The increased awareness of the potential role played by
mineral and bone disorder in the appearance of
cardiovascular disease in renal patients has produced research efforts aimed at discovering possible pathogenic links. Accordingly, the diagnostic significance of the classic bone markers of
mineral disorders and of the new markers in the setting of
chronic kidney disease-
mineral and bone disorders (
CKD-MBD) needs to be re-evaluated along with increasing information. In this article we include classic markers of bone metabolism and some of the noncollagenous bone
proteins that are gaining experimental and clinical significance in
CKD-MBD. Among classic markers of
secondary hyperparathyroidism and of
renal osteodystrophy, we analyzed
parathyroid hormone,
alkaline phosphatase,
tartrate-resistant acid phosphatase, and bone
collagen-derived
peptides. We underlined, for each, the relevance of parent
proteins (
peptides or
isoforms) that affect assay methods and, eventually, the diagnostic or prognostic significance. Also, we considered their relationship with cardiovascular mortality. Among the numerous noncollagenous bone
proteins, we examined
matrix Gla protein (MGP),
osteocalcin (OC),
osteoprotegerin, and the small
integrin-binding
ligand N-linked
glycoprotein family. For MGP and OC we report the relevant involvement with the process of calcification (MGP) and with
glucose and energy metabolism (OC). Both of these
proteins require
vitamin K to become active and this is a specific problem in renal patients who frequently are deficient of this
vitamin. Finally, recent acquisitions on the fascinating family of the small
integrin-binding
ligand N-linked
glycoprotein proteins are recapitulated briefly to underline their potential clinical interest and their complex involvement with all aspects of
CKD-MBD. Their diagnostic role in clinical practice awaits further studies.