Patients with insomnia disorder ages 40-79 years were recruited. Each participant was assessed with Pittsburgh Sleep Quality Index (PSQI), 4-day wrist actigraphy, and qEEG derived from a 64-channel electroencephalogram system. These variables were compared between age groups (40-64 years vs. 65-79 years) and sexes.
Among 173 participants, 61 (35%) were 65-79 years and 64 (35%) were males. The older group reported shorter (p = 0.009) total sleep time (TST) than the middle-aged group based on the PSQI, while women slept longer than men based on actigraphy (p = 0.040). Regarding EEG, women had higher relative beta power than men (p = 0.006). Older patients showed slower dominant occipital frequency than younger patients (p = 0.008). The age effect was more noticeable on both clinical variables and qEEG for women. Compared to younger women, older women reported shorter TST in the PSQI (p = 0.025), underestimated their sleep time (PSQI TST/actigraphic TST, p = 0.034), and showed reduced alpha power in frontal area (p = 0.009).
Clinicians should be aware of the age and sex difference on manifestation of insomnia, which may further impact individual’s behaviors, such as staying in bed for longer time or seeking for sleep aids.