Table 3 Biochemical testing in osteoporosis and associated diagnoses (↑ = increased; ↓ = decreased)

Blood count

Inflammatory diseases and malignancy

Serum protein electrophoresis and free kappa and lambda light chains

Multiple myeloma

ESR

↑ Differential diagnosis of inflammatory causes of vertebral deformities

Serum calcium

↑ Primary hyperparathyroidism or other causes of hypercalcemia

↓ e.g., secondary hyperparathyroidism, malabsorption

Serum phosphorus

↑ Renal insufficiency grade IV

↑ Secondary renal hyperparathyroidism

↓ Malabsorption

Alkaline phosphatase (AP)

↑ Osteomalacia, Paget’s disease

Serum PTH

↑ Hyperparathyroidism

Serum creatinine

↓ Renal osteodystrophy

25-Hydroxyvitamin D3

↑ Vitamin D intoxication

↓ Vitamin D deficiency, osteomalacia

Urine calcium/24 h

↓ Intestinal malabsorption

↑ Urinary stones

TSH

< 0.3 mU/L endogenous or caused by l-thyroxine medication as a risk factor for fractures

Testosterone in men

Hypogonadism

Anti-tissue transglutaminase antibodies

Celiac disease

Urinary free cortisol

↑ Adrenal hypersecretion

Serum tryptase or urine N-methylhistamine

↑ Mastocytosis

Bone marrow aspiration and biopsy and undecalcified iliac crest bone biopsy with double tetracycline labeling

Renal failure, vitamin D-resistant osteomalacia, mastocytosis, and rare metabolic bone diseases

Bone resorption parameters

High bone turnover as a fracture risk