Risk Factors and Outcome of Decreased Bone Mineral Density in Patients with CKD Stages 5-5D

Background: CKD-MBD encompasses a range of abnormalities in mineral metabolism and hormone regulation, ultimately leading to bone loss, fractures, and increased mortality. Although bone mineral density (BMD) testing does not provide information on bone turnover, the 2017 KDIGO guidelines began recommending BMD testing in patients with CKD stages 3- 5D at risk for osteoporosis due to growing evidence of the link between decreased BMD and clinical outcomes. However, data on BMD in advanced CKD remains limited. Methods: This retrospective observational study evaluated BMD in CKD stages 5–5D patients and its association with baseline biochemical factors and all-cause mortality. Results: A total of 193 patients with 237 BMD measurements between 2011 and 2022 were included. The average follow-up period was 57.6 months. Multivariate linear regression analysis revealed that lower BMD and osteoporosis at the total hip, femoral neck, and lumbar spine were associated with traditional risk factors, including aging, lower body mass index, and female sex. In addition, lower serum calcium and elevated alkaline phosphatase levels, indicative of inadequate calcium storage, correlated with decreased BMD. Markers of impaired nutritional status, such as decreased serum creatinine, phosphate, total lymphocyte count, and increased mean corpuscular volume, were also linked to lower BMD and osteoporosis. BMD further declined in CKD stage 5D. In both univariate and multivariate analyses, decreased BMD, lower T-scores, and osteoporosis at the total hip and lumbar spine were predictive of all-cause mortality. Conclusion: Decreased BMD and osteoporosis in CKD stages 5–5D were associated with traditional risk factors, insufficient calcium storage, and impaired nutritional status. Furthermore, lower BMD and osteoporosis at the total hip and lumbar spine were significant predictors of all-cause mortality