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Osteoporosis: Review of the Clinical Practice Guidelines Ambulatory Internal Medicine Group Practice Seminar Series October 2007 Lianne Tile MD MEd FRCPC References • Consensus Statement from the Osteoporosis Society of Canada (OSC) – CMAJ 2002 • Canadian Task Force on Preventive Health Care – CMAJ 2004 • Parathyroid hormone for the treatment of osteoporosis: a systematic review – CMAJ 2006 Objectives • At the end of this presentation you will: – – – – Know the definition of osteoporosis Understand the recommendations for screening Have an approach to initial evaluation Be familiar with nonpharmacological and pharmacological options for prevention and treatment Case • A 70 year old woman is seen in clinic for follow-up of refractory hypertension • She wonders whether she has osteoporosis • How do you make the diagnosis of osteoporosis? • Who should be screened for osteoporosis? Background • 1 in 4 Canadian women • 1 in 8 Canadian men have osteoporosis • A 50-year-old Caucasian woman has lifetime fragility fracture risk of at least 40% • Prevalence of vertebral fractures is >25% for Canadian women/men > age 50 Osteoporosis - Definition • A systemic skeletal disease characterized by low bone mass and micro-architectural deterioration of bone tissue with resultant increase in fragility and risk of fracture • Bone strength depends on bone density and bone quality WHO Definition of Osteoporosis • Based on bone mineral density measured by DEXA (hip and lumbar spine are preferred sites) • T-score is the number of standard deviations above or below the BMD for young adults of the same gender and race – Normal BMD: T-score above –1.0 – Osteopenia: T-score between –2.5 and –1.0 – Osteoporosis: T-score below –2.5 – Severe osteoporosis: T-score below –2.5 with a fragility fracture – Note: WHO definitions apply to postmenopausal women • Z-score is age matched but…what really matters is osteoporotic fractures Four key risk factors: 1. Advancing age 2. Prior fragility fracture (after age 40) 3. Family history of osteoporotic fracture 4. Low bone mineral density (BMD) Why is a history of fracture so important? • ↑ risk of future fragility fractures (x1.5–9.5) • risk of future fractures depends on – number of prior fractures – site of initial fracture – Age – Fall risk Who should undergo BMD testing? • Each guideline is slightly different • All recommend testing if – Age > 65 – Fragility fracture – Long-term (> 3 months) steroid use • Osteoporosis Society of Canada recommends screening in those over 50 with 1 major or 2 minor risk factors (see next slide) Major and Minor Risk Factors Major Minor Age > 65 Rheumatoid arthritis Vertebral compression fracture History of hyperthyroidism Fragility fracture after age 40 Anticonvulsant therapy Family history of osteoporsis/ # Low dietary calcium intake Steroids > 3 months Smoking Malabsorption Excess caffeine intake Primary hyperparathyroidism Weight < 57 kg Propensity to fall Weight loss > 10% Osteopenia on x-ray Chronic heparin therapy Hypogonadism Early menopause (< age 45) OSC Guideline, 2002 Rational Clinical Exam: Does this woman have osteoporosis? • Greatest positive likelihood ratios with: – – – – – Weight <51kg Tooth count <20 Rib-pelvis distance <2 finger breadths Wall-occiput distance >0 cm Self reported humped back JAMA 2004; 292:2890-2900 Case - Continued • You review the major and minor risk factors for osteoporosis, and determine that your patient has low dietary calcium intake and a family history of a hip fracture in her mother • She is also concerned her back in humped • Based on this, you send her for BMD testing Case - continued • What is the diagnosis? • What additional investigations should be done at this time? • Should your patient be treated for osteoporosis, if so, how? • What if she was 10 years younger? Taking corticosteroids? • This woman has BMD evidence of osteoporosis • Further assessment should include: – History: • Detailed history including diet and lifestyle factors, screen for risk factors and secondary causes of bone loss • Past medical history and medications • Previous fractures, height loss, kyphosis • Fall risk assessment – Lab tests for secondary causes of osteoporosis: • CBC, ALP, calcium, PO4, creatinine in all • TSH, vitamin D, PTH, serum protein electrophoresis, testosterone in selected patients – Spine xrays if exam suggests vertebral fractures Physical exam: look for changes in the spine that suggest vertebral fractures A B A. Height Loss > 6 cm historically or > 2 cm measured prospectively B. Wall-Occiput Distance > 0 cm C. Rib-Pelvis Distance < 2 finger breadths C Rational Clinical Exam: Does This Woman Have Osteoporosis? Amanda D. Green; Cathleen S. ColónEmeric; Lori Bastian; Matthew T. Drake; Kenneth W. Lyles JAMA 2004; 292: 2890-2900 Case - continued • No prior fractures as an adult • History and medications do not suggest a secondary cause of bone loss • Mild thoracic kyphosis on examination • Laboratory investigations reveal a normal CBC, calcium, ALP, creatinine and SPEP • Spinal x-rays (done because of kyphosis) show an old T8 compression fracture Treatment • Since her T-score is < -2.5 and she has a vertebral fracture, you recommend treatment for her osteoporosis Start with Nutrition and Lifestyle (for everyone!) • Calcium from diet and/or supplements – Age 19-50: 1,000 mg/day – Age > 50, steroid use, osteoporosis: 1,500 mg/day – Note: 1 glass of milk ~ 300 mg calcium • Vitamin D – Age < 50: 400 I.U./day – Age > 50 or low BMD: 800-1000 I.U./day • Limit caffeine (< 4 cups coffee/day) • Smoking cessation • Weight-bearing exercise 3 times per week When should you consider pharmacologic therapy? • Always look at risk of fractures! • Four Key Risk Factors are: • Age (and fall risk) • Prior fragility fracture (after age 40) • Family history of osteoporotic fracture • Low bone mineral density (BMD) Canadian Guidelines Recommend Pharmacological Options • Antiresorptive agents – – – – – Bisphosphonates Selective estrogen receptor modulators Hormone replacement therapy Calcitonin IV Bisphosphonates • Bone formation agents – PTH • Choose based on efficacy, safety, toxicity Alendronate (Fosamax) / Risedronate (Actonel) – good quality studies show decreases in risk of spine and nonvertebral fractures – Evidence for effectiveness in women and men – Taken weekly, on an empty stomach, 1 hour before eating, must remain upright – Adverse effects: GERD or esophageal erosions, use with caution in renal insufficiency, osteonecrosis of the jaw is a very rare association – recommended as first line therapy, covered by ODB Etidronate (Didrocal) – shown to prevent spine but not hip fractures – taken cyclically: 400 mg/d x 14 days q 3 mo as Didrocal “kit”: 14 tablets of etidronate followed by 10 weeks of calcium 500 mg – Well tolerated – recommended as second line therapy SERMs: Raloxifene (Evista) – Estrogen agonist effect on bone, heart; antagonist on breast; neutral on endometrium – Decreases risk of invasive breast cancer, neutral for cardiovascular disease – Studies show decreased risk of vertebral but not hip fractures – Taken daily – Adverse effects include hot flushes, increased risk of thromboembolic disease (similar to HRT) – covered by ODB under limited use criteria Hormone Replacement Therapy (HRT) • Good quality data (Women’s Health Initiative) showing decreased risk of fractures at all sites • BUT increased risk of coronary artery disease, stroke, venous thromboembolism and breast cancer • Although HRT is effective therapy for prevention and treatment of osteoporosis, risks will outweigh benefits for most women Calcitonin • Intranasal calcitonin (Miacalcin) – fair quality data showing decreased risk of fractures – Reduces pain in acute vertebral fractures – well tolerated, safe in renal failure, mild nasal irritation in 30% – recommended as second-line therapy – not covered by ODB Bone Formation Agents • PTH 1-34 (Forteo) – Significantly increases bone density, decreases risk of vertebral and nonvertebral fractures – Daily sc injection for 18 months (self administered) – Less effective if given with a bisphosphonate – Tumors seen in animal studies, so PTH is not recommended in high bone turnover states or in cancer patients – Very expensive, not covered New Treatment Options • IV Bisphosphonates – IV Zoledronic acid 5 mg given once a year reduces fracture risk similar to oral bisphosphonates – There is further evidence that it decreases mortality when given post hip fracture – Not yet approved in Canada for osteoporosis treatment • Vertebroplasty – Injection of bone cement into vertebral fracture for pain relief (done by interventional radiologist) • New therapies on the horizon – Strontium ranelate – RANK ligand inhibitors Back to the Case • You recommend calcium 500 mg (elemental) TID, vitamin D 1000 IU daily, and weight bearing exercise • You offer treatment with alendronate, risedronate or raloxifene, and discuss the benefits and side effects of each • She agrees to start alendronate 70 mg per week and understands how to use it correctly • You arrange a follow up BMD in 1-2 years’ time