Background: Elderly patients with chronic kidney disease (CKD) are at high risk for osteoporosis. Inflammation and abnormal bone metabolism are key underlying mechanisms, yet the diagnostic utility of combining their respective biomarkers remains unclear. This study aimed to evaluate the diagnostic efficacy of inflammatory and bone turnover markers for osteoporosis in elderly CKD patients.

Methods: This single-center retrospective cohort study included 194 elderly (≥60 years) patients with chronic kidney disease who underwent bone mineral density testing between March 2021 and March 2024. Patients were divided into osteoporosis and non-osteoporosis groups based on dual-energy X-ray absorptiometry (DXA) T-score. Inflammatory markers were collected within 24 hours of admission, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), neutrophil count, lymphocyte count, monocyte count, platelet count, platelet distribution width, erythrocyte distribution width, mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and systemic immune-inflammation index (SII) were calculated. Bone turnover markers included serum type I procollagen N-terminal propeptide (P1NP), osteocalcin (OC), and type I collagen crosslinked C-terminal peptide (CTX). Univariate and multivariate logistic regression analyses were performed to identify independent factors influencing osteoporosis, and receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy of individual markers and combined models.

Results: Multivariate logistic regression showed that elevated ESR and SII levels among inflammation-related markers were independently associated with osteoporosis in elderly CKD patients; among bone turnover markers, P1NP, OC, and CTX levels were all independent predictors of osteoporosis (all p < 0.05). The comprehensive model combining ESR, SII, P1NP, OC, and CTX showed excellent discriminative performance, with an area under the ROC curve (AUC) of 0.86 (95% confidence interval (CI): 0.80–0.91), suggesting that the combined assessment of inflammatory and bone metabolism markers can significantly improve the accuracy of osteoporosis identification in elderly CKD patients.

Conclusion: In elderly CKD patients, both inflammatory status and abnormal bone turnover are closely associated with osteoporosis risk. Combining inflammatory markers such as ESR and SII with bone turnover markers such as P1NP, OC, and CTX can improve the screening efficacy for osteoporosis. Combined assessment of inflammatory and bone remodeling markers holds promise as an important supplementary tool for bone health management in patients with chronic kidney disease-mineral and bone disorder (CKD-MBD), providing a more reliable foundation for early intervention.