title: A randomized double-blind placebo-controlled trial to investigate the effects of nasal calcitonin on bone microarchitecture measured by high-resolution peripheral quantitative computerized tomography in postmenopausal women - study protocol.
abstract: BACKGROUND
  Bone microarchitecture is a significant determinant of bone strength. So far, the assessment of bone microarchitecture has required bone biopsies, limiting its utilization in clinical practice to one single skeletal site. With the advance of high-resolution imaging techniques, non-invasive in vivo measurement of bone microarchitecture has recently become possible. This provides an opportunity to efficiently assess the effects of anti-osteoporotic therapies on bone microarchitecture. We therefore designed a protocol to investigate the effects of nasal salmon calcitonin, an inhibitor of osteoclast activity, on bone microarchitecture in postmenopausal women, comparing weight bearing and non-weight bearing skeletal sites.
  
  
  METHODS
  One hundred postmenopausal women will be included in a randomized, placebo-controlled, double-blind trial comparing the effect of nasal salmon calcitonin (200 UI/day) to placebo over two years. Bone microarchitecture at the distal radius and distal tibia will be determined yearly by high-resolution peripheral quantitative computerized tomography (p-QCT) with a voxel size of 82 mum and an irradiation of less than 5 muSv. Serum markers of bone resorption and bone formation will be measured every 6 months. Safety and compliance will be assessed. Primary endpoint is the change in bone microarchitecture; secondary endpoint is the change in markers of bone turnover.
  
  
  OBJECTIVE
  The present study should provide new information on the mode of action of nasal calcitonin. We hypothezise that - compared to placebo - calcitonin impacts on microstructural parameters, with a possible difference between weight bearing and non-weight bearing bones.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT00372099.
authors.affiliation: Service of Bone Diseases, Department of Rehabilitation and Geriatrics, University Hospitals of Geneva, 24, Rue Micheli-du-Crest, 1211 Geneva 14, Switzerland. rene.rizzoli@hcuge.com
authors.forename: Laura
authors.initials: L
authors.lastname: Richert
authors.forename: Brigitte
authors.initials: B
authors.lastname: Uebelhart
authors.forename: Marc
authors.initials: M
authors.lastname: Engelhardt
authors.forename: Moise
authors.initials: M
authors.lastname: Azria
authors.forename: René
authors.initials: R
authors.lastname: Rizzoli