loss of bone mass, normal composition → bone weakness → increased susceptibility to fragility fractures / minimal trauma fractures (fractures caused by everyday activities / from a standing height or less)

demographics: Elderly, ****Post menopausal women

Aetiology

• Primary osteoporosis (most common)
  • Type I (postmenopausal osteoporosis)
    • Estrogen stimulates osteoblasts and inhibits osteoclasts
    • decreased estrogen levels → increased bone resorption
  • Type II (senile osteoporosis):
    • gradual loss of bone mass as patients age (especially > 70 years) → it’s believed that osteoblasts just gradually lose the ability to form bone,
  • Idiopathic osteoporosis: juvenile and young adults
• Secondary osteoporosis
  • Drug-induced/iatrogenic
    • Most commonly due to systemic long-term therapy with corticosteroids (e.g., in patients with autoimmune disease) à causes increase bone resorption while also reducing bone formation
  • Endocrine/metabolic: hypercortisolism, hypogonadism, hyperthyroidism, hyperparathyroidism, renal disease
  • Multiple myeloma

Risk Factors

• Excessive alcohol consumption
• Cigarette smoking
• female
• age
• Immobilization or inadequate physical activity
• Malabsorption, malnutrition (e.g., diet low in calcium and vitamin D), anorexia → incr PTH → bone resorption
• Low body weight
• Family history of osteoporosis
• Personal history of fracture
• endocrine disorders