A case-control sleep study in children with polyarticular juvenile rheumatoid arthritis.

Objective: To investigate the relationship between clinical manifestations and sleep abnormalities in patients with juvenile rheumatoid arthritis (JRA).
Methods: Twenty-one patients with active polyarticular JRA and 20 healthy controls were enrolled consecutively. Pain and functional impairment were assessed with standardized, validated Brazilian questionnaires. Sleep evaluation was based on parent reporting of their child's sleep habits and polysomnography; subjects underwent an adaptation night in the sleep laboratory. Sleep architecture was analyzed and spectral analysis of non-rapid eye movement (REM) sleep was carried out by electroencephalography.
Results: Patients with JRA exhibited higher indexes of periodic leg movements (PLM; p = 0.02), isolated leg movements (LM), and arousals, as well as increases in alpha activity in non-REM sleep (all p < 0.01), in spite of similar frequency of sleep complaints in comparison to controls. Among JRA patients, greater alpha activity in non-REM sleep was observed in the participants with greater joint involvement assessed by the Escola Paulista de Medicina-Pediatric Range of Motion Scale (p = 0.03) or joint count (p = 0.02). Correlation was observed between morning stiffness and PLM and/or LM (rS = 0.75, Sr = 0.74, p < 0.001 for both), and between self-rating scores of pain and alpha activity in non-REM sleep (rS = 0.74, p < 0.001).
Conclusion: Pain symptoms and disability are related to sleep fragmentation in patients with active polyarticular JRA.