Osteoporossis: Causes

Question 1

What are the 2 significant risk factors for developing OP?

Answer 1

Advancing age

Female sex

Question 2

Tell me how the prevalence increases from 50 to 80 years of age in women.

Answer 2

Prevalence of osteoporosis increases from 2% at 50 years to more than 25% at 80 years in women.

Question 3

What are the other “most important” risk factors as used by FRAX.

Answer 3

• History of glucocorticoid use
• Rheumatoid arthritis
• Alcohol excess
• History of parental hip fracture
• Low BMI
• Current smoking

Question 4

What are some other risk factors?

Answer 4

• Sedentary lifestyle
• Premature menopause
• Caucasians and Asians
• Endocrine disorders: hyperthyroidism, hypogonadism (e.g. Turner’s, testosterone deficiency), growth hormone deficiency, hyperparathyroidism, diabetes mellitus
• Multiple myeloma, lymphoma
• Gastrointestinal disorders: inflammatory bowel disease, malabsorption (e.g. Coeliac’s), gastrectomy, liver disease
• CKD
• Osteogenesis imperfecta, homocystinuria

Question 5

What are some other medications, other than glucocorticoids, that can cause osteoporosis?

Answer 5

• SSRIs
• Antiepileptics
• PPIs
• Glitazones
• Long term heparin therapy
• Aromatase inhibitors e.g. anastrozole (Arimidex)

Question 6

What are some other tests you can do to look for secondary causes?

Answer 6

• Lateral radiographs of lumbar and thoracic spine/DXA-based vertebral imaging
• Multiple Myeloma - Protein immunoelectrophoresis and urinary Bence-Jones proteins
• 25OHD
• PTH
• Serum testosterone, SHBG, FSH, LH (in men),
• Serum prolactin
• Cushing’s - 24 hour urinary cortisol/dexamethasone suppression test
• Endomysial and/or tissue transglutaminase antibodies (coeliac disease)
• Isotope bone scan - tumours, fractures or infections.