Serum Receptor Activator of Nuclear Factor-κβ Ligand and Osteoprotegerin Levels and Ratio in Correlation with Bone Mineral Density

Osteoporosis is a disorder represented by manifestations of low bone mass, decreased bone tissue, and disrupted bone microarchitecture. The diagnosis of osteoporosis so far has been based on fracture manifestations after minimal trauma or by detecting low Bone Mineral Density (BMD). Measurement of Receptor Activator of Nuclear Factor-κβ Ligand (RANKL) and Osteoprotegerin (OPG) levels has opened the discourse of a more specific assessment of osteoblast and osteoclast regulation. The RANKL/OPG ratio can represent resorption and bone formation more significantly when correlated with BMD features. This study aimed to analyze the correlation between serum RANKL and OPG levels and ratio with BMD. A total of 58 post-menopausal females from 13 elderly in Integrated Community Health Care Surabaya and Sidoarjo were enrolled. Data were collected by recording age, onset of menarche, onset of menopause, and Body Mass Index (BMI). Serum RANKL and OPG levels were evaluated using sandwich ELISA from Elabscience®. The RANKL/OPG ratio was obtained from the ratio between measured RANKL and OPG levels in serum. The proximal femur and lumbar spine BMDs were measured using Hologic® Discovery™ QDR™ Dual-Energy X-ray Absorptiometry (DEXA). Pearson's correlation test in this study showed no significant correlation between BMD and RANKL levels (lumbar: p=0.203; hip: p=0.283). The insignificant result was also shown in the correlation between BMD and OPG levels (lumbar: p=0.412; hip: p=0.617). A significant result between lumbar BMD and RANKL/OPG ratio was only found in the osteopenia subjects (p=0.001). The RANKL/OPG ratio had a significant correlation only with osteopenia-BMD in post-menopausal females. Therefore, it could be used as supporting data in osteoporosis screening.