Study on the frequency and risk factors of moderate-to-severe sleep apnea syndrome in rheumatoid arthritis

AbstractObjectives: We aimed to investigate the frequency of moderate-to-severe sleep apnea syndrome (SAS) that possibly influences long-term prognosis in patients with rheumatoid arthritis (RA), and to analyze the risk factors for this group.Methods: We examined respiratory disturbance index (RDI) by polysomnography in 62 hospitalized RA patients. Risk factors of moderate-to-severe SAS (RDI ≥20) were analyzed using a multivariate logistic regression analysis.Results: RA was complicated by moderate-to-severe SAS in 13/62 (20.9%) cases. The highest stage of temporomandibular joint abnormality (TMJA) and a high value of health assessment questionnaire-disability index (HAQ-DI) were significant risk factors, according to the results of the multivariate logistic regression analysis (p < 0.0001 and p = 0.010, respectively). Contrary to these results, RDI was not related to the disease activity indexes of RA and other clinical characteristics.Conclusion: We clarified that the highest TMJA stage and a high value...