Mansour A, et al. - The association between serum osteoprotegerin (OPG), receptor activator of nuclear factor kappaB ligand (RANKL) concentration, and bone mineral density (BMD) in patients with kidney stone disease was assessed in this analysis. Participants in the study were 44 nephrolithiasis patients with either low bone mass or normal BMD. By dual-energy X-ray absorptiometry (DEXA), BMD was measured at lumbar spine (L1-L4) and femoral neck. Using the ELISA method, the serum OPG and RANKL were determined. In patients with nephrolithiasis, high serum fasting OPG levels might be indicative of femoral neck BMD. However, no significant association was found between RANKL and bone densities.