Risk factors for insomnia in a rural population

Risk factors for insomnia and burnout: A longitudinal population-based cohort study

Insomnia and burnout are highly prevalent in the general population, calling for understanding of its causes. Taking a broad approach, the aim of this study was to determine various mental and somatic risk factors for development of insomnia and burnout and stratifying for sex and age group. Questionnaire data were used from a Swedish population-based sample aged 18-79 years, from which cohorts without insomnia (n = 1702) and without burnout (n = 1972) at baseline were followed-up after 3 years. Self-reports of eight mental and somatic conditions at baseline were used as independent variables in logistic regression analyses to predict development of insomnia and burnout at 3-year follow-up. All eight studied conditions were significant risk factors for development of both insomnia (odds ratio, OR = 1.62-2.73) and burnout (OR = 2.20-3.21). Burnout and poor self-rated health had the highest ORs for insomnia, and poor self-rated health, anxiety and somatic symptoms had the highest ORs for burnout. The ORs were generally similar between men and women, whereas age groups tended to differ in some of the risk factors. The study highlights the importance of a broad assessment of both mental and somatic conditions in the prevention of insomnia and burnout.

The effect of nonrestorative sleep on incident hypertension 1-2 years later among middle-aged Hispanics/Latinos

BACKGROUND

Insomnia is known to be a major risk factor for incident hypertension. Nonrestorative sleep (NRS), which refers to insufficiently rested sleep, has reported to associate with various diseases. This study aimed to investigate the longitudinal association between insomnia-related symptoms including NRS and incident hypertension 1-2 years later by age group (young, 18-39 years and middle-age, 40-64 years) using existing cohort data involving Hispanics/Latinos.

METHODS

This study included 1100 subjects who had participated in both the Hispanic Community Health Study/Study of Latinos and its follow-up study, the Sueño Ancillary Study, and met additional eligibility criteria. Incident hypertension was assessed by self-reported history and/or the use of antihypertensives. The Women's Health Initiative Insomnia Rating Scale (WHIIRS) was used to evaluate insomnia-related symptoms (difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, difficulty returning to sleep, and NRS). Logistic regression analyses were conducted to assess the degree to which insomnia-related symptoms at baseline predicted incident hypertension.

RESULTS

Among the participants (64% middle-aged, 36% young adults), 140 (12.7%) developed hypertension during the follow-up period. Among the sleep-related symptoms, only NRS predicted incident hypertension after adjusting for sociodemographic factors and physical condition (odds ratio: 1.88, 95% confidence interval: 1.10-3.21, p = 0.022) in middle-aged adults. None of the insomnia-related symptoms were associated with incident hypertension in the young adults. No association was found between WHIIRS-defined insomnia (total score ≥ 9) and incident hypertension in middle-aged adults or young adults.

CONCLUSION

The present findings suggest the importance of focusing on NRS to help prevent the development of hypertension in middle-aged adults.

Associations of nonrestorative sleep and insomnia symptoms with incident depressive symptoms over 1-2 years: Longitudinal results from the Hispanic Community Health Study/Study of Latinos and Sueño Ancillary Study

BACKGROUND

Nonrestorative sleep (NRS), defined as insufficiently rested or refreshed sleep, is considered to play an important role in the development of depression. The aim of this study is to investigate the predictive ability of insomnia-related symptoms, including NRS, for incident depressive symptoms (DEPs) in a longitudinal manner.

METHODS

We used data of 1196 samples aged 18-64 years who participated in both the Hispanic Community Health Study/Study of Latinos conducted in 2008-2010 and the follow-up study (Sueño Ancillary Study) conducted in 2010-2013. DEPs and insomnia-related symptoms (difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], early morning awakening [EMA], difficulty returning to sleep [DRS], and NRS) were evaluated by the 10-item Center for Epidemiologic Studies Depression Scale and the Women's Health Initiative Insomnia Rating Scale, respectively. A logistic regression analysis was used to evaluate the predictive ability of each insomnia-related symptom at baseline for incident DEPs in couple-years.

RESULTS

In the univariate logistic regression analysis, all insomnia-related symptoms had significant associations with incident DEPs (DIS, odds ratio [OR] = 1.6; DMS, OR = 1.6; EMA, OR = 1.5; DRS, OR = 1.9; NRS, OR = 2.5). After adjusting for sociodemographic factors and the confounding effects of other insomnia-related symptoms, only NRS (OR = 2.2, 95% confidence interval = 1.4-3.5, p = .001) was significantly associated with incident DEPs.

CONCLUSIONS

NRS was a risk factor for incident DEPs, which includes a predictive ability for other insomnia-related symptoms. Our results suggest that focusing on NRS is an effective strategy for preventing depression in public health promotions.

Effects of carbon dioxide and green space on sleep quality of the elderly in rural areas of Anhui Province, China

Sleep quality leads to many healthy problems, which has caused global concern. Most studies have focused on the sleep quality in some large cities, ignoring the elderly in rural areas who may have more serious sleep problems. Therefore, this study aimed to understand the sleep status of the elderly in rural areas of Anhui Province and the influence of environmental factors on it. The data of carbon dioxide (CO₂) concentrations for this study were obtained from the Dalhousie University atmospheric composition analysis group. The data of normalized differential vegetation index (NDVI) in 2014 was produced and processed by remote sensing inversion on the basis of medium resolution satellite images. The 2686 individuals were selected from rural areas of Anhui Province by multi-stage stratified cluster sampling. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. The independent, interactive, and mediating effects of CO₂ and green space on sleep quality were evaluated by generalized linear model, interaction model, and mediating effect model, respectively. In this study, we found that the prevalence of sleep disturbance in the elderly was 58.40%. In the univariate model, we found that the risk of sleep disturbance increased by 1.6% for each 1 μg/m³ increase in concentrations of CO₂, while decreased by 1.5% for every 0.1 increase in NDVI. In the interaction model, the negative correlation between green space and sleep quality decreased with concentrations of CO₂ increased. In addition, green space was a mediating factor between CO₂ and sleep quality in the mediating effect model.

Anxiety, Insomnia, and Napping Predict Poorer Sleep Quality in an Autistic Adult Population

Autistic adults have a high prevalence of sleep problems and psychiatric conditions. In the general population sleep problems have been associated with a range of demographic and lifestyle factors. Whether the same factors contribute to different types of disturbed sleep experienced by autistic adults is unknown and served as the main aim of this study. An online survey was conducted with 493 autistic adults. Demographic information (e.g., age, gender), about lifestyle (e.g., napping), and information about comorbid conditions was collected. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality and the Epworth Sleepiness Scale (ESS) was used to assess daytime somnolence. Stepwise multiple regression analyses were used to examine predictors of each subscale score on the PSQI, as well as PSQI and ESS total scores. Results indicated that individuals who reported having a diagnosis of anxiety and insomnia were more likely to have poorer sleep quality outcomes overall. Furthermore, individuals who reported habitually napping had higher daytime dysfunction, increased sleep disturbances, and increased daytime sleepiness. These results provide novel insights into the demographic and lifestyle factors that influence sleep quality and daytime somnolence in autistic adults and can be used for targeted sleep interventions.

Greenspace exposure and sleep: A systematic review

Green space is considered a critical environmental factor for sleep quality and quantity. However, no systematic review exploring this relationship exists. The purpose of this systematic review was to 1) explore research related to green space and sleep, and 2) examine the impact of green space exposure on sleep quality and quantity. Papers from eight electronic databases were eligible for inclusion if they met the following criteria: well-designed, any analysis exploring green space and sleep, provided sleep and green space measurement, published in peer-reviewed journals, and written in English. Thirteen eligible studies related to green space and sleep were selected after peer-review procedures. Cross-sectional studies (n = 7) used either a questionnaire or the combination of Geographic Information Systems and remote sensing images for green space measurement, while questionnaires were primarily used to measure both sleep quality and quantity. Intervention studies (n = 5) were categorized into three types: walking program, gardening, and working in a forest. Eleven out of thirteen studies concluded that green space exposure was associated with improvement in both sleep quality and quantity. The findings support the evidence of a positive association between green space exposures and sleep quality and quantity, and also suggest green exercise and therapeutic gardening as possible intervention methods to improve sleep outcomes.

A secondary analysis of the role of geography in engagement and outcomes in a clinical trial of an efficacious Internet intervention for insomnia

BACKGROUND

Online interventions for insomnia can increase access to treatments for those with limited access to services. What remains unknown is whether individuals from more isolated (vs. more densely populated) regions engage with, and benefit as much from, an online intervention. This secondary analysis examined the relationship of geographical indices with engagement and outcomes of an efficacious, fully automated online cognitive behavioral therapy for insomnia (CBT-I) program (Sleep Healthy Using the Internet-SHUTi).

METHOD

303 participants (M _age  = 43.3; SD = 11.6) were randomly assigned to SHUTi or an online patient education condition and assessed at baseline and post intervention. Rural code of participants was determined using participant zip codes. Distance to the nearest sleep medicine provider was calculated as the distance between the center of the nearest provider's city (from a publicly available list of CBT-I providers) and the center of the participants' zip code. Adherence outcomes were number of intervention core completions, sleep diaries, and logins. Sleep outcomes were insomnia severity as well as sleep onset latency and wake after sleep onset derived from online sleep diaries.

RESULTS

Individuals were from a range of geographic locations. Most lived in fairly densely populated areas; however, there was a large variation in distance to the nearest sleep medicine provider. Findings indicate that the efficacy, adherence, and engagement with SHUTi were not impacted by where people lived. Controlling for age and gender did not impact any of the relationships among geography variables (i.e., distance, ruralness) and adherence or sleep related outcomes.

CONCLUSIONS

Internet interventions must demonstrate that they can overcome obstacles posed by geography. This is the first study to examine the geographic location of participants and its association with engagement with, and outcomes of, online CBT-I.

Neural Plasticity Is Involved in Physiological Sleep, Depressive Sleep Disturbances, and Antidepressant Treatments

Depression, which is characterized by a pervasive and persistent low mood and anhedonia, greatly impacts patients, their families, and society. The associated and recurring sleep disturbances further reduce patient's quality of life. However, therapeutic sleep deprivation has been regarded as a rapid and robust antidepressant treatment for several decades, which suggests a complicated role of sleep in development of depression. Changes in neural plasticity are observed during physiological sleep, therapeutic sleep deprivation, and depression. This correlation might help us to understand better the mechanism underlying development of depression and the role of sleep. In this review, we first introduce the structure of sleep and the facilitated neural plasticity caused by physiological sleep. Then, we introduce sleep disturbances and changes in plasticity in patients with depression. Finally, the effects and mechanisms of antidepressants and therapeutic sleep deprivation on neural plasticity are discussed.

Sleep Disturbance and Short Sleep as Risk Factors for Depression and Perceived Medical Errors in First-Year Residents

Study Objectives

While short and poor quality sleep among training physicians has long been recognized as problematic, the longitudinal relationships among sleep, work hours, mood, and work performance are not well understood. Here, we prospectively characterize the risk of depression and medical errors based on preinternship sleep disturbance, internship-related sleep duration, and duty hours.

Methods

Survey data from 1215 nondepressed interns were collected at preinternship baseline, then 3 and 6 months into internship. We examined how preinternship sleep quality and internship sleep and work hours affected risk of depression at 3 months, per the Patient Health Questionnaire 9. We then examined the impact of sleep loss and work hours on depression persistence from 3 to 6 months. Finally, we compared self-reported errors among interns based on nightly sleep duration (≤6 hr vs. >6 hr), weekly work hours (<70 hr vs. ≥70 hr), and depression (non- vs. acutely vs. chronically depressed).

Results

Poorly sleeping trainees obtained less sleep and were at elevated risk of depression in the first months of internship. Short sleep (≤6 hr nightly) during internship mediated the relationship between sleep disturbance and depression risk, and sleep loss led to a chronic course for depression. Depression rates were highest among interns with both sleep disturbance and short sleep. Elevated medical error rates were reported by physicians sleeping ≤6 hr per night, working ≥ 70 weekly hours, and who were acutely or chronically depressed.

Conclusions

Sleep disturbance and internship-enforced short sleep increase risk of depression development and chronicity and medical errors. Interventions targeting sleep problems prior to and during residency hold promise for curbing depression rates and improving patient care.

Depressive Symptoms Are Associated With Objectively Measured Sleep Parameters in Kidney Transplant Recipients

STUDY OBJECTIVES

Both depression and sleep complaints are very prevalent among kidney transplant (kTx) recipients. However, details of the complex relationship between sleep and depression in this population are not well documented. Thus, we investigated the association between depressive symptoms and sleep macrostructure parameters among prevalent kTx recipients.

METHODS

Ninety-five kTx recipients participated in the study (54 males, mean ± standard devation age 51 ± 13 years, body mass index 26 ± 4 kg/m2, estimated glomerular filtration rate 53 ± 19 ml/min/1.73 m2). Symptoms of depression were assessed by the Center for Epidemiologic Studies - Depression Scale (CES-D). After 1-night polysomnography each recording was visually scored and sleep macrostructure was analyzed.

RESULTS

The CES-D score was significantly associated with the amount of stage 2 sleep (r = 0.20, P < .05), rapid eye movement (REM) latency (r = 0.21, P < .05) and REM percentage (r = -0.24, P < .05), but not with the amount of slow wave sleep (r = -0.12, P > .05). In multivariable linear regression models the CES-D score was independently associated with the amount of stage 2 sleep (β: 0.205; confidence interval: 0.001-0.409; P = .05) and REM latency (β: 0.234; confidence interval: 0.001-0.468; P = .05) after adjustment for potential confounders.

CONCLUSIONS

Depressive symptoms among kTx recipients are associated with increased amount of stage 2 sleep and prolonged REM latency. Further studies are needed to confirm our findings and understand potential clinical implications.

Associations between time in bed and suicidal thoughts, plans and attempts in Korean adolescents

OBJECTIVES

To examine the hypothesis that respondents with any of three specific sleep patterns would have a higher likelihood of suicidality than those without reports of these patterns in Korean adolescents.

SETTING

Data from the 2011-2013 Korea Youth Risk Behavior Web-based Survey were used.

PARTICIPANTS

191,642 subjects were included. The survey's target population was students in grades 7 through 12 in South Korea.

INDEPENDENT VARIABLE

Sleep time.

PRIMARY AND SECONDARY OUTCOME MEASURES

Suicidal thoughts, plans and attempts.

RESULTS

The odds of suicidal thoughts in subjects with very short or long time in bed were 1.487-fold higher (95% CI 1.219 to 1.815) or 0.611-fold lower (95% CI 0.460 to 0.811), respectively, than for subjects with 7 h/day in bed; the odds were similar for suicidal plans. The odds of suicidal thoughts in subjects with early or late awakening times were 1.231-fold higher (95% CI 1.050 to 1.442) or 1.528-fold lower (95% CI 1.000 to 2.334), respectively, than for subjects with 7 h/day in bed; these odds were lower for suicidal plans and attempts. The odds of suicidal thoughts in subjects with early bedtime were 1.748-fold higher (95% CI 1.302 to 2.346), the odds of suicidal plans in people with an early bedtime were 2.494-fold higher (95% CI 1.671 to 3.722) and the odds of suicide attempts in subjects with late bedtime were 1.313-fold higher (95% CI 1.005 to 1.716) than for subjects with a bedtime of 23:00.

CONCLUSIONS

The sleep-related time is associated with suicide-related behaviours in Korean adolescents. Multilateral approaches are needed to identify the greatest risk factors for suicidal behaviours.

Effect of a homeopathic-complex medicine on state and trait anxiety and sleep disorders: a retrospective observational study

PURPOSE

The primary objective of this open-label, retrospective, observational study was to examine change in indicators of anxiety changed after treatment period of at least 1 month with the homeopathic-complex medicine Datif-PC(®). A secondary objective was to describe the quantitative changes in the sleep pattern of the subjects included in the study.

METHODS

The study population consisted of 71 subjects suffering from mild to moderate anxiety, who were treated with a homeopathic-complex medicine. The subjects had attended at least 2 consultations during the year 2010, with the second visit taking place at least 30 days after the first baseline visit. At both visits, subjects were administered the State-Trait Anxiety Inventory (STAI)-Y questionnaire (consisting of trait and state subscales) to assess their level of anxiety. Sleep quality was assessed based on the subjects' self-reported number of hours slept and number of night-time awakenings, before and after treatment.

RESULTS

Compared to baseline, the average (STAI)-state score at visit 2 decreased by more than 6 points, while the STAI-trait score decreased by more than 3 points. This was statistically significant (p < 0.0001) for both subscales. These findings were stable in subgroup analyses (gender, age and anxiety level). The average number of hours slept per night increased significantly at visit 2 compared to baseline (from 5.1 ± 1.1 to 5.56 ± 0.9 h, p < 0.0001). A marked decrease in the average number of night-time awakenings was also observed at the second visit (-42%, p < 0.0001).

CONCLUSIONS

This retrospective observational study suggests that treatment of anxiety and sleep disorders with Datif-PC(®) can produce notable improvements even in a short period of time. Furthermore, the observed effects were not affected by sex, age or baseline anxiety. Further controlled, randomized studies are justified.

A Systematic Review Assessing Bidirectionality between Sleep Disturbances, Anxiety, and Depression

STUDY OBJECTIVES

To investigate whether sleep disturbances are bidirectionally related to anxiety and depression, and thus identify potential risk factors for each problem.

DESIGN

A systematic review was conducted on 9 studies (8 longitudinal, 1 retrospective) that assessed bidirectionality between a sleep disturbance, and anxiety or depression. Treatment studies were excluded, along with those solely based on clinical samples or cohorts at high risk of suffering from a sleep disturbance, anxiety and depression. Eligible studies were identified by searching PubMed, PsychINFO, Embase, and Scopus databases, and reference lists of eligible studies. Publication dates ranged from the beginning of each database to December 2011.

MEASUREMENTS AND RESULTS

Syntheses of longitudinal studies suggested insomnia and sleep quality were bidirectionally related to anxiety and depression, and depression/anxiety, respectively. Childhood sleep problems significantly predicted higher levels of depression and a combined depression/anxiety variable, but not vice-versa. A one-way relationship was found where anxiety predicted excessive daytime sleepiness, but excessive daytime sleepiness was not associated with depression.

CONCLUSIONS

Definitive conclusions regarding bidirectionality cannot be made for most sleep disturbances due to the small number and heterogeneity of cohort samples used across studies. Nevertheless, best available evidence suggests insomnia is bidirectionally related to anxiety and depression. Clinical and theoretical implications are discussed.

CITATION

Alvaro PK; Roberts RM; Harris JK. A systematic review assessing bidirectionality between sleep disturbances, anxiety, and depression. SLEEP 2013;36(7):1059-1068.

Association between physical activity and insomnia symptoms in rural communities of southeastern Missouri, Tennessee, and Arkansas

PURPOSE

The purpose of this study is to examine whether physical activity is associated with less insomnia symptoms in the rural communities.

METHODS

This study used cross-sectional data collected from a 2005 telephone survey for evaluation of a community walking trails intervention to promote physical activity in rural communities including 6 communities in the Missouri Ozark region and 6 communities in Arkansas and Tennessee (n = 1,234). The exposure variable is self-reported regular current physical activity. The outcome includes symptoms of insomnia operationalized as having trouble falling asleep, staying asleep, and waking up too early nearly every day. Logistic regression was used to calculate prevalence odds ratios (PORs) and 95% confidence intervals (95% CI).

FINDINGS

The study sample includes mostly white (95%), married (62%), overweight/obese (61%) women with a high school degree and a mean age of 54. Fourteen percent of participants reported having insomnia symptoms. Self-report of currently being physically active regularly was associated with decreased odds of insomnia symptoms (adjusted POR: .37; 95% CI, 0.14-0.99) among participants with under or normal body weight, after controlling for age, gender, education level, marital status, and chronic diseases. There was also a negative linear correlation between the number of days and total minutes of vigorous physical activity and insomnia symptoms.

CONCLUSIONS

In these rural communities, we observed a significant relationship between regular physical activity and decreased insomnia symptoms.

DSM-IV psychiatric comorbidity according to symptoms of insomnia: a nationwide sample of Korean adults

PURPOSE

The diagnosis of insomnia is based on the presence of four different symptoms: difficulty in initiating sleep (DIS), difficulty in maintaining sleep (DMS), early morning awakening (EMA), and non-restorative sleep (NRS). This study investigated the differences in sociodemographic correlates and psychiatric comorbidity between the four symptoms of insomnia in the general population of South Korea.

METHODS

A sample of the population aged 18-64 (N = 6,510) was questioned using a face-to-face interview. Insomnia was defined as having at least one of the four following symptoms three or more times per week: DIS, DMS, EMA, and NRS. Psychiatric disorders were evaluated using the Korean version of Composite International Diagnostic Interview. Logistic regression analysis was used to test each of the sleep outcomes (DIS, DMS, EMA, or NRS) for an association with sociodemographic and clinical variables.

RESULTS

The prevalence of DIS, DMS, EMA, and NRS were 7.9 % (95 % CI 6.6-9.5 %), 7.9 % (95 % CI 6.5-9.6 %), 4.9 % (95 % CI 3.9-6.0 %), and 14.8 % (95 % CI 12.6-17.4 %), respectively. The overall prevalence of insomnia was 19.0 % (95 % CI 16.1-22.2 %). Being separated, divorced, or widowed, being single, having a part-time job, having a psychiatric illness, and having a physical illness were all significantly related to insomnia. Older age also increased the risk of DMS and EMA, and younger age was a risk factor for NRS. The presence of most psychiatric disorders was significantly related to insomnia. However, the relationship between the psychiatric illness and each insomnia symptom varied and was dependent on the insomnia symptom.

CONCLUSIONS

Most psychiatric disorders were significantly associated with each insomnia symptom in different ways. Differences in sociodemographic and clinical correlates between the four insomnia symptoms implied the heterogeneous characteristics of insomnia as defined by the current diagnostic criteria.

Trajectories of sleep complaints from early midlife to old age: longitudinal modeling study

STUDY OBJECTIVES

To estimate trajectories of sleep lost over worry as a function of age, using longitudinal modeling, and compare these trajectories with those for insomnia symptoms.

DESIGN AND SETTING

Data from two prospective, occupational cohorts (the Whitehall II and Finnish Public Sector studies) comprising 84,384 observations from four to eight repeat measurements in 1985-2010.

PARTICIPANTS

There were 16,408 men and women age 34-79 yr.

MEASUREMENTS AND RESULTS

Age-related trajectories of sleep lost over worry and insomnia symptoms (sleep initiation or maintenance problems, nonrefreshing sleep) were estimated using repeated-measures log-binomial regression analysis and generalized estimating equations. These analyses were adjusted for year of birth and time of measurement to minimize confounding by cohort or period effects. The prevalence ratio for insomnia symptoms was higher in older age groups compared with participants age 34-45 yr. In contrast, the age-related trajectory of sleep lost over worry included two phases: a period of high prevalence of sleep complaints at age 34-60 yr followed by a declining trajectory at older ages. Compared with participants age 34-45 yr, prevalence ratios for sleep lost over worry were 0.63 (0.49-0.80) and 0.59 (0.41-0.84) in the Whitehall II study participants ages 61-65 and 71-79 years. Corresponding figures were 0.62 (0.52-0.75) and 0.46 (0.32-0.66) in the Finnish Public Sector study.

CONCLUSION

This study shows a general age-related decrease in sleep lost over worry between late midlife and old age, a pattern strikingly different from the age-related increase in insomnia symptoms.

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.

The association of sleep duration and depressive symptoms in rural communities of Missouri, Tennessee, and Arkansas

PURPOSE

To determine the association between sleep duration and depressive symptoms in a rural setting.

METHODS

We conducted a cross-sectional study using data from Wave 3 of the Walk the Ozarks to Wellness Project including 12 rural communities in Missouri, Arkansas, and Tennessee (N = 1,204). Sleep duration was defined based on average weeknight and weekend hours per day: short (<7), optimal (7-8), and long (>8). The primary outcome was self-reported elevated depressive symptoms. Multivariable logistic regression was used to estimate adjusted prevalence odds ratios (aPOR) and 95% confidence intervals (95% CI).

FINDINGS

Elevated depressive symptoms were common in this rural population (17%). Depressive symptoms were more prevalent among subjects with short (26.1%) and long (24%) sleep duration compared to those with optimal (11.8%) sleep duration. After adjusting for age, gender, race, education, employment status, income, and BMI, short sleep duration was associated with increased odds of elevated depressive symptoms (aPOR = 2.12, 95% CI: 1.49, 3.01), compared to optimal sleep duration. Conversely, the association between long sleep duration and depressive symptoms was not statistically significant after covariate adjustment. Similar findings were observed when we excluded individuals with insomnia symptoms for analysis.

CONCLUSIONS

This study suggests that short sleep duration (<7 hours per night) and depressive symptoms are common among rural populations. Short sleep duration is positively associated with elevated depressive symptoms. The economic and health care burden of depression may be more overwhelming among rural populations, necessitating the need to target modifiable behaviors such as sleep habits to improve mental health.

Insomnia in untreated sleep apnea patients compared to controls

Insomnia and obstructive sleep apnea (OSA) often coexist, but the nature of their relationship is unclear. The aims of this study were to compare the prevalence of initial and middle insomnia between OSA patients and controls from the general population as well as to study the influence of insomnia on sleepiness and quality of life in OSA patients. Two groups were compared, untreated OSA patients (n = 824) and controls ≥ 40 years from the general population in Iceland (n = 762). All subjects answered the same questionnaires on health and sleep and OSA patients underwent a sleep study. Altogether, 53% of controls were males compared to 81% of OSA patients. Difficulties maintaining sleep (DMS) were more common among men and women with OSA compared to the general population (52 versus 31% and 62 versus 31%, respectively, P < 0.0001). Difficulties initiating sleep (DIS) and DIS + DMS were more common among women with OSA compared to women without OSA. OSA patients with DMS were sleepier than patients without DMS (Epworth Sleepiness Scale: 12.2 versus 10.9, P < 0.001), while both DMS and DIS were related to lower quality of life in OSA patients as measured by the Short Form 12 (physical score 39 versus 42 and mental score 36 versus 41, P < 0.001). DIS and DMS were not related to OSA severity. Insomnia is common among OSA patients and has a negative influence on quality of life and sleepiness in this patient group. It is relevant to screen for insomnia among OSA patients and treat both conditions when they co-occur.

Characteristics of chronic pain associated with sleep difficulty in older adults: the Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly (MOBILIZE) Boston study

OBJECTIVES

To evaluate pain severity and distribution in relation to sleep difficulty in older adults.

DESIGN

Population-based cross-sectional study.

SETTING

Community within a 5-mile radius of the study center at the Institute for Aging Research, Hebrew SeniorLife (HSL), Boston.

PARTICIPANTS

Seven hundred sixty-five participants of the Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly (MOBILIZE) Boston Study aged 64 and older.

MEASUREMENTS

Pain severity was measured using the Brief Pain Inventory (BPI) Pain Severity Subscale. Musculoskeletal pain distribution was grouped according to no pain, single site, two or more sites, and widespread pain (upper and lower extremities and back pain). Three aspects of sleep difficulty were measured using items from the Center for Epidemiologic Studies Depression Scale, Revised (trouble getting to sleep, sleep more than usual, and restless sleep).

RESULTS

Prevalence of trouble getting to sleep according to BPI severity was 17.8%, 19.7%, 32.0%, and 37.0% for the lowest to highest pain severity quartiles, respectively. Similar relationships between pain and sleep were observed across sleep measures according to pain severity and distribution. Adjusted for sociodemographic characteristics, chronic conditions, and health behaviors, chronic pain was strongly associated with trouble sleeping (≥ 1 d/wk) (single-site pain, odds ratio (OR)=1.77, 95% confidence interval (CI)=1.10-2.87; multisite pain, OR=2.38, 95% CI=1.48-3.83; widespread pain, OR=2.55, 95% CI=1.43-4.54, each compared with no pain). Similar associations were observed for restless sleep and sleeping more than usual. For specific pain sites alone or in combination with other sites of pain, only modest associations were observed with sleep problems.

CONCLUSION

Widespread or other multisite pain and moderate to severe pain are strongly associated with sleep difficulty in older adults. Further research is needed to better understand the burden and consequences of pain-related sleep problems in older adults.

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.

Association between depression and insomnia subtypes: a longitudinal study on the elderly in Japan

STUDY OBJECTIVE

To examine the association between depression and three subtypes of insomnia, namely, difficulty initiating sleep (DIS), early morning awakening (EMA), and difficulty maintaining sleep (DMS).

DESIGN

Cross-sectional and longitudinal study.

SETTING

Community dwellers in Japan.

PARTICIPANTS

Nationally representative samples of adults aged 65 and over (total N=4,997) were selected by a multistage stratified random sampling method in 1999 and were interviewed face-to-face in 1999, 2001, 2003, and 2006. Those who responded to the 3rd survey conducted in 2003 and the 4th survey conducted in 2006 were used in this study.

MEASUREMENT AND RESULTS

Depression was evaluated according to the 11-item short form of the CES-D scale at 2 points in time. Insomnia subtypes were assessed by self-reported measures. A logistic regression was employed to examine the association between insomnia subtypes and the presence of depression, controlling for relevant factors. A cross-sectional analysis based on the 2003 data demonstrated statistically significant odds ratios (ORs) for DIS and EMA. In the longitudinal study, DIS at the time of the 3rd survey was found to be significantly related to the presence of depression at the time of the 4th survey, with an odds ratio (95%CI) of 1.592 (1.012 to 2.504). EMA (OR 1.070; 95% CI, 0.664 to 1.723) and DMS (OR 1.215; 95% CI, 0.860 to 1.716), however, were not found to be significantly related to the presence of depression.

CONCLUSION

The longitudinal study revealed a statistically significant relationship, controlling for other relevant factors, between DIS and the presence of depression three years later, but not between EMA or DMS and depression. Based on our findings, we recommend that the association between insomnia subtypes and depression be studied longitudinally in clinical settings.

Prevalence and correlates of frequent nightmares: a community-based 2-phase study

STUDY OBJECTIVES

To determine the prevalence of frequent nightmares and their correlates in a large community-based cohort of middle-aged Hong Kong Chinese.

DESIGN

A 2-phase design involving a cross-sectional survey of 8558 subjects (men, 47.6%) with a mean age of 40.9 years (SD 5.5, range 20-78) and subsequently followed by a detailed clinical evaluation of the psychopathology and personality profile of 252 subjects.

SETTING

Community.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

The prevalence of frequent nightmares, as defined by at least once per week, was 5.1%. Female sex, low monthly family income, insomnia symptoms, sleep-disordered breathing symptoms, and sleep-related daytime consequences were significantly associated with nightmare frequency. The risk of having a psychiatric disorder was 5.74 times greater for subjects with frequent nightmares (95% confidence interval 2.03-16.26), especially mood disorders (odds ratio = 15.57, 95% confidence interval 3.77-64.37). After exclusion of concomitant psychiatric morbidities, subjects with frequent nightmares still scored significantly higher on neuroticism in the personality scale (p < 0.05).

CONCLUSIONS

Frequent nightmares were not uncommon in the general population and were associated with a constellation of factors, including sociodemographic characteristics and comorbid sleep and psychiatric disorders. Moreover, frequent nightmares were independently related to the neuroticism personality trait, irrespective of psychiatric diagnosis. Prospective studies should be conducted to investigate various predisposing, precipitating, and perpetuating factors and the associated repercussions of nightmares.

Using difficulty resuming sleep to define nocturnal awakenings

OBJECTIVE

Nocturnal awakenings are one of the most prevalent sleep disturbances in the general population. Little is known, however, about the frequency of these episodes and how difficulty resuming sleep once awakened affects subjective sleep quality and quantity.

METHOD

This is a cross-sectional telephone study with a representative sample consisting of 8937 non-institutionalized individuals aged 18 or over living in Texas, New York and California. The interviews included questions on sleeping habits, health, sleep and mental disorders. Nocturnal awakenings were evaluated according to their frequency per week and per night, as well as their duration.

RESULTS

A total of 35.5% of the sample reported awakening at least three nights per week. Of this 35.5%, 43% (15.2% of the total sample) reported difficulty resuming sleep once awakened. More than 80% of subjects with insomnia symptoms (difficulty initiating or maintaining sleep or non-restorative sleep) also had nocturnal awakenings. Difficulty resuming sleep was associated with subjective shorter sleep duration, poorer sleep quality, greater daytime impairment, greater consultations for sleep disturbances and greater likelihood of receiving a sleep medication.

CONCLUSIONS

Nocturnal awakenings disrupt the sleep of about one-third of the general population. Using difficulty resuming sleep identifies individuals with significant daytime impairment who are most likely to seek medical help for their sleep disturbances. In the absence of other insomnia symptoms, nocturnal awakenings alone are unlikely to be associated with daytime impairments.

Problems associated with short sleep: bridging the gap between laboratory and epidemiological studies

Existing data from laboratory studies suggest a number of negative consequences of acute reductions in sleep time. Also, epidemiological data suggest links between shorter self-reported sleep duration and negative health outcomes. These bodies of work are growing, revealing several key points of convergence and opportunities for future exploration. In addition, they begin to highlight possible problems experienced by "short sleepers," who sleep approximately 6h or less per night. While it is likely that this group is heterogeneous, comprised both of individuals with less need for sleep and those not sleeping enough, the laboratory and epidemiological findings point towards directions that can be more fully explored in verified short sleepers. This paper discusses problems associated with the terminology used to describe "short sleep," summarizes laboratory studies exploring neurobehavioral performance, metabolism and obesity, and psychological health and epidemiological studies exploring mortality risk, obesity and metabolism, cardiovascular disease, and general health/psychosocial stress, describes studies of verified short sleepers and explores areas of convergence, laying out possible future directions.

Fatigue, insomnia and nervousness: gender disparities and roles of individual characteristics and lifestyle factors among economically active people

BACKGROUND

Individuals with certain personal, family and job characteristics are at elevated risk of poor mental health. Yet, the respective role of obesity, smoking, alcohol abuse, low education, income, living and family conditions, and socio-occupational category in fatigue/insomnia (FI), nervousness (N) and frequent drug use for those disorders (DFI and DN) among men and women and in gender disparities are not well known.

METHODS

We studied gender differences in FI, N, DFI, DN, and in their correlated, and whether the gender differences were mediated by individual and lifestyle factors among 3,450 active subjects aged 18-64, randomly selected from North-eastern France. Subjects completed a post-mailed questionnaire. Data were analyzed via adjusted odds ratio (ORa) computed with the logistic regression model.

RESULTS

Women were more affected than men for FI (21.3 vs. 13.1%, OR adjusted for age ORa 1.80, 95% CI 1.50-2.16), DFI (11.6 vs. 7.1%, ORa 1.74, 1.38-2.21), N (14.7 vs. 9.9%, ORa 1.58, 1.28-1.94), and for DN (12.1 vs. 5.7%, ORa 2.29, 1.79-2.94). These differences were not mediated by the individual characteristics studied. Multivariate analysis showed that the risk patterns varied between the two sexes. Smoking was related to N in men as well as in women; alcohol abuse to DFI in men only; lack of family support to all outcome variables in men and women; low educational level to DFI in men only; low income to FI, N and DN in men and to FI and DN in women; being unmarried to DN in men; being divorced/separated to N and DN in women; being a manual worker to FI and being a farmer to DFI in men; and being a manual worker to DN and being an employee to FI in women (1.50 <or= ORa <or= 2.95).

CONCLUSIONS

Women suffered more from fatigue/insomnia and nervousness and used more drug for those disorders than men. Socio-demographic and lifestyle factors played significant roles among men and women but they did not explain the gender disparities.

Sleep problems and suicidality in the National Comorbidity Survey Replication

OBJECTIVE

Links between sleep problems and suicidality have been frequently described in clinical samples; however, this issue has not been well-studied in the general population. Using data from a nationally representative survey, we examined the association between self-reported sleep difficulties and suicidality in the United States.

METHODS

The WHO Composite International Diagnostic Interview was used to assess sleep problems and suicidality in the National Comorbidity Survey Replication (NCS-R). Relationships between three measures of sleep (difficulty initiating sleep, maintaining sleep, early morning awaking), and suicidal thoughts, plans, and attempts were assessed in logistic regression analyses, while controlling for demographic characteristics, 12-month diagnoses of mood, anxiety and substance use disorders, and chronic health conditions.

RESULTS

In multivariate models, the presence of any of these sleep problems was significantly related to each measure of suicidality, including suicidal ideation (OR=2.1), planning (OR=2.6), and suicide attempt (OR=2.5). Early morning awakening was associated with suicidal ideation (OR=2.0), suicide planning (OR=2.1), and suicide attempt (OR=2.7). Difficulty initiating sleep was a significant predictor of suicidal ideation and planning (ORs: 1.9 for ideation; 2.2 for planning), while difficulty maintaining sleep during the night was a significant predictor of suicidal ideation and suicide attempts (ORs: 2.0 for ideation; 3.0 for attempt).

CONCLUSIONS

Among community residents, chronic sleep problems are consistently associated with greater risk for suicidality. Efforts to develop comprehensive models of suicidality should consider sleep problems as potentially independent indicators of risk.

Gender and socio-economic patterning of self-reported sleep problems in Britain

Sleep is fundamental to health and well-being, yet relatively little research attention has been paid to sleep quality. This paper addresses how socio-economic circumstances and gender are associated with sleep problems. We examine (i) socio-economic status (SES) patterning of reported sleep problems, (ii) whether SES differences in sleep problems can be explained by socio-demographic characteristics, smoking, worries, health and depression, and (iii) gender differences in sleep problems, addressing the relative contribution of SES, smoking, worries, health and depression in explaining these differences. Logistic regression is used to analyse the British Psychiatric Morbidity Survey 2000, which interviewed 8578 men and women aged 16-74. Strong independent associations are found between sleep problems and four measures of SES: household income, educational qualifications, living in rented housing and not being in paid employment. Income differences in sleep problems were no longer significant when health and other characteristics were adjusted. The higher odds of sleep problems among the unemployed and adults with low education remained significant following adjustment. Women reported significantly more sleep problems than men, as did the divorced and widowed compared with married respondents. Gender differences in sleep problems were halved following adjustment for socio-economic characteristics, suggesting that SES inequalities play a major part in accounting for gender differences in sleep problems. Our study casts doubt on the primacy of physiological explanations underlying these gender differences. Since disadvantaged socio-economic characteristics are strongly associated with sleep problems, we conclude that disrupted sleep may be a mechanism through which low SES is linked to poor health.