Differences Between Men and Women Aged 65 and Older in the Relationship Between Self-Reported Sleep and Cognitive Impairment: A Nationwide Survey in Taiwan

Abstract

Objectives: To examine the prevalence of self-reported sleep disturbances and cognitive impairment in men and women aged 65 and older and to determine sex-specific effects on the relationship between self-reported sleep and cognitive impairment.

Design: A secondary data analysis from the 2009 Taiwan National Health Interview Survey.

Participants: Individuals aged 65 and older (N = 2,413, n = 1,094 men, n = 1,319 women).

Measurements: Subjective sleep characteristics including sleep duration, difficulty initiating sleep, difficulty maintaining sleep, early-morning awakening, daytime sleepiness, difficulty breathing during sleep, habitual snoring, and daytime napping were measured using survey questions. The Mini-Mental State Examination was used to identify cognitive impairment.

Results: The prevalence of cognitive impairment was 16.3% for men and 27.1% for women. Men and women with cognitive impairment had higher prevalence of self-reported sleep disturbances than those without. There was a significant effect of the interaction between sex and difficulty breathing during sleep on cognitive impairment (adjusted odds ratio (aOR) = 0.39, 95% confidence interval (CI) = 0.20-0.77). In men, difficulty breathing during sleep (aOR = 2.31, 95% CI = 1.39-3.84), habitual snoring (aOR = 2.30, 95% CI = 1.49-3.54), and prolonged sleep duration (> 8.5 hours) (aOR = 1.95, 95% CI = 1.11-3.43) correlated significantly with cognitive impairment. In women, only prolonged sleep duration (>8.5 hours) was associated with higher likelihood of cognitive impairment (aOR = 2.32, 95% CI = 1.33-4.03).

Conclusion: This nationwide survey confirmed sex differences in the association between various self-reported sleep disturbances and cognitive impairment in people aged 65 and older.

Keywords: cognitive impairment; elderly people; sex difference; sleep.