Osteoporosis of the Spine: Test and Diagnosis

Laboratory parameters of the 1st order – obligatory laboratory tests (unless otherwise shown).

Blood tests

  • Blood count
  • ESR (erythrocyte sedimentation rate) or CRP (C-reactive protein).
  • Serum calcium
  • Serum phosphate
  • Serum creatinine, creatinine clearance if applicable.
  • Alkaline phosphatase (AP)
  • Gamma-GT
  • TSH (thyroid-stimulating hormone)
  • Serum electrophoresis
  • If necessary, hydroxy vitamin D3 (as a case-by-case decision).
  • Testosterone in men (optional).

Urinalysis (24-h urine)

  • Creatinine clearance
  • Phosphate and protein excretion in urine
  • Crosslinks – deoxypyridinoline (DPD) and pyridinoline (PYD crosslinks) – monitoring bone resorption (osteoporosis) and increased cartilage degradation.

Bone turnover markers (as a case-by-case decision).

  • Bone formation marker
    • Ostase – bone-specific alkaline phosphatase/bone alkaline phosphatase (BAP =).
    • Osteocalcin (OC)
    • P1NP (procollagen type 1 N-terminal propeptide)
    • PICP (procollagen I carboxy-terminal propeptide)
    • 25-(OH)-cholecalciferol and 1.25-di-(OH)-cholecalciferol
  • Bone resorption marker
    • Β-Crosslaps (β-CTX) – considered a reliable marker of increased bone loss (osteoporosis), especially in postmenopausal women; blood collection for Beta-CrossLaps only fasting between 07:00 and 09:00 a.m.
    • TRAP 5b (tartrate-resistant acid phosphatase); due to limited stability, sample must be transported to the laboratory on the same day
    • Crosslinks (pyridinoline, deoxypyridinoline) in 1st morning urine; determination in bone metastases (beneficial).
    • ICTP – I-carboxyterminal telopeptide.
Cause of disease / laboratory findings PTH 25-OH vitamin D (calcifediol) 1,25-dihydroxyvitamin D (calcitriol)
End-organ resistance; disruption of receptor function; senile osteoporosis (?). Increased Normal Normal to elevated
1,25-di-(OH)-cholecalciferol deficiency; renal insufficiency. Increased Normal Degraded
Primary vitamin D deficiency; dietary vitamin D deficiency; impaired absorption; decreased sun exposure Increased Decreased Degraded

2nd order laboratory parameters – depending on the results of the medical history, physical examination, etc. – for differential diagnostic clarification

Hormone tests

  • Parathyroid hormone (PTH)
  • 25-OH cholecaliferol – 25-OH vitamin D
  • 17-Beta-estradiol
  • Testosterone
  • Thyroid hormones – thyroxine (T4) and triiodothyronine (T3)

Molecular genetic testing

  • Vitamin D3 receptor gene – wg gene defect.
  • Gene defect in collagen type I alpha-1 gene.

Further studies