Association between Creatinine Clearance and Mortality in Chinese Patients with Osteoporotic Fractures: A Retrospective Cohort Study

Ming Su^1,2Peng Zhou^1,2MinZhe Xu^1,2Yaqin Gong^2,3Jian Jin⁴Wen-Bin Hu⁵Ke Lu^1,2*Chong Li^1,2*Yi Yin^1,2*

• ¹Department of Orthopedics, Affiliated Kunshan Hospital of Jiangsu University, Suzhou, Jiangsu, China
• ²Kunshan Biomedical Big Data Innovation Application Laboratory, Jiangsu, China
• ³Information Department, Affiliated Kunshan Hospital of Jiangsu University, Suzhou, Jiangsu, China
• ⁴Kunshan municipal Health and Family Planning Information Center, Suzhou, Jiangsu, China
• ⁵Chronic disease department, Kunshan Center for Disease Control and Prevention, Suzhou, Jiangsu, China

Background: Creatinine clearance (CCR) is a vital biomarker for evaluating renal function, indicating the efficiency of kidneys in filtering blood waste. However, the link between CCR and mortality in hospitalized patients with osteoporotic fractures (OPFs) remains unclear. The increasing prevalence of OPFs in elderly populations, coupled with known complications of renal dysfunction, underscores the critical importance of understanding this relationship. This study aimed to investigate the association between CCR levels and mortality in a cohort of hospitalized patients with OPF, with the goal of establishing evidence-based guidelines for risk stratification and management strategies.A retrospective cohort study analyzed data from 3,177 patients hospitalized with OPFs between December 6, 2018, and December 31, 2023. Multivariate Cox regression was used to evaluate the relationship between CCR and mortality while adjusting for potential confounding variables including laboratory parameters, clinical characteristics and lifestyle factors. Subgroup analyses, smoothed curve fitting with threshold analyses, Kaplan-Meier curves, and sensitivity analyses were performed.Results: A linear correlation between CCR and mortality was observed, with each 1-point increment in CCR correlating with a 2% reduction in mortality risk (hazard ratio (HR) = 0.98; 95% confidence interval (CI): 0.97, 0.98; P < 0.01). Patients were categorized into three groups based on CCR: Group 1 (CCR ≤ 80 ml/min), Group 2 (80 < CCR ≤ 120 ml/min), and Group 3 (CCR > 120 ml/min). Group 2 exhibited a 51% lower hazard of mortality than Group 1 (HR = 0.49, 95% CI: 0.34, 0.71; P < 0.01), while Group 3 showed an 87% reduction in mortality risk (HR = 0.13, 95% CI: 0.05, 0.36; P < 0.01).Subgroup analyses confirmed the robustness of these findings even after adjusting for other covariates.Linear association was detected using smoothed curve fitting and threshold analysis. Kaplan-Meier survival curves revealed a negative relationship between CCR levels and the cumulative mortality hazard. Sensitivity analyses demonstrated a stable direct association between CCR and the cumulative mortality hazard.This study demonstrated a significant association between CCR and mortality among hospitalized patients with OPFs, validating CCR as a valuable prognostic marker for assessing mortality risk.