Serum Osteoprotegerin Level Is Negatively Associated with Bone Mineral Density in Patients Undergoing Maintenance Hemodialysis

• Main Authors: Chia-Wen Lu, Chih-Hsien Wang, Bang-Gee Hsu, Jen-Pi Tsai
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Medicina
• Subjects: bone mineral density; hemodialysis; osteoprotegerin; osteopenia; osteoporosis
• Online Access: https://www.mdpi.com/1648-9144/57/8/762
• ISSN: 1010-660X; 1648-9144

Background and Objectives: Osteoprotegerin (OPG), a potent osteoclast activation inhibitor, decreases bone resorption and plays a role in mediating bone mineral density (BMD). Our aim was to evaluate the relationship between BMD and serum OPG in maintenance hemodialysis (MHD) patients. Materials and Methods: Fasting blood samples were obtained from 75 MHD patients. BMD was measured by dual-energy X-ray absorptiometry in lumbar vertebrae (L2–L4). The WHO classification criteria were applied to define osteopenia and osteoporosis. A commercial enzyme-linked immunosorbent assay was used to measure serum OPG values. Results: Among all MHD patients, seven (9.3%) and 20 patients (26.7%) were defined as osteoporosis and osteopenia, respectively. Female patients had lower lumbar BMD than males (<i>p</i> = 0.002). Older age (<i>p</i> = 0.023), increased serum OPG (<i>p</i> < 0.001) urea reduction rate (<i>p</i> = 0.021), Kt/V (<i>p</i> = 0.027), and decreased body mass index (<i>p</i> = 0.006) and triglycerides (<i>p</i> = 0.020) were significantly different between the normal, osteopenia, and osteoporosis groups. Lumbar spine BMD was positively correlated with body mass index (BMI) (<i>p</i> < 0.001) but negatively correlated with OPG (<i>p</i> < 0.001) and age (<i>p</i> = 0.003). After grouping patients into T scores < −1 and < −2.5, female sex and OPG (adjusted odds ratio [aOR] 1.022, 95% confidence interval [C.I.] 1.011–1.034, <i>p</i> < 0.001) were predictors of T scores < −1, whereas only OPG was predictive of T scores < −2.5 (aOR 1.015, 95% C.I. 1.005–1.026, <i>p</i> = 0.004) by multivariate stepwise logistic regression analysis. The areas under the curve for predicting T scores < −1 or < −2.5 were 0.920 (95% C.I. 0.834–0.970, <i>p</i> < 0.001) and 0.958 (95% C.I. 0.885–0.991, <i>p</i> < 0.001), respectively. Conclusions: Increased serum OPG negatively correlated with lumbar BMD and could be a potential biomarker predictive of osteoporosis in MHD patients.