We examined the prevalence of extraarticular manifestations (EAM) in Korean patients with rheumatoid arthritis (RA). Risk factors for development of EAM were identified from patients' general characteristics and clinical or laboratory data.
Using a retrospective medical record review, 405 patients, who fulfilled the American College of Rheumatology 1987 criteria for RA, were consecutively enrolled. EAM such as serositis, vasculitis, neuropathy, ocular lesions, sicca symptoms, pulmonary fibrosis, cervical myelopathy, and rheumatoid nodules were assessed. Statistical analysis was performed using a chi-square test, Fisher's exact test, 2-sample t-test, and multivariate logistic regression analysis.
The overall prevalence of EAM in our patients was estimated to be 21.5% (n = 87). The most common EAM was rheumatoid nodule (8.4%, n = 34). Univariate analysis revealed anti-cyclic citrullinated peptide (anti-CCP) antibody positivity, smoking, alcohol consumption, and disease duration to be the risk factors associated with development of EAM. Multivariate logistic regression analysis also revealed a positive anti-CCP antibody, smoking, alcohol consumption, and disease duration to be closely associated with the development of EAM (p = 0.003, OR 5.006, 95% CI 1.729-14.494; p = 0.002, OR 5.260, 95% CI 1.876-14.753; p = 0.001, OR 0.218, 95% CI 0.086-0.553; p < 0.001, OR 1.061, 95% CI 1.032-1.091, respectively).
The prevalence of EAM in Korean RA patients is lower than in European, North American, and Mediterranean populations. Longer disease duration, smoking history, and positive anti-CCP antibody contributed significantly to the occurrence of EAM. Alcohol consumption in patients with RA had a negative association with EAM.