Osteoporosis

Reduction in bone mass via loss of matrix
Excessive bone loss
Normal mineral:matrix ratio

Causes
Old age (post-menopause)
Endocrine
 - premature ovarian failure (early menopause)
- Cushings
- thyrotoxicosis
Drugs
Steroids
Heparin

Ix
pl Bone profile = normal
DEXA
- Identify fast bone losers
- Monitor therapy (HRT, bisphosphonates)

Osteomalacia

...aka rickets in children

Defective mineralisation of bone (calcium deficiency) + Increased osteoid

Causes
Dietary/Malab - Ca/vit D def
x Exp to sunlight
Disordered vit D metabolism
- renal Dis (decreased 1-hydroxylation)
- vit D-dep rickets (1alpha-hydroxylase def)
- a-convulsive therapy (induces metabolism)
Low phosphate (Renal Tubular Leak)

Ix
low sCa & PO4
high ALP (osteoblastic response) - interpret with age-related ref range
low circulating 25-OH cholecalciferol (?diet def)
elev sPTH (2ry HPThm)