title: Bone histomorphometric evaluation of pamidronate treatment in clinically manifest osteoporosis.
abstract: The effect of pamidronate therapy on bone histology was studied in patients with osteoporosis with at least one vertebral fracture in a randomized, double-masked, placebo-controlled, multi-center trial. Patients received pamidronate 150 mg/day or placebo in addition to calcium 500 mg/day and vitamin D3 400 IU/day. Transiliac bone biopsies were obtained before and after 1 or 2 years of treatment. Of these, 23 pairs of biopsies obtained from 14 women and 9 men (mean age +/- SD, 61.5 +/- 10 years) were of sufficient quality for histomorphometry. Histomorphometry was performed on sections stained with Goldner's trichrome, using a drawing tube and a digitizer. Urinary hydroxyproline excretion decreased significantly (p < 0.005) following pamidronate treatment, indicating a decrease in bone resorption. Osteoid volume and osteoid surface also decreased significantly in the pamidronate group (p < 0.004 and p < 0.003 respectively), consistent with a secondary decrease in bone formation. Osteoid variables did not change in the placebo-treated patients. Cortical thickness, trabecular bone volume and trabecular thickness did not change after pamidronate or placebo treatment. Wall thickness, however, showed a borderline increase following pamidronate treatment. After pamidronate, eroded surface and mineral apposition rate did not change significantly in the placebo and pamidronate groups. Mineralizing surface and activation frequency showed a borderline decrease in the placebo and pamidronate groups. The decrease in mineralization lag time was of borderline significance in the pamidronate group, corroborating the absence of any negative effect on mineralization. In conclusion, pamidronate treatment led to a decrease in bone turnover and did not interfere with bone mineralization.
authors.affiliation: Department of Endocrinology, Academic Hospital Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Bravenboer
authors.forename: S E
authors.initials: SE
authors.lastname: Papapoulos
authors.forename: P
authors.initials: P
authors.lastname: Holzmann
authors.forename: N A
authors.initials: NA
authors.lastname: Hamdy
authors.forename: J C
authors.initials: JC
authors.lastname: Netelenbos
authors.forename: P
authors.initials: P
authors.lastname: Lips
mesh_terms: D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D016723:Bone Remodeling / Q000187:drug effects; D001842:Bone and Bones / Q000473:pathology*; D004164:Diphosphonates / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000188:drug therapy* / Q000473:pathology*; D000077268:Pamidronate; D012737:Sex Factors; D016103:Spinal Fractures / Q000188:drug therapy / Q000209:etiology; D018709:Statistics, Nonparametric
chemical_list: D000893:Anti-Inflammatory Agents; D004164:Diphosphonates; D000077268:Pamidronate