Osteoporosis

Key points:

- Osteoporosis is under-recognised and under-treated, even in people who present with a minimal trauma fracture.

- A minimal trauma fracture is sufficient for a presumptive diagnosis of osteoporosis medicines can start prior to obtaining BMD results with dual energy x-ray absorptiometry (DXA).

- Guidelines recommend risk factor assessment and that modifiable risk factors be addressed in all postmenopausal women aged >45 years and men aged > 50 years.

- A full diagnostic investigation is indicated for:

• women> 50 YEARS and men> 60 years with other clinical risk factors 
• Patients > 45 years with a minimal trauma fracture or suspected vertebral fracture 
• patients who have causes of secondary osteoporosis (medical conditions or medicines such as long-term, high-dose corticosteroids)
• adults aged over 70 years 

- Clinical risk factors (CRFs), use the mneumonic of shattered 

Previous minimal trauma fracture, family history 

• S: steroid use (oral corticosteroid use > 5mg/day)
• H: hyperthyroidism, hyper parathyroidism and hypercalciuria 
• A: Alcohol and tobacco use 
• T: Thin (BMI < 22)
• T: Testosteron decrease (e.g. anti androgen ca, prostate Rx)
• E: Early menopause 
• R: renal or liver failure 
• E: Erosive/inflammatory bone disease (e.g. myeloma or rheumatoid arthritis)
• D: Dietary Calcium decrease/malabsorption , DM1 

- The strongest risk factor is age > 70. Peak bone mass is achieved by age 30. Bone loss occurs steadily from the age of about 40, with accelerated loss in perimenopausal period (4-6%) before slowing again after the age of 70 (1-2% per year).

- Basic investigations: DEXA, Ca, PO, ALP, FBE, UEC, LFT, myeloma screen if indicated

• Hip bone mineral density best predictor for hip fracture
• Lumbar spine bone mineral density best for monitoring treatment effect
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- Management:

• lifestyle measures
• quit smoking and reduce ETOH consumption 
• Weight bearing exercise may increase bone mineral density 
• Balance exercises such as tai chi reduce risk of falls 
• Calcium and vitamin D supplements 
• recommended dietary intake of calcium is between 1000 and 1300 mg per day, depending on age and sex
• Most Australians do not reach the recommended dietary intake so daily supplements of 500-600 mg of calcium are sometimes needed
• Safety of calcium is still a controversial topic as there is evidence that it may increase risks of MI
• Home based fall prevention program, with visual assessment and a home visit
• Medications 
• Bisphosphonates and Denosumab
• Criteria: minimal trauma fracture or age > 70 with T score <=-2.5
• Bisphosphonates: well tolerated, some significant side effects: oesophageal cancer? (not proven), osteonecrosis of the jaw (see dentist prior to commence treatment) and do not use with the other antiresorptive or anabolic agents
•  Denosumab: use with caution in patients with severely impaired kidney function as denosumab may exacerbate hypocalcaemia 
• Raloxifene 
• postmenopausal woman with a minimal trauma fracture and risk of vertebral fractures predominatly
• reduces vertebral fracture but not non vertebral fractures in postmenopausal women
• Reduces risk of breast cancer so suitable for women at high breast cancer risk
• Associated with increased risk of DVT or pulmonary embolism in meta-analyses
• Strontium ranelate
• Criteria: unable to tolerate other medications or contraindicated to other medications
• assess patient risk of developing CVD before treatment due to safety concerns in patients with history of CVD, embolism or stroke 
• Teriparatide 
• Reduces vertebral and non - vertebral fractures in postmenopausal women 
• limited evidence in men
• must be initiated by a consultant physician
• Vitamin D deficiency
• 600 IU per day for people under 70
• 800 IU per day of people over 70 
• 1000-2000 IU per day may be required for sun avoiders or those at high risk of deficiency
• Monitor treatment response and review therapy to encourage adherence
• BMD measurements 2 years after the commencement of therapy or 1-2 years after therapy changes significantly