Prevalence, Risk Factors, and Impact of Excessive Daytime Sleepiness in an Elderly Korean Population

Abstract

Background and Objective Excessive daytime sleepiness (EDS) is commonly reported by the elderly, but has not been well-described in older adults in Korea. This study aimed to estimate the prevalence and risk factors of EDS, and investigated the relationship between EDS and cognitive impairment in an older Korean population. Methods The cross-sectional and community-based study recruited 333 people ≥ 60 years of age. All participants underwent full-time nocturnal polysomnography and completed questionnaires assessing sociodemographic factors. EDS was defined as Epworth Sleepiness Scale score > 10. Cognitive functions were estimated using the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease neuropsychological assessment battery and subjective memory complaint questionnaire. Results The overall prevalence of EDS was 18.9% with no significant difference between genders. In multivariate analysis using a multiple logistic regression model, obesity [odds ratio (OR) = 2.379, p = 0.022], educational attainment (OR = 0.929, p = 0.019) and total arousal (OR = 2.785, p = 0.008) were identified as the risk factors for EDS. Subjective memory impairment was related to EDS after controlling for confounding variables (p < 0.001). Conclusions Korean elderly have a high prevalence and risk factors of EDS, which has modest effects on cognitive functioning. EDS in older adults should be adequately addressed and treated, instead of being considered as a normal aging process.

Keywords

• Excessive daytime sleepiness
• Prevalence
• Risk factors
• Cognitive impairment
• Polysomnography