Treatment With Alendronate in Patients With Ankylosing Spondylitis (AS)
Condition: Ankylosing Spondylitis; Osteoporosis
MeSH terms: Spondylitis; Osteoporosis; Spondylarthritis; Spondylitis, Ankylosing
Study type: Observational

Summary: 
      This prospective study will assess the effects of treatment with alendronate in osteoporotic
      patients with ankylosing spondylitis.

      Primary objectives:

        -  To investigate if alendronate effect bone mineral density (BMD) assessed by dual energy
           x-ray absorptiometry (DXA) in lumbar spine, hip and distal forearm and assessed by
           quantitative computed tomography (QCT) in lumbar spine and by Xtreme CT in radius and
           tibia.

      Secondary objectives:

        -  To investigate if alendronate effects markers of bone remodeling

        -  To investigate if alendronate influences disease activity (BASDAI), spinal function
           (BASFI), spinal movement (BASMI) and health related quality of life (SF-36).
    

Detailed description: 
      Ankylosing spondylitis (AS) is a common inflammatory rheumatic disease with a prevalence of
      0.5-1.0%. Men are more commonly affected by the disease as compared to women, ratio 2.6-4:1.
      Pain in the back is a frequent symptom of debut. This pain is often associated with
      sacroilitis. In later stages also the lumbar, thoracic and cervical spine are hit by the
      disease. Peripheral joints, eyes, heart, lungs and urinary tract may also be influenced.

      The risk of osteoporosis is increased in AS. However, this field has not yet been
      significantly studied probably due to several reasons such as the predominance of men with
      the disease and men are more seldom investigated for osteoporosis compared to women. When AS
      progresses syndesmophytes of the spine are developed which makes it difficult to assess bone
      mineral density (BMD) correctly with the conventional method, dual energy x-ray
      absorptiometry (DXA). Fractures in the spine are easy to foreseen since the pain of the
      patient might be misjudged to be related to increased disease activity. Fractures are also
      overlooked in radiographs in AS. AS is associated with both increased bone formation and
      increased bone resorption. The bone remodeling process in the spine renders the spine less
      flexible and stiffer and as a consequence also a quite small trauma may result in a fracture.
      These fractures are often instable risking injuring the spinal cord and nerves.

      Treatment with bisphosphonates in AS have indicated an anti-inflammatory effect. The effects
      of treatment with bisphosphonate on BMD assessed by DXA, QCT and Xtreme CT in AS has not yet
      been fully investigated.
    

Intervention name(s): alendronate
Intervention type(s): Drug
Intervention description(s): One tablet of alendronate à 70 mg once a week during two years.
Intervention MeSH terms: Alendronate
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients with AS and osteoporosis.
      
Biospecimen description: 
      serum and plasma
    
Keywords: Ankylosing spondylitis; spondarthritis; Osteoporosis; Bone mineral density; Dual energy x-ray absorptiometry; Quantitative computed tomography