Original ArticleNarcolepsy is complicated by high medical and psychiatric comorbidities: a comparison with the general population
Introduction
Narcolepsy is a debilitating neurodegenerative disorder characterized by daytime sleep attacks and rapid eye movement (REM) sleep abnormalities (e.g., sleep-onset REM periods, sleep paralysis, hypnagogic hallucinations). Narcolepsy is a rare disorder affecting less than 0.05% of the general population [1]. However, impacts on daytime functioning are considerable and many affected individuals have severe limitations in their daily life activities [2]. Some studies have reported a poorer health-related quality of life, as measured by the Short Form (36) Healthy Survey in narcoleptic patients when compared to the general population [3], [4]. However, quality of life for these individuals tends to improve over time [4], possibly due to adaptation strategies for coping with the impact of the disease [4], [5].
Individuals affected by narcolepsy represent a vulnerable segment of the population. However, we only have a partial understanding of this vulnerability. Narcoleptic individuals often have morbid obesity, and several also have sleep apnea syndrome (up to 25%) [6]. Both conditions put these individuals at greater risk for developing other serious health concerns such as cardiovascular diseases. Unfortunately, few studies have examined which health conditions and psychiatric disorders are associated with narcolepsy [7], [8]. Understanding comorbid conditions associated with narcolepsy is of utmost importance when devising an appropriate treatment plan. Our study aims to present a detailed look at the mental and organic health concerns that affect narcoleptic individuals when compared with a matched general population sample.
Section snippets
Narcolepsy sample
A total of 320 narcoleptic participants were included in the study. Most of them were referred by sleep specialists. Twenty-two participants came from the general population and were diagnosed with narcolepsy by a sleep specialist.
General population sample [9]
Fifteen states were selected to represent the US population based on the number of residents and geographic area. The 15 states that were included were Arizona, California, Colorado, Florida, Idaho, Missouri, New York, North Carolina, North Dakota, Oregon,
General description of the samples
The narcolepsy sample was composed of 109 men and 211 women. The mean age was 40.27 (±14.73) years and the BMI was 28.53 (±6.78). Half of the participants were married (50.3%) and working (55.6%). Most of them were white (82.3%). The matched general population sample included 472 men and 992 women. The mean age was 43.78 (±14.57) years, and the BMI was 26.79 (±3.98). Half of them were married (50.9%) and most were working (66.1%). Most of them also were white (78.6%).
Comorbid organic conditions
Table 1 presents the most
Discussion
Our study clearly illustrates the medical history complexity of individuals with narcolepsy. In addition to having a debilitating disease, most of the narcoleptic participants also had at least one medical condition or a psychiatric disorder that required treatment. We found that a large number of narcoleptic individuals (27.5%) also had upper respiratory tract diseases, mainly asthma and allergies, which would indicate a compromised immune system. A few years ago, it was hypothesized that the
Conflict of interest
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2013.03.002.
Acknowledgment
This study was supported by a grant from the National Institutes of Health (R01NS044199), the Arrillaga Foundation, and an unrestricted educational grant from Jazz Pharmaceuticals.
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