The Association Between Asthma and Narcolepsy: A Nationwide Case-Control Study in Taiwan

Abstract

Tien-Yu Chen,1– 3,* Vincent Yi-Fong Su,4,5,* Chung-Hsin Lee,6 Chi-Hsiang Chung,7– 9 Chia-Kuang Tsai,3,10 Chung-Kan Peng,3,11 Hsiao-Ching Lai,1 Wu-Chien Chien,7– 9,12 Nian-Sheng Tzeng1,13 1Department of Psychiatry, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan; 2Institute of Brain Science, National Yang Ming Chiao Tung University, Taipei, 112, Taiwan; 3Sleep Medicine Center, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan; 4Department of Internal Medicine, Taipei City Hospital, Taipei, Taiwan; 5Faculty of Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, 112, Taiwan; 6Department of Neurosurgery, Neurological Institute, Taichung Veterans General Hospital, Taichung, Taiwan; 7Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; 8School of Public Health, National Defense Medical Center, Taipei, Taiwan; 9Taiwanese Injury Prevention and Safety Promotion Association, Taipei, Taiwan; 10Department of Neurology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan; 11Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan; 12Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan; 13Student Counseling Center, National Defense Medical Center, Taipei, Taiwan*These authors contributed equally to this workCorrespondence: Wu-Chien ChienDepartment of Medical Research, Tri-Service General Hospital, National Defense Medical Center, 7115R, No. 325, Section 2, Cheng-Kung Road, Neihu District, Taipei, 11490, TaiwanTel [phone], Ext. 19189Fax [phone]Email [email protected] TzengDepartment of Psychiatry, Tri-Service General Hospital, National Defense Medical Center, 325, Section 2, Cheng-Kung Road, Neihu District, Taipei City, 11490, TaiwanTel [phone]Fax [phone]Email [email protected]: Asthma, which is caused by inflammation of the airways, affects the sensitivity of nerve endings. Narcolepsy is a chronic sleep disorder that may be caused by autoimmunity. Recent studies have reported a positive association between narcolepsy and asthma. We aimed to examine the association between asthma and narcolepsy and determine the effects of therapeutic corticosteroid or bronchodilator use.Materials and Methods: We conducted a nationwide population-based, nested case-control study using Taiwan’s National Health Insurance Research Database (NHIRD) between 2000 and 2013. Subjects with narcolepsy (ICD-9-CM code 347) were enrolled, with 1:3 estimated propensity score-matched controls based on sex, age, and index year. The association between narcolepsy and asthma was assessed using multiple logistic regression analyses. The covariates included sex, age, monthly insurance premiums, geographical area of residence, urbanization level of residence, level of care, and presence of diseases related to immune response and central nervous system. The effects of corticosteroid and bronchodilator use were also analyzed.Results: Overall, 2008 subjects were identified from the NHIRD (502 patients with narcolepsy and 1506 controls). The participants with narcolepsy had almost three times the level of previous asthma diagnosis than controls. Compared to those without asthma, patients with asthma had an adjusted odds ratio (OR) of 3.181 for narcolepsy comorbidity (95% confidence interval [CI]: 2.048– 4.941, p< 0.001). The use of inhaled corticosteroids was associated with a lower risk of narcolepsy comorbidity, with an adjusted OR of 0.465 (95% CI, 0.250– 0.634; p< 0.001), in patients with asthma when compared to those without treatment.Conclusion: This study demonstrated a significantly higher level of previous asthma diagnosis in patients with narcolepsy. The use of inhaled corticosteroids was associated with a lower risk of narcolepsy comorbidity in asthma patients, compared to those without treatment.Keywords: asthma, narcolepsy, corticosteroid, bronchodilators

Keywords

• asthma
• narcolepsy
• corticosteroid
• bronchodilators