osteocalcin in serum

Indications

• monitoring calcitriol therapy

Reference interval

• 2.4-11.7 ng/mL (adults)
• values are higher in children & post-menopausal women

Clinical significance

• increased levels of osteocalcin in the serum reflect osteoblastic activity, NOT bone resorption
• serum osteocalcin is considered a sensitive marker of bone metabolism
• higher serum osteocalcin associated with lower risk of hip fracture in men but not in women
• during osteoclastic activity, osteocalcin is released into the circulation as fragments cleared by the kidney, subsequently appearing in the urine as gamma-carboxyglutamate residue containing peptides
• serum osteocalcin levels generally parallel serum alkaline phosphatase levels

Increases

• clinical disorders
  • Paget's disease of the bone
  • renal osteodystrophy
  • hyperthyroidism (primary & secondary)
  • metastatic skeletal disease
  • chronic renal failure
  • osteoporosis (some patients)
  • adolescent growth spurt
• pharmaceutical agents
  • in vivo effects
    • anticonvulsants, calcitriol, estrogens

Decreases

• clinical disorders
  • primary biliary cirrhosis
  • pregnancy
  • growth hormone deficiency
• pharmaceutical agents
  • in vivo effects
    • glucocorticoids

Methods

RIA

Specimen

• serum (fasting)
• freeze immediately
• stable for 14 months at -20 degrees C

More general terms

• special chemistry test

More specific terms

• osteocalcin bovine in serum/plasma

Additional terms

• osteoblast
• osteocalcin; bone GLA protein; gamma-carboxyglutamic acid-containing protein (BGP, BGLAP)
• Paget's disease of the bone; osteitis deformans
• renal osteodystrophy

Component of

• bone/joint panel