MKSAP quiz: Fracture risk
This month's quiz asks readers to evaluate a 38-year-old woman with antiphospholipid syndrome, recurrent diffuse alveolar hemorrhage, and secondary diabetes mellitus who is taking prednisone.
A 38-year-old woman presents for first assessment of bone health 4 months into prednisone therapy. Medical history is significant for treatment of antiphospholipid syndrome with recurrent diffuse alveolar hemorrhage and secondary diabetes mellitus. She is not sexually active. She has had no fractures. Medications are prednisone, cyclophosphamide, neutral protamine Hagedorn (NPH) insulin, calcium citrate/vitamin D3, sulfamethoxazole-trimethoprim, and omeprazole. She is expected to continue prednisone therapy, 7.5 mg or more, for at least the next 6 months.
On physical examination, vital signs are normal. BMI is 37. The remainder of the examination is normal.
Bone mineral density by dual-energy x-ray absorptiometry shows a lumbar spine Z-score of –2.1 and total hip Z-score of –3.1. Radiograph of the spine shows no vertebral compression.
Which of the following is the most appropriate treatment?
A. Alendronate
B. Teriparatide
C. Zoledronic acid
D. No additional therapy
MKSAP Answer and Critique
The correct answer is A. Alendronate. This item is available to MKSAP 18 subscribers as item 33 in the Endocrinology and Metabolism section. More information about MKSAP 18 is available online.
The most appropriate treatment is alendronate. The American College of Rheumatology recommends that in all adults and children, an initial clinical fracture risk assessment for glucocorticoid-induced osteoporosis should be performed as soon as possible, but at least within 6 months of the initiation of long-term glucocorticoid treatment. Patients are categorized according to fracture risk. High fracture risk in patients younger than 40 years is defined as by a previous osteoporotic fracture. Moderate fracture risk is defined as hip or spine bone mineral density Z score less than –3 or rapid bone loss (>10% at the hip or spine over 1 year) and continuing glucocorticoid treatment at >7.5 mg/day for >6 months. Low risk is defined as no osteoporotic risk factors other than glucocorticoid use. Other criteria are used for defining low, moderate, and high fracture risk in patients age 40 years and older. Oral bisphosphonates are recommended as first-line therapy for patients with moderate to high fracture risk, such as this woman, regardless of age. This includes women of childbearing potential provided they are not planning a pregnancy during the period of bisphosphonate treatment.
Optimized calcium and vitamin D intake, lifestyle modifications, and reassessment of fracture risk including bone mineral density testing every 2 to 3 years is recommended over osteoporosis medications for patients younger than 40 at low risk of fracture. However, this patient is not low risk, and treatment with an oral bisphosphonate is indicated.
Teriparatide is indicated for the treatment of men and women with osteoporosis associated with sustained systemic glucocorticoid therapy at high risk for fracture. Although it increases bone mineral density at the spine and hip more than oral bisphosphonate therapy, it is less desirable due to expense and the requirement of daily injections.
Zoledronic acid is indicated for the treatment and prevention of glucocorticoid-induced osteoporosis in patients who cannot tolerate oral bisphosphonates. Due to uncertain impact on pregnancy outcomes, it is considered a third-line agent in younger women.
Key Point
- Oral bisphosphonates are recommended as first-line therapy in adult men and women on chronic glucocorticoid therapy with moderate to high fracture risk regardless of age.