Sleep duration and sleep disturbances partly explain the association between depressive symptoms and cardiovascular mortality: the Whitehall II cohort study

Depressive symptoms are associated with an increased risk of death, but most of this association remains unexplained. Our aim was to explore the contribution of sleep duration and disturbances to the association between depressive symptoms, all‐cause and cardiovascular disease mortality. A total of 5813 (4220 men and 1593 women) aged 50–74 years at baseline, participants of the British Whitehall II prospective cohort study, were included. Depressive symptoms, sleep duration and disturbances were assessed in 2003–04. Mortality was ascertained through linkage to the national mortality register until August 2012, with a mean follow‐up of 8.8 years. Depressive symptoms were associated with an increased risk of mortality from all causes [hazard ratio (HR) = 1.51; 95% confidence interval (CI): 1.16–1.97)] and cardiovascular diseases (HR = 1.63; 95% CI: 1.01–2.64) after adjustment for sociodemographic characteristics. Further adjustment for sleep duration and disturbances reduced the association between depressive symptoms and cardiovascular mortality by 21% (HR = 1.53; 95% CI: 0.91–2.57). Sleep seems to have a role, as a mediator or confounder, in explaining the association between depressive symptoms and cardiovascular mortality. These findings need replication in larger studies with longer follow‐up.     

Association between morningness‐eveningness,sleep duration,weekend catch‐up sleep and depression among Korean high‐school students

The present study aimed to examine the association between morningness‐eveningness preferences, sleep duration, weekend catch‐up sleep duration and depression among Korean high‐school students. A total of 8,655 high‐school students participated from 15 districts in South Korea and completed an online self‐report questionnaire. The following sleep characteristics were assessed: weekday and weekend sleep duration, weekend catch‐up sleep duration, morningness‐eveningness preference, perceived sufficiency of sleep, self‐reported snoring and sleep apnea, daytime sleepiness, and sleep environment. Age, gender, body mass index, number of private classes, proneness to internet addiction, and depressive mood were also evaluated. A logistic regression analysis was conducted to compute odds ratios for the association between depression and sleep characteristics, after controlling for relevant covariates. Eveningness preference was a significant predictor of depressive mood (adjusted OR, 1.71; 95% CI, 1.47–1.99). Weekend CUS durations that were ≥2 hr and enrollment in numerous private classes were associated with a lower risk for depression (0.68, 0.55–0.85; 0.76, 0.60–0.95; respectively). Female gender, underweight and obese body weight, short weekday sleep durations, excessive daytime sleepiness, perceived excessiveness and insufficiency of sleep, self‐reported snoring and sleep apnea, proneness to internet addiction and a non‐optimal sleep environment were associated with an increased risk for depression. Eveningness preference and insufficient weekday sleep duration were associated with an increased risk for depression. Weekend CUS duration ≥2 hr reduced the risk for depression. Diverse aspects, including sleeping habits and sleep‐related environmental factors, should be considered to reduce depressive symptoms in late adolescents.     

Multiple sleep latency test in narcolepsy type 1 and narcolepsy type 2: A 5‐year follow‐up study

Excessively sleepy teenagers and young adults without sleep‐disordered breathing are diagnosed with either narcolepsy type 1 or narcolepsy type 2, or hypersomnia, based on the presence/absence of cataplexy and the results of a multiple sleep latency test. However, there is controversy surrounding this nomenclature. We will try to find the differences between different diagnoses of hypersomnia from the results of the long‐term follow‐up evaluation of a sleep study. We diagnosed teenagers who had developed excessive daytime sleepiness based on the criteria of the International Classification of Sleep Disorders, 3rd edition. Each individual received the same clinical neurophysiologic testing every year for 5 years after the initial diagnosis of narcolepsy type 1 (n = 111) or type 2 (n = 46). The follow‐up evaluation demonstrated that narcolepsy type 1 (narcolepsy‐cataplexy) is a well‐defined clinical entity, with very reproducible clinical neurophysiologic findings over time, whereas patients with narcolepsy type 2 presented clear clinical and test variability. By the fifth year of the follow‐up evaluation, 17.6% of subjects did not meet the diagnostic criteria of narcolepsy type 2, and 23.9% didn't show any two sleep‐onset rapid eye movement periods in multiple sleep latency during the 5‐year follow‐up. Therefore narcolepsy type 1 (narcolepsy‐cataplexy) is a well‐defined syndrome, with the presentation clearly related to the known consequences of destruction of hypocretin/orexin neurons. Narcolepsy type 2 covers patients with clinical and test variability over time, thus bringing into question the usage of the term “narcolepsy” to label these patients.     

Disagreement between subjective and actigraphic measures of sleep duration in a population-based study of elderly persons

Sleep duration is an important concept in epidemiological studies. It characterizes a night's sleep or a person's sleep pattern, and is associated with numerous health outcomes. In most large studies, sleep duration is assessed with questionnaires or sleep diaries. As an alternative, actigraphy may be used, as it objectively measures sleep parameters and is feasible in large studies. However, actigraphy and sleep diaries may not measure exactly the same phenomenon. Our study aims to determine disagreement between actigraphic and diary estimates of sleep duration, and to investigate possible determinants of this disagreement. This investigation was embedded in the population-based Rotterdam Study. The study population consisted of 969 community-dwelling participants aged 57-97 years. Participants wore an actigraph and kept a sleep diary for, on average, six consecutive nights. Both measures were used to determine total sleep time (TST). In 34% of the participants, the estimated TST in the sleep diaries deviated more than 1 h from actigraphically measured TST. The level of disagreement between diary and actigraphic measures decreased with subjective and actigraphic measures of sleep quality, and increased with male gender, poor cognitive function and functional disability. Actigraphically measured poor sleep was often accompanied by longer subjective estimates of TST, whereas subjectively poor sleepers tended to report shorter TST in their diaries than was measured with actigraphy. We recommend, whenever possible, to use multiple measures of sleep duration, to perform analyses with both, and to examine the consistency of the results over assessment methods.     

A prospective study of change in sleep duration: associations with mortality in the Whitehall II cohort

STUDY OBJECTIVES: Although sleep curtailment has become widespread in industrialised societies, little work has examined the effects on mortality of change in sleep duration. We investigated associations of sleep duration and change in sleep duration with all-cause, cardiovascular, and non-cardiovascular mortality. DESIGN: Prospective cohort study. Data are from baseline (Phase 1, 1985-88) and Phase 3 (1991-93), with mortality follow-up of 17 and 12 years respectively. SETTING: The Whitehall II study of 10,308 white-collar British civil servants aged 35-55 at baseline. PARTICIPANTS: 9781 participants with complete data were included in the analyses at Phase 1, and 7729 of the same participants were included in the analyses at Phase 3 and the analyses of change in sleep duration. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: U-shaped associations were observed between sleep (< or =5, 6, 7, 8, > or =9 hours) at Phase 1 and Phase 3 and subsequent all-cause, cardiovascular, and non-cardiovascular mortality. A decrease in sleep duration among participants sleeping 6, 7, or 8 hours at baseline was associated with cardiovascular mortality, hazard ratio 2.4 (95% confidence intervals 1.4-4.1). However, an increase in sleep duration among those sleeping 7 or 8 hours at baseline was associated with non-cardiovascular mortality, hazard ratio 2.1 (1.4-3.1). Adjustment for the socio-demographic factors, existing morbidity, and health-related behaviours measured left these associations largely unchanged. CONCLUSIONS: This is the first study to show that both a decrease in sleep duration and an increase in sleep duration are associated with an increase in mortality via effects on cardiovascular death and non-cardiovascular death respectively.     

Association between left atrial enlargement and obstructive sleep apnea in a general population of 71‐year‐old men

Left atrial enlargement has been shown to be associated with obstructive sleep apnea in patients with coronary artery disease and in sleep clinic cohorts. However, data from the general population are limited. The aim of this study was to investigate whether there is an association between obstructive sleep apnea and left atrial enlargement in a random sample from a general population of 71‐year‐old men. As part of the longitudinal population study The Study of Men Born in 1943, we analysed cross‐sectional data for 411 men, all 71 years old, who had participated in an overnight home sleep study and a standardized echocardiographic examination. Of the 411 men, 29.4% had moderate to severe obstructive sleep apnea [apnea–hypopnea index score of ≥15 (n = 121)]. These participants showed a significantly higher frequency of systolic heart failure, hypertension, overweight, had greater waist circumference as well as higher left atrial areas compared with men with no or mild obstructive sleep apnea (23.7 ± 5.5 cm² versus 21.6 ± 4.5 cm², P < 0.001). In a linear regression analysis, obstructive sleep apnea was significantly associated with left atrial enlargement after adjusting for overweight, atrial fibrillation, heart failure with reduced ejection fraction, hypertension and mitral regurgitation. Compared with individuals without obstructive sleep apnea, the mean left atrial area was 1.7 ± 1.5 cm² larger in men with severe obstructive sleep apnea (P < 0.05) and 1.3 ± 1.1 cm² larger among men with moderate obstructive sleep apnea (P < 0.05). In this cross‐sectional study of 71‐year‐old men from the general population, left atrial area was independently associated with prevalence and severity of obstructive sleep apnea.     

Increased risk for new‐onset hypertension in midlife male snorers: The 14‐year follow‐up study

While the association between sleep‐related breathing disorders such as snoring and hypertension has been well established, it still remains unclear whether the association differs by age and gender. Therefore, in this 14‐year follow‐up study, we examined the independent association between self‐reported snoring and the incidence of hypertension by gender and age groups in a large cohort of Korean adults. A total of 4,954 adults, aged 40–69 years, free of hypertension at baseline were enrolled. Participants were divided into three groups based on a self‐reported snoring frequency: never; occasional (snoring <4 nights per week); and habitual snorer (snoring ≥4 nights). At baseline and biennial follow‐up visits, blood pressure was measured by trained examiners. Incident hypertension was defined as the first occurrence at any follow‐up examination where the participants had blood pressure ≥140/90 mmHg or were being treated with antihypertensive medication. After adjusting for known cardiovascular risk factors, only in men aged ≤45 years was habitual snoring significantly associated with a 1.5 times higher risk for incident hypertension than never snoring. In this age group, habitual snoring was significantly associated with increased risk for the development of hypertension, regardless of the presence of excessive daytime sleepiness. In women, snoring was not significantly associated with hypertension incidence in any age group. The present study suggests that young male snorers may be at high risk for the future development of hypertension, which has important clinical implications for early detection and treatment of snoring to reduce the burden of cardiovascular disease.     

Self-reported seasonality is associated with complaints of sleep problems and deficient sleep duration: the Hordaland Health Study

Change in sleep duration dependent on time of year is a central characteristic of seasonal affective disorder (SAD). In a community health survey, we analysed associations between seasonality, subjective sleep problems and sleep duration. Totally, 8860 subjects (3531 men and 5329 women) aged between 40 and 44 years were included in the study. Seasonal changes in mood and behaviour were measured by the Global Seasonality Score (GSS) questionnaire, and subjects were grouped in high (GSS > or = 11), moderate (GSS 8-10) or low (GSS < 8) seasonality groups. Sleep symptomatology was assessed using a modified version of the Karolinska Sleep Questionnaire. Significant sleep duration deficiency was defined as the difference between subjective sleep need and sleep duration of at least 1 h. Sleep problems suggesting insomnia as well as increased daytime sleepiness were more prevalent in the high/moderate seasonality groups compared with the low seasonality group. Seasonality was furthermore associated with shorter sleep duration and increased subjective sleep need. Significant sleep duration deficiency was more prevalent in subjects reporting high (men 20% and women 21%) and moderate (men 13% and women 19%) seasonality than subjects reporting low (men 10% and women 14%) seasonality. In conclusion, we found seasonal changes in mood and behaviour to be associated with several sleep-related complaints. Sleep duration deficiency increased with increasing seasonality, mainly due to increasing subjective sleep need.     

Relationships of sleep duration with sociodemographic and health‐related factors,psychiatric disorders and sleep disturbances in a community sample of Korean adults

The aim of this study is to examine relationships of sleep duration with sociodemographic and health‐related factors, psychiatric disorders and sleep disturbances in a nationwide sample in Korea. A total of 6510 subjects aged 18–64 years participated in this study. Logistic regression was used to calculate the odd ratios and 95% confidence intervals of the covariates, psychiatric disorders and sleep disturbances across the following sleep duration categories: 5 h or less, 6, 7, 8 and 9 h or more per day. Low levels of education, unemployment and physical illness were associated with sleeping for 5 h or less and 9 h or more. Being older and widowed/divorced/separated, high levels of physical activity, pain/discomfort, obesity and high scores on the General Health Questionnaires were associated with sleeping for 5 h or less. Female, being younger and underweight were associated with sleeping for 9 h or more. Alcohol dependence, anxiety disorder and social phobia were associated significantly with sleeping for 5 h or less and 9 h or more. Other psychiatric disorders were more common in subjects who slept for 5 h or less (e.g. alcohol use disorder, mood disorder, major depressive disorder, dysthymic disorder, obsessive‐compulsive disorder and specific phobia) or 9 h or more (e.g. post‐traumatic stress disorder). In addition, subjects who slept for 5 h or less reported more sleep disturbances than did subjects who slept for 7 h. Short or long sleep is associated with psychiatric disorders and/or sleep disturbance, therefore attention to the mental health of short or long sleepers is needed.     

Actigraphic sleep fragmentation,efficiency and duration associate with dietary intake in the Rotterdam Study

Short self‐reported sleep duration is associated with dietary intake and this association may partly mediate the link between short sleep and metabolic abnormalities. Subjective sleep measures, however, may be inaccurate and biased. The objective of this study was to evaluate the associations between actigraphic measures of sleep fragmentation, efficiency and duration and energy and macronutrient intakes. We used data from a subgroup of 439 participants of the population‐based cohort, Rotterdam Study. Sleep was assessed using 7‐day actigraphy and sleep diaries, and dietary data with a validated food frequency questionnaire. We assessed the associations of actigraphic sleep parameters with dietary intake using multivariable linear regression models. Higher sleep fragmentation was associated with 4.19 g lower carbohydrate intake per standard deviation of fragmentation {β [95% confidence interval (CI) = ?4.19 (?8.0, ?0.3)]; P = 0.03}. Each additional percentage increase in sleep efficiency was associated with 11.1 kcal lower energy intake [β (95% CI) = ?11.1 (?20.6, ?1.7); P = 0.02]. Furthermore, very short sleep duration (<5.5 h) was associated with 218.1 kcal higher energy intake [β (95% CI = 218.06 (33.3, 402.8), P = 0.02], relative to the reference group (≥6.5 to <7.5 h). We observed associations between higher sleep fragmentation with lower carbohydrate intake, and both lower sleep efficiency and very short sleep duration (<5 h) with higher energy intake. The association between sleep and higher energy intake could mediate, in part, the link between short sleep or sleep fragmentation index and metabolic abnormalities.     

Prevalence and association analysis of obstructive sleep apnea with gender and age differences – Results of SHIP‐Trend

Identification of obstructive sleep apnea and risk factors is important for reduction in symptoms and cardiovascular risk, and for improvement of quality of life. The population‐based Study of Health in Pomerania investigated risk factors and clinical diseases in a general population of northeast Germany. Additional polysomnography was applied to measure sleep and respiration with the objective of assessing prevalence and risk factors of obstructive sleep apnea in a German cohort. One‐thousand, two‐hundred and eight people between 20 and 81 years old (54% men, median age 54 years) underwent overnight polysomnography. The estimated obstructive sleep apnea prevalence was 46% (59% men, 33% women) for an apnea–hypopnea index ≥5%, and 21% (30% men, 13% women) for an apnea–hypopnea index ≥ 15. The estimated obstructive sleep apnea syndrome prevalence (apnea–hypopnea index ≥5; Epworth Sleepiness Scale >10) was 6%. The prevalence of obstructive sleep apnea continuously increased with age for men and women with, however, later onset for women. Gender, age, body mass index, waist‐to‐hip ratio, snoring, alcohol consumption (for women only) and self‐reported cardiovascular diseases were significantly positively associated with obstructive sleep apnea, whereas daytime sleepiness was not. Diabetes, hypertension and metabolic syndrome were positively associated with severe obstructive sleep apnea. The associations became non‐significant after adjustment for body mass. Women exhibited stronger associations than men. The prevalence of obstructive sleep apnea was high, with almost half the population presenting some kind of obstructive sleep apnea. The continuous increase of obstructive sleep apnea with age challenges the current theory that mortality due to obstructive sleep apnea and cardiovascular co‐morbidities affect obstructive sleep apnea prevalence at an advanced age. Also, gender differences regarding obstructive sleep apnea and associations are significant for recognizing obstructive sleep apnea mechanisms and therapy responsiveness.     

An open‐ended primary‐care group intervention for insomnia based on a self‐help book – A randomized controlled trial and 4‐year follow‐up

Chronic insomnia is a common and burdensome problem for patients seeking primary care. Cognitive behavioural therapy has been shown to be effective for insomnia, also when presented with co‐morbidities, but access to sleep therapists is limited. Group‐treatment and self‐administered treatment via self‐help books have both been shown to be efficacious treatment options, and the present study aimed to evaluate the effect of an open‐ended group intervention based on a self‐help book for insomnia, adapted to fit a primary‐care setting. Forty primary‐care patients with insomnia (mean age 55 years, 80% women) were randomized to the open‐ended group intervention based on a cognitive behavioural therapy for insomnia self‐help book or to a care as usual/wait‐list control condition. Results show high attendance to group sessions and high treatment satisfaction. Participants in the control group later received the self‐help book, but without the group intervention. The book‐based group treatment resulted in significantly improved insomnia severity, as well as shorter sleep‐onset latency, less wake time after sleep onset, and less use of sleep medication compared with treatment as usual. The improvements were sustained at a 4‐year follow‐up assessment. A secondary analysis found a significant advantage of the combination of the book and the open‐ended group intervention compared with when the initial control group later used only the self‐help book. An open‐ended treatment group based on a self‐help book for insomnia thus seems to be an effective and feasible intervention for chronic insomnia in primary‐care settings.     

Sleep problems and depressive symptoms in toddlers and 8‐year‐old children: A longitudinal study

Sleep and depression are interlinked throughout the lifespan, but very few studies have examined the directionality of the sleep–depression link in children. The aim of the current study was to prospectively examine the bidirectional association between sleep problems and internalizing problems and depressive symptoms in toddlers and children aged 1.5 and 8 years. Data stem from the large ongoing population‐based longitudinal study, the Norwegian Mother, Father and Child Cohort Study, recruited from October 1999 to July 2009. A total of 35,075 children were included. Information on sleep duration, nocturnal awakenings and internalizing problems (Child Behaviour Checklist) was provided by the mothers at 1.5 years, whereas data on sleep duration and depressive symptoms (Short Mood and Feelings Questionnaire) were provided by the mothers when the children were 8 years old. Odds ratios (ORs) were calculated using logistic regression analyses. After accounting for previous internalizing problems, short sleep duration (≤10 hr) and frequent (≥3) nightly awakenings at 1.5 years predicted the development of depressive symptoms at 8 years of age (adjusted OR = 1.28; 95% confidence interval [CI] 1.08–1.51, and adjusted OR = 1.27, 95% CI 1.08–1.50, respectively). Also, internalizing problems at 1.5 years predicted onset of later short sleep duration (adjusted OR = 1.83, 95% CI 1.32–2.54) after accounting for early sleep problems. This prospective study demonstrated a bidirectional association between sleep and internalizing/depressive symptoms from toddlerhood to middle childhood. Intervention studies are needed to examine whether targeting either of these problems at this early age may prevent onset of the other.     

Association of objectively measured sleep with frailty and 5-year mortality in community-dwelling older adults

Study ObjectivesTo determine whether actigraphy-measured sleep was independently associated with risk of frailty and mortality over a 5-year period among older adults.MethodsWe used data from Waves 2 (W2) and 3 (W3) (2010–2015) of the National Social Life, Health and Aging Project, a prospective cohort of community-dwelling older adults born between 1920 and 1947. One-third of W2 respondents were randomly selected to participate in a sleep study, of whom N = 727 consented and N = 615 were included in the analytic sample. Participants were instructed to wear a wrist actigraph for 72 h (2.93 ± 0.01 nights). Actigraphic sleep parameters were averaged across nights and included total sleep time, percent sleep, sleep fragmentation index, and wake after sleep onset. Subjective sleep was collected via questionnaire. Frailty was assessed using modified Fried Frailty Index. Vital status was ascertained at the time of the W3 interview. W3 frailty/mortality status was analyzed jointly with a four-level variable: robust, pre-frail, frail, and deceased. Associations were modeled per 10-unit increase.ResultsAfter controlling for baseline frailty (robust and pre-frail categories), age, sex, education, body mass index, and sleep time preference, a higher sleep fragmentation index was associated with frailty (OR = 1.70, 95% CI: 1.02–2.84) and mortality (OR = 2.12, 95% CI: 1.09–4.09). Greater wake after sleep onset (OR = 1.24, 95% CI: 1.02–1.50) and lower percent sleep (OR = 0.41, 95% CI: 0.17–0.97) were associated with mortality.ConclusionsAmong community-dwelling older adults, actigraphic sleep is associated with frailty and all-cause mortality over a 5-year period. Further investigation is warranted to elucidate the physiological mechanisms underlying these associations.     

Down syndrome in adults: a 27‐year follow‐up of adaptive skills

In 1988, we assessed the adaptive skills of 45 adults with Down syndrome (DS) (21 women and 24 men, age 20–58) with the Portage scale. Since then, we have followed them and also screened for signs of clinical dementia with the Present Psychiatric State – Learning Disabilities assessment. The mean adaptive age (AA) of the study group decreased with increasing age; the age of 35 being the turning point in the clinical course of DS. The mean AA was 4.4 years between ages 20 and 34, 3.4 years between ages 35 and 49, and 2.4 years between ages 50 and 66. Inter‐individual variation was, however, large. Between ages 20 and 25, the AA of the study subjects ranged from 2.3 to 6 years; and after the age of 50, from 0.3 to 4.8 years. By the end of the study, all subjects showed signs of clinical dementia. These appeared most frequently as reduced self‐care skills, loss of energy, forgetfulness, and impaired understanding. We found no connection between apolipoprotein E genotype and the clinical course of DS. We recommend follow‐up of adaptive skills and screening for dementia signs in adults with DS.     

Changes in sleep quality with age–a 36‐year follow‐up study of Finnish working‐aged adults

Long‐term follow‐up data on changes in sleep quality among middle‐aged adults is scarce. We assessed sleep quality in a population‐based cohort (n = 4847) of twins born between 1945 and 1957 during a follow‐up of 36 years, with four measurement points in 1975, 1981, 1990 and 2011. Sleep quality was categorized as sleeping well, fairly well, fairly poorly or poorly. The mean age at the beginning of follow‐up was 24.0, and at the end was 60.3 years. Of all the adults, 71.1% slept well or fairly well at each time‐point throughout the follow‐up and 0.5% poorly or fairly poorly. The proportion of those sleeping poorly or fairly poorly increased linearly over time; 3.5% among both sexes at the start, and 15.5% among men and 20.9% among women at the end of the follow‐up. The last survey indicated a strong association between self‐rated health and sleep quality: sleeping poorly or fairly poorly was reported 15 times more frequently by those rating their health as fairly poor than by those rating their health as very good. There was a strong association between indicators of depression and poor sleep. Although many studies have reported increasing frequencies in sleep problems, our results, based on a long‐term cohort study, indicate that the majority of people sleep well or fairly well. Sleep quality declines with age, but only a very small fraction of the adults in this long follow‐up consistently slept poorly.