Primary
Type 1
- postmenopausal
- high turnover / osteoclast mediated
- F x 6
Type 2
- age-related / senile
- low turnover / osteoblast mediated
- F x 2
Can have both
Secondary / DDD NICE
Disuse
- prolonged bed rest
- inactivity
- paralysis
- space travel
Diet
- low Ca, vit C
- anorexia nervosa
Drugs
- heparin
- methotrexate
- ethanol
- steroids
Neoplasms
- metastatic disease
- myeloma
- lymphoma
- leukemia
- mastocytosis
Idiopathic
- adolescent (10-18yrs)
- middle-age men
Chronic Illness
- RA
- cirrhosis
- sarcoidosis
- renal tubular acidosis
Endocrine Abnormalities
- pituitary hypersecretion
- adrenal cortex excess
- ovary- oestrogen deficiency
- testis - testosterone deficiency
- hyperparathyroidism
- hyperthyroidism
- hypophosphatasia