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

Abstract

Excessive daytime sleepiness (EDS) is defined as the inability to stay awake and alert during major waking episodes of the day, resulting in unintended lapses into drowsiness or sleep, based on the second edition of International Classification of Sleep Disorders.1 EDS is one of the most disabling conditions caused by poor nocturnal sleep and is common in the elderly. Up to 30% of older people globally experience EDS.2 EDS can lead to poorer occupational and social functioning,3 and is strongly related to an increased risk of vehicular and occupational accidents.4 EDS also reduces cognitive functions in the elderly.5 Despite these adverse effects of EDS, the accurate representations of the burden of EDS in elderly Koreans are unclear. While several population-based studies of EDS in elderly people have been conducted in other countries,6-9 to our knowledge no study has evaluated EDS in older adults in Korea. The causes of EDS are multifaceted, with various risk factors. A number of studies of older adults have examined contributory factors associated with EDS in the elderly. EDS often occurs because of severe sleep-disordered breathing, subjective poor sleep quality, increased rapid eye movement sleep, pain, and use of sedating medications.10 Risk factors for EDS are nighttime awakening, depression, snoring, non-use of sleeping pills, and limitations in mobility.11 Accumulating evidence suggests that sleep is pivotal for memory consolidation, maintaining Received: October 21, 2014 Revised: November 28, 2014 Accepted: December 24, 2014