Alopecia areata: the role of sleep disorder and comorbid diseases

Abstract

Background: Sleep exerts a strong regulatory influence on the immune system. To date, there have been few studies on the association between sleep and alopecia areata and comorbid diseases. Objectives: The aim of this study was to investigative the role of sleep disorder as a risk factor for alopecia areata and related comorbid diseases. Methods: This study was a retrospective study based on the Korean National Health Insurance Service-National Sample Cohort database of patients with sleep disorder, alopecia areata, and age- and gender- matched control subjects from 2002 to 2013. Results: A total of 25,800 patients with a sleep disorder and 12,199 patients with alopecia areata were identified. Using multivariable Cox proportional hazard models, patients with sleep disorder were found to be at significantly increased risk for alopecia areata compared to matched controls. The risks were higher in younger age groups (< 45 years). Patients with alopecia areata were at an increased risk for Graves’ disease, Hashimoto thyroiditis, vitiligo, lupus erythematosus, rheumatoid arthritis, thyroid cancer, and prostate cancer compared to matched controls. Interestingly, patients with alopecia areata were at a decreased risk for gastric, colorectal, liver, lung, breast, and cervical cancer. Conclusion: This study demonstrated that individuals with sleep disorder have a significantly increased risk of alopecia areata, especially under the age of 45. In addition, patients with alopecia areata were more likely to experience various autoimmune diseases, thyroid cancer, and prostate cancer, whereas the risk of gastric, colorectal, liver, lung, breast, and cervical cancer was lower than in control subjects.