Sex differences in patients with narcolepsy type 1: Clinical manifestations, sleep profiles, and symptoms evolution

To investigate the sex-related differences in clinical manifestations, sleep characteristics, and symptom evolution of Chinese patients with narcolepsy type 1 (NT1).

A total of 1415 NT1 patients were recruited from Peking University People's Hospital and other sleep centers in China. Clinical and sleep characteristics were compared between sex groups across different age groups adjusted for potential confounders. Telephone interviews assessed the evolution of daytime sleepiness and cataplexy frequency in a subset of patients.

In children with NT1, girls showed a slight higher spontaneous arousal index during sleep compared with boys (9.31 ± 5.81 vs. 8.2 ± 5.13). Girls had less sleep apnea hypopnea index ≥1 than boys (56.6% vs. 65.9%). Although both had high HLA-DQB1*06:02 positivity, girls had a lower rate than that in boys (96.1% vs. 99.2%). In adults, women experienced longer diagnostic delays (11.2 ± 12.2 vs. 6.54 ± 7.79 years). Women had less apnea-hypopnea index ≥15 (22.2% vs. 46.1%) and less sleep-onset rapid eye movement periods (3.06 ± 1.27 vs. 3.6 ± 1.31) on MSLT than men. Hypocretin-1 levels were slight higher in women versus men (27.2 ± 19 vs. 20.2 ± 12.4). Patients with childhood-onset NT1 diagnosed in adulthood showed different sex-related differences in these parameters. At follow-up, untreated male NT1 showed improvements in cataplexy frequency and daytime sleepiness (17.5 ± 4.61 vs. 13.8 ± 5.88) than female NT1.

Sex associates with NT1 features differently in children and adults. Prospective longitudinal studies are warranted to clarify sex-specific disease progression and optimize management strategies for NT1.