The incidence of extra-articular manifestations in southern Chinese patients with inflammatory joint diseases.

Abstract

Inflammatory joint diseases (IJDs) are chronic arthritis, but frequently present with co-morbidities of other organs and systems, which is known as extra-articular manifestations (EAMs). It is still unclear which clinical characteristics or bio-markers can predict the development of EAMs. The aim of this study was to estimate the proportion of EAMs in southern Chinese patients with IJDs and to explore the risk factors. This was a retrospective cohort study of a total 1135 IJDs patients, including 788 rheumatoid arthritis (RA) patients, 307 ankylosing spondylitis (AS) patients and 40 psoriatic arthritis (PsA) patients. Demographic data, disease characteristics, laboratory blood tests, medical imaging, and the presence of EAMs were recorded. We found 459 (40.44%) patients presented with EAMs: 30.84% had cardiovascular involvement, 7.67% had pulmonary involvement, 5.29% had osteoporosis/low bone mineral density, 2.29% had ocular, 0.79% had gastrointestinal and 0.26% had renal involvements. Multivariate logistic regression showed older age (odds ratio [OR] 1.06, P<.001) and higher anti-cyclic citrullinated peptide antibody (anti-CCP) levels (OR 1.003, P=.019) were independent risks of EAMs in RA patients. In the AS group, older age (OR 1.07, P<.001) and higher disease activity (OR 3.24-7.42, both P<.05), were independent risks of EAMs. In the PsA group, longer disease duration (OR 1.01, P=.036) and higher disease activity (OR 1.15, P=.004) were univariate associated factors. These results suggested the high prevalence of EAMs, and it is important to regularly screen for EAMs, as they influence treatment decisions and impact on patients' quality of life.