Racial/ethnic disparities in sleep duration and sleep disturbances among pregnant and non‐pregnant women in the United States

Sleep disturbances among pregnant women are increasingly linked to suboptimal maternal/birth outcomes. Few studies in the USA investigating sleep by pregnancy status have included racially/ethnically diverse populations, despite worsening disparities in adverse birth outcomes. Using a nationally representative sample of 71,644 (2,349 pregnant) women from the National Health Interview Survey (2004–2017), we investigated relationships between self‐reported pregnancy and six sleep characteristics stratified by race/ethnicity. We also examined associations between race/ethnicity and sleep stratified by pregnancy status. We used average marginal predictions from fitted logistic regression models to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) for each sleep dimension, adjusting for sociodemographic and health characteristics. Pregnant women were less likely than non‐pregnant women to report short sleep (PR_Overall = 0.75; 95% CI, 0.68–0.82) and more likely to report long sleep (PR_Overall = 2.06; 95% CI, 1.74–2.43) and trouble staying asleep (PR_Overall = 1.34; 95% CI, 1.25–1.44). The association between pregnancy and sleep duration was less pronounced among women aged 35–49 years compared to those <35 years. Among white women, sleep medication use was less prevalent among pregnant compared to non‐pregnant women (PR_White = 0.45; 95% CI, 0.31–0.64), but this association was not observed among black women (PR_Black = 0.98; 95% CI, 0.46–2.09) and was less pronounced among Hispanic/Latina women (PR_{Hispanic/Latina} = 0.82; 95% CI, 0.38–1.77). Compared to pregnant white women, pregnant black women had a higher short sleep prevalence (PR_Black = 1.35; 95% CI, 1.08–1.67). Given disparities in maternal/birth outcomes and sleep, expectant mothers (particularly racial/ethnic minorities) may need screening followed by treatment for sleep disturbances. Our findings should be interpreted in the historical and sociocultural context of the USA.     

Association between short sleep and suicidal ideation and suicide attempt among adults in the general population

OBJECTIVE: To determine the association between sleep, mental disorders, and suicidal ideation (SI) and suicide attempt (SA) among adults in the community. DESIGN: Cross-sectional. SETTING: National Comorbidity Survey (n = 8098). PARTICIPANTS: A representative sample of adults in the United States. MEASUREMENTS AND RESULTS: Multiple logistic regression analyses were used to determine the association between usual number of hours of sleep during a 24-h period and SI and SA (past 12 months and lifetime). Analyses were adjusted for differences in demographic characteristics and comorbid mental disorders. Additional analyses examined the relationship between hours of sleep and the odds of SA among adults with SI, compared with SI without SA. Short sleep was associated with significantly increased odds of SI (OR 2.5, 95% CI: 1.6-3.9) and SA (OR 3.0, 95% CI: 1.4-6.4), and with SA among those with SI (past 12 months). These associations persisted after adjusting for differences in demographic characteristics and mental disorders, though the links between short sleep and SA among those with SI were no longer statistically significant after adjusting for panic, mood, and substance use disorders. CONCLUSIONS: Short sleep appears to be associated with increased likelihood of SI and SA, independent of the effects of comorbid mental disorders, among adults in the community. Among adults with SI, short sleep is associated with increased odds of SA, and this association seems largely related to the presence of panic attacks, mood, and substance use disorders. Future studies should investigate the nature of these relationships, and whether and how mental health problems may play a role.     

Simplified sleep restriction for insomnia in general practice: a randomised controlled trial

Background

Insomnia is common in primary care. Cognitive behavioural therapy for insomnia (CBT-I) is effective but requires more time than is available in the general practice consultation. Sleep restriction is one behavioural component of CBT-I.

Aim

To assess whether simplified sleep restriction (SSR) can be effective in improving sleep in primary insomnia.

Design and setting

Randomised controlled trial of patients in urban general practice settings in Auckland, New Zealand.

Method

Adults with persistent primary insomnia and no mental health or significant comorbidity were eligible. Intervention patients received SSR instructions and sleep hygiene advice. Control patients received sleep hygiene advice alone. Primary outcomes included change in sleep quality at 6 months measured by the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and sleep efficiency (SE%). The proportion of participants reaching a predefined ‘insomnia remission’ treatment response was calculated.

Results

Ninety-seven patients were randomised and 94 (97%) completed the study. At 6-month follow-up, SSR participants had improved PSQI scores (6.2 versus 8.4, P<0.001), ISI scores (8.6 versus 11.1, P = 0.001), actigraphy-assessed SE% (difference 2.2%, P = 0.006), and reduced fatigue (difference −2.3 units, P = 0.04), compared with controls. SSR produced higher rates of treatment response (67% [28 out of 42] versus 41% [20 out of 49]); number needed to treat = 4 (95% CI = 2.0 to 19.0). Controlling for age, sex, and severity of insomnia, the adjusted odds ratio for insomnia remission was 2.7 (95% CI = 1.1 to 6.5). There were no significant differences in other outcomes or adverse effects.

Conclusion

SSR is an effective brief intervention in adults with primary insomnia and no comorbidities, suitable for use in general practice.     

Sleep complaints associated with wish to die after a suicide crisis—an exploratory study

The present study explores whether sleep concerns are associated with wish to die throughout a 1‐month time interval following a suicide crisis. Sixty‐eight patients admitted to the emergency department of a general or psychiatric hospital were enrolled. Sleep difficulties were assessed using the Insomnia Severity Index (ISI), the Epworth Sleepiness Scale, self‐reported satisfaction with sleep and time in bed. Suicidal ideation was assessed through the presence of a wish to die at 1 month following a suicide crisis. Co‐existing psychiatric diagnoses were assessed using the French version of the Mini International Neuropsychiatric Interview (MINI). Potential covariate factors such as personal and family history of suicidal behaviours and sociodemographic variables were accounted for. We found that wish to die was associated significantly with insomnia severity, low satisfaction with sleep and sleep duration 1 month after the suicide crisis, even after controlling for covariates. This exploratory study is limited by a small sample size, and results cannot be generalized to patients with psychotic disorders or alcohol use disorders. Also, other factors related potentially to suicidal ideation, such as depression severity, stressful events or levels of family support, were not accounted for. However, overall our study supports the assessment of sleep complaints as a potential indicator of suicide risk in the weeks that follow a suicide crisis.     

Sleep disturbances as a predictor of cause-specific work disability and delayed return to work

Study Objective:

To examine sleep disturbances as a predictor of cause-specific work disability and delayed return to work.

Design:

Prospective observational cohort study linking survey data on sleep disturbances with records of work disability (≥ 90 days sickness absence, disability pension, or death) obtained from national registers.

Setting:

Public sector employees in Finland.

Participants:

56,732 participants (mean age 44.4 years, 80% female), who were at work and free of work disability at the study inception.

Measurements and Results:

During a mean follow-up of 3.3 years, incident diagnosis-specific work disability was observed in 4,028 (7%) employees. Of those, 2,347 (60%) returned to work. Sleep disturbances 5-7 nights per week predicted work disability due to mental disorders (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.3-1.9) and diseases of the circulatory system (HR = 1.6, 95% CI 1.2-2.1), musculoskeletal system (HR = 1.6, 95% CI 1.4-1.8) and nervous system (HR = 1.5, 95% CI 1.0-2.2), and injuries and poisonings (HR = 1.6, 95% CI 1.2-2.1) after controlling for baseline age, sex, socioeconomic status, night/shift work, health behaviors (e.g., smoking, exercise), diagnosed somatic diseases, use of pain killers, depression, and anxiety. In addition, sleep disturbances prior to disability were associated with higher likelihood of not returning to work after work disability from musculoskeletal diseases (HR = 1.2, 95% CI 1.1-1.7) and, in men, after work disability due to mental disorders (HR = 4.4, 95% CI 1.7-11.1).

Conclusions:

Sleep disturbances are associated with increased risk for subsequent disabling mental disorders and various physical illnesses. They also predict the outcome of work disability due to musculoskeletal disorders.

Citation:

Salo P; Oksanen T; Sivertsen B; Hall M; Pentti J; Virtanen M; Vahtera J; Kivimäki M. Sleep disturbances as a predictor of cause-specific work disability and delayed return to work. SLEEP 2010;33(10):1323-1331.     

Association of hostility with sleep duration and sleep disturbances in an employee population

Background: Sleep disturbances are common among the general population, and hostile persons have been proposed to be at greater risk of several serious health problems and diseases. Purpose: This study examined the relationships between hostility, sleep disturbances, and sleep duration in a large non-clinical sample of 5,433 employees working in 12 Finnish hospitals. Method: Data were collected by questionnaire surveys in 1998 and 2000. Results: Higher hostility was cross-sectionally associated with increased sleep disturbances but not with sleep duration after adjustment for gender, age, marital status, education, shift work, smoking, alcohol consumption, physical activity, body mass index, psychiatric morbidity, and somatic disease. A stratified analysis distinguishing individuals with stable hostility across the two measurements and those with transient hostility (>0.5 SD difference between measurements) replicated the association with increased sleep disturbance in both groups, but among those with transient hostility, there additionally was a cross-sectional association between higher hostility and shorter sleep duration. Conclusion: Our evidence suggests that hostility is an independent risk factor for sleep disturbances and that transient hostility may also predispose shorter sleep duration. However, the effect sizes for all these associations were small, suggesting limited clinical significance for our findings.     

Chronic disease and lifestyle factors associated with change in sleep duration among older adults in the Singapore Chinese Health Study

Identifying risk factors for future change in sleep duration can clarify whether, and if so how, sleep and morbidity are bidirectionally related. To date, only limited longitudinal evidence exists characterizing changes to sleep duration among older adults. This study aimed to identify factors associated with change in sleep duration in a large sample of older adults (≥ 60 years) residing in Singapore (n = 10 335). These adults were monitored as part of the Singapore Chinese Health Study, which collected information regarding daily sleep duration at baseline (assessed in 1993–1998) and at a follow‐up wave conducted over a mean of 12.7 years later (assessed in 2006–2010). Among adults sleeping 6–8 h at baseline (n = 8265), most participants (55.6%) remained 6–8 h sleepers at follow‐up, while 8.4% became short (< 6 h) and 36.0% became long (> 8 h) sleepers. A history of stroke, diabetes, cancer, hip fracture and greater age all independently increased the odds of having long sleep duration at follow‐up, while greater educational attainment and weekly physical activity were both associated with reduced odds of becoming a long sleeper. Other than greater baseline age, the only factor related to higher odds of becoming a short sleeper was concurrent stomach/duodenal ulcer at follow‐up. Long sleep duration among older adults may therefore reflect longstanding disease processes, whereas the aetiology of short sleep may predominately involve factors other than those examined. Future research is needed to distinguish if/when long sleep duration serves the disease recovery process, and when long sleep duration complicates disease and requires sleep medicine interventions.     

Short and long sleep duration are associated with prevalent cardiovascular disease in Australian adults

A growing number of studies from a range of different countries have observed an association between sleep duration and cardiovascular disease. The objective of this paper was to examine the associations between sleep duration and prevalent cardiovascular disease in a large sample of Australian adults, and identify the sociodemographic and health-related factors moderating these associations. Participants included 218,155 Australian adults aged 45years and over. The results indicated that 6h versus 7h sleep was associated with increased odds of heart disease [odds ratio (OR)=1.11 (1.06-1.17)], diabetes [OR=1.15 (1.09-1.22)], stroke [OR=1.25 (1.14-1.38)] and high blood pressure [OR=1.08 (1.04-1.11)]. Long sleep (≥9h sleep) was also related to elevated odds of heart disease [OR=1.14 (1.09-1.19)], diabetes [OR=1.25 (1.19-1.31)], stroke [OR=1.50 (1.38-1.62)] and high blood pressure [OR=1.04 (1.01-1.08)] compared to 7h sleep. Some of these relationships varied by age, and were not evident in adults aged 75years and over. The magnitude of some associations varied significantly by body mass index, smoking and physical activity. These findings provide further insight into the nature of the relationship between sleep and cardiovascular health.     

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.     

Association between sleep duration and all‐cause mortality in old age: 9‐year follow‐up of the Bambuí Cohort Study,Brazil

This study investigates the association of sleep duration with risk of all‐cause mortality among elderly Brazilians using data from a 9‐year population‐based cohort study and applying a multivariable longitudinal categorical and continuous analysis using Cox’s proportional hazards models. This analysis used data from the Bambui Health and Ageing Study (BHAS), conducted in Bambuí city (approximately 15 000 inhabitants) in southeastern Brazil. The study population comprised 1512 (86.8%) of all eligible 1742 elderly residents. In multivariable analysis, using sleep duration as categorical variable and controlling for multiple measures of sociodemographic and health status, those who slept 9 h or more per night were found to be at higher risk of mortality than those who slept 7 h [hazard ratio (HR): 1.53; 95% confidence interval (CI): 1.12–2.09]. Excluding those whose deaths occurred within 2 years after entry, this association remained significant (HR: 1.56; 95% CI: 1.12–2.18). In analyses using sleep duration as a continuous variable, a linear correlation was found between sleep duration and mortality in all adjusted models in the whole sample (HR: 1.08; 95% CI: 1.02–1.15) and following exclusion of those whose deaths occurred within 2 years after entry (HR: 1.13; 95% CI: 1.06–1.21). Both linear and quadratic terms were significant, reflecting a predicted relationship, with mortality predominantly increasing in association with long sleep duration but with the addition of a slight decrease in association with shorter sleep duration. In conclusion, long rather than short sleep duration was associated principally with all‐cause mortality in this sample. It is therefore reasonable to suggest that clinicians should be aware of the potential adverse prognosis associated with prolonged sleep.     

Pregnancy and perinatal complications associated with risks for common psychiatric disorders in a population‐based sample of female twins

The association between pregnancy and perinatal complications (PPCs) and risks for adult psychiatric disorders other than psychoses has received relatively limited attention. In this study, we aim to characterize the associations between PPCs and risks for anxiety, affective, substance use, and eating disorders in a population‐based sample of twins. Personal interviews were conducted with 1,806 female twin subjects to assess their lifetime history of alcoholism, anorexia nervosa, bulimia nervosa, generalized anxiety disorder, major depression, panic disorder, simple phobias, and social phobias. PPCs were retrospectively assessed at personal interview with the subject's parents. The associations between PPCs and risks for psychiatric disorders are characterized using logistic regression. In this sample of twins, gestational age is associated with a significantly increased risk for anorexia nervosa and pregnancy complications are associated with a significantly increased risk for both anorexia nervosa and bulimia nervosa. Pregnancy and perinatal complications may be associated with an increased risk for eating disorders in women. © 2001 Wiley‐Liss, Inc.     

Sleep and dream habits in a sample of French college students who report no sleep disorders

There is a lack of up‐to‐date data on sleep and dream habits of college students. To fill in this gap, we used an online questionnaire sent to the student mailing lists of two major universities of Lyon (Lyon 1 and Lyon 2) for the recruitment of an functional magnetic resonance imaging study with sleep disorders as exclusion criteria. In the sample (1,137 French college students, 411 males, mean age = 22.2 ± 2.4 years, body mass index = 22.0 ± 3.2 kg m^?2), on average, the participants reported spending about 8 hr in bed during weekdays, 9 hr during the weekends, and 90.9% of them reported no difficulty falling asleep. Less than 0.4% of students reported to have sleep‐walking episodes regularly, but nearly 7% reported regular sleep‐talking episodes. The average dream recall frequency was about 3 mornings per week with a dream in mind. Dream recall frequency was positively correlated with the clarity of dream content and the frequency of lucid dreaming, and was negatively correlated with age. Fourteen percent of the students reported frequent lucid dreams, and 6% reported frequent recurrent dreams. We found a gender effect for several sleep and dream parameters, including dream recall frequency and time in bed, both of which were higher in women than in men. We have also observed differences between academic disciplines, namely humanities students (Lyon 2) reported spending more time in bed than sciences students (Lyon 1). These results confirm a gender difference for several sleep and dream parameters, and suggest a link between academic disciplines and sleep duration.     

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.     

Efficacy and safety of as-needed, post bedtime dosing with indiplon in insomnia patients with chronic difficulty maintaining sleep

OBJECTIVE: To evaluate the efficacy and tolerability of immediate release indiplon capsules in patients with chronic insomnia using an "as-needed" dosing strategy in response to difficulty falling back to sleep following a middle of the night, nocturnal awakening. METHODS: Adult outpatients (N=264; 71% female; age, 46 years) who met DSM-IV criteria for primary insomnia, with average total sleep time (TST) < 6.5 hours and >8 nights in the past month with nocturnal awakenings, were randomized to 4 weeks of double-blind treatment with 10 mg or 20 mg indiplon capsules, or placebo. The primary endpoint was latency to sleep onset post-dosing after a middle of the night awakening (LSOpd). Secondary endpoints included patients' subjective assessment of total sleep time (sTSTpd). Next day residual effects were evaluated by a 100 mm Visual Analog Scale (VAS) rating of sleepiness. RESULTS: Both doses of indiplon significantly reduced LSOpd at all time-points. Compared to placebo (45.2 min), the 4-week least squares (LS) mean LSOpd was 36.5 min in the indiplon 10 mg group (P = 0.0023) and 34.4 min in the indiplon 20mg group (P < 0.0001). The 4-week LS mean sTSTpd was higher in the indiplon 10 mg group (253 min) and 20mg group (278 min) compared to placebo (229 min; P < 0.01 for both comparisons). There was no increase observed in VAS ratings of next-day sleepiness for either dose of indiplon when compared to placebo. Indiplon was well-tolerated at both doses. CONCLUSIONS: Patients with chronic insomnia with nocturnal awakenings achieved significant and sustained improvement in sleep parameters while utilizing an as-needed post bedtime dosing strategy with indiplon capsules. Indiplon was well-tolerated, with no self-rated, next-day residual effects.     

Psychosocial work characteristics,sleep disturbances and risk of subsequent depressive symptoms: a study of time‐varying effect modification

Job strain and low social support at work are recognized risk factors for depression. However, people with poor sleep may represent a high‐risk group more likely to benefit from interventions against work stress. The present study examined whether the associations between these work stressors and depressive symptoms differed by strata of sleep disturbances (effect modification/effect moderation) considering repeat measures of work characteristics and sleep. The study was based on five biennial measurements of the Swedish Longitudinal Occupational Survey of Health, including 1537 respondents recurrently in paid work, from an originally representative sample of the Swedish working population. High work demands, low decision authority and low social support were measured waves 2 and 4, sleep disturbances (putative moderator/modifier) waves 1 and 3, and depressive symptoms (outcome) wave 5. Causal effect modification, whether the effect of working conditions differed by strata of sleep disturbances, was analysed by structural nested mean modelling estimated using a regression‐with‐residuals with inverse‐probability‐of‐treatment weighting approach. High demands and low social support, but not low decision authority, influenced subsequent depressive symptoms. The relationship between social support and depressive symptoms was not apparently modified by sleep disturbances. However, disturbed sleep wave 3 modified the effect of high demands wave 4 (coefficient 1.77, P < 0.05) on depressive symptoms wave 5. The results indicate that high job demands is a stronger risk factor for depressive symptoms in people with pre‐existing sleep disturbances, suggesting that targeted workplace interventions may be more effective when it comes to preventing negative effects of job demands.     

Sleep duration associated with mortality in elderly, but not middle-aged, adults in a large US sample

STUDY OBJECTIVES: To explore age differences in the relationship between sleep duration and mortality by conducting analyses stratified by age. Both short and long sleep durations have been found to be associated with mortality. Short sleep duration is associated with negative health outcomes, but there is little evidence that long sleep duration has adverse health effects. No epidemiologic studies have published multivariate analyses stratified by age, even though life expectancy is 75 years and the majority of deaths occur in the elderly. DESIGN: Multivariate longitudinal analyses of the first National Health and Nutrition Examination Survey using Cox proportional hazards models. SETTING: Probability sample (n = 9789) of the civilian noninstitutionalized population of the United States between 1982 and 1992. PARTICIPANTS: Subjects aged 32 to 86 years. MEASUREMENTS AND RESULTS: In multivariate analyses controlling for many covariates, no relationship was found in middle-aged subjects between short sleep of 5 hours or less and mortality (hazards ratio [HR] = 0.67, 95% confidence interval [CI] 0.43-1.05) or long sleep of 9 hours or more and mortality (HR = 1.04, 95% CI 0.66-1.65). A U-shaped relationship was found only in elderly subjects, with both short sleep duration (HR = 1.27, 95% CI 1.06-1.53) and long sleep duration (HR = 1.36, 95% CI 1.15-1.60) having significantly higher HRs. CONCLUSIONS: The relationship between sleep duration and mortality is largely influenced by deaths in elderly subjects and by the measurement of sleep durations closely before death. Long sleep duration is unlikely to contribute toward mortality but, rather, is a consequence of medical conditions and age-related sleep changes.     

Insomnia,Depression, and Physical Disorders in Late Life: A 2-year Longitudinal Community Study in Koreans

Study Objectives:

To investigate prevalence, incidence, and persistence of insomnia, and their bidirectional longitudinal associations with depression and physical disorders.

Design:

A community based longitudinal study.

Setting:

Elders living in private households in South Korea.

Participants:

1204 people ≥ 65 years of age were evaluated at baseline; 909 of them (75%) were re-interviewed after 2 years.

Measurements and Results:

Insomnia was defined as difficulty in initiation or maintenance of sleep ≥ 3 nights per week over the last month. Diagnosis of depression (Geriatric Mental State) and number of physical disorders were ascertained. Sociodemographic and clinical covariates included age, gender, education, housing, past occupation, current employment, living area, life events, social deficit, physical activity, cognitive impairment, anxiety, and daily drinking. Of those (27%) with insomnia at baseline, 40% had insomnia at follow-up. Of those without insomnia at baseline, 23% had insomnia at follow-up. Baseline depression was significantly associated with prevalence and incidence of insomnia. Baseline number of physical disorders was significantly associated with prevalence, incidence, and persistence of insomnia. Baseline insomnia was independently associated with incident depression and an increase in reported physical disorders.

Conclusions:

Insomnia was common and often persistent in this population. Insomnia was closely and reciprocally related to depression and physical disorders.

Citation:

Kim JM; Stewart R; Kim SW; Yang SJ; Shin IS; Yoon JS. Insomnia, depression, and physical disorders in late life: a 2-year longitudinal community study in Koreans. SLEEP 2009;32(9):1221-1228.     

Cold extremities and difficulties initiating sleep: evidence of co‐morbidity from a random sample of a Swiss urban population

Difficulties initiating sleep (DIS) can frequently occur in psychiatric disorders but also in the general population. The primary vasospastic syndrome is a functional disorder of vascular regulation in otherwise healthy subjects complaining of thermal discomfort from cold extremities (TDCE). Laboratory studies have shown a close relationship between long sleep onset latency and increased distal vasoconstriction in healthy young subjects. Considering these findings, the aims of the Basel Survey were to assess the prevalence rates for DIS and TDCE and to determine whether both symptoms can be associated in the general population. In a random population sample of Basel‐Stadt, 2800 subjects (age: 20–40 years) were requested to complete a questionnaire on sleep behavior and TDCE (response rate: 72.3% in women, n = 1001; 60.0% in men, n = 809). Values of DIS and TDCE were based on questionnaire‐derived scores. In addition, TDCE was externally validated in a separate group of subjects (n = 256) by finger skin temperature measurements—high TDCE values were significantly associated with low finger skin temperature. A total of 31.1% of women and 6.9% of men complain of TDCE. In contrast, prevalence rates of DIS were only slightly higher in women in comparison to men (9.3% versus 6.7%, P < 0.1). Irrespective of gender, each seventh subject complaining of TDCE had concomitant DIS and the relative risk in these subjects was approximately doubled. Therefore, a thermophysiological approach to DIS may be relevant for its differential diagnosis and its treatment.