Association of systemic lupus erythematosus and sleep disorders: a nationwide population-based cohort study

Objective: Using a population-based cohort study, we investigated whether sleep disorders (SDs) increase the risk of systemic lupus erythematosus (SLE). Patients and methods: We identified patients with SDs and a control cohort from 1998-2001 by using the Taiwan Longitudinal Health Insurance Database 2000. Two controls for each patient with an SD were selected and randomly frequency-matched according to age, gender, and index year. The follow-up person-years were estimated for the patients from the index date to SLE diagnosis, loss to follow-up, or the end of 31 December 2011. We used the Cox proportional hazards models to evaluate how SDs influence the risk of SLE after adjustments for demographic factors and comorbidities. Results: A total of 144,396 subjects (48,132 SD cases and 96,264 controls) were followed for 1,477,055 person-years. The patients with SDs displayed higher incidence density rate of developing SLE than did the controls (1.03 vs 0.46 per 10,000 person-years). After adjustment for covariates, the patients with SDs exhibited a 2.20-fold higher adjusted hazard ratio (aHR) of developing SLE than the controls (95% confidence interval (CI) = 1.44-3.36). Women exhibited a greater prevalence of SDs and SLE compared to men. Patients with SDs aged 49 years and younger exhibited a significantly increased risk of SLE compared to the controls (aHR = 2.30, 95% CI = 1.33-3.98). Patients with SDs living in urban areas exhibited a significantly increased risk of SLE. Conclusion: This large population-based cohort study revealed that SDs increase the risk of SLE development.