The level of increased bone formation after 24 months of treatment with teriparatide (rhPTH (1-34), TPTD) is similar in patients who were either treatment-naïve (TN) or had lower bone turnover initially due to previous alendronate (ALN) therapy. INTRODUCTION: Bone anabolic effects of TPTD in postmenopausal women with osteoporosis may be blunted during the initial phase after switching from ALN to TPTD. To explore the long-term implications, we examined histomorphometric and biochemical markers of bone turnover of patients on TPTD therapy after long-term ALN treatment. METHODS: Paired biopsies were obtained after tetracycline double labeling at baseline and after 24 months of TPTD treatment from 29 ALN-pretreated (64.5 ± 16.4 months) and 16 TN patients. Biochemical markers were measured at baseline, during the treatment, or at study end. RESULTS: Compared with the baseline, after 24-month TPTD, activation frequency (Ac.F.) and osteoid surface (OS) increased in both groups: 0.11-0.34 cycles per year, 3.96-9.8% in the ALN-pretreated group and 0.19-0.33 cycles per year, 6.2-11.3% (p < 0.05) in the TN group, respectively. Biochemical and histomorphometric markers correlated positively both at baseline and endpoint. Serum amino terminal propeptide of type I procollagen (PINP) correlated with Ac.F. (r = 0.57, p < 0.001 and r = 0.48, p < 0.01) and OS (r = 0.51, p < 0.01 and r = 0.56, p < 0.01) at baseline and endpoint, respectively. Following 3 months of treatment, increases in biochemical markers like PINP predicted the increase in Ac.F. (r = 0.52, p < 0.01) and OS (r = 0.54, p < 0.01) after 24 months. CONCLUSIONS: The increased level of formation is similar in patients who were either TN or had lower bone turnover initially due to previous ALN therapy. Elevated bone formation in postmenopausal women with osteoporosis was sustained over a 24-month period by TPTD. Biochemical markers of bone formation are a good surrogate for the assessment of TPTD effects.

• MeSH
• Alendronate therapeutic use   MeSH
• Lumbar Vertebrae physiopathology   MeSH
• Biomarkers blood   MeSH
• Biopsy MeSH
• Adult MeSH
• Bone Density Conservation Agents therapeutic use   MeSH
• Bone Density drug effects   MeSH
• Femur Neck physiopathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Drug Substitution MeSH
• Osteogenesis drug effects   MeSH
• Osteoporosis, Postmenopausal drug therapy   pathology   physiopathology   MeSH
• Bone Remodeling drug effects   MeSH
• Aged MeSH
• Teriparatide therapeutic use   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Controlled Clinical Trial MeSH
• Multicenter Study MeSH
• Research Support, Non-U.S. Gov't MeSH