Obstructive sleep apnea and fatigue in patients with inflammatory arthritis taking TNF-inhibitors

p>Background: Fatigue is common in inflammatory arthritis (IA). Obstructive sleep apnea (OSA) causes fatigue and is common in IA. OSA and IA are associated with systemic inflammation, including elevated levels of tumor necrosis factor alpha (TNFα). Tumor necrosis factor inhibitors (TNFi) reduce musculoskeletal symptoms and fatigue in IA. The effects of TNFi on OSA are unknown. Our goal was to explore the relationships between TNFi, fatigue, and OSA in IA. Methods: Consecutive patients starting TNFi for IA and high risk for OSA were enrolled. OSA was assessed with the Apnea Hypopnea Index (AHI) and percent time below 90% oxygen saturation (%time < 90%). Fatigue was assessed with the Functional Severity Scale (FSS). Sleep was assessed with the Functional Outcome of Sleep Questionnaire (FOSQ). IA was assessed with the patient global assessment of arthritis (PGA). Parameters were compared before and after TNFi. Changes in OSA, sleep, and fatigue outcomes were adjusted for changes in the PGA. Findings: Eighteen participants completed the study between September 2011 and February of 2014. The mean age was 54 years. 72% were male. Before and after TNFi: mean AHIs were 12.5 and 13.1, respectively (p=0.97); mean %times < 90% were 29.5 and 35.4, respectively (p=0.18); and mean FSS scores were 43.1 and 41.3, respectively (p=0.08); mean FOSQ scores were 11.4 and 11.8, respectively (p=0.09). Conclusions: OSA parameters did not improve with TNFi, but there were statistically non-significant trends toward improvement in fatigue and sleepiness with TNFi.