Sex effect on time to diagnosis and clinical features of narcolepsy type 1 and 2

Abstract

Study objectives: Sex influences sleep through physiological differences and impacts the clinical presentation and quality of life in patients with sleep disorders. However, there is a paucity of evidence regarding differences between men and women affected by narcolepsy. This study aimed to explore the sex-based dissimilarities in time to diagnosis and clinical features in narcolepsy.

Methods: This retrospective observational study included adult patients with narcolepsy type 1 (NT1) and type 2 (NT2). Clinical, polysomnographic, and biofluid parameters were compared between men and women.

Results: The study analyzed 42 patients: 27 with NT1 (64.3 %) and 15 with NT2 (35.7 %). Among these, 18 were male (42.9 %; mean age 34.72 ± 12.89 years) and 24 were female (57.1 %; mean age 37.96 ± 13.2 years). No significant sex differences were observed in the age at onset of symptoms. Notably, females had significantly longer diagnostic delay compared to males (p = 0.04) and a higher rate of misdiagnosis before receiving the diagnosis of narcolepsy (p < 0.001). Male patients exhibited significantly longer stage 2 of Non-REM sleep percentage compared to females patients (p = 0.024). There were no significant differences in psychiatric comorbidities (p = 0.30).

Conclusions: Women with narcolepsy experience longer time to obtain the correct diagnosis and are more frequently misdiagnosed with other disorders compared to men. The present findings highlight a potential sex-based disparity in diagnostic practices that may negatively impact the well-being of women with narcolepsy, as their symptoms are more commonly misdiagnosed.

Keywords: Cataplexy; Diagnosis delay; Excessive daytime sleepiness; Misdiagnosis; Sleep disorders.