Review Article on the Relationship between Spondyloarthritis and Osteoporosis

Introduction: To investigate the relationship between spondyloarthritis (SpA) and osteoporosis including any association or prediction, and hence suggesting a plan of screening and management for osteoporosis in SpA. Methods: 168 and 538 research articles with keywords “osteoporosis” and “spondyloarthritis” or “ankylosing spondylitis” conducted between 1990 and 2021 were collected in Medline and PubMed, respectively. Focused review was conducted in 34 articles. Results: Osteoporosis is a common comorbidity in both ankylosing spondylitis and spondyloarthropathy as suggested by multiple studies across different countries, with a reduction in bone mineral density (BMD) and altered bone microarchitecture in vertebrae and cortical bone of proximal femur, leading to an increased risk of vertebral fractures and sarcopenia. Associated factors include male sex, advanced age, long disease duration, high serum erythrocyte sedimentation rate (ESR), decreased femoral and lateral lumbar BMD, and high radiological indices. It is likely to be related to chronic systemic inflammation and immobility. Serum uric acid level, certain genes and antibodies may also contribute to the pathology. The likelihood of osteoporosis in SpA can be evaluated by trabecular bone score, which are negatively correlated with serum levels of ESR and C-reactive protein (CRP). Alendronate with adequate dietary intake of calcium and vitamin D is the recommended management. Conclusion: The prevalence of osteoporosis is higher in patients with SpA due to the chronic presence of pro-inflammatory cytokines, functional impairment, and steroid therapy. With the help of inflammatory markers, imaging and radiological indices, the risk of osteoporosis, and vertebral fractures can be predicted. The management plan should be modified to include prevention and treatment of osteoporosis.