Long sleepers sleep more and short sleepers sleep less: a comparison of older adults who sleep well

To determine some of the risks and benefits of being a long or short sleeper, psychological adjustment, lifestyle, and sleep parameters were investigated in 239 older adults. Responses of people who slept well and who were either long or short sleepers were studied on 48 variables investigating sleep parameters and sleep-related affect and beliefs; daytime fatigue and sleepiness; demographic factors, including age, sex, and income satisfaction; sleep lifestyle factors, including naps, bedtimes, arising times, and the regularity of these; general lifestyle factors, including regularity of mealtimes, overall daytime pleasantness, perceived busyness, diversity and valence of daily activities, and potentially stressful major life events. In addition, 14 variables evaluated aspects of psychological adjustment, including cognitive and somatic arousal, nocturnal tension, anxious, negative, unpleasant and worrying self-talk, depression, anxiety, overall psychopathology, neuroticism, and life satisfaction. Overall, the results indicate that short sleepers get up earlier, spend less time in bed, and have lower sleep efficiencies than their long sleeper counterparts. They eat breakfast earlier, and of course, they sleep less. Only one of the 14 psychological adjustment variables was significant. In view of the many differences between short and long sleepers described in prior research, the lack of differences observed between long and short sleepers is noteworthy.     

Sleep quality subtypes in midlife women.

Eighty-two midlife women (40-59 years) were classified as poor or good sleepers according to either self-reported sleep quality or a sleep efficiency index (SEI) criterion, for comparison of wakefulness, fragmentation and other somnographic sleep variables; as well as psychological (SCL-90) and somatic symptom distress. When classified solely by self-report, the good and poor sleeper groups did not differ on any somnographic variables but self-declared poor sleepers had higher psychological distress scores than good sleepers (p less than or equal to 0.01). When classified solely by the SEI criterion, the good and poor sleepers did not differ on psychological distress but, as expected, differed on various somnographic wakefulness as well as rapid eye movement and stage 2 sleep variables. Further analysis of four subgroups derived by combining objective and subjective, good and poor sleep scores indicated that 15% of this sample (n = 12) perceived but had no objective evidence of poor sleep, and this group scored highest in psychological distress. Only seven women perceived poor sleep in concert with demonstrating low SEI. They scored highest in menopausal symptoms but not in general psychological distress.     

A three-phase epidemiological study of short and long sleepers in a middle-aged Chinese population: prevalence and characteristics

Epidemiological studies of short and long sleepers have not been conducted previously. We collected socioeconomic, psychological, and polysomnographic characteristics of 6501 parents (3252 men and 3249 women) of 4036 primary school children in Guangzhou city. The study data were collected in three phases. The overall prevalence of short (5 h or less) and long (10 h or more) sleep duration was 0.52 and 0.64%, respectively. Long sleepers had higher Eysenck Personality Questionnaire neuroticism scores [odds ratio (OR)=1.224, 95% confidence interval (CI)=1.047-1.409] and lower education levels (OR=0.740, 95%CI=0.631-0.849) than short sleepers. In the polysomnographic assessment, short, long, and normal sleepers (7-8 h) shared similar durations of Stage 3 sleep (short=25.7±10.7, long=20.3±7.9, and normal=28.0±12.8 min, F=1.402, P=0.181). In daytime multiple sleep latency tests, short sleepers (10/19, 52.6%) were more prone to have a short sleep latency (≤8 min) than long sleepers (2/23, 8.7%). In addition to different sleep durations, neuroticism might also contribute to differences between short and long sleepers in social achievements. Stage 3 sleep might be essential for humans. The short sleep latency (≤8 min) of short sleepers in multiple sleep latency tests should be interpreted cautiously, since it was of the same severity as required for a diagnosis of narcolepsy or idiopathic hypersomnia.     

Role of Nocturnal Cognitive Arousal in the Complaint of Insomnia Among Older Adults

Self-reported cognitive activity has been hypothesized to contribute directly to problematic sleep. We evaluated this formulation by examining nocturnal sleep parameters, daytime functioning and psychological adjustment cross-sectionally (N = 183) in four groups of older adults: good and poor sleepers with high and low cognitive arousal. Results indicate that when sleep quality was controlled for, individuals with high and low nocturnal cognitive arousal did not differ on either nocturnal or daytime aspects of the insomnia complaint. They were, however, less well adjusted psychologically. The pattern of findings suggests that high cognitive arousal contributes indirectly to the overall insomnia experience through its association with psychological maladjustment, rather than interfering with sleep per se. Treatment of late-life insomnia should include assessment and, possibly, clinical management of psychological adjustment.     

Role of nocturnal cognitive arousal in the complaint of insomnia among older adults

Self-reported cognitive activity has been hypothesized to contribute directly to problematic sleep. We evaluated this formulation by examining nocturnal sleep parameters, daytime functioning and psychological adjustment cross-sectionally (N = 183) in four groups of older adults: good and poor sleepers with high and low cognitive arousal. Results indicate that when sleep quality was controlled for, individuals with high and low nocturnal cognitive arousal did not differ on either nocturnal or daytime aspects of the insomnia complaint. They were, however, less well adjusted psychologically. The pattern of findings suggests that high cognitive arousal contributes indirectly to the overall insomnia experience through its association with psychological maladjustment, rather than interfering with sleep per se. Treatment of late-life insomnia should include assessment and, possibly, clinical management of psychological adjustment.     

短睡眠者与失眠症患者的睡眠生理和心理活动差别分析

目的：比较短睡眠者,失眠症患者和睡眠正常者的睡眠生理及心理活动特点,并对失眠症状的影响因素进行分析。方法：对三组对试选用MMPI人格评定,昼间心理生理唤醒实验,人睡前情评定及多导睡眠图整夜睡眠描记。结果：短睡眠组的睡眠潜伏期长于失眠症组,睡眠总时间和睡眠效率与失眠症组无显著差别;但醒起时间,醒觉时间和日间功能障碍分显著低于失眠症组,与睡眠正常组无显著性判别,MMPI评定,短睡眠组在疑病,抑郁,癔病及精神衰弱项目分低于失眠症组,与睡眠正常组无显著性差别,社会内向性项目分低于失眠症组和睡眠正常组,轻躁狂项目分高于失眠症组和睡眠正常组,短睡眠组的夜间人睡前焦虑水平低,白天心理生理唤醒值与睡眠生理指标的相关系数低于失眠症组。结论：短睡眠者的睡眠潜伏期长,睡眠总时间短,但睡眠质量好,人格特征,夜间情绪水平接近正常人。     

Time Estimation in Good and Poor Sleepers

Time estimation was examined in 148 older good and poor sleepers in analogue and naturalistic sleep settings. On analogue tasks, both “empty” time and time listening to an audiobook were overestimated by both good and poor sleepers. There were no differences between groups. “Empty” time was experienced as “dragging.” In the sleep setting, most poor sleepers underestimated nocturnal sleep and overestimated awake times related to their own sleep problem: sleep onset vs. sleep maintenance insomnia. Good sleepers did the opposite. Severity of sleep problem and size of time estimation errors were unrelated. Greater night-to-night wake time variability was experienced by poor than by good sleepers. Psychological adjustment was unrelated to time estimations and to magnification or minimization of sleep problems. The results suggest that for poor sleepers who magnify their sleep problem, self-monitoring can be of benefit by demonstrating that the sleep problem is not as severe as believed.     

Self-reported sleep duration in Finnish general population

Self-reported short or long sleep duration has been repeatedly found to be associated with increased mortality and health risks. However, there is still an insufficient amount of detailed knowledge available to characterize the short and long sleep duration groups in general population. Consequently, the underlying mechanisms potentially explaining the health risks associated with short and long sleep duration are unclear. In the present study, the self-reported sleep duration in a sample of Finnish general population was studied, and its possible associations with such factors as self-perceived health, sociodemographic characteristics, lifestyle, sleep difficulties and daytime concomitants were analyzed. In particular, an effort was made to define mutually statistically-independent determinants of sleep duration. In the Finnish Health 2000 Survey, a representative sample of 8,028 subjects of 30 years of age or older and a sample of 1,894 subjects of 18-29 years of age were invited to take part in the health interview and health examination. The participation rate of the study was over 80%. The most important and statistically-independent determinants of short and long sleep duration were gender, physical tiredness, sleep problems, marital status, main occupation and physical activity. However, in the multivariable model they only accounted for approximately 16% of the variance in sleep duration in short and long sleepers, suggesting multiple sources of variance. The present study also suggests a dose-response like relationship between the sleep duration and many of its determinants within both short and long sleepers. A more detailed analysis of the clinical status of the short and long sleep duration groups is needed to evaluate the possible importance of these findings for health risks associated with sleep duration.     

American time use survey: sleep time and its relationship to waking activities

STUDY OBJECTIVES: To gain some insight into how various behavioral (lifestyle) factors influence sleep duration, by investigation of the relationship of sleep time to waking activities using the American Time Use Survey (ATUS). DESIGN: Cross-sectional data from ATUS, an annual telephone survey of a population sample of US citizens who are interviewed regarding how they spent their time during a 24-hour period between 04:00 on the previous day and 04:00 on the interview day. PARTICIPANTS: Data were pooled from the 2003, 2004, and 2005 ATUS databases involving N=47,731 respondents older than 14 years of age. INTERVENTIONS: N/A. RESULTS: Adjusted multiple linear regression models showed that the largest reciprocal relationship to sleep was found for work time, followed by travel time, which included commute time. Only shorter than average sleepers (<7.5 h) spent more time socializing, relaxing, and engaging in leisure activities, while both short (<5.5 h) and long sleepers (> or =8.5 h) watched more TV than the average sleeper. The extent to which sleep time was exchanged for waking activities was also shown to depend on age and gender. Sleep time was minimal while work time was maximal in the age group 45-54 yr, and sleep time increased both with lower and higher age. CONCLUSIONS: Work time, travel time, and time for socializing, relaxing, and leisure are the primary activities reciprocally related to sleep time among Americans. These activities may be confounding the frequently observed association between short and long sleep on one hand and morbidity and mortality on the other hand and should be controlled for in future studies.     

Sleep and mortality: a population-based 22-year follow-up study

STUDY OBJECTIVES: Long and short sleep have been associated with increased mortality. We assessed mortality and 3 aspects of sleep behavior in a large cohort with 22-year follow-up. DESIGN/SETTING: Prospective, population-based cohort study. PARTICIPANTS: 21,268 twins aged > or =18 years responding to questionnaires administered to the Finnish Twin Cohort in 1975 (response rate 89%), and 1981 (84%). INTERVENTIONS: N/A. MEASUREMENTS: Subjects were categorized as short (<7 h), average, or long (>8 h) sleepers; sleeping well, fairly well, or fairly poorly/poorly; no, infrequent, or frequent users of hypnotics and/or tranquilizers. Cox proportional hazard models were used to obtain hazard ratios (HR) for mortality during 1982-2003 by sleep variable categories and their combinations. Adjustments were done for 10 sociodemographic and lifestyle covariates known to affect risk of death. RESULTS: Significantly increased risk of mortality was observed both for short sleep in men (+26%) and in women (+21%), and for long sleep (+24% and +17%), respectively, and also frequent use of hypnotics/tranquilizers (+31% in men and +39% in women). Snoring as a covariate did not change the results. The effect of sleep on mortality varied between age groups, with strongest effects in young men. Between 1975 and 1981, sleep length and sleep quality changed in one-third of subjects. In men there was a significant increase for stable short (1.34) and stable long (1.29) sleep for natural deaths, and for external causes in stable short sleepers (1.62). CONCLUSIONS: Our results show complicated associations between sleep and mortality, with increased risk in short and long sleep.     

Sleep duration and mortality: a systematic review and meta-analysis

Epidemiologic studies have shown that sleep duration is associated with overall mortality. We conducted a systematic review of the associations between sleep duration and all-cause and cause-specific mortality. PubMed was systematically searched up to January, 2008 to identify studies examining the association between sleep duration and mortality (both all-cause and cause-specific) among adults. Data were abstracted serially in a standardized manner by two reviewers and analyzed using random-effects meta-analysis. Twenty-three studies assessing the associations between sleep duration and mortality were identified. All examined sleep duration measured using participant self-report. Among the 16 studies which had similar reference categories and reported sufficient data on short sleep and mortality for meta-analyses, the pooled relative risk (RR) for all-cause mortality for short sleep duration was 1.10 [95% confidence interval (CI): 1.06, 1.15]. For cardiovascular-related and cancer-related mortality, the RRs associated with short sleep were 1.06 (95% CI: 0.94, 1.18) and 0.99 (95% CI: 0.88, 1.13), respectively. Similarly, among the 17 studies reporting data on long sleep duration and mortality, the pooled RRs comparing the long sleepers with medium sleepers were 1.23 (95% CI: 1.17, 1.30) for all-cause mortality, 1.38 (95% CI: 1.13, 1.69) for cardiovascular-related mortality, and 1.21 (95% CI: 1.11, 1.32) for cancer-related mortality. Our findings indicate that both short sleepers and long sleepers are at increased risk of all-cause mortality. Further research using objective measures of sleep duration is needed to fully characterize these associations.     

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.     

Poor sleepers who do not complain of insomnia: Myths and realities about psychological and lifestyle characteristics of older good and poor sleepers

Psychological adjustment, lifestyle, and sleep parameters were investigated in 634 older community residents. Participants were divided into three categories: good sleepers, poor sleepers experiencing high distress, and poor sleepers experiencing minimal distress. Results indicate that (1) highly distressed poor sleepers manifested an anxious, depressed, negative cognitive-affective set; (2) many coped well with age related changes in sleep quality—they resembled good sleepers in the relative absence of psychological maladjustment they displayed; (3) the three groups had similar lifestyles, but they differed in the cognitive-affective evaluation of their activities, (4) the insomnia complaint is itself multifaceted and is comprised of three distinct elements—difficulty sleeping, distress, and daytime fatigue; (5) sleep practices (e.g., naps, bedtimes) are not implicated in chronic poor sleep; and (6) many commonly held assumptions about sleep disruptions in older individuals are myth rather than reality. Implications for better understanding and treating insomnia in older individuals are discussed.This article was prepared during the tenure of grants from the Conseil Québécois de la recherche sociale, Health and Welfare Canada, and the Direction générale de l'enseignement collégial. We are grateful for the generous support of these organizations. In addition, we would like to thank the dedicated members of our research team: Sally Bailes, Ann Gay, Jason Lavers, John Martos, Kathleen McAdams, Vicki Tagalakis, and most especially, Harriet Lennox for their substantial contribution to this research.Dawson College.Sir Mortimer B. Davis—Jewish General Hospital.Concordia University.McGill University.     

Sleep duration and personality in Croatian twins

The objective of this study was to examine which genetic and environmental influences contribute to individual differences in sleep duration in a sample of Croatian adolescent/early adult twins, as well as to investigate the relationship between personality and sleep duration. Participants included 339 twin pairs (105 monozygotic and 234 dizygotic) aged between 15 and 22 years. They reported on their average sleep duration and personality. The broad heritability estimate (additive and non‐additive genetic influences) for sleep duration was 0.63, while personality estimates ranged between 0.47 and 0.62. Significant negative phenotypic associations with neuroticism and openness were mainly genetically mediated 100 and 80%, respectively. Only 6% of the sleep duration variance was explained by genetic influences shared with neuroticism and openness. In regression analysis, age, gender and five personality traits explained 5% of sleep duration variance, with neuroticism and openness as significant predictors. Comparison of short, moderate and long sleepers showed that participants in the short sleepers group had significantly higher neuroticism scores than groups of moderate and long sleepers, as well as a significantly higher openness score than the group of long sleepers. This indicates that personality traits of neuroticism and openness contribute to the prediction of sleep duration due to overlapping genetic influences that contribute to both these personality traits and sleep duration. However, as phenotypic overlap of personality and sleep duration is relatively weak, heritability of sleep duration is not only related to individual differences in personality traits, so future research needs to examine other phenotypic correlates of sleep duration.     

Short Sleep Duration in Prevalent and Persistent Psychological Distress in Young Adults: The DRIVE Study

Objectives:

Young people are sleeping less. Short sleep duration has a range of negative consequences including a hypothesized link with psychological distress, which has yet to be studied

Design:

Prospective cohort study

Setting:

Community-based sample from Australia

Participants:

Twenty thousand (20,822) young adults (aged 17-24) identified through the state vehicle licensing authority. A random sample (n = 5000) was approached for follow-up 12-18 months later, with 2937 providing full data.

Main Outcome Measure:

Psychological distress, determined by a Kessler 10 score > 21, at baseline; and as both onset and persistence of distress at follow-up.

Results:

Shorter sleep duration was linearly associated with prevalent psychological distress: relative risk (RR) 1.14 (95%CI 1.12 to 1.15). Only the very short (< 5 h) sleepers among those not distressed at baseline had an increased risk for onset of psychological distress (RR 3.25 [95% CI 1.84, 5.75]). Of 945 cohort participants reporting psychological distress at baseline, 419 (44%) were distressed at follow-up. Each hour less of sleep increased the risk of psychological distress persisting after adjustment for potential confounding variables: RR 1.05 (95%CI 1.01 to 1.10). Long sleep duration showed no association with distress at any time point.

Conclusions:

Self-reported shorter sleep duration is linearly associated with prevalent and persistent psychological distress in young adults. In contrast, only the very short sleepers had a raised risk of new onset of distress. Different approaches to sleep duration measurement yield different results and should guide any interventions to improve subjective sleep duration in young adults.

Citation:

Glozier N; Martiniuk A; Patton G; Ivers R; Li Q; Hickie I; Senserrick T; Woodward M; Norton R; Stevenson M. Short sleep duration in prevalent and persistent psychological distress in young adults: the DRIVE study. SLEEP 2010;33(9):1139-1145.     

Symptom-Focused Rumination and Sleep Disturbance

Rumination can prolong negative mood, disrupt sleep, and increase depression risk. Although there is evidence that poor sleepers ruminate, no studies have identified the ruminative content relevant for sleep disturbance. This study investigated (a) the association between rumination and sleep and (b) the ruminative content of poor sleepers. Results revealed that self-defined poor sleepers (n = 104) were more prone than self-defined good sleepers (n = 139) to ruminate and that the ruminative content was symptom focused (e.g., poor sleepers ruminated on causes of dysphoria, concentration, and fatigue symptoms). As dysphoria, reduced concentration, and fatigue are all commonly experienced daytime symptoms of insomnia, this preliminary finding of symptom-focused rumination should be further evaluated as a risk factor for further sleep disturbance in clinical samples as well as a possible link between insomnia and depression.     

The association between sleep duration and weight gain in adults: a 6-year prospective study from the Quebec Family Study

STUDY OBJECTIVE: To investigate the relationship between sleep duration and subsequent body weight and fat gain. DESIGN: Six-year longitudinal study. SETTING: Community setting. PARTICIPANTS: Two hundred seventy-six adults aged 21 to 64 years from the Quebec Family Study. More than half of the sample is drawn from families with at least 1 parent and 1 offspring with a body mass index of 32 kg/m2 or higher. MEASUREMENTS AND RESULTS: Body composition measurements and self-reported sleep duration were determined. Changes in adiposity indices were compared between short- (5-6 hours), average- (7-8 hours), and long- (9-10 hours) duration sleeper groups. After adjustment for age, sex, and baseline body mass index, short-duration sleepers gained 1.98 kg (95% confidence interval: 1.16-2.82) more and long-duration sleepers gained 1.58 kg (95% CI: 1.02-2.56) more than did average-duration sleepers over 6 years. Short- and long-duration sleepers were 35% and 25% more likely to experience a 5-kg weight gain, respectively, as compared with average-duration sleepers over 6 years. The risk of developing obesity was elevated for short- and long-duration sleepers as compared with average-duration sleepers, with 27% and 21% increases in risk, respectively. These associations remained significant after inclusion of important covariates and were not affected by adjustment for energy intake and physical activity participation. CONCLUSIONS: This study provides evidence that both short and long sleeping times predict an increased risk of future body weight and fat gain in adults. Hence, these results emphasize the need to add sleep duration to the panel of determinants that contribute to weight gain and obesity.     

Twenty-four-hour sleep-wake function and personality patterns in chronic insomniacs and healthy controls

A comparison was made between 16 middle-aged chronic insomniacs and 16 normal sleepers, matched by age and sex, in a psychophysiological study, including polysomnographic night sleep recordings, MMPI personality profiles, testing of cognitive performance, and relaxation capability during daytime. Both objective and subjective criteria of night sleep demonstrated a clear separation of the two groups. Insomniacs had psychosomatic personality profiles. A test for unintentional sleep suggested that poor sleep function in insomniacs is related to deficient sleep-controlling mechanisms, rather than psychological trait and state factors. Only sleep onset difficulties were susceptible to situational factors. Daytime performance was not generally impaired in insomniacs, but they had greater difficulties in the morning. Subjective daytime sleepiness was significantly higher and might represent a particular psychological problem for active behavior. Interrelations of various deficiencies in sleep-wake behavior seem to delineate specific aspects of the chronic insomniac syndrome.     

Sleep Disturbances and Glucoregulation in Patients with Type 2 Diabetes

We investigated the frequency of sleep disturbances and the association between sleep disturbances and glucoregulation in type 2 diabetic patients. The frequency of sleep disturbances in 614 type 2 diabetic patients was investigated using validated sleep questionnaires. There were 381 male and 233 female patients. The mean age was 59.7 ± 11.1 yr; the mean body mass index was 24.9 ± 4.4 kg/m²; the mean HbA1c was 7.8% ± 1.5%; and the mean duration of diabetes was 10.3 ± 8.4 yr. The questionnaires revealed insomnia in 48.2% of the patients while 8.5% reported excessive daytime sleepiness. A total of 49% of the patients was poor sleepers, while 28.5% had depression. Multivariate logistic regression analysis showed that there was no significant association between HbA1c and other sleep disturbances, such as poor sleep, insomnia, and short duration of sleep. Sleep disturbances were very common in patients with type 2 diabetes mellitus, whereas there was no association between poor or short sleep and glucoregulation. Awareness and identifying sleep complaints in such patients are necessary to improve their quality of daily life.