Comorbidities in a community sample of narcolepsy

Abstract

Study objective: To assess comorbidities in a community-based cohort of narcolepsy.

Methods: A 2000-2014 community-based narcolepsy cohort was identified in Olmsted County, Minnesota. Records were reviewed by a certified sleep specialist for accuracy of diagnosis, and comorbidities were extracted and analyzed. Comorbidities in narcolepsy subjects, both at diagnosis and upon follow-up, were compared with those in unaffected and age- and sex-matched cohort using conditional logistic regression.

Results: At diagnosis, there was increased association of narcolepsy with anxiety (OR 4.56, 95% CI 1.99-10.44), thyroid disease (3.07, 1.19-7.90), hypertension (2.69, 1.22-5.93), and hyperlipidemia (2.49, 1.05-5.92). At the end of the prolonged observation period of 9.9 years (SD 7.27 years), there was increased association of narcolepsy with peripheral neuropathy (11.21, 1.16-108.11), non-migrainous headache (6.00, 1.73-20.83), glucose intolerance (2.39, 1.05-5.45), and automobile-related trauma (2.43, 1.08-5.45). Persistently increased both at diagnosis and after a prolonged observation period were associations of narcolepsy with obstructive sleep apnea (OSA) (69.25, 9.26-517.99 decreasing to 13.55, 5.08-36.14), chronic low back pain (5.46, 2.46-12.11 to 2.58, 1.39-4.77), depression (4.88, 2.45-9.73 to 3.79, 2.12-6.79), psychiatric disorders in general (4.73, 2.49-9.01 to 3.40, 1.94-5.98), endocrinopathies (4.15, 1.81-9.56 to 2.45, 1.33-4.49), and obesity (2.27, 1.13-4.56 to 2.07, 1.15-3.7).

Conclusions: In this community-based study of narcolepsy comorbidities, both at diagnosis and after prolonged follow-up, persistent comorbidities were revealed, including OSA, chronic low back pain, psychiatric disorders in general, endocrinopathies, and obesity. The comprehensive management of narcolepsy requires monitoring for and managing these important associated health conditions.

Keywords: Community-based study; Comorbidity; Narcolepsy; Population surveillance.

Figure 1. Percentage of patients affected by narcolepsy-associated comorbidities at the time of diagnosis and after prolonged observation

Percentage of patients with narcolepsy (cases) and control cohort affected by individual comorbidities at the time of diagnosis or index date (A), and after prolonged observation (B). Stars indicate significantly elevated odds ratios.