Study of Bone Mineral Density and Trabecular Bone Score in Patients With Ankylosing Spondylitis
Study of Bone Mineral Density and Trabecular Bone Score in Patients With Ankylosing Spondylitis
Osteoporosis is a common complication of AS even in the early stages of disease. Yet, AS is
 also characterized by new bone growth that leads to syndesmophytes formation and subsequent
 vertebral ankyloses.
Accordingly, previously-published studies have demonstrated large discrepancies in the
 reported incidence of osteoporosis, based on measurement of bone mineral density (BMD), in
 patients with AS ranging from 18.7% to 62%. Measurement of trabecular bone score (TBS) is a
 novel tool used to evaluate bone microarchitecture. Aim of the work: to compare bone quality
 using TBS between AS patients and healthy controls and to evaluate factors associated with
 TBS in patients with AS. Patients and methods: A total of 40 male AS patients recruited from
 Outpatient Clinic of Rheumatology, Mansoura University Hospital. 40 age-matched healthy males
 as matched control. TBS was analyzed using DXA images over exactly the same region as the
 lumbar BMD assessment (L1-L4). Lumbar spine DXA images were reanalyzed using TBS iNight
 software version 2.1 (Med-I maps, Merignac, France). Patients were divided in 3 TBS groups
 according to guidelines for fracture risk: any TBS >1.31 was considered as normal; TBS values
 between 1.23 and 1.31 were consistent as partially degraded structure; and any TBS <1.23 was
 considered as degraded structure
Inclusion Criteria:

 -  A total of 40 consecutive male AS patients were invited to participate in this study.
 Patients were recruited from Outpatient Clinic of Rheumatology, Mansoura University
 Hospital, between January and September 2019. AS was diagnosed according to modified
 New York criteria. During the same period, 40 age-matched healthy males were invited
 to participate in the study as a control group.

 Exclusion Criteria:

 -  patients or controls with thyroid or parathyroid disorders, presence of chronic renal
 or liver disease, and use of any medication that could potentially interfere with bone
 metabolism including bisphosphonates, teriparatide, anticonvulsants, anticoagulants,
 calcium and corticosteroids. None of the participants was using vitamin D supplements.