Markers of bone turnover.
| Bone Resorption | Bone Formation† Bone Formation Inhibitors* |
|---|---|
| Hydroxyproline | † Total alkaline phosphatase |
| Collagen crosslinks | † Bone alkaline phosphatase |
| Pyridinolines (pyridinoline, deoxypyridinoline) | † Osteocalcin |
| Crosslinked telopeptides (NTx, CTx) | † Procollagen type I propeptides |
| Trap5b (tartrate resistant acid phosphatase) | † Osteoprotegerin |
| Cathepsin K | * DKK-1 |
| RANKL | * Sclerostin |
RANKL: receptor activator of nuclear factor kappa ligand; the main stimulator of mature osteoclasts; cathepsin K: the main osteoclastic protease; DKK-1: Dickkopf-1; inhibits differentiation of osteoblasts; sclerostin: antagonizes osteoblast differentiation by blocking the Wnt pathway.