Prevalence and correlates of insomnia in the Swedish population aged 19-75 years

ObjectiveTo assess the prevalence of insomnia symptoms, their associated factors and daytime symptoms in the general population of Sweden.MethodsThis is a cross-sectional postal survey performed in the general population of Sweden aged between 19 and 75 years (6 million inhabitants). A total of 1209 out of 1705 randomly selected participants from the National Register of the Total Population completed the questionnaire. The participation rate was 71.3%. Participants filled out a paper–pencil questionnaire composed of 157 items covering sociodemographic characteristics, sleeping habits and environment, sleep quality and sleep symptoms, and health status.ResultsWe found 32.1% (95% confidence interval: 29.5–34.8%) of the sample reported having difficulty initiating (DIS) or maintaining sleep (DMS) or non-restorative sleep accompanied with sufficient sleep (NRS) at least 4 nights per week: 6.3% of the sample had DIS, 14.5% had DMS and 18.0% had NRS. Results from logistic regressions showed that restless legs symptoms, breathing pauses during sleep and depressive or anxious mood were associated with DIS and DMS but not NRS. Living in an urban area (OR:2.0) and drinking alcohol daily (OR:4.6) were associated only with NRS. Daytime symptoms were reported by over 75% of subjects with insomnia symptoms. DIS, DMS and NRS were associated with daytime fatigue but not excessive sleepiness as measured by the Epworth scale. DIS was associated with the use of sleeping pills or natural sleeping aid compounds in multivariate models.ConclusionsInsomnia symptoms occurring at least 4 nights per week are frequent in Sweden, affecting about a third of the population. Subjects with NRS have a distinctly different profile than those with DIS or DMS, which suggests different etiological causes for this symptom.     

Alcohol consumption and sleep problems in Hong Kong adolescents

ObjectiveWe aimed to investigate the relationship between alcohol consumption and sleep problems among Hong Kong adolescents.MethodsIn the 2006 and 2007 Hong Kong Student Obesity Surveillance project, 33,692 secondary students completed an anonymous questionnaire on lifestyles and health. Alcohol consumption was categorized as nondrinkers (reference group), those who drank less than 1 day per week (less than weekly drinkers), and those who drank 1 to 7 days per week (weekly drinkers, including some daily drinkers). Students reported if they had any sleep problems in the past 30 days, including difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), snoring, and difficulty breathing during sleep (DBS). Insomnia was defined as any reports of DIS, DMS, or EMA. Logistic regression was used to assess the association between alcohol and each sleep problem. Multiple imputations were used to impute missing data.ResultsCompared with nondrinkers, less than weekly and weekly drinkers were more likely to report snoring with adjusted odds ratios (AOR) of 1.64 (95% confidence interval [CI], 1.40–1.92) and 1.82 (95% CI, 1.55–2.14), respectively (P < .001). The corresponding figures were 1.24 (95% CI, 1.02–1.50) and 1.50 (95% CI, 1.24–1.82) for DBS (P < .001) and 1.12 (95% CI, 1.02–1.22) and 1.15 (95% CI, 1.04–1.27) for insomnia (P = .002). Weekly drinking was positively associated with DMS but negatively associated with DIS and EMA. Less than weekly drinking was positively associated with DIS, DMS, and EMA.ConclusionsBoth less than weekly drinking and weekly drinking were associated with snoring, DBS, and insomnia. The association of individual symptoms of insomnia with drinking varied with the frequency of consumption.     

Characteristics of insomnia in a primary care setting: EQUINOX survey of 5293 insomniacs from 10 countries

ObjectiveTo describe the characteristics of insomnia in primary care physicians’ (PCPs’) practices in 10 countries and to understand how the difficulty of maintaining sleep (DMS) was or was not associated with other insomnia symptoms such as difficulty initiating sleep (DIS), early morning awakenings (EMA) or nonrestorative sleep (NRS) in PCPs patients with insomnia.MethodsInternational, noninterventional, cross-sectional, observational survey conducted in a primary care setting in subjects complaining of sleep disturbances in 10 countries. A questionnaire based on DSM-IV and ICSD criteria was administered.ResultsThirteen thousand one hundred twenty-four subjects were enrolled by 647 physicians; 5293 of them (32.6%) had insomnia and were surveyed. The population was predominantly female (63.9%) with a mean age of 47.8 ± 15.3 years; 39.9% of these patients have already been treated for sleep difficulties. Combination of all types of insomnia symptoms (DIS + DMS + EMA + NRS) was the most frequently reported combination (38.6% of the subjects), while the percentage of subjects presenting with only one type of insomnia symptom (DIS, DMS, EMA or NRS) was very low: 3%, 1.8%, 0.9% and 1.4% respectively. DMS was on average the most commonly reported insomnia symptom (80.2%). Multiple logistic regression showed that DMS, EMA and NRS symptoms were significantly linked with each other and also to other insomnia criteria (sleep satisfaction, sleep quality, sleep duration, number of hours of sleep, frequency of insomnia symptoms, wake up rested / unrested and non restorative sleep).ConclusionsPatients visiting PCPs with insomnia are likely to present with severe and poly-symptomatic insomnia.     

Sleep time and sleep-related symptoms across two generations – results of the community-based RHINE and RHINESSA studies

Study objectivesTo analyze the association between sleep-related symptoms and sleep length in parents and their children in relation to other risk factors in both generations.MethodThe participants were parents (n = 5,855, age 54.3 ± 6.5 years, 45.2% men) who participated in the community-based Respiratory Health in Northern Europe (RHINE) study and one random member of their adult offspring (n = 5,855, age 30.2 ± 7.7 years, 41.5% men) who participated in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) study. Both generations responded to identical questionnaires on sleep symptoms, including difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), snoring, nocturnal sweating, nocturnal gastroesophageal reflux (nGER), sleep time and excessive daytime sleepiness (EDS). Insomnia was defined as either, or both, DIS and DMS in combination with EDS.ResultsAll sleep variables except nocturnal sweating were more common in offspring whose parents had reported the same symptom. After adjusting for age, gender, BMI, smoking, physical activity, education, center and parents' total number of children, there were independent associations between sleep symptoms in parents and offspring for DIS (adj. OR, 95% CI: 1.52, 1.20–1.93), DMS (1.34, 1.15–1.56), snoring (1.45, 1.15,1.83), nGER (1.65, 1.15–2.37), insomnia (1.39, 1.13–1.73), short sleep time (<6 h/night) (2.51, 1.72–3.68) and EDS (1.48, 1.26,1.72). There were no independent relationships between symptoms in parents and offspring for EMA, nocturnal sweating or long sleep time (>9 h/night).ConclusionThe familiar aggregation of many sleep disturbances was not explained by investigated lifestyle and environmental factors. This supports a heritable factor in sleep problems.     

Gender differences in insomnia--a study in the Hong Kong Chinese population

OBJECTIVE: To study the epidemiology of insomnia in the adult Chinese population in Hong Kong and to examine the potential gender-related demographic and lifestyle factors in insomnia. METHODS: A population study via random telephone survey with a structured questionnaire was carried out for noninstitutionalized Chinese adults aged 18-65 by trained lay interviewers. The questionnaire included demographic data, sleep habits and problems, insomnia symptoms and lifestyle questions. RESULTS: A total of 9851 subjects (46.4% male; 53.6% female) were included in the final analysis. The overall prevalence of Hong Kong Chinese as suffering from insomnia during the preceding month (with a frequency of sleep disturbance of at least three times per week) was 11.9% (95% CI 11.2-12.6), including difficulty in initiating sleep (DIS) (4.5%; 95% CI 4.1-5.0), difficulty in maintaining sleep (DMS) (6.9%; 95% CI 6.4-7.5) and early morning awakening (EMA) (4.0%; 95% CI 3.6-4.4). Females were about 1.6 times at higher risk for insomnia than males. The prevalence of insomnia was also shown to increase with age. Multivariate analysis showed that unemployment, lower economic status, alcohol consumption, regular medication and psychiatric disturbance were all associated with higher risks of insomnia in both sexes. Furthermore, lower education level and being retired was associated with a higher risk of insomnia in males, but being a housewife, divorced/widowed, and complaining of a nocturnal noisy environment were associated with a higher risk of insomnia in females. Among all these factors, psychiatric disturbance was the most influential risk factor for insomnia in both sexes. The reasons for gender differences of insomnia may include their differences in the prevalence of psychiatric morbidities, symptom endorsement, gonadal steroids, sociocultural factors and coping strategies. CONCLUSIONS: Overall, 11.9% of the Hong Kong Chinese adult population complained of frequent insomnia in the preceding month. There was a higher prevalence of insomnia in females. Although there were common risk factors for insomnia in both sexes, there existed gender-specific risk factors.     

Prevalence of insomnia and associated factors in South Korea

INTRODUCTION: In Western countries, insomnia is associated with daytime impaired functioning, as well as physical and psychiatric illnesses. However, little information exists on insomnia in Asian countries. This study investigates the prevalence and correlates of insomnia in the general population of South Korea. METHODS: A representative sample of the South Korean general population composed of 3719 noninstitutionalized individuals aged 15 years or older were interviewed by telephone using the Sleep-EVAL system. The participation rate was 91.4%. The interviews covered sleep habits, sleep symptomatology, physical and psychiatric illnesses. DSM-IV sleep and psychiatric disorder diagnoses were also assessed. RESULTS: Insomnia symptoms occurring at least three nights per week were reported by 17.0% of the sample; difficulty initiating sleep (DIS) was mentioned by 4.0% of the sample, difficulty maintaining sleep (DMS) by 11.5%, early morning awakenings (EMA) by 1.8%, and nonrestorative sleep (NRS) by 4.7% of the sample. DSM-IV insomnia disorder diagnoses were found in 5% of the sample. Over 50% of subjects with insomnia symptoms reported important daytime consequences and another 20% reported mild or moderate consequences. However, the proportion of insomnia subjects seeking medical help for their sleep problems was very low (6.8%). CONCLUSIONS: As in Western countries, insomnia is widespread in South Korea, affecting nearly one in five individuals. Many of them would benefit from medical help; however, few insomnia subjects are consulting for this problem. An educational effort is needed for both the general population and the physicians.     

The association between sleep disturbance and second-hand smoke exposure: a large-scale,nationwide, cross-sectional study of adolescents in Japan

ObjectiveThis study investigated the association between secondhand-smoke (SHS) exposure and sleep disturbance symptoms.MethodsThis study was a cross-sectional survey of junior and senior high school students throughout Japan. A total of 85,931 adolescents responded, and 84,988 questionnaires were included in the analysis.ResultsAdolescents who had never smoked accounted for 88.0% of respondents; among that group 39.1% reported having been exposed to SHS over the previous week. The results of multiple logistic regression analyses indicated that the adjusted odds ratios for insomnia symptoms such as difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS) and early morning awakening (EMA), as well as sleep disturbance symptoms such as subjectively insufficient sleep and short sleep duration (<6 h), tended to be higher both among never-smoking adolescents with SHS exposure and among smoking adolescents, as compared with never-smoking adolescents without SHS exposure. When adolescents with one or more of DIS, DMS, and EMA were defined as having insomnia, the adjusted odds ratio for insomnia was highest for adolescents who smoked, followed in descending order by those exposed to SHS both inside and outside the home, those exposed to SHS only inside the home, those exposed to SHS only outside the home, and never-smoking adolescents without SHS exposure (p < 0.001).ConclusionsThe present study has revealed that SHS exposure is associated with sleep disturbance. Thus, in addition to smoking cessation programs, it is also necessary to endorse measures to protect adolescents from SHS exposure in order to promote good sleep in this population.     

Prevalence of Sleep Disturbances and Their Associations With Demographic and Clinical Characteristics and Quality of Life in Older Adults in Macao

PURPOSE

To examine the prevalence of sleep disturbances (difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], and early morning awakening [EMA]), their socio‐demographic and clinical correlates, and quality of life (QOL) in older adults in Macao.

DESIGN AND METHODS

Four hundred fifty‐one subjects were interviewed using standardized instruments.

FINDINGS

The prevalence of at least one type of sleep disturbance was 38.1%; the figures of DIS, DMS, and EMA were 18.6, 31.3, and 23.9%, respectively. Female sex and depressive symptoms were independently associated with more frequent sleep disturbances. Sleep disturbances were independently associated with lower physical QOL.

PRACTICE IMPLICATIONS

Sleep disturbances are common in older adults in Macao. Appropriate strategies should be implemented to prevent and treat sleep disturbances and concerted attempts should be made to improve access to treatment.     

Psychological factors and insomnia among male civil servants in Japan

OBJECTIVE: This study aims at assessing the relative impact of psychological factors on insomnia among daytime workers. BACKGROUND: Insomnia affects 5-45% of non-shift workers, making it a serious public health concern. METHODS: The study population was 3435 male civil servants aged 35 years and over. A self-administered questionnaire survey was conducted in 2002. Annual health examination data compiled in the same year were also obtained. Insomnia was assessed in three domains: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and poor quality of sleep (PQS). Association of each factor with insomnia was examined by age-adjusted logistic regression models. Factors significantly associated with insomnia in age-adjusted analyses were entered in the stepwise logistic regression models to test the relative impact of each factor. RESULTS: Prevalence of insomnia was 12.3% (DIS), 20.4% (DMS), and 32% (PQS). In stepwise logistic models, high perceived stress was associated with all types of insomnia with odds ratios (95% confidence interval) of 2.27 (1.58-3.26), 2.15 (1.57-2.95), and 2.96 (2.19-3.99), for DIS, DMS, and PQS, respectively. Poor psychological well-being or not having confidants was also associated with insomnia. Somatic conditions such as illnesses or history of hospitalization were related to DIS and DMS. CONCLUSIONS: Psychological factors were strongly associated with DIS and PQS after controlling for possible confounders. In dealing with insomnia, such factors must not be neglected.     

What are the contributing factors for insomnia in the general population?

Lack of a systematic assessment of insomnia has led to large variations in its reported prevalence in the general population. This study aims to provide new guidelines to assess insomnia prevalence. A cross-sectional telephone survey using the Sleep-EVAL system was done with 24,600 general population-based subjects 15 years and older representative of general populations (France, the UK, Germany, Italy, Portugal, and Spain) consisting of 251,405,391 inhabitants. The overall participation rate was 81.0%. Within the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) symptomatology for insomnia, 27.2% (95% confidence interval: 26.6–27.8%) of the sample reported difficulty initiating sleep (DIS) (10.1%) or maintaining sleep (DMS) (disrupted sleep (DS): 18.0%; early morning awakening (EMA): 10.9%) or nonrestorative sleep (NRS) (8.9%) at least three times per week; 48.5% of them were concomitantly suffering of a DSM-IV sleep/mental disorder. A factor analysis identified several variables strongly related to each of the major factors of insomnia allowing: (1) The narrowing of the definition of insomnia: the prevalence of insomnia decreased to 16.8% with 64.5% of insomnia subjects having a DSM-IV sleep/mental disorder; (2) The identification of a sleep-deprived (voluntary or not) group without insomnia symptoms, representing 2.1% (1.9–2.3%) of the sample. Interestingly, the latter group closely matched the definition of insufficient sleep syndrome as described by the International Classification of Sleep Disorders (ICSD). Using more delineated criteria to assess insomnia increases the recognition of subjects complaining about sleep. Classifications should be amended to improve the correct identification of insomnia. Sleep-deprived subjects should also not be neglected.     

Prevalence of insomnia symptoms: results from an urban district in Ankara,Turkey

Objective. Characteristics of insomnia symptoms in Turkey are not well established. The goal of this study was to determine the prevalence of insomnia and related symptoms in an urban district of Turkey. Method. The study was carried out in Ankara, in an urban district with a population of 2665. Out of the 1332 people in the sample, 1034 in the 15–65 age range were included in the study. Interviews were conducted according to the “Sleep Disorders Assessment Questionnaire” developed by the researchers. The Insomnia Severity Index (ISI) was also given to the subjects with a sleep problem to measure the subjective quality and quantity of insomnia symptoms. Results and conclusion. A total of 29.4% of all participants reported a sleep problem, out of which 23.7% defined one or more of the insomnia symptoms which included difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), non-restorative sleep (NRS) and sleep deprivation (SD). Insomnia risk was found to be significantly increased with age, female sex, smoking and chronic medical illness. A total of 75.9% of participants who reported insomnia symptoms did not seek medical help for their complaint. According to the ISI, among the subjects with insomnia symptoms, 79 (32.2%) had subthreshold insomnia, 43 (17.6%) had clinical insomnia, 12 (4.9%) had severe clinical insomnia, while 88 (35.9%) did not score in the range indicating insomnia. The findings are discussed in the light of previous research and in relation to sociocultural factors emphasizing the need for public education on sleep disorders as medical conditions.     

Effects of eszopiclone on safety, subjective measures of efficacy, and quality of life in elderly and nonelderly Japanese patients with chronic insomnia, both with and without comorbid psychiatric disorders: a 24-week, randomized, double-blind study

Background

The primary objective of this study was to evaluate long-term (24-week) safety of eszopiclone in elderly and nonelderly Japanese patients with chronic insomnia. The secondary objectives were to evaluate short-term (4-week) efficacy and to assess for rebound insomnia or dependence after long-term treatment.

Methods

Patients (n?=?164 elderly; n?=?161 nonelderly), with or without psychiatric comorbidities, were randomized to receive low-dose (1?mg, elderly; 2?mg, nonelderly) or high-dose (2?mg, elderly; 3?mg, nonelderly) eszopiclone. The safety evaluation included adverse events, vital signs, clinical laboratory parameters, and electrocardiogram. Efficacy was assessed using patient reports of sleep latency (SL), total sleep time (TST), wake time after sleep onset (WASO), number of awakenings (NA), quality of sleep, depth of sleep, daytime sleepiness, daytime ability to function, and the 36-item Short Form (SF-36) Health Survey.

Results

The rate of adverse events was 81.5% in the 1-mg elderly group, 79.5% in the 2-mg elderly group, 82.1% in the 2-mg nonelderly group, and 87.0% in the 3-mg nonelderly group. Dysgeusia was the most common adverse event and was dose-related. Of 12 serious adverse events, none were considered by the investigator to be related to study medication. No rebound insomnia was observed. Eszopiclone significantly improved SL, TST, WASO, NA, and daytime sleepiness and function from baseline to Week 4, irrespective of age and psychiatric comorbidity. Improvements were also observed in SF-36 Mental Health Component scores in elderly and nonelderly patients with psychiatric comorbidities.

Conclusions

Irrespective of age, eszopiclone appeared safe as administered in this study for 24?weeks. Eszopiclone improved sleep variables in insomnia patients with and without psychiatric disorders and health-related quality of life in those with psychiatric disorders.

Trial registration

ClinicalTrials.gov #NCT00770692; http://clinicaltrials.gov/ct2/show/NCT00770692.     

The prevalence of insomnia and its socio-demographic and clinical correlates in older adults in rural China: a pilot study

Objectives: To investigate the prevalence of insomnia (DIS: difficulty initiating sleep; DMS: difficulty maintaining sleep; and EMA: early morning awakening), its socio-demographic and clinical correlates, and the treatment patterns in older adults in rural China.

Method: A sample of 263 subjects was recruited in Mianyang and interviewed using standardized instruments. Basic socio-demographic and clinical data were collected.

Results: The expected mean total sleep time (TST) of the whole sample was 6.8 ± 2.2 hours, and the actual mean TST was 6.3 ± 2.1 hours. The 1-year prevalence of at least one type of insomnia was 7.6%; the rates of DIS, DMS, and EMA were 5.7%, 7.2%, and 6.8%, respectively. On multivariate analyses, female sex and psychiatric disorders were independently associated with more frequent insomnia.

Conclusion: Insomnia is not uncommon in older adults in rural China, and the low percentage of subjects treated suggests that improved access to treatment might be indicated.     

Association between reduced serum BDNF levels and insomnia with short sleep duration among female hospital nurses

ObjectivePrevious studies have suggested that brain-derived neurotrophic factor (BDNF) is associated with sleep regulation in humans. However, its relationship with self-reported sleep problems has not been clarified. The aim of the present study was to examine the association between serum BDNF levels and sleep problems among hospital nurses.MethodsParticipants were enrolled from among nurses working at a general hospital in Tokyo, Japan. Data from 577 women (age: 35.45 ± 10.90 years) were analyzed. This cross-sectional survey was conducted from November to December 2015. Serum BDNF concentrations were evaluated. Participants completed a self-reported questionnaire on sleep including the presence or absence of insomnia symptoms (ie, difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and early morning awakening [EMA]), and sleep duration. Insomnia with short sleep duration (ISS) was defined as: DIS, or DMS, or EMA; and <6 h sleep duration.ResultsAmong 577 participants, 21.3% reported insomnia, 41.4% slept less than 6 h, and finally 12.5% suffered from ISS. Serum BDNF levels were significantly lower in subjects with ISS than in those without ISS. The serum BDNF levels in insomniacs were significantly lower than in non-insomniacs for short sleep duration (<6 h), while serum BDNF levels did not differ between insomniacs and non-insomniacs for normal sleep duration (≥6 h).ConclusionThis is the first documented study to indicate that ISS is associated with reduced serum BDNF levels. These results may lead to clarification of the underlying pathophysiological relationship between BDNF and poor sleep.     

Mental health in Ecuadorian migrants from a population-based survey: the importance of social determinants and gender roles

Purpose

To describe the prevalence of and the risk factors for poor mental health in female and male Ecuadorian migrants in Spain compared to Spaniards.

Method

Population-based survey. Probabilistic sample was obtained from the council registries. Subjects were interviewed through home visits from September 2006 to January 2007. Possible psychiatric case (PPC) was measured as score of ??5 on the General Health Questionnaire-28 and analyzed with logistic regression.

Results

Of 1,122 subjects (50% Ecuadorians, and 50% women), PPC prevalence was higher in Ecuadorian (34%, 95% CI 29?C40%) and Spanish women (24%, 95% CI 19?C29%) compared to Ecuadorian (14%, 95% CI 10?C18%) and Spanish men (12%, 95% CI 8?C16%). Shared risk factors for PPC between Spanish and Ecuadorian women were: having children (OR 3.1, 95% CI 1.4?C6.9), work dissatisfaction (OR 4.1, 95% CI 1.6?C10.5), low salaries (OR 2.5, 95% CI 1.1?C5.9), no economic support (OR 1.8, 95% CI 0.9?C3.4), and no friends (OR 2.2, 95% CI 1.1?C4.2). There was an effect modification between the nationality and educational level, having a confidant, and atmosphere at work. Higher education was inversely associated with PPC in Spanish women, but having university studies doubled the odds of being a PPC in Ecuadorians. Shared risk factors for PPC in Ecuadorian and Spanish men were: bad atmosphere at work (OR 2.4, 95% CI 1.3?C4.4), no economic support (OR 3.5, 95% CI 1.3?C9.5), no friends (OR 2.5, 95% CI 0.9?C6.6), and low social support (OR 1.6, 95% CI 0.9?C2.9), with effect modification between nationality and partner??s emotional support.

Conclusions

Mental health in Spanish and Ecuadorian women living in Spain is poorer than men. Ecuadorian women are the most disadvantaged group in terms of prevalence of and risk factors for PPC.     

Insomnia and daytime neuropsychological test performance in older adults

Objectives/BackgroundThere is good documentation of the impact of insomnia on daytime cognitive function based on self-reports, but not on neuropsychological test performance. The study investigated the association of difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and early morning awakening (EMA) complaints with daytime domain-specific neuropsychological performance in older adults.Participants/MethodsParticipants were 859 older adults (mean 71.9 years) in the Singapore Longitudinal Ageing Studies. They were interviewed and assessed at community-based eldercare activity centres and completed a sleep survey questionnaire and a battery of neuropsychological tests (Digit span, Rey Auditory Verbal Learning Test, Story memory, Brief Visuospatial Memory Test-Revised, Color Trails Test (1 and 2), Block design, and Verbal fluency).ResultsInsomnia complaints were present in 18.0% (n = 155) of participants. Controlling for the presence of other insomnia complaints, psychosocial and medical variables, and depression, EMA was independently and significantly associated with worse executive functioning (p = 0.031). DIS and DMS were not independently associated with poorer performance on any cognitive domain.ConclusionThe association of EMA among older adults with decreased executive functioning and underlying mechanistic factors should be further investigated.     

Smoking and sleep disorders in Chinese adolescents

ObjectiveTo investigate the association between adolescent smoking and sleep disorders.MethodsIn the Hong Kong student obesity surveillance project, 29,397 Chinese students, aged 12–18 years, completed a health survey. Insomnia was defined as having any of the following three symptoms: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS) and early morning awakening (EMA). The presence of snoring and difficulty breathing during sleep (DBS) was also reported. Logistic regression yielded adjusted odds ratios (ORs) for each sleep disorder by smoking status.ResultsCompared with never smokers, the ORs (95% CI) of insomnia were 1.39 (1.25–1.54) for experimenters (smoked once or a few times) and 0.91 (0.83–1.00) for current smokers. The corresponding ORs were 1.42 (1.16–1.74) and 3.58 (3.15–4.06) for snoring (P for trend < 0.001) and 1.40 (1.10–1.79) and 3.39 (2.97–4.03) for DBS (P for trend < 0.001). Current smokers compared with never smokers were less likely to report DIS (OR = 0.43, 95% CI = 0.38–0.50, P < 0.001) and EMA (OR = 0.83, 95% CI = 0.73–0.94, P = 0.003), but more likely to report DMS (OR = 1.45, 95% CI = 1.28–1.63, P < 0.001).ConclusionsIn terms of dosage, adolescent smoking was associated with snoring and DBS, with increasing ORs from never smokers to experimental and current smokers. Current smoking was associated positively with DMS, but negatively with DIS and EMA.     

The impact of obesity and weight gain on development of sleep problems in a population-based sample

ObjectivesThe objective of this study was to investigate the role of obesity and weight gain in the development of sleep problems in a population-based cohort.Material and methodsA population-based sample of men (n = 1896, aged 40–79 years) and women (n = 5116, age ≥20 years) responded to questionnaires at baseline and follow-up after 10–13 years. Sleep problems were assessed through questions about difficulties initiating sleep (DIS), difficulties maintaining sleep (DMS), excessive daytime sleepiness (EDS), and insomnia. Body mass index (BMI) was calculated from self-reported weight and height at both baseline and follow-up, while confounding factors (physical activity, tobacco and alcohol use, somatic disease, and snoring) were based on responses at baseline.ResultsAlthough overweight and obese subjects reported more sleep problems at baseline, there was no independent association between BMI level at baseline and development of new sleep problems. Subjects in the quartile with the highest rise in BMI with a weight gain exceeding 2.06 kg/m² had a higher risk of developing DMS [adjusted odds ratio (OR) 1.58; 95% confidence interval (CI) 1.25–2.01), EDS (2.25; 1.65–3.06], and insomnia (2.78; 1.60–4.82). Weight gain was not associated with the development of DIS.ConclusionsWeight gain is an independent risk factor for developing several sleep problems and daytime sleepiness. The presence of overweight and weight gain should be considered when treating patients with sleep problems.     

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

ObjectiveSleep problems in humans have been reported to impact seriously on daily function and to have a close association with well-being. To examine the effects of individual sleep problems on physical and mental health, we conducted a nationwide epidemiological survey and examined the associations between sleep problems and perceived health status.MethodsCross-sectional surveys with a face-to-face interview were conducted in August and September, 2009, as part of the Nihon University Sleep and Mental Health Epidemiology Project (NUSMEP). Data from 2559 people aged 20 years or older were analyzed (response rate 54.0%). Participants completed a questionnaire on perceived physical and mental health statuses, and sleep problems including the presence or absence of insomnia symptoms (i.e., difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], and early morning awakening [EMA]), excessive daytime sleepiness (EDS), poor sleep quality (PSQ), short sleep duration (SSD), and long sleep duration (LSD).ResultsThe prevalence of DIS, DMS, and EMA was 14.9%, 26.6%, and 11.7%, respectively, and 32.7% of the sample reported at least one of them. At the complaint level, the prevalence of EDS, PSQ, SSD, and LSD was 1.4%, 21.7%, 4.0%, and 3.2%, respectively. Multiple logistic regression analyses revealed that DMS, PSQ, SSD, and LSD were independently associated with poor perceived physical health status; DIS, EDS, and PSQ were independently associated with poor perceived mental health status.ConclusionsThis study has demonstrated that sleep problems have individual significance with regard to perceived physical or mental health status.