Effects of Teriparatide Treatment and Discontinuation in Postmenopausal Women and Eugonadal Men with Osteoporosis

CONTEXT: In postmenopausal women, bone mineral density (BMD) declines after teriparatide therapy is stopped. The pattern of BMD loss after teriparatide therapy is stopped in men is less clear. OBJECTIVE: The aim of the study was to determine whether the pattern of teriparatide-induced bone accrual and post-teriparatide bone loss differs between postmenopausal women and eugonadal men. DESIGN: We conducted a prospective cohort substudy. PATIENTS: The study included 14 postmenopausal women and 17 eugonadal men, ages 46-85 yr, with lumbar spine or femoral neck BMD T-scores below -2. INTERVENTION: Teriparatide (37 microg sc daily) was administered for 24 months, followed by 12 months off therapy. MAIN OUTCOME MEASURES: We measured BMD at various anatomic sites by dual-energy x-ray absorptiometry, trabecular spine BMD by quantitative computed tomography, and bone turnover markers during the treatment and observation periods. The response to teriparatide administration and discontinuation was compared between females and males. RESULTS: BMD of the spine, femoral neck, total hip, and trabecular spine increased similarly during the treatment period in men and women, whereas BMD at the radius was stable in men but decreased by 8.1 +/- 3.3% in women (P < 0.0001). After teriparatide was stopped, BMD at the posterior-anterior spine decreased by 7.1 +/- 3.8% in women and by 4.1 +/- 3.5% in men (P = 0.036). BMD at the total hip and femoral neck decreased by 3.8 +/- 3.9 and 3.1 +/- 4.3%, respectively, in women but remained stable in men (P < 0.05 for both sites). BMD at the distal radius remained stable in men but increased in women by 1.6 +/- 3.1% (P = 0.069). CONCLUSIONS: Teriparatide appears to increase BMD similarly in postmenopausal women and eugonadal men with osteoporosis. After teriparatide is stopped, the decline in BMD is greater in women than in men. If confirmed in larger cohorts, these findings would suggest that the indication for immediate antiresorptive therapy after teriparatide may not be as urgent in men as in women.