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.     

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.     

Evidence from the waking electroencephalogram that short sleepers live under higher homeostatic sleep pressure than long sleepers

We used the waking electroencephalogram to study the homeostatic sleep regulatory process in human short sleepers and long sleepers. After sleeping according to their habitual schedule, nine short sleepers (sleep duration < 6 h) and eight long sleepers (> 9 h) were recorded half-hourly during approximately 40 h of wakefulness in a constant routine protocol. Within the frequency range of 0.25-20.0 Hz, spectral power density in the 5.25-9.0 and 17.25-18.0 Hz ranges was higher in short sleepers than in long sleepers. In both groups, increasing time awake was associated with an increase of theta/low-frequency alpha activity (5.25-9.0 Hz), whose kinetics followed a saturating exponential function. The time constant did not differ between groups and was similar to the previously obtained time constant of the wake-dependent increase of slow-wave activity (0.75-4.5 Hz) in the sleep electroencephalogram. In addition, the time constant of the decrease of slow-wave activity during extended recovery sleep following the constant routine did not differ between groups. However, short sleepers showed an abiding enhancement of theta/low-frequency alpha activity during wakefulness after recovery sleep that was independent of the homeostatic process. It is concluded that, while the kinetics of the homeostatic process do not differ between the two groups, short sleepers live under and tolerate higher homeostatic sleep pressure than long sleepers. The homeostat-independent enhancement of theta/low-frequency alpha activity in the waking electroencephalogram in the short sleepers may be genetically determined or be the result of long-term adaptation to chronically short sleep.     

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.     

A sleep diary and questionnaire study of naturally short sleepers

Whereas most people require more than 6 h of sleep to feel well rested, there appears to be a group of people who can function well on between 3 and 6 h of sleep. The aims of the present study were to compare 12 naturally short (3-6 h) sleepers (9 males 3 females, mean age 39.6 years, SD age 10.1 years) recruited by a media publicity campaign with age, gender and chronotype matched medium length (7-8.5 h) sleepers on various measures. Measurement instruments included diaries and questionnaires to assess sleep duration and timing, as well as questionnaire assessments of sleep pathology, morningness-eveningness, extroversion, neuroticism, pathological daytime sleepiness, subclinical hypomania, optimism, depressive symptoms, exercise, and work habits. Few measures showed reliable differences between naturally short sleepers and controls except the obvious ones related to sleep duration. There was, however, some evidence for subclinical hypomanic symptoms in naturally short sleepers.     

The relationship between a night's sleep and subsequent daytime functioning in older poor and good sleepers

Those suffering insomnia symptoms generally report daytime impairments. However, research has not assessed whether this relationship holds on a nightly basis, despite the strongly held belief that a night of poor sleep impairs mood and functioning the following day. The objective of this study was to test this relationship in a group of older poor sleepers with insomnia symptoms compared with good sleepers. This study utilized a within‐subjects design to investigate day‐to‐day subjective daytime functioning and its relation to the previous night's sleep. Seventeen older individuals (mean age: 67.5 years) were identified with a retrospective questionnaire and 2 weeks of sleep–wake diary to have poor sleep consistent with insomnia. Seventeen good sleepers (mean age: 67.8 years) were selected using the same measures. Participants reported their beliefs about sleep and daytime functioning on the Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS‐16). One week later they commenced a 14‐day period of sleep–wake diaries and concurrent responses to a modified Daytime Insomnia Symptom Scale (DISS). Results showed significant night‐to‐day covariation between sleep efficiency and daytime functioning for individuals with poor sleep (r = 0.34), but not for good sleepers (r = 0.08). Those poor sleepers who held this covariation belief most strongly were those who subsequently showed this night‐to‐day relationship the most strongly (r = 0.56). This was not true for good sleepers. For those suffering insomnia, these findings demonstrate their belief that a poor sleep is followed by an impaired daytime, consistent with their experience.     

Auditory arousal thresholds of good sleepers and poor sleepers with and without flurazepam.

Auditory arousal thresholds of good (N = 12) and poor (N = 12) sleepers (sleep onset insomniacs) were obtained during stage 2, stage 4, and REM sleep at various times of the night. Despite claims of being "light" sleepers who are easily awakened by noise, poor sleeper auditory arousal thresholds were the same as those of good sleepers. Flurazepam (30 mg) increased the auditory arousal thresholds of poor sleepers (N = 6), but the increase was statistically significant only during the period of peak effect which occurred 1--2 hr after ingestion. Consistent with poor sleeper complaints of trouble falling asleep, the return to sleep (i.e., sleep latency) was significantly longer for poor than for good sleepers following stimulus arousals during the first stage 2 and first stage 4 periods of the night. Sleep latencies for good and poor sleepers did not differ significantly following subsequent arousals. The sleep latency following the first stage 2 stimulus arousal was significantly reduced in poor sleepers during flurazepam-induced sleep.     

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.     

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.     

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.     

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.     

The Good Sleeper Scale-15 items: a questionnaire for the standardised assessment of good sleepers

Research with ‘good sleepers’ is ubiquitous, yet there are no standardised criteria to identify a ‘good sleeper’. The present study aimed to create and validate a questionnaire for identifying good sleepers for use in research studies known as the Good Sleeper Scale-15 items (GSS-15). Data were derived from a population-based survey of Australian adults (n = 2,044). A total of 23 items were chosen for possible inclusion. An exploratory factor analysis (EFA) was conducted on ~10% of the survey dataset (n = 191) for factor identification and item reduction. A confirmatory factor analysis (CFA) was conducted on the remaining data (n = 1,853) to test model fit. Receiver operating characteristic curves and correlations were conducted to derive cut-off scores and test associations with sleep, daytime functioning, health, and quality-of-life. The EFA identified six factors: ‘Sleep Difficulties’, ‘Timing’, ‘Duration’, ‘Regularity’, ‘Adequacy’, and ‘Perceived Sleep Problem’. The CFA showed that model fit was high and comparable to other sleep instruments, χ² (63) = 378.22, p < 0.001, root mean square error of approximation = 0.05, with acceptable internal consistency (α = 0.76). Strong correlations were consistently found between GSS-15 global scores and outcomes, including ‘a good night′s sleep’ (r = 0.7), ‘feeling un-refreshed’ (r = −0.59), and ‘experienced sleepiness’ (r = −0.51), p < 0.001. Cut-off scores were derived to categorise individuals likely to be a good sleeper (GSS-15 score ≥40) and those very likely to be a good sleeper (GSS-15 score ≥45). The GSS-15 is a freely available, robust questionnaire that will assist in identifying good sleepers for the purpose of sleep research. Future work will test relationships with other sleep measures in community and clinical samples.     

A two-dimensional approach to assessing affective states in good and poor sleepers

This study examined a two-dimensional approach to assessing affective states among good and poor sleepers using the self-assessment manikin (SAM), a brief non-verbal self-report measure of affective states with separate ratings of valence and arousal. A sample of 286 undergraduate students completed the Pittsburgh Sleep Quality Index (PSQI) and the SAM. Participants were classified post hoc as either good (PSQI ≤ 5) or poor sleepers (PSQI > 5) using the PSQI and used the SAM to rate their current affective states (day) and their affective state at bedtime (night) the previous night. Compared to good sleepers, poor sleepers reported more negative affect and arousal at night and more negative affect during the day. Among poor sleepers, lower sleep quality and shorter sleep duration on the components of the PSQI were associated with more negative daytime valence. Among good sleepers, higher scores on the sleep medication and daytime dysfunction components of the PSQI were associated with more negative daytime valence. These findings indicate that the SAM appears to detect differences between good and poor sleepers on both valence and arousal of current daytime and retrospective night-time emotional states. This approach could be useful for the assessment of affective states related to sleep disturbance.     

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.     

Anxiety as a personality dimension of short and long sleepers

To clarify the interpretation of a difference in anxiety level that Hicks and Pellegrini (1977) had reported as being incongruent with Hartmann's (1973) clinical findings that consistent short sleepers tend to be non-worriers while consistent long sleepers tend to worry, grops of 25 short- and long-sleeping undergraduate students were administred the Hindi version of Sinha Anxiety Scale. Higher mean score was found in the short sleepers than in the long sleepers. The difference between these means was significant at the 0.001 level. These findings supported Hicks and Pellegrini's earlier results, which questioned the validity of the clinical observations that were the basis for Hartmann's conclusions.     

Short sleep duration and adiposity in Chinese adolescents

OBJECTIVE: To investigate the relationship between sleep duration and adiposity measurements in rural Chinese adolescents. METHODS: This report is based on a cross-sectional analysis of 500 Chinese adolescent twins. Anthropometric measurements and direct adiposity measurements using dual-energy X-ray absorptiometry (DEXA) were taken for all subjects. Standard sleep questionnaires and a 7-day diary were administered to assess sleep duration. RESULTS: Sleep duration decreased with increasing age during adolescence, reaching a nadir at approximately 15 years of age. While BMI and body fat increased through the entire range of adolescence for both genders, after the age of 12, females had much higher amounts of total and truncal fat than males. Graphic plots showed that among females, both long and short sleepers tended to have higher adiposity measures than medium duration sleepers. The association of short sleep duration with higher adiposity measures was significant even after adjustment for covariates. This association was stronger for total and truncal fat and waist circumference (P < 0.05) than for BMI (P = 0.06). In contrast, consistent relationships between sleep duration and adiposity measures were not seen in males. CONCLUSION: Even in this relatively lean Chinese adolescent cohort, short sleep duration was significantly associated with higher adiposity measures and lower lean body mass in females. The results of this study indicate that the observed association between short sleep duration and higher BMI is most likely mediated by factors associated with total and central adiposity rather than lean body mass.     

Physical exercise performed before bedtime improves the sleep pattern of healthy young good sleepers

To investigate the influence of different intensities and durations of exercise before bedtime on the sleep pattern and core body temperature of individuals considered good sleepers, we selected 17 healthy males and all underwent 5 nonconsecutive days of study. Measurements of polysomnographic parameters and core body temperature were taken at baseline and after each experimental protocol, performed at night. We found increased sleep efficiency (p = .016) among all protocols compared with baseline data and increase in REM sleep latency (p = .047) between two experiments; there was decrease in the percentage of stage 1 sleep (p = .046) and wake after sleep onset (p = .003). Core body temperature did not change significantly during the nights following exercise. Exercise performed before sleep does not impair sleep quality; rather, its practice improves sleep in good sleepers who are nonathletes, and may be considered to improve sleep pattern.