Sleep Med Psychophysiol.  2005 Dec;12(2):117-121.

Relatively Decreased Level of Subjective Daytime Sleepiness and Its Associated Factors in Patients with Primary Insomnia

• Lee YJ
• Lee J
• Sohn CH
• Lee EH
• Moon PS
• Jeong DU

Abstract

OBJECTIVES
The purpose of this study was to assess the difference of subjective daytime sleepiness level between primary insomnia patients and healthy control subjects. We also investigated the relationship between subjective daytime sleepiness level and variables of nocturnal polysomnograghic sleep architecture of insomnia patients. METHOD: Total subjects were 87 patients with primary insomnia diagnosed with polysomnography and 88 normal controls. The daytime sleepiness level in each group was measured by Korean version of Epworth Sleepiness Scale (ESS). The correlations of ESS score and nocturnal polysomnographic variables were calculated in the patient group. RESULTS: Patients with insomnia had the lower ESS scores than the control group. In patients group, the ESS score showed significant negative correlations with total sleep time, sleep efficiency%, and stage 2 sleep time%. The ESS score also showed significant positive correlations with number of awakenings, number of awakenings more than 2 minutes, and wake after sleep onset time. CONCLUSIONS: Insomnia patients showed lower level of subjective daytime sleepiness that may indicate their higher alertness comparing to control subjects. Daytime sleepiness of patients with insomnia was associated with polysomnographic variables including total sleep time, sleep efficiency%, stage 2 sleep time% and disrupted continuity of nocturnal sleep.

Keyword

Primary insomnia; Daytime sleepiness; Epworth Sleepiness Scale

MeSH Terms

Humans
Polysomnography
Sleep Initiation and Maintenance Disorders*