and physical performance were used to derive the diagnostic nomogram. A total of 246 consecutive patients (47 with and 199 without sarcopenia) were included for validation of the diagnostic model. Results The average age of the enrolled patients was 60.4 +/- 12.1 years, 59.8% were males and 90.5% received dialysis using an arteriovenous fistula. Overall, the sarcopenia rate was 16.4%. The training and validation sets showed no significant differences in sarcopenia rate (15.1% and 19.1%, respectively; P = .160). The nomogram derived from the training set for sarcopenia, which was based on only four features-age, sex, body weight and grip strength-achieved high C-indexes of 0.929 [95% confidence interval (CI) 0.904-0.953] and 0.955 (95% CI 0.931-0.979) in the training and external sets, respectively, and had a well-fitted calibration curve. The cut-off value was 0.725, with a sensitivity of 0.909 and a specificity of 0.816. The nomogram accurately diagnosed sarcopenia with fewer variables and more simplified diagnostic procedures. Conclusions The nomogram had a good diagnostic capability for sarcopenia in patients on HD and may be a convenient tool for clinical use.