Subtypes of sleep disturbance: associations among symptoms, comorbidities, treatment, and medical costs

Associations of endurance, muscle strength, and balanced exercise with subjective sleep quality in sedentary workers: A cross-sectional study

BACKGROUND

The optimal exercise combination for improving sleep quality among sedentary workers is unclear.

OBJECTIVE

To reveal what combination of exercises contributes to good sleep quality.

METHODS

In this cross-sectional study, we enrolled 5,201 sedentary workers who underwent health examinations in 2019. Data on sleep quality, basic attributes, energy expenditure, and lifestyle aspects such as exercise and physical activity, supper time close to bedtime, and alcohol intake were obtained. The subjects reported their exercise habits by selecting up to three forms of exercise from a list of 182 options, which were classified into three types: endurance (e.g., jogging), muscle strength (e.g., bench pressing), and balanced types which combined both endurance and muscle strength characteristics. (e.g., walking). These forms were then categorized into eight combination patterns: endurance only; muscle strength only; balanced only; endurance and muscle strength; endurance and balanced; muscle strength and balanced; all types; and absence of any exercise habits. Binary logistic regression analysis was used to examine the associations between the exercise combination patterns and sleep quality.

RESULTS

Good sleep quality was significantly associated with "endurance" (OR = 1.419; 95% CI 1.110-1.814), "balanced only" (OR = 1.474; 95% CI 1.248-1.741), and "endurance and balance" (OR = 1.782; 95% CI 1.085-2.926) exercise patterns. No significant associations were found between the combinations that included muscle strength exercises and sleep quality.

CONCLUSION

The endurance or balanced-type exercises, or a combination of both, may help to improve the sleep quality of sedentary workers as part of occupational health management.

The relationship between sleep health and multimorbidity in community dwelling populations: Systematic review and global perspectives

Previous research has identified a relationship between sleep problems and multimorbidity, defined as the co-occurrence of two or more chronic health conditions in the same individual. This systematic review sought to summarize the literature on the association between sleep duration and quality and multimorbidity in adult community-dwelling populations. A comprehensive search of the PubMed, Embase and CINAHL databases identified studies published between January 1990 and January 2023. Studies were included if they focused on community-dwelling populations, used an observational design, measured sleep quality or duration, used multimorbidity as the main study outcome, and explored the relationship between sleep and multimorbidity. Two reviewers independently conducted study screening, data extraction, and bias assessments. Twenty-four cross-sectional and five prospective cohort studies met the inclusion criteria, with studies from 16 countries and two with cross-country comparisons, and a total participant number of 481,862. Overall, poorer sleep quality and sleep duration outside current recommendations were consistently associated with multimorbidity, though with varying strength. This association was present regardless of specific multimorbidity definitions from different studies. Definitions of sleep duration and quality were inconsistent across studies, possibly contributing to mixed evidence on the observed association. Most studies were cross-sectional, limiting the assessment of the temporal direction of association. Our results corroborate relationships between poor sleep and risk of multimorbidity in adult community-dwelling populations around the world. Examining this relationship may help increase public health awareness of sleep as a modifiable risk factor for the prevention of chronic disease and healthy aging.

The sleep patterns and their associations with mental health among nursing home residents: a latent profile approach

BACKGROUND

Nursing home residents commonly experience poor sleep conditions. However, few studies have explored the potential sleep patterns among nursing home residents. This study aimed to identify the sleep patterns in nursing home residents, compare residents' characteristics across sleep patterns, and examine the relationships between sleep patterns and residents' mental health (i.e., depressive and anxiety symptoms).

METHODS

This cross-sectional study was conducted in 27 nursing homes in Jinan, China, from March to June 2018. In total, 353 participants were recruited via convenience sampling, and of which, 326 completed the survey. A latent profile analysis was performed to identify sleep patterns based on the seven dimensions of the Pittsburgh Sleep Quality Index. Bivariate analyses were conducted to compare residents' characteristics among the sleep patterns. Mixed-effects logistic regression analyses were adopted to investigate the relationships between sleep patterns and residents' mental health.

RESULTS

Three sleep patterns were identified, including 'good sleepers', 'poor sleepers without hypnotic use', and 'poor sleepers with hypnotic use'. Residents' gender, education, pain, instrumental activities of daily living, and number of chronic conditions were significantly differentiated across the sleep patterns. Compared with 'good sleepers', 'poor sleepers without hypnotic use' were significantly associated with more depressive symptoms (OR = 3.73, 95% CI = 2.09, 6.65, p < 0.001), but not with anxiety symptoms (OR = 2.04, 95% CI = 0.97, 4.29, p = 0.062); whereas 'poor sleepers with hypnotic use' had significantly more depressive (OR = 5.24, 95% CI = 2.54, 10.79, p < 0.001) and anxiety symptoms (OR = 5.02, 95% CI = 2.13, 11.83, p < 0.001).

CONCLUSIONS

This study reveals three distinct sleep patterns in nursing home residents and their significant associations with residents' mental health. These findings can inform future research to develop appropriate and tailored intervention strategies for improving sleep and promoting mental health for nursing home residents.

Cross-Sectional and Longitudinal Associations between Subjective Sleep Difficulties and Self-Perceptions of Aging

BACKGROUND

Only one study has explored the associations of subjective sleep difficulties with self-perceptions of aging. It focused on a global indicator of self-perceptions of aging (subjective age) despite individuals reporting different experiences of aging in relation to different life domains. The concept of awareness of negative age-related change, capturing perceived losses across five domains (e.g., physical health, cognition), may be more appropriate when relating subjective sleep difficulties to self-perceptions of aging. We examined whether nine different indicators of subjective sleep difficulties predict levels of awareness of negative age-related change and subjective age, measured concurrently and one year later, while controlling for covariates (mood and daily function).

PARTICIPANTS/METHODS

We used data from the PROTECT cohort study; 4,482 UK residents (mean age = 66.1; SD = 6.9) completed measures of awareness of age-related change, subjective age, mood, daily function, and subjective sleep difficulties.

RESULTS

Based on linear regression analyses, poorer quality of sleep, lower alertness after awakening, satisfaction with sleep, depth of sleep, more frequent early awakening, difficulty falling asleep, more times awake during a night, fewer hours of sleep during the night and more hours of sleep during the day predicted higher awareness of negative age-related change at baseline and follow-up (p< .001). Associations were small in size. Associations between subjective sleep difficulties and subjective age were either negligible or statistically non-significant.

CONCLUSIONS

Although subjective sleep difficulties are one of the many factors associated with awareness of negative age-related change, addressing sleep difficulties, alongside negative mood, and poor daily functioning, may promote a small additional increase in positive self-perceptions of aging.

Sleep Quality and Insomnia Severity among Italian University Students: A Latent Profile Analysis

Insomnia is a widespread sleep disorder associated with physical and mental health conditions. Although the heterogeneity of insomnia presentations has been acknowledged, research investigating clinically meaningful insomnia subtypes is still ongoing. This study aimed at exploring insomnia subtypes according to widely-used measures of symptoms severity and sleep quality among Italian university students using a latent profile analysis. Data were collected from 490 students reporting relevant insomnia symptoms through an online cross-sectional survey comprising the Insomnia Severity Index, the Pittsburgh Sleep Quality Index, the 21-item Depression Anxiety Stress Scale, and the Short Form-12. Latent profile analysis identified five insomnia subtypes. The severe insomnia (8.8%) group showed the highest insomnia severity, with diverse complaints concerning sleep quality and daytime functioning. Moderate insomnia with sleep duration complaints (8.4%) and moderate insomnia with medication use (15.9%) subgroups were characterized by middle range insomnia severity, with problems of sleep continuity and sleep medication use, respectively. Subthreshold insomnia with sleep latency complaints (20.4%) and subthreshold insomnia (46.5%) groups showed attenuated insomnia symptoms. Higher psychological complaints and worse quality of life were associated with greater sleep complaints. Overall, these findings highlight the relevance of sleep quality domains in identifying insomnia subtypes and might help optimize insomnia treatments.

Depressive and stress symptoms in insomnia patients predict group cognitive-behavioral therapy for insomnia long-term effectiveness: A data-driven analysis

BACKGROUND

Insomnia Disorder is characterized by high degree of phenotypic heterogeneity, that might influence treatment response.

METHODS

123 of 294 insomnia patients initially recruited (66.7% females, age=40.59±11.89) were assessed before and after group Cognitive-Behavioral Therapy for Insomnia (CBT-I), as well as at follow-up (7.8±1.6 years after the end-of-treatment). By use of latent class analysis (LCA) we identified insomnia subtypes according with baseline scores of insomnia severity and features, anxiety, depression, stress and sleepiness symptoms, circadian rhythm, and treatment effectiveness (Delta score of Insomnia Severity Index-ISI between baseline and end-of-treatment).

RESULTS

By LCA we revealed three classes: "PURE INSOMNIA", "INSOMNIA+ANXIETY+DEPRESSION+STRESS", and "INSOMNIA+ANXIETY". The improvements in insomnia severity was maintained up to 10 years after the end-of-treatment, but with differences between classes (p<0.05). Class "INSOMNIA+ANXIETY+DEPRESSION+STRESS" showed at the end-of-treatment the largest percentage of responders (63.5% = Insomnia Severity Index decrease ≥8). However, at follow up the effect was less and 48.1% had a moderate or severe insomnia (Insomnia Severity Index >14).

LIMITATIONS

The lack of a control group and the absence of a complete clinical assessment at the follow-up limit the interpretability of our results.

CONCLUSIONS

Our data driven analysis suggest insomnia heterogeneity can be categorized into sub-classes by depression, anxiety, and stress symptoms. In addition, insomnia patients with stress and depression symptoms maintained highest percentage of clinical depression at the end-of-treatment and insomnia at follow-up, in comparison with others classes. Stress and depression symptoms should be considered risk factors that play an important role in the long-term outcome of CBT-I.

Insomnia Disorders: Nosology and Classification Past, Present, and Future

Insomnia is the most common sleep disorder in the adult population. However, the definition of insomnia disorder has varied across major classification systems and changed over time. In the present study, the investigators traced the evolution of insomnia disorder across classification systems, contemplated the empirical basis for its current definitions, and surveyed ongoing research efforts that may clarify insomnia nosology in the future. Three major classification systems for insomnia are the International Classification of Sleep Disorders, the International Classification of Diseases, and DSM. Despite their divergent origins, these classification systems have converged to nearly identical contemporary insomnia definitions. Over time, the emphasis in classification approaches has shifted from symptomatology to etiology to treatment implications. Additionally, the historical multitude of insomnia subtypes has gradually consolidated into a few core diagnoses, reflecting inadequate evidence with which to support subtyping. Current insomnia definitions include frequency and duration criteria to operationalize these diagnoses, while the diagnostic criterion of nonrestorative sleep has been eliminated (with some controversy). In ongoing research efforts, the quest for insomnia biomarkers has not thus far yielded clinically deployable breakthroughs. Data-driven insomnia subtyping suggests a promising new approach in deriving empirically based subtypes; conversely, the transdiagnostic perspective proposes the elimination of categorical distinctions in favor of finding common processes underlying all psychiatric disorders. The continual evolution of insomnia nosology highlights that much remains to be learned about these conditions; all current diagnostic classification systems are best regarded as "works in progress." Nevertheless, refinement and convergence of classification approaches is essential to standardizing insomnia research, diagnosis, and treatment.

Are lifestyle pattern changes associated to poor subjective sleep quality?: a cross-sectional study by gender among the general Japanese population underwent specified medical check-ups in 2014 and 2015

OBJECTIVES

Subjective sleep quality (SSQ) is defined by the satisfaction of one's overall sleep experience and is composed of sleep depth and restfulness. It has not been clarified how poor SSQ is associated to changes in lifestyles. The purpose is to reveal the association of lifestyle pattern changes and poor SSQ.

DESIGN

A cross-sectional study.

SETTING

The data on basic attributes, SSQ and lifestyle such as presence/absence of smoking, exercise, physical activity, supper time close to bedtime, drinking habits and alcohol intake amount per day were obtained from database and questionnaire of specified medical check-ups in fiscal year 2014-2015 in Japan. The analysis was conducted in 2019.

PARTICIPANTS

The subjects comprised 49 483 residents (26 087 men and 23 396 women), aged 40-74 years who had undergone an annual specified medical check-up from 2014 to 2015 in Fukushima Prefecture, Japan.

OUTCOME MEASURE

Status of SSQ in 2015 was assessed using a question asking whether or not the subjects usually got enough sleep. Poor SSQ in 2015 and lifestyle pattern changes in 2014-2015 were compared between those who were in healthy status both in 2014 and 2015 (referent) and non-referent, using binary logistic regression analysis.

RESULTS

Unhealthy lifestyle pattern for 2014-2015 was significantly associated to poor SSQ in 2015: 'absent to absent' in exercise for men (OR=1.472; 95% CI 1.316 to 1.647) and women (OR=1.428; 95% CI 1.285 to 1.587), physical activity for men (OR=1.420; 95% CI 1.270 to 1.588) and women (OR=1.471; 95% CI 1.322 to 1.638) and 'present to present' in supper time for men (OR=1.149; 95% CI 1.020 to 1.294) and women (OR=1.288; 95% CI 1.102 to 1.505).

CONCLUSIONS

Healthcare workers may be able to contribute to the improvement of SSQ, focusing on changeable lifestyles.

Subgrouping Poor Sleep Quality in Community-Dwelling Older Adults with Latent Class Analysis - The Yilan Study, Taiwan

The manifestation of older adults with poor sleep quality is heterogeneous. Using data-driven classifying methods, the study aims to subgroup community-dwelling older adults with poor sleep quality. Adults aged 65 and older participated in the Yilan study. Poor sleep quality was defined using the Pittsburgh Sleep Quality Index. Latent class analysis with the 7 subscores of the Pittsburgh Sleep Quality Index as the indicators was used to generate empirical subgroups. Differences in comorbidity patterns between subgroups were compared. A total of 2622 individuals, of which 1011 (38.6%) had Pittsburgh Sleep Quality Index -defined poor sleep quality, participated. Three groups for poor sleep quality were specified in the latent class analysis: High Insomnia (n = 191, 7.3%), Mild Insomnia (n = 574, 21.9%), and High Hypnotics (n = 246, 9.4%). The High Insomnia and Mild Insomnia groups shared similar profiles but different severities in the 7 domains of the Pittsburgh Sleep Quality Index. In contrast, the High Hypnotics group had the lowest Pittsburgh Sleep Quality Index total scores and insomnia severity but had similar mental and physical comorbid patterns as the High Insomnia group. This finding suggests that poor sleep quality in community-dwelling older adults had various feature-based subgroups. It also implicates the development of group-centered interventions.

Heightened sleep propensity: a novel and high-risk sleep health phenotype in older adults

OBJECTIVES

To reveal sleep health phenotypes in older adults and examine their associations with time to 5-year all-cause and cardiovascular mortality.

DESIGN

Prospective longitudinal cohorts.

SETTING

The Study of Osteoporotic Fractures and Outcomes of Sleep Disorders in Older Men Study.

PARTICIPANTS

N = 1722 men and women aged ≥65 years matched 1:1 on sociodemographic and clinical measures.

MEASUREMENTS

Self-reported habitual sleep health characteristics (satisfaction, daytime sleepiness, timing, efficiency, and duration) measured at an initial visit and longitudinal follow-up for mortality.

RESULTS

Latent class analysis revealed 3 sleep health phenotypes: (1) heightened sleep propensity (HSP; medium to long duration, high sleepiness, high efficiency/satisfaction; n = 322), (2) average sleep (AS; medium duration, average efficiency, high satisfaction, low sleepiness; n = 1,109), and (3) insomnia with short sleep (ISS; short to medium duration, low efficiency/satisfaction, moderate sleepiness; n = 291). Phenotype predicted time to all-cause mortality (χ2 = 9.4, P = .01), with HSP conferring greater risk than AS (hazard ratio [95% confidence interval] = 1.48 [1.15-1.92]) or ISS (1.52 [1.07-2.17]), despite ISS reporting the poorest mental and physical health. Although sex did not formally moderate the relationship between phenotype and mortality, subgroup analyses indicated that these findings were driven primarily by women. Phenotype did not predict cardiovascular mortality.

CONCLUSIONS

These analyses support the utility of examining multidimensional sleep health profiles by suggesting that the combination of long sleep, high efficiency/satisfaction, and daytime sleepiness-previously identified as independent risk factors-may be components of a single high-risk sleep phenotype, HSP. Further investigation of sex differences and the mechanisms underlying mortality risk associated with HSP is warranted.

Insomnia-related Memory Impairment in Individuals With Very Complex Chronic Pain

OBJECTIVE

To investigate the specific effect of insomnia on neuropsychological functioning in patients with very complex chronic pain.

BACKGROUND

Individuals with insomnia disorder or chronic pain often experience cognitive deficits, with both conditions appearing to correlate with impairments in neuropsychological functions. As insomnia often occurs comorbid with chronic pain, distinguishing the differential effects of these two syndromes on an individual's neuropsychological functioning can be challenging. Comorbid depressive symptoms in these individuals, which may also affect cognitive function, may further obscure the associations between chronic pain, insomnia, and the neuropsychological profile.

METHODS

The neuropsychological function of 22 individuals with very complex chronic pain was assessed using specialized tests examining aspects of memory and executive functioning. The severity of insomnia, depression, and anxiety was measured using questionnaires, and pain levels were assessed using a visual analog scale. Pain medications were transformed to the morphine-equivalent daily dose.

RESULTS

Insomnia severity was found to predict memory function, accounting for 32.4% of the variance: A 1 SD increase in insomnia severity decreased memory function by 0.57 SD. The negative correlation between insomnia and memory was significant even after controlling for pain level, morphine-equivalent daily dose, and comorbid levels of anxiety and depression.

CONCLUSIONS

Insomnia severity independently predicted memory function in patients with very complex chronic pain, even after controlling for other factors known to impair cognitive function. Insomnia may possibly explain some of the cognitive impairments related to chronic pain; thus, screening for, and treating, sleep disturbances may be a central aspect of chronic pain rehabilitation.

Gender and Age Differences in Sleep Problems in Children: Person-Oriented Approach With Multigroup Analysis

OBJECTIVE/BACKGROUND

This study aimed to identify subtypes of sleep problems in children and to examine whether these patterns differed between gender and age groups.

PARTICIPANTS

There were 3,052 children (951 elementary school boys, 943 elementary school girls, 603 junior high school boys, and 555 junior high school girls) aged 7-16 years from two school-based epidemiological samples.

METHODS

Sleep problems were measured by the Sleep Habit Questionnaire based on parent reports.

RESULTS

Using the latent class modeling, a person-oriented approach, with a multigroup analysis, we identified four classes of sleep problems: moderate to high sleep problems (1.1%-3.1%), sleep-related breathing problems and parasomnias dominant (14.9%-21.1%), insomnias dominant and parasomnias (1.0%-3.1%), and no or low sleep problems (74.7%-81.4%), with varied prevalence rates of sleep problems across gender and age groups.

CONCLUSIONS

This study identified four classes of sleep problems across gender and age groups but with different prevalence rates of sleep problems, suggesting the complex interaction of gender and age in the subtypes of sleep problems. The gender- and age-specific interventions for sleep problems are suggested. Future studies are warranted to replicate these classes and to identify associated factors with each class.

Impact Of Phenotypic Heterogeneity Of Insomnia On The Patients' Response To Cognitive-Behavioral Therapy For Insomnia: Current Perspectives

Insomnia is one of the most common mental disorders and the most frequent sleep disorder encountered in clinical practice, with a prevalence of about 7% in the European population. Insomnia Disorder (ID) is defined as a disturbance of sleep initiation or maintenance, followed by a feeling of non-restorative sleep and several diurnal consequences ranging from occupational and social difficulties to cognitive impairment. Cognitive-Behavioral Therapy for Insomnia (CBT-I) is considered the first-choice therapy for this disorder because its effectiveness has been proven to be greater in the long term with fewer side effects in comparison to pharmacotherapy. Although its effectiveness has been well established, it has been reported that nearly 40% of patients do not achieve remission after treatment. This finding could be the consequence of heterogeneity of ID between patients. It has been proposed that this heterogeneity might be ascribable to indices that are not related to sleep quality and quantity, such as comorbidities, life events, and personality traits. However, several works focused on the role of sleep markers, in particular objective total sleep time, for the phenotypization of ID and treatment response. The aim of this work is to summarize the available scientific literature regarding the impact of ID subtype on CBT-I response.

Anxiety sensitivity and sleep disturbance: Investigating associations among patients with co-occurring anxiety and substance use disorders

Sleep disturbance is a common problem among individuals with anxiety and substance use disorders (SUD). Anxiety sensitivity (AS) is elevated in patients with anxiety disorders and SUD and has been linked to sleep-related problems, including insomnia and somnolence (i.e., daytime sleepiness). We examined the unique roles of AS cognitive, physical, and social concerns in sleep disturbance among a sample of 99 residential SUD patients with anxiety disorders. Clinical levels of insomnia or somnolence were evidenced by 53.5% of the sample. Consistent with predictions, AS physical concerns was significantly associated with insomnia, and AS cognitive concerns was significantly related to insomnia and somnolence. Hierarchical linear regression models were conducted to test the association of AS cognitive and physical concerns with insomnia and somnolence symptoms while controlling for relevant factors. AS cognitive concerns accounted for unique variance, above and beyond withdrawal symptoms, anxiety, and depressive symptoms, in the model examining insomnia symptoms (B=0.30, SE=0.13, p=0.023). Results suggest that AS cognitive concerns may represent an important transdiagnostic mechanism underlying sleep disturbance among individuals with dual diagnosis.

Characterization of Patients Who Present With Insomnia: Is There Room for a Symptom Cluster-Based Approach?

STUDY OBJECTIVES

This study examined empirically derived symptom cluster profiles among patients who present with insomnia using clinical data and polysomnography.

METHODS

Latent profile analysis was used to identify symptom cluster profiles of 175 individuals (63% female) with insomnia disorder based on total scores on validated self-report instruments of daytime and nighttime symptoms (Insomnia Severity Index, Glasgow Sleep Effort Scale, Fatigue Severity Scale, Beliefs and Attitudes about Sleep, Epworth Sleepiness Scale, Pre-Sleep Arousal Scale), mean values from a 7-day sleep diary (sleep onset latency, wake after sleep onset, and sleep efficiency), and total sleep time derived from an in-laboratory PSG.

RESULTS

The best-fitting model had three symptom cluster profiles: "High Subjective Wakefulness" (HSW), "Mild Insomnia" (MI) and "Insomnia-Related Distress" (IRD). The HSW symptom cluster profile (26.3% of the sample) reported high wake after sleep onset, high sleep onset latency, and low sleep efficiency. Despite relatively comparable PSG-derived total sleep time, they reported greater levels of daytime sleepiness. The MI symptom cluster profile (45.1%) reported the least disturbance in the sleep diary and questionnaires and had the highest sleep efficiency. The IRD symptom cluster profile (28.6%) reported the highest mean scores on the insomnia-related distress measures (eg, sleep effort and arousal) and waking correlates (fatigue). Covariates associated with symptom cluster membership were older age for the HSW profile, greater obstructive sleep apnea severity for the MI profile, and, when adjusting for obstructive sleep apnea severity, being overweight/obese for the IRD profile.

CONCLUSIONS

The heterogeneous nature of insomnia disorder is captured by this data-driven approach to identify symptom cluster profiles. The adaptation of a symptom cluster-based approach could guide tailored patient-centered management of patients presenting with insomnia, and enhance patient care.

Fighting insomnia and battling lethargy: the yin and yang of palliative care

There is an interdependent relationship between insomnia and fatigue in the medical literature, but both remain distinct entities. Insomnia entails problematic sleep initiation, maintenance, or restoration with an accompanying decrease in perceived daytime function. Lethargy is a symptom that has a wide differential diagnosis that heavily overlaps with cancer-related fatigue; however, insomnia may contribute to worsened fatigue and lethargy in cancer patients. Insomnia is a major risk factor for mood disturbances such as depression, which may also contribute to lethargy in this at-risk population. The pathophysiology of fatigue and insomnia is discussed in this review, including their differential diagnoses as well as the emerging understanding of the roles of neurotransmitters, branched-chain amino acids, and inflammatory cytokines. Treatment approaches for insomnia and fatigue are also discussed and reviewed, including the role of hypnotics, psychotropics, hormonal agents, and alternative therapies.

Sleep complaints and incident disability in a community-based cohort study of older persons

OBJECTIVE

Sleep complaints are associated with adverse health consequences. We hypothesized that non-disabled older persons with more sleep complaints have an increased risk of developing disability.

METHODS

Subjects included 908 older clergy participating in the Religious Order Study without clinical dementia, history of stroke, or Parkinson disease. At baseline, participants rated their difficulty falling asleep, frequency of nocturnal awakenings, sleep efficacy, and napping frequency, from which a summary dyssomnia measure was derived. Self-report assessment of disability included instrumental activities of daily living (IADLs), basic activities of daily living (ADLs), and Rosow-Breslau mobility disability at baseline and at annual evaluations.

RESULTS

Mean follow-up was 9.6 (SD: 4.2) years. At baseline, more than 60% had one or more sleep complaints. In a series of Cox proportional hazards models controlling for age, sex, and education, a one-point higher dyssomnia score at baseline was associated with about 20% increased risk of IADL disability (hazard ratio: 1.20; 95% confidence interval [CI]: 1.04-1.39; χ(2)1 = 7.62; p <0.05), about 27% increased risk of ADL disability (hazard ratio: 1.27; 95% CI: 1.10-1.47; χ(2)1 = 12.15; p <0.01), and about 27% increased risk of mobility disability (hazard ratio: 1.27; 95% CI: 1.09-1.48; χ(2)1 = 11.04; p <0.01). These associations did not vary by age, sex, or education and remained significant after controlling for potential confounders including body mass index, chronic medical conditions, and several common medications. Controlling for depressive symptoms attenuated the association between sleep complaints and incident IADL and ADL disabilities but the association between sleep complaints and incident mobility disability remained significant.

CONCLUSION

Non-disabled older adults with more sleep complaints have an increased risk of developing disability.

Subtypes of sleep problems in patients with Alzheimer disease

OBJECTIVE

Sleep disturbances are common in patients with Alzheimer disease (AD) and can contribute to cognitive dysfunction and a negative impact on patients' and caregivers' quality of life. The purpose of this study was to evaluate whether subtypes of sleep disturbance could be identified in patients with AD and to assess the relation of these subtypes to patient characteristics and caregiver mood.

METHODS

As part of routine clinical assessment, primary caregivers of 344 patients with AD completed a questionnaire that included five items about the patients' sleep. Patients' cognitive and functional status and their mood were assessed as was caregivers' mood. Latent class analysis was used to define subgroups of patients based on their sleep patterns. After identification of groups of sleep disturbance, the relation of group membership to patient and caregiver characteristics was also evaluated.

RESULTS

Analyses revealed groups with moderate and severe sleep problems as well as a group without problems. Patients with more severe sleep disturbance were older, less well educated, and had poorer cognitive and functional status. Caregiver and patient depression was related to membership in the severe group, suggesting that both may contribute to caregivers' ratings of more severe sleep disturbance, whereas only patient depression was related to membership in the moderate group.

CONCLUSION

Sleep problems in patients with AD are related to poorer cognitive and functional status and patient and caregiver depression. Caregiver depression was most closely related to more severe patient sleep disturbance.

Associations between cytokine gene variations and self-reported sleep disturbance in women following breast cancer surgery

PURPOSE OF THE RESEARCH

To attempt to replicate the associations found in our previous study of patients and family caregivers between interleukin 6 (IL6) and nuclear factor kappa beta 2 (NFKB2) and sleep disturbance and to identify additional genetic associations in a larger sample of patients with breast cancer.

METHODS AND SAMPLE

Patients with breast cancer (n = 398) were recruited prior to surgery and followed for six months. Patients completed a self-report measure of sleep disturbance and provided a blood sample for genomic analyses. Growth mixture modeling was used to identify distinct latent classes of patients with higher and lower levels of sleep disturbance.

KEY RESULTS

Patients who were younger and who had higher comorbidity and lower functional status were more likely to be in the high sustained sleep disturbance class. Variations in three cytokine genes (i.e., IL1 receptor 2 (IL1R2), IL13, NFKB2) predicted latent class membership.

CONCLUSIONS

Polymorphisms in cytokine genes may partially explain inter-individual variability in sleep disturbance. Determination of high risk phenotypes and associated molecular markers may allow for earlier identification of patients at higher risk for developing sleep disturbance and lead to the development of more targeted clinical interventions.

Patterns of sleep quality during and after postacute rehabilitation in older adults: a latent class analysis approach

Sleep quality is related to emotional, physical, psychological and cognitive functioning and functional independence in later life. After acute health events, older adults are likely to utilize postacute rehabilitation services to improve functioning and facilitate return to independent living. Patterns of how sleep changes with postacute rehabilitation, and predictors of such patterns, are unknown. The current investigation employed latent class analysis (LCA) methods to classify older adults (n = 233) into groups based on patterns of self-reported sleep quality pre-illness, during postacute rehabilitation and up to 1 year following postacute rehabilitation. Using LCA, older adults were grouped into (1) consistently good sleepers (46%), (2) good sleepers who transitioned into poor sleepers (34%), (3) consistently poor sleepers (14%) and (4) poor sleepers who transitioned into good sleepers (6%). In three planned analyses, pain was an independent predictor of membership in classes 1 or 2 (good pre-illness sleep quality) versus classes 3 or 4 (poor pre-illness sleep quality), and of membership in class 1 (consistently good sleep) versus class 2 (good sleep that transitioned to poor sleep). A lower Mini-Mental State Examination score was a predictor of membership in class 1 versus class 2. There were no statistically significant predictors of membership in class 3 versus class 4. Demographics, comorbidities and depressive symptoms were not significant predictors of class membership. These findings have implications for identification of older adults at risk for developing poor sleep associated with changes in health and postacute rehabilitation. The findings also suggest that pain symptoms should be targeted to improve sleep during postacute rehabilitation.

Identification of distinct subgroups of breast cancer patients based on self-reported changes in sleep disturbance

PURPOSE

The purposes of this study were to identify distinct subgroups of patients based on self-reported sleep disturbance prior to through 6 months after breast cancer surgery and evaluate for differences in demographic, clinical, and symptom characteristics among these latent classes.

METHODS

Women (n = 398) who underwent unilateral breast cancer surgery were enrolled prior to surgery. Patients completed measures of functional status, sleep disturbance (i.e., General Sleep Disturbance Scale (GSDS); higher scores indicate higher levels of sleep disturbance), fatigue, attentional fatigue, depressive symptoms, and anxiety prior to surgery and monthly for 6 months.

RESULTS

Three distinct classes of sleep disturbance trajectories were identified using growth mixture modeling. The high sustained class (55.0%) had high and the low sustained class (39.7%) had low GSDS scores prior to surgery that persisted for 6 months. The decreasing class (5.3%) had high GSDS score prior to surgery that decreased over time. Women in the high sustained class were significantly younger, had more comorbidity and poorer function, and were more likely to report hot flashes compared to the low sustained class. More women who underwent mastectomy or breast reconstruction were in the decreasing class. Decreasing and high sustained classes reported higher levels of physical fatigue, attentional fatigue, depressive symptoms, and anxiety compared to the low sustained class.

CONCLUSIONS

A high percentage of women has significant sleep disturbance prior to surgery that persists during subsequent treatments (i.e., radiation therapy and chemotherapy). Clinicians need to perform routine assessments and initiate appropriate interventions to improve sleep prior to and following surgery.

Evidence of associations between cytokine genes and subjective reports of sleep disturbance in oncology patients and their family caregivers

The purposes of this study were to identify distinct latent classes of individuals based on subjective reports of sleep disturbance; to examine differences in demographic, clinical, and symptom characteristics between the latent classes; and to evaluate for variations in pro- and anti-inflammatory cytokine genes between the latent classes. Among 167 oncology outpatients with breast, prostate, lung, or brain cancer and 85 of their FCs, growth mixture modeling (GMM) was used to identify latent classes of individuals based on General Sleep Disturbance Scale (GSDS) obtained prior to, during, and for four months following completion of radiation therapy. Single nucleotide polymorphisms (SNPs) and haplotypes in candidate cytokine genes were interrogated for differences between the two latent classes. Multiple logistic regression was used to assess the effect of phenotypic and genotypic characteristics on GSDS group membership. Two latent classes were identified: lower sleep disturbance (88.5%) and higher sleep disturbance (11.5%). Participants who were younger and had a lower Karnofsky Performance status score were more likely to be in the higher sleep disturbance class. Variation in two cytokine genes (i.e., IL6, NFKB) predicted latent class membership. Evidence was found for latent classes with distinct sleep disturbance trajectories. Unique genetic markers in cytokine genes may partially explain the interindividual heterogeneity characterizing these trajectories.

The longitudinal course of insomnia symptoms: inequalities by sex and occupational class among two different age cohorts followed for 20 years in the west of Scotland

STUDY OBJECTIVES

The natural history of insomnia symptomatology is poorly understood. Cross-sectional associations have been demonstrated among socioeconomic disadvantage, female sex, and poor sleep but it is unclear how these social factors predict patterns of insomnia symptoms over time. The aim of this article is to describe longitudinal patterns of insomnia symptoms as people age and investigate how they vary by sex and occupational class.

DESIGN

A prospective cohort study with 20 yr of follow-up from 1987 to 1988.

SETTING

West of Scotland.

PARTICIPANTS

One cohort approximately 36 yr of age at baseline aging to 57 yr (n = 1,444), and another aging from approximately 56 to 76 yr (n = 1,551).

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

At approximately 5-yr intervals, respondents self-reported trouble initiating and maintaining sleep. Latent class analysis identified 4 main sleep patterns: a healthy pattern with little sleeping trouble across the 20 yr; an episodic pattern, characterized by trouble maintaining sleep; a chronic pattern with trouble maintaining and initiating sleep throughout the study; and a pattern where symptoms developed during the 20-yr follow-up. Chronic patterns were more likely in the older cohort than the younger one, for women than men in the older cohort, and for those from a manual rather than a nonmanual occupational class in both cohorts. In the middle-aged cohort a developing pattern was more likely for women than men.

CONCLUSIONS

Chronic symptoms, characterized by both trouble maintaining and initiating sleep, are patterned by social factors.

Sleep America: managing the crisis of adult chronic insomnia and associated conditions

INTRODUCTION

Chronic insomnia, a public health crisis affecting 10-15% of the U.S. population and costing billions of dollars annually, typically presents with one or more comorbid psychiatric or organic conditions. Historical classification of chronic insomnia as "secondary" to a presenting comorbid condition has resulted in under-recognition and under-treatment of both the insomnia and comorbid condition(s). Though critical in any model of comorbid disease management, chronic insomnia receives little, if any, public policy attention.

METHOD

We conducted a systematic review of recent empirical studies, review papers, books, government documents, press releases, advertisements, and articles pertaining to the classification, epidemiology, treatment, and physiology of sleep, insomnia, and comorbid conditions. Data were located primarily through MEDLINE, PsycINFO, SCOPUS, and PUBMED databases.

OBJECTIVE AND RESULTS

Our goal was to provide an overview of the systems for classifying insomnia and available epidemiological data, and to review theoretical models regarding the etiology and maintaining factors of chronic insomnia along with research on the complex, bidirectional associations between chronic insomnia and various affective (and other) conditions.

CONCLUSIONS

After thorough review of the literature, we propose several public policy measures as an initial step in managing chronic insomnia in the United States. These include introducing a nation-wide multi-modal educational and awareness campaign titled "Sleep America;" increasing the availability and demand for behavioral sleep medicine - the initially preferred treatment approach; and increasing the use of monitoring and enforcement activities by regulatory authorities to curtail false and misleading claims by sponsors of supplements or treatments for insomnia. Through the adoption of such measures, we hope to galvanize a national interest in healthy sleep and the evidence-based treatment of chronic insomnia.

Sentra PM (a Medical Food) and Trazodone in the Management of Sleep Disorders

Sleep disorders are a common and poorly treated disease state. This double blind, four arm placebo-controlled, randomized trial compared (1) low dose trazodone, (2) Sentra PM, a neurotransmitter based medical food, (3) the joint administration of trazodone and the medical food Sentra PM and (4) placebo. There were 111 subjects studied in 12 independent sites. Subjects underwent baseline screening, informed consent and an initial sleep questionnaire. After 14 days subjects underwent a second evaluation by questionnaire. At baseline and Day 14 the subjects underwent 24 hour ECG recordings that were analyzed in the frequency domain of heart rate variability. The specific high frequency parasympathetic autonomic nervous system activity was analyzed. The primary endpoints were sleep latency and parasympathetic autonomic nervous system improvement in sleeping hours. The results showed improvement in sleep latency for the Sentra PM and combination of Sentra PM and trazodone (−41 and −56 minutes P < 0.001). There was an improvement in quality of sleep for the amino acid formulation Sentra PM and the combination (3.86 and 6.48 Likert units on a 10 point scale P < 0.001). There was an activation of circadian activity percent at night in the medical food and combination groups while there was no change in parasympathetic activity in either the placebo or trazodone group. These data indicate that Sentra PM can improve the quality of sleep, the response to trazodone as a sleep medication and parasympathetic autonomic nervous system activity.

Cognitions and Insomnia Subgroups

PURPOSE

This study explored cognitive predictors of multiple symptoms of insomnia (difficulty with sleep initiation, maintenance, and early morning awakenings) among a sample of individuals seeking cognitive-behavior therapy for insomnia.

METHODS

Participants consisted of 146 clinical patients with insomnia of which 67 (45.89%) were classified as Single Symptoms subgroup and 79 (54.11%) as Combined subgroup. A receiver operating curve (ROC) analysis was conducted to identify predictors of Combined versus Single Symptom subgroups. The set of predictor variables included demographics, sleep-related cognitions, circadian preferences, depression symptoms, and self-report sleep parameters with insomnia subgroups (Combined versus Single Symptom only) as the dependent variable.

RESULTS

The ROC analysis identified two significant predictors: Self Efficacy Scale (SES) < 23 and a 3-item subscale of the Glasgow Content of Thoughts Inventory (GCTI) assessing "thoughts about the environment" with scores ≥ 5. Post-hoc comparisons revealed that individuals with combined symptoms who had SES score < 23 had significantly longer sleep onset latency (SOL) and more number of nights with SOL>30 minutes, poorer sleep quality, higher insomnia severity, less morningness tendency, higher depression symptom severity, and more anxiety about anxiety and about sleep compared to individuals with SES score ≥ 23.

CONCLUSIONS

These findings indicate that low self-efficacy and increased thoughts about the environment are associated with having multiple symptoms of insomnia. Further research should examine the specific role of self-efficacy and thought content in the etiology of individuals who suffer from multiple symptoms of insomnia.

Nighttime insomnia symptoms and perceived health in the America Insomnia Survey (AIS)

STUDY OBJECTIVES

To explore the distribution of the 4 cardinal nighttime symptoms of insomnia-difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), and nonrestorative sleep (NRS)-in a national sample of health plan members and the associations of these nighttime symptoms with sociodemographics, comorbidity, and perceived health.

DESIGN/SETTING/PARTICIPANTS

Cross-sectional telephone survey of 6,791 adult respondents.

INTERVENTION

None.

MEASUREMENTS/RESULTS

Current insomnia was assessed using the Brief Insomnia Questionnaire (BIQ)-a fully structured validated scale generating diagnoses of insomnia using DSM-IV-TR, ICD-10, and RDC/ICSD-2 inclusion criteria. DMS (61.0%) and EMA (52.2%) were more prevalent than DIS (37.7%) and NRS (25.2%) among respondents with insomnia. Sociodemographic correlates varied significantly across the 4 symptoms. All 4 nighttime symptoms were significantly related to a wide range of comorbid physical and mental conditions. All 4 also significantly predicted decrements in perceived health both in the total sample and among respondents with insomnia after adjusting for comorbid physical and mental conditions. Joint associations of the 4 symptoms predicting perceived health were additive and related to daytime distress/impairment. Individual-level associations were strongest for NRS. At the societal level, though, where both prevalence and strength of individual-level associations were taken into consideration, DMS had the strongest associations.

CONCLUSIONS

The extent to which nighttime insomnia symptoms are stable over time requires future long-term longitudinal study. Within the context of this limitation, the results suggest that core nighttime symptoms are associated with different patterns of risk and perceived health and that symptom-based subtyping might have value.

Medical comorbidity of sleep disorders

PURPOSE OF REVIEW

Recently published literature indicates that sleep disorders present with medical comorbidities quite frequently. The coexistence of a sleep disorder with a medical disorder has a substantial impact for both the patient and the health system.

RECENT FINDINGS

Insomnia and hypersomnia are highly comorbid with medical conditions, such as chronic pain and diabetes, as well as with various cardiovascular, respiratory, gastrointestinal, urinary and neurological disorders. Restless legs syndrome and periodic leg movement syndrome have been associated with iron deficiency, kidney disease, diabetes, and neurological, autoimmune, cardiovascular and respiratory disorders. Rapid eye movement behaviour disorder has been described as an early manifestation of serious central nervous system diseases; thus, close neurological monitoring of patients referring with this complaint is indicated.

SUMMARY

Identification and management of any sleep disorder in medical patients is important for optimizing the course and prognosis. Of equal importance is the search for undetected medical disorder in patients presenting with sleep disorders.