The association between sleep problems and perceived health status: A Japanese nationwide general population survey

Abstract

Objective

Sleep problems in humans have been reported to impact seriously on daily function and to have a close association with well-being. To examine the effects of individual sleep problems on physical and mental health, we conducted a nationwide epidemiological survey and examined the associations between sleep problems and perceived health status.

Methods

Cross-sectional surveys with a face-to-face interview were conducted in August and September, 2009, as part of the Nihon University Sleep and Mental Health Epidemiology Project (NUSMEP). Data from 2559 people aged 20 years or older were analyzed (response rate 54.0%). Participants completed a questionnaire on perceived physical and mental health statuses, and sleep problems including the presence or absence of insomnia symptoms (i.e., difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], and early morning awakening [EMA]), excessive daytime sleepiness (EDS), poor sleep quality (PSQ), short sleep duration (SSD), and long sleep duration (LSD).

Results

The prevalence of DIS, DMS, and EMA was 14.9%, 26.6%, and 11.7%, respectively, and 32.7% of the sample reported at least one of them. At the complaint level, the prevalence of EDS, PSQ, SSD, and LSD was 1.4%, 21.7%, 4.0%, and 3.2%, respectively. Multiple logistic regression analyses revealed that DMS, PSQ, SSD, and LSD were independently associated with poor perceived physical health status; DIS, EDS, and PSQ were independently associated with poor perceived mental health status.

Conclusions

This study has demonstrated that sleep problems have individual significance with regard to perceived physical or mental health status.

Introduction

Insomnia has been recognized as one of the most common difficulties in modern society. Epidemiological studies have reported that the prevalence of insomnia symptoms in the general population ranges from 17.3% to 48% [1], [2], [3] and is consistent when the insomnia criteria used are comparable.

The restorative function of sleep is undoubtedly essential for maintenance of both physical and mental health. Previous studies in several countries have indicated that insomnia is associated with perceived health [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20]. Léger et al. [15] reported that the severity of insomnia was correlated with perceived health, and Hajak [12] found that impairment of perceived health in individuals with severe insomnia was somewhat greater than that in individuals with long-standing physical illness.

Apart from insomnia, excessive daytime sleepiness (EDS) [9], [17], short sleep duration (SSD) [18], [21], [22], [23], long sleep duration (LSD) [18], [21], [23], and poor sleep quality (PSQ) [24] have also been associated with poor perceived health.

Several studies have suggested that sleep problems disturb both perceived physical and mental health [8], [9], [12], [14], [15], [16], while recently it has been suggested that sleep problems have different effects on physical and mental health [11], [17], [20]. A cross-sectional study of older women suggested that sleep difficulty was significantly associated with poor perceived mental health, but not with poor perceived physical health [11]. A study of hypnotic medication use suggested that this was associated with deterioration of physical health, but not mental health [20]. A retrospective study found that insomnia was associated with changes in perceived mental health, but not with changes in perceived physical health [17].

With regard to the association between sleep problems and perceived health, most previous studies did not focus on the subtypes of sleep problems, i.e., difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), or early morning awakening (EMA). More recently, a 3-year follow-up study of an elderly population demonstrated that sleep-onset insomnia, but not other subtypes of insomnia, was a risk factor for depression [25]. A 12-year follow-up study of community-dwelling adults showed that sleep-maintenance insomnia, but not other subtypes, was a significant risk factor for the development of type 2 diabetes mellitus, suggesting that the consequences of various insomnia subtypes may differ [26]. Furthermore, few previous studies selected subjects from the general adult population; in most cases, the subjects were selected from a particular age group or community.

Here we conducted an epidemiological study of sleep problems and perceived health status in a large sample of the Japanese general adult population. We investigated the associations between sleep problems and perceived physical and mental health status, focusing on sleep problem subtypes. Our particular interest was focused on the associations of individual sleep problems with perceived physical and mental health statuses by adjusting for confounding relationships.