Bone Turnover Markers (BTM)

General

Synonym/Acronym:

  • Bone resorption/destruction: NTx (collagen cross-linked N-telopeptide of type I collagen)
  • Bone formation: Osteocalcin (bone GLA protein, BGP)

Rationale
To assist in identifying an imbalance in bone turnover and evaluate the effectiveness of treatment for osteoporosis.

Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction. As appropriate, provide the required urine collection container for NTX and specimen collection instructions.

Normal Findings
Method: Electrochemiluminescent immunoassay.

NTx(Collagen Cross-Linked N-Telopeptide of Type I Collagen)
7–9 yr
  Male167–578 nmol bone collagen equivalents (BCE)/mmol creatinine
  Female201–626 nmol bone collagen equivalents (BCE)/mmol creatinine
10–12 yr
  Male152–505 nmol bone collagen equivalents (BCE)/mmol creatinine
  Female173–728 nmol bone collagen equivalents (BCE)/mmol creatinine
13–15 yr
  Male103–776 nmol bone collagen equivalents (BCE)/mmol creatinine
  Female38–515 nmol bone collagen equivalents (BCE)/mmol creatinine
16–17 yr
  Male34–313 nmol bone collagen equivalents (BCE)/mmol creatinine
  Female20–144 nmol bone collagen equivalents (BCE)/mmol creatinine
Adult male21–83 nmol bone collagen equivalents (BCE)/mmol creatinine
Adult female (premenopausal)17–94 nmol BCE/mmol creatinine
Adult female (postmenopausal)26–124 nmol BCE/mmol creatinine
Osteocalcin
Age and SexConventional UnitsSI Units (Conventional Units × 1)
6 mo–6 yr
  Male39–121 ng/mL39–121 mcg/L
  Female44–130 ng/mL44–130 mcg/L
7–9 yr
  Male66–182 ng/mL66–182 mcg/L
  Female73–206 ng/mL73–206 mcg/L
10–12 yr
  Male85–232 ng/mL85–232 mcg/L
  Female77–262 ng/mL77–262 mcg/L
13–15 yr
  Male70–336 ng/mL70–336 mcg/L
  Female33–222 ng/mL33–222 mcg/L
16–17 yr
  Male43–237 ng/mL43–237 mcg/L
  Female24–99 ng/mL24–99 mcg/L
Adult
  Male3–40 ng/mL3–40 mcg/L
  Female
  Premenopausal5–30 ng/mL5–30 mcg/L
  Postmenopausal9–50 ng/mL9–50 mcg/L

Critical Findings and Potential Interventions
N/A

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