The test is meant to help evaluate the rate of bone resorption and formation, monitor some metabolic bone diseases such as osteoporosis, and help detect metabolic bone disorders such as Paget disease.
The normal range is not standardized, but there are reference values reported by Eastell,2012 from a sample of 194 healthy Caucasian women aged 35-39.
Biochemical markers of bone resorption:
NTX mean(27.1 nmolBCE/mmolcr) range(12-60)
CTX mean(0.297 ng/mL) range(0.111-0.791)
Biochemical markers of bone formation:
Bone ALP, BAP mean(10.1 ng/mL) range(5.8-17.5)
PINP mean(38 ng/mL) range(17.3-83.4 ng/mL)
A high level of one or more bone markers in urine and/or blood suggests an increased rate of resorption and/or formation of bone, but it is not diagnostic.
An elevated level of bone markers may occur when the following conditions occur.
- Paget disease
- Cancer that has spread to the bone (metastatic bone disease)
- Osteomalacia in adults and rickets in children—lack of bone mineralization, often due to vitamin D or calcium deficiency
- Chronic kidney disease (renal osteodystrophy)
- Excess use or high doses of glucocorticoids or Cushing syndrome
- A low or normal level suggests no excessive bone turnover.
Keywords: Biochemical Markers of Bone Remodeling, Bone Formation Markers, Bone Markers, Bone Resorption Markers, Bone Turnover Tests, Bone-specific Alkaline Phosphatase, C-telopeptide, CTx, Deoxypyridinoline, DPD, N-telopeptide, NTx, Osteocalcin, P1NP, Procollagen Type 1 N-Terminal Propeptide, Pyridinium Crosslinks, Tartrate-resistant Acid Phosphatase,TRAP