AB0956 EPIDEMIOLOGY AND RISK FACTORS ASSOCIATED WITH HIP INVOLVEMENT IN ANKYLOSING SPONDYLITIS
Authors: R. Belkacemi, C. Haouichet, L. Ali
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Hip involvement is a frequent complication in ankylosing spondylitis(AS) compared to other sub types of spondyloarthritis and it is more frequent in Maghreb countries unlike in European countries. Its occurrence remains a major concern in the follow up of the disease. <h3>Objectives:</h3> To estimate the frequency of hip involvement in patients with AS in Tlemcen, wilaya located in western Algeria, and to determine the risk factors associated with its occurrence. <h3>Methods:</h3> Cross sectional descriptive study of patients with AS diagnosed according to the modified New York criteria, not associated with psoriasis and chronic inflammatory bowel disease, residing in Tlemcen carried out between September 2020 and May 2022. The survey was conducted on a general population using a questionnaire to detect symptoms evocative of AS, which was sent to doctors practicing in the various districts of the wilaya. All patients suspected of having AS were then referred to a rheumatology consultation at the Tlemcen university hospital to confirm the diagnosis and collect sociodemographic, clinical, biological and radiological data. The diagnosis of hip involvement was based on clinical and radiological criteria (BASRI hip≥1) <h3>Results:</h3> 235 patients with AS were included in the study, 153(65,1%)were male with a sex ratio of 1,86, the mean age was 39,83±11,72 years. The frequency of hip involvement in AS was estimated at 82 patients (34,9%) with 95% CI [28,9-40,9], it was inaugural in 22(26,8%) of patients with a median time to onset of 5 years, the mean Harris hip score was 55,77±19,21. Bivariate analysis identified several variables with a significant association with hip involvement, some of which were retained in the multivariate analysis and considered to be at potential risk of hip involvement: juvenile onset of the disease (OR: 0,228, CI:[0,083-0,629], p=0,004), low socioeconomic position evaluated by a composite index including level of education and professional category(OR:0,603, CI:[0,36-0,99], p=0,046), high axial site enthesitis according to the MASES score(OR:1,510, CI:[1,11-2,045], p=0,008, and high disease activity by ASDAS CRP score(OR:9,15, CI:[3,66-22,84], p=0,0001). The other variables identified in the bivariate analysis were considered to be markers of severity: low body mass index, spinal deformity, higher scores of BASMI, BASFI, ASQoL, restrictive lung syndrome, severe radiographic structural damage to the sacroiliac and spine (Table 1). <h3>Conclusion:</h3> Our study shows that hip involvement in patients with AS in Algeria is a frequent complication, appearing early in the course of the disease and potentially leading to significant morbidity. It is important to detect hip involvement at an early stage in patients at risk in order to improve the prognosis. <h3>REFERENCES:</h3> [1] Genoud PA. Indice de position socioéconomique: un calcul simplifié. Fribourg: Université de Fribourg. 2011 [2] Vander Cruyssen B, Vastesaeger N, Collantes-Estévez E. Hip disease in ankylosing spondylitis. Current opinion in rheumatology. 2013;25(4):448-54. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>