A repeat dual-energy x-ray absorptiometry (DEXA) scan should be repeated in 2 years in this patient with low bone mass and relatively low 10-year fracture risk. The Fracture Risk Assessment Tool (FRAX) calculator defines the 10-year fracture risk for patients with T-scores in the −1.0 to −2.5 ranges. The FRAX calculator (www.shef.ac.uk/FRAX) incorporates multiple risk factors including sex, fracture history, femoral neck bone mineral density, glucocorticoid use, smoking, BMI, age, and alcohol intake to determine projected fracture risk. If the risk of major osteoporotic fracture is greater than or equal to 20% or the risk of hip fracture is greater than or equal to 3%, then the patient's benefit from therapy exceeds the risk, and she should be offered treatment. Because of her history of low body weight and limited nutritional intake during the time of development of peak bone mass, she is at increased risk for low bone mass or osteoporosis and is therefore an appropriate candidate for early screening. Her DEXA scan shows low bone mass. Spine film shows no evidence of fracture. Additionally, her calcium and vitamin D levels are normal. Continuing lifestyle activities (such as maximizing weight-bearing exercise and avoidance of tobacco or excessive alcohol) in addition to calcium and vitamin D supplementation is appropriate management of this patient.
Raloxifene is a selective estrogen receptor modulator (SERM) that is a treatment option for women with osteoporosis because it has been shown to increase bone mineral density and reduce the risk of vertebral (but not nonvertebral) fractures. However, raloxifene is also associated with an increased risk of thromboembolic events and vasomotor symptoms. There is limited data supporting use of raloxifene or other SERMs for treating patients with low bone mass, although some guidelines recommend considering treatment in patients with low bone mass and 10-year fracture risk determined by the FRAX calculator of greater than or equal to 20% for a major osteoporotic fracture or greater than or equal to 3% for hip fracture. Raloxifene would therefore not be appropriate therapy for this patient.
Cholecalciferol (D3), a metabolite of vitamin D, is commonly used to supplement low serum vitamin D levels in patients with vitamin D deficiency. This patient has normal serum vitamin D levels; therefore, there is no indication for treatment with vitamin D metabolites.
Bisphosphonates are considered first-line therapy for osteoporosis, although they are not used routinely in women with low bone mass. Similar to the use of SERM therapy, guidelines recommend consideration of treatment with a bisphosphonate for low bone mass only if there is 10-year fracture risk determined by the FRAX calculator of greater than or equal to 20% for a major osteoporotic fracture or greater than or equal to 3% for hip fracture.