Background/Purpose: Self-reported sleep disturbances (SDs) are common in RA. Most studies of sleep in RA have focused on SDs in general. Obstructive sleep apnea (OSA) is one specific type of SD, which has well characterized negative health effects and for which treatment is available. We examined the frequency OSA symptoms, risk, diagnosis, and treatment, and factors associated with OSA risk.

Methods: Data were from Forward – The National Databank for Rheumatic Diseases, for which participants complete questionnaires every 6 months. RA diagnoses were physician-reported. In one questionnaire, items about the presence of symptoms, physician diagnoses (MD-DX), and treatment of OSA were included. Risk of OSA was assessed using a validated questionnaire with positive predictive value of ~85%¹. Items included snoring, daytime sleepiness, observations of apnea episodes by others, presence/treatment of hypertension (Table 1). Presence of ≥2 of these symptoms plus age>50 or BMI >35 indicates high risk for OSA. Use of continuous positive air pressure (CPAP) devices were also assessed. Frequencies of OSA symptoms, risk, diagnosis, and treatment were tabulated. Multivariate logistic regression analyses identified independent predictors of high risk of OSA. Potential predictors included age, sex, smoking, low income, chronic obstructive pulmonary disease (COPD), other comorbid conditions, obesity, disease duration, self-reported RA disease activity (RA Disease Activity Index, RADAI), medications, and pain.

Results: Subject characteristics and prevalence of OSA symptoms are shown in Table 1 (n = 2623). 16% reported MD-DX OSA and an additional 8% were at high risk of OSA, compared to OSA prevalence of ~2-4% in the general population. 9% used CPAP (58% of MD-DX OSA; 34% of those at high risk for OSA). Independent predictors of OSA risk were obesity, smoking, more comorbid conditions, and RADAI (Table 2).

Conclusion: OSA was more common in RA than in the population, with only 2/3 of those at high risk reporting an OSA diagnosis. Half of those with a diagnosis reported treatment. Some predictors of OSA were similar to predictors in the population (age, obesity), but disease activity was also associated with OSA. Self-reported sleep problems are associated with poor RA disease outcomes. In other conditions, OSA is linked to heightened inflammation, so it could be a cause of increased RA disease activity. Further research is needed to tease out disease-specific causes and effects of OSA and other sleep disturbances in RA.

¹ Chung F et al: Anesthesiol 2008;108:812; J Clin Sleep Med 2014;10:951