Bone mineral densitometry and quantitative bone ultrasound in evaluating bone changes in postmenopausal women with severe osteoporosis treated with teriparatide

Objectives: The aim of this study was to evaluate the bone structure changes in postmenopausal women who underwent teriparatide (hPTH [1-34]) therapy. Methods: Eight-teen osteoporotic (T-score <2.5 SD) women (median age 58 years, range 53-61) with vertebral atraumatic fractures, unsatisfactory treated with bisphosphonates, were prospectively enrolled in the study. All patients underwent both osteodensitometry using dual energy X-ray absorptiometry (DXA) at the lumbar spine, femoral neck and total hip, and serial phalangeal quantitative bone ultrasound (QUS) using Hologic QDR 4500C (Hologic, Whaltham, MA, USA) and DBM Sonic 1200/1 densitometers (IGEA, Carpi, Italy), respectively. They were administered teriparatide 20 microg daily, and supplemented with elemental calcium (1000 mg) and vitamin D (800 IU) daily for 18 months. Results: The compliance to both medications was excellent. Teriparatide significantly (p<0.01) increased percentage of change in T-score at 18- month follow-up. The amplitude-dependent speed of sound and the ultrasound bone profile index decreased at 6 (-1.9% and -10.7%, p=0.03) and 12 months (-2.4% and -25.6%, p=0.002) over baseline, and raised at the end of therapy. Both bone specific alkaline phosphatase and osteocalcin serum levels increased (>50%) during therapy. Conclusions: Our study confirms that teriparatide is effective in increasing markers of bone formation. QUS may reflect the effect of teriparatide on cortical bone, mimicking DXA results at femoral level. The initial decrease of QUS parameters may be related to the classic effects of PTH on long bones, characterized by an increase of both periosteal bone formation and