Associations of nonrestorative sleep with insomnia, depression, and daytime function

doi:10.1016/j.sleep.2010.08.007

Sleep Medicine

Volume 11, Issue 10, December 2010, Pages 965-972

https://doi.org/10.1016/j.sleep.2010.08.007 Get rights and content

Abstract

Study objectives

Nonrestorative sleep (NRS) complaints are common but associations with insomnia, daytime function or depressive symptoms are not well-established. This study aims to (1) describe insomnia related symptoms and sleep quality in those with NRS compared to those with no NRS; (2) identify the independent associations between NRS, insomnia severity, and depression; and (3) identify the association between NRS and daytime function independent of insomnia severity and depression.

Design

Cross sectional survey of enrollees at a health plan in the Midwestern United States.

Measurement

Respondents were surveyed about the presence and frequency of NRS complaints, depression, insomnia severity and related symptoms. Multivariate regression was used to examine the study’s three research aims.

Participants

Study sample consisted of 541 subjects with NRS and 717 who reported never experiencing any NRS symptoms.

Results

We found a statistically significant interaction between NRS and total sleep duration such that the association between sleep duration and sleep quality was attenuated in those with NRS compared to those without NRS (b = −0.26, SE = 0.07, p < 0.0001). In multivariate analysis, subthreshold, moderate and severe insomnia were associated with NRS (OR [95%CI] = 5.93 [4.24–8.31], 9.22 [6.15–13.83] and 6.10 [3.34–11.14], respectively). NRS was independently associated with daytime physical function, cognitive function and emotional function OR [95%CI] = 2.21 [1.59–3.08], 1.90 [1.37–2.64] and 1.71 [1.23–2.36], respectively.

Conclusion

NRS is a complex concept that should be further defined and studied in the larger context of sleep quality, other insomnia related symptoms, daytime function and depression.

Section snippets

Background

Nonrestorative sleep (NRS) is defined as a subjective experience of unrefreshing sleep [1] or a “feeling that sleep is restless, light, or of poor quality even though the duration may appear normal” [2]. The construct first arose in the 1970s in studies of chronic fatigue and fibromyalgia syndromes [1], [3], [4] and was incorporated as a symptom of insomnia in the DSM III-R of 1987. More recently, studies have begun to examine the prevalence and correlates of NRS [2], [5], [6]. Prevalence

Methods

This analysis is based on a subsample from a larger study that surveyed subjects with an insomnia related health care claim and a randomly selected subsample of individuals who had no insomnia related health care claims. Potential study participants were identified from a health plan in the Midwestern United States consisting of roughly 150,000 members. Subjects were excluded from the study if they had an insurance claim diagnosis for sleep apnea (OSA) or sleep disturbance unspecified. Study

Measures

Respondents were surveyed about the presence and frequency of NRS complaints, depression, insomnia severity, frequency of sleep onset and/or maintenance insomnia, and the use of both prescription and over-the-counter sleep-promoting medications (SPM).

Analysis

The primary analysis sample consisted of 541 subjects who reported NRS (3 or more nights per week) and 717 subjects who reported never experiencing NRS symptoms in the past four weeks and who had data available for all study variables, bringing the total sample size to 1258 respondents. Insomnia symptoms could be reported in either group. The groups differed only in reporting the presence or absence of NRS. Univariate analyses were conducted using Pearson correlation, with a Bonferroni

Aim 1: Insomnia related symptoms and sleep quality in those who report NRS compared with those with no NRS symptoms

Descriptive characteristics of the sample stratified by the presence or absence of NRS are presented in Table 1. Of the NRS group, 49.1% rated their NRS symptoms as severe or very severe while 37.3% and 13.6% rated it as moderate or mild, respectively. The NRS group was slightly younger than the non-NRS group (mean [SD] = 50.8 [14.3] vs. 53.0 [14.8]; p < 0.01). More of the NRS group was female (75.8% vs. 65.7%, p < 0.01) and had current depression (48.4% vs. 24.1%, p < 0.0001). The NRS group had a

Discussion

Our study confirms some previously published findings [2], [8], [9], [19], [20] and also provides new insights into the interactions among depression, NRS, and other insomnia symptoms. Specifically, for some individuals, NRS exists even in the absence of other insomnia symptoms and is associated with increased total sleep duration. In addition, depression is associated with NRS, independent of insomnia severity, and there is a significant interaction between NRS and total sleep duration that

Disclosure of financial interests or relationships

Khaled Sarsour, David Van Brunt and Joseph A Johnston are employees of Eli Lilly and Company.

Dr. Walsh has provided consulting services to the following companies: Pfizer, Sanofi-Aventis, Cephalon, Schering-Plough/Organon, Neurocrine, Takeda America, Actelion, Sepracor, Jazz, Respironics, Transcept, Neurogen, GlaxoSmithKline, Somaxon, Eli Lilly, Evotec, Merck, Kingsdown, Vanda, Ventus, and Somnus.

Research support has been provided to Dr. Walsh’s institution by the following companies: Pfizer,

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Cited by (41)

Development and validation of the Japanese version of the Restorative Sleep Questionnaire in community samples
2023, Sleep Medicine
This study aimed to validate the Japanese version of the Restorative Sleep Questionnaire Weekly version (RSQ-W-J) and estimate the RSQ-W-J cut-off score to identify the degree of non-restorative sleep (NRS) that interferes with daytime function.
An online survey was conducted, and 513 participants (241 men, 272 women; mean age, 47.88 ± 16.66 years) completed the questionnaires. The RSQ-W-J, Multidimensional Fatigue Inventory, Athens Insomnia Scale, Patient Health Questionnaire-9, Epworth Sleepiness Scale, Sleep Debt Index, NRS and the degree of daytime dysfunction, and the diagnostic criteria for chronic insomnia were used as implementation scales.
The RSQ-W-J was confirmed to have a single-factor structure. Both the Cronbach α coefficient and test-retest reliability of RSQ-W-J were high (α = 0.91; intraclass correlation coefficient [ICC]_agreement = 0.85). The RSQ-W-J was significantly negatively correlated with the scales of fatigue, insomnia, depressive symptoms, daytime sleepiness, and sleep debt. In addition, the RSQ-W-J scores of the insomnia group, in which participants met the diagnostic criteria for chronic insomnia, NRS group, in which participants had NRS only, and sleep debt group, in which participants had sleep debt, were significantly lower than those in the normal sleep group. Furthermore, the insomnia group scored significantly lower than the sleep debt group. The RSQ-W-J cut-off score, which indicates whether or not NRS interferes with daytime function, was estimated to be 45.8 points.
The RSQ-W-J was shown to be useful for comprehensively measuring the degree of restorative sleep.
Nonrestorative Sleep
2023, Encyclopedia of Sleep and Circadian Rhythms: Volume 1-6, Second Edition
Nonrestorative sleep (NRS) is a subjective symptom of sleep disturbance that is characterized by complaints of light or unrefreshing sleep. The mechanisms of NRS are not well understood, but many theories regarding its etiology relate to the restorative theory of sleep function. Diagnosis of NRS relies entirely on subjective patient report, as there are very few well-defined physiological markers.
Chronic fatigue syndrome and sleep
2023, Encyclopedia of Sleep and Circadian Rhythms: Volume 1-6, Second Edition
Chronic Fatigue Syndrome (CFS) is a complex multisystem disease characterized by fatigue, cognitive dysfunction, non-restorative sleep, and autonomic dysfunction. 87–95% of patients with CFS report non-restorative sleep. Disrupted quantity and quality of sleep lower pain tolerance and causes extreme fatigue in these patients. Etiology is not well understood, but CFS and sleep disorders seem to have a common pathway. Sleep disorders such as obstructive sleep apnea, restless leg syndrome, and insomnia coexist with CFS. A bidirectional relationship exists between Sleep disorders and CFS, and if left untreated, each can affect and worsen the other. A multidisciplinary approach is required to treat CFS, which also includes a focus on various sleep disorder treatments.
Longitudinal assessment of lifestyle factors associated with nonrestorative sleep in Japan
2023, Sleep Medicine
Citation Excerpt :
NRS is associated with physical health problems such as obesity, sleep disordered breathing, diabetes mellitus, coronary disease, gastroesophageal reflux disease, and allergic rhinitis [2,6–9]. NRS is also strongly linked with mental health disorders, including anxiety, depression, adjustment disorders, and suicide [10–12]. Thus, NRS is regarded not only as a sleep problem but also as an important general health issue.
Nonrestorative sleep (NRS) is common in the general global population. This study surveyed the incident/remission rate of NRS and identified related lifestyle factors in a general Japanese adult cohort.
Data from a Japanese health check–based cohort between the fiscal years 2011 and 2018 were obtained. NRS was assessed through a single item question, and socio-demographic and clinical data were assessed through self-reports. To identify potential correlates of NRS incidence/remission, Cox regression analysis (or survival analysis) was performed.
Among the 135 609 individuals surveyed at baseline, data from 93 548 were considered for analysis. NRS exhibited incidence and remission rates of 11.3% and 15.4%, respectively. New NRS incidence was predicted by eating fast (hazard ratio [HR]: 1.07, 95% confidence interval [CI]: 1.04–1.10), dining close to bedtime (HR: 1.33, 95% CI: 1.27–1.38), midnight snacking (HR: 1.09, 95% CI: 1.04–1.13), skipping breakfast (HR: 1.16, 95% CI: 1.10–1.22), non-regular exercise (HR: 1.12, 95% CI: 1.07–1.17), lower levels of physical activity (HR: 1.19, 95% CI: 1.14–1.24), and slow walking speed (HR: 1.34, 95% CI: 1.29–1.39), while heavy drinking was less predictive of NRS. However, the same factors (except for heavy drinking) were found to predict NRS remission.
We found that unhealthy lifestyle behaviors, particularly dining close to bedtime and slow walking speed, were positively associated with NRS incidence, while they were negatively associated with NRS remission. These results can be useful in developing more effective health promotion policies to achieve good sleep.
A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults
2020, Sleep Medicine
Non-restorative sleep (NRS) affects 10% people worldwide, leading to poor sleep quality, as well as physical and cognitive fatigue. This is the first human study in which an extract of ashwagandha (Withania somnifera Dunal L.) was evaluated for effects in improving overall sleep quality in subjects with NRS.
In this randomized, double-blind, placebo-controlled trial, 150 healthy subjects scoring high on non-restorative sleep measures were given 120 mg of standardized ashwagandha extract (Shoden®) once daily for six weeks. Subjects were evaluated using the Restorative Sleep Questionnaire-weekly version and World Health Organization Quality of Life-Bref (WHOQOL) scale. Sleep actigraphy was used to measure the onset of sleep latency, sleep efficiency, total sleep time and wake after sleep onset. Safety of the treatment was determined by testing of vitals, hematology, biochemistry and urinalysis.
A total of 144 subjects completed the study, with no dropouts due to adverse events. A 72% increase in self-reported sleep quality was found for the treatment group, compared with 29% in the placebo group (p < 0.001). Based on activity monitoring data, the treatment group showed significant improvement in sleep efficiency (SE) (p < 0.01), total sleep time (p < 0.001) and sleep latency (p < 0.01) and wake after sleep onset (WASO) (p < 0.05) versus placebo after six weeks. In the ashwagandha group quality of life (QOL) scores showed significant improvement in physical (p < 0.001), psychological (p < 0.001), and environment domains (p < 0.01).
Supplementation with the standardized ashwagandha extract for six weeks improved the overall quality of sleep by significantly improving the NRS condition in healthy subjects. No treatment related adverse events were reported in the study.
Clinical Trials Registry-India (www.ctri.nic.in). Registration number: CTRI/2017/02/007801.
Nonrestorative sleep in healthy, young adults without insomnia: associations with executive functioning, fatigue, and pre-sleep arousal
2018, Sleep Health
Citation Excerpt :
In addition, perceived daily EF accounted for the association between NRS and pre-sleep arousal, consistent with mediation. Prior studies have found that NRS is associated with reported cognitive difficulties, though the association has often been with single-item concurrent measures.11,32 In the current study, NRS was associated with both perceived daily EF difficulties and performance on a behavioral measure of EF.
Previous research suggests that nonrestorative sleep (NRS), even in the absence of insomnia symptoms or other sleep disorders, may be associated with daytime dysfunction. This study examined the association between NRS and daytime dysfunction in healthy adults screened for insomnia and sleep apnea.
Multi-day assessment approach.
Community-based adults and college students.
Healthy young adults without insomnia and sleep apnea (n = 79; 68% female, mean age = 27.5, SD = 6.5).
Laboratory protocol included a behavioral assessment of executive functioning (EF), self-report of prior month sleep-related daytime dysfunction, and depressive symptoms in the prior two weeks. Subsequently, participants completed an experience sampling assessment that included morning ratings of NRS, repeat affect ratings throughout the day via palm-pilot, nighttime ratings of pre-sleep arousal and EF disturbances, ambulatory cardiac impedence monitoring, and wrist actigraphy.
NRS was significantly associated with poorer performance on behaviorally-assessed EF, perceived EF difficulties, daily ratings of fatigue, and past-month reported daytime dysfunction. These associations remained significant after controlling for age and sleep duration (measured by actigraphy). NRS was also associated with increased sympathetic nervous system activation prior to bedtime. Further, reported pre-sleep arousal was associated with NRS, and this association was mediated by perceived EF difficulties.
Findings indicate that, even among healthy, young adults without insomnia or sleep apnea, NRS is associated with poorer cognitive functioning and may be a precursor to insomnia.

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Original ArticleAssociations of nonrestorative sleep with insomnia, depression, and daytime function

Abstract

Study objectives

Design

Measurement

Participants

Results

Conclusion

Section snippets

Background

Methods

Measures

Analysis

Aim 1: Insomnia related symptoms and sleep quality in those who report NRS compared with those with no NRS symptoms

Discussion

Disclosure of financial interests or relationships

Sleep Med Rev

J Psychiatr Res

Sleep Med

J Psychosom Res

Biol psychiatry

Sleep Medicine Clinics

Sleep Med

Sleep Med

The Stockholm Female Coronary Risk Study. J Psychosom Res

Prevalence and correlates of nonrestorative sleep complaints

Arch Intern Med

Fibromyalgia, sleep disorder and chronic fatigue syndrome

Ciba Found Symp

Original Article
Associations of nonrestorative sleep with insomnia, depression, and daytime function