Bone markers and chronic kidney diseases

Patients suffering from chronic kidney diseases are at higher fracture risk due to impaired bone quality. Bone quality is mediated by bone turnover, together with bone microarchitecture, mineralization, microfractures and bone matrix and composition. Since bone histomorphometry can only be performed in specialized centers, is invasive, costly and cannot be used for the follow-up of patients, bone turnover markers (BTMs) are thus generally presented as an alternative for the evaluation of bone turnover. In this critical review, we will present the advantages and limitations of BTMs. Notably, knowledge of the limitations is very important for a good interpretation of the results. Among them, we will insist on the lack of standardization and on the high variability that can come from the preanalytical, the analytical and the postanalytical phases. More studies comparing bone biopsies results and BTMS are also definitely needed.