title: Comorbidity and mortality of narcolepsy: a controlled retro- and prospective national study.
abstract: OBJECTIVE
  To identify the factual morbidity and mortality of narcolepsy in a controlled design.
  
  
  METHODS
  National Patient Registry.
  
  
  METHODS
  All national diagnosed patients (757) with health information at least 3 years prior to and after diagnose of narcolepsy.
  
  
  METHODS
  Randomly selected four citizens (3,013) matched for age, sex, and socioeconomic status from the Danish Civil Registration System Statistics.
  
  
  RESULTS
  Increased morbidity prior to narcolepsy diagnosis included (odds ratio, 95% confidence interval):- diseases of the endocrine, nutritional, and metabolic systems (2.10, 1.32-3.33); nervous system (5.27, 3.65-7.60); musculoskeletal system (1.59, 1.23-2.05); and other abnormal symptoms and laboratory findings (1.66, 1.25-2.22). After the diagnosis, narcolepsy patients experienced diseases of the endocrine, nutritional, and metabolic (2.31, 1.51-3.54), nervous (9.19, 6.80-12.41), musculoskeletal (1.70, 1.28-2.26), eye (1.67, 1.03-2.71), and respiratory systems (1.84, 1.21-2.81). Specific diagnoses were diabetes (2.4, 1,2-4.7, P < 0.01), obesity (13.4, 3.1-57.6, P < 0.001), sleep apnea (19.2, 7.7-48.3, P < 0.001), other sleep disorders (78.5, 11.8-523.3, P < 0.001), chronic obstructive pulmonary disease (2.8, 1.4-5.8, P < 0.01), lower back pain (2.5, 1.4-4.2, P < 0.001), arthrosis/arthritis (2.5, 1.3-4.8, P < 0.01), observation of neurological diseases (3.5, 1.9-6.5, P < 0.001), observation of other diseases (1.7, 1.2-2.5, P < 0.01), and rehabilitation (5.0, 1.5-16.5, P < 0.005). There was a trend towards greater mortality in narcolepsy (P = 0.07).
  
  
  CONCLUSIONS
  Patients with narcolepsy present higher morbidity several years prior to diagnose and even higher thereafter. The mortality rate due to narcolepsy was slightly but not significantly higher.
authors.affiliation: Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Glostrup Hospital, Copenhagen, Denmark. POJE@glo.regionh.dk
authors.forename: Poul
authors.initials: P
authors.lastname: Jennum
authors.forename: Rikke
authors.initials: R
authors.lastname: Ibsen
authors.forename: Stine
authors.initials: S
authors.lastname: Knudsen
authors.forename: Jakob
authors.initials: J
authors.lastname: Kjellberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000175:diagnosis / Q000453:epidemiology / Q000401:mortality*; D011446:Prospective Studies; D012042:Registries; D012189:Retrospective Studies; D055815:Young Adult
keywords: Narcolepsy; morbidity; mortality; sleep apnea