Association of sarcopenia with bone metabolism markers and development of an internally validated screening model for sarcopenia in maintenance hemodialysis patients

Abstract

Sarcopenia is a prevalent complication in maintenance hemodialysis (MHD) patients and is associated with adverse outcomes. This study aimed to investigate the relationship between sarcopenia and bone metabolism markers and to develop a clinical screening model for sarcopenia in MHD patients. In this cross-sectional study, total of 292 MHD patients were classified into sarcopenia and non-sarcopenia groups according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) critical value. Demographic characteristics, laboratory parameters, and anthropometric measurements, including body composition assessed by bioelectrical impedance analysis (BIA), were collected. A nomogram was constructed to screen for sarcopenia. The overall prevalence of sarcopenia was 26.4% (77/292). Patients with sarcopenia were older and exhibited lower levels of albumin (ALB), body mass index (BMI), phase angle, bone mineral content, calcium-phosphorus product (Ca×P), intact parathyroid hormone (iPTH), β-type I collagen cross-linked carboxy-terminal peptide (β-CTX), and osteocalcin (OC), along with higher levels of neutrophil-to-lymphocyte ratio (NLR), neutrophil ratio (NEUR), and C-reactive protein (CRP) ( P < 0.05). Grip strength and appendicular skeletal muscle mass index (ASMI) were positively correlated with bone mineral content, calcitonin (CT), and 25-hydroxy vitamin D [25-(OH)D], and negatively correlated with age, NLR, and NEUR. Multivariate analysis identified older age, higher NLR, lower BMI, and lower phase angle as independently associated factors for sarcopenia. A nomogram incorporating these four variables yielded an area under the ROC curve of 0.882 (95% CI: 0.841–0.924). The calibration curve indicated good agreement between predicted and observed outcomes in internal validation. Decision curve analysis demonstrated a positive net benefit across a broad range of threshold probabilities, supporting the potential clinical utility of the nomogram. Age, NLR, BMI, and phase angle are independently associated factors for sarcopenia in MHD patients. The nomogram based on these variables demonstrates promising discriminative ability in internal validation but requires external validation in independent cohorts before clinical implementation. Exploratory findings regarding bone metabolism markers warrant further investigation in prospective studies. Not applicable.