A randomized, double-blind, placebo-controlled pilot study of the efficacy of alendronate on the prevention of bone loss in patients with early ankylosing spondylitis

Objectives: The aim of this study is the considering the efficacy of alendronate on the prevention of bone loss in the patients with early ankylosing spondylitis. Design, setting and conduct: In a randomized double blind placebo controlled study in the Emam Reza hospital of Tabriz University of Medical Sciences, patients with early ankylosing spondylitis which diagnosed by the (ASAS) after explaining the study aims and obtaining written informed consent will be recruited to the study. The early ankylosing spondylitis criteria are: Schober index≥5; Normal hip joint in the pelvic radiography; Absence or rarity of syndesmophytes in the spine radiography (Taylor index≤1). They will be randomized and allocated with the Randlist software to the treatment and control groups. Participants: Early ankylosing spondylitis patients according to the Assessment of SpondyloArthritis international Society (ASAS) criteria Exclusion criteria: 1. Using of drugs which increase bone density like bisphosphonates; 2. Using of steroids and biological agents; 3. Coexistence of other disease which decreases bone density: including hyperparathyroidism, diabetes, hyper and hypothyroidism, osteomalacia, liver failure, renal failure. Intervention: A group of patients will receive alendronate sodium 70 mg tablet (Ostomod, Modava company) 70mg/week (one tablet at week) for 12 months and another group will receive placebo. Alendronate tablets and placebo tablets were overencapsulated to look similar. Before intervention and 12 months after intervention densitometry will be performed by the dual energy X-ray absorptiometry method with Hologic QDR model instrument from lumbar and pelvic area. Patients, assessing physicians and densitometry technicians are blind. Both groups will receive calcium 1000mg/d and vitamin D 400mg/d supplements. For control of the inflammatory symptoms standard treatment including one non steroidal anti-inflammatory drug (NSAID) with anti-inflammatory dose will be started. Main outcome measures: Bone density which will be measured by the dual energy X-ray absorptiometry method with Hologic QDR model instrument from the lumbar and pelvic area and data will be entered in a questionnaire.

Vice chancellor for research, Tabriz University of Medical Sciences