Sleep difficulties in infants at risk for developmental delays: a longitudinal study

Objectives We compared the sleep of infants at risk forneuromotor delays to that of infants without such risks, andexamined the predictive validity of risk indicators to the developmentof sleep problems. Methods Conveniently recruitedinfants (n = 142) were assessed for neuromotor achievementsand sleep behaviors at 4–6 months and 10–12 monthsof age. Assessment tools were the Harris Infant Neuromotor Testand Morrell's Infant Sleep Questionnaire. Based on a cumulativerisk index, three groups were defined: higher risk (n = 28),lower risk (n = 42), and no risk (n = 72). Results Atboth ages, the sleep scores were similar among the groups. Inthe no risk and lower risk group, sleep difficulties decreasedwith age, while for infants in the higher risk group, more difficultieswere reported over time. Overall, the neuromotor attainmentswere not related to sleep fragmentation or settling difficulties. Conclusions Ina diverse sample of infants, with and without risks for developmentaldelays, overall, sleep patterns were similar. It appears thatthe neuromotor achievements are not associated with sleep-wakeregulation, as measured by caregivers’ report.     

Sleep quality and depression during pregnancy: a prospective study

For the first time, the relationship between depressive symptoms and sleep quality was explored prospectively during pregnancy. Participants (n = 273) completed the Pittsburgh Sleep Quality Index and Beck Depression Inventory at three 8-week intervals, starting from 15-23 weeks gestation. In addition to sleep quality and depression remaining relatively stable during pregnancy, findings revealed that sleep quality earlier in pregnancy predicted higher levels of depressive symptoms at later stage in pregnancy (after controlling for prior depression levels). In contrast, there was no evidence to suggest that depressive symptoms earlier in pregnancy impacted on sleep quality later on. Given that depressive symptomatology can lead to major depression and given the prevalence of pre- and postnatal depression, our findings suggest that screening for sleep problems during pregnancy may be of clinical significance.     

The meaning of good sleep: a longitudinal study of polysomnography and subjective sleep quality

SUMMARY  The present study sought to investigate the meaning of subjectively good sleep, using a longitudinal and intraindividual design. Eight subjects slept in an isolation unit according to an irregular schedule of 6h sleeps and 1h naps, designed to give normal amounts of time in bed (1/3 of total), but variable sleep quality. Eight sleeps and eight naps were used for longitudinal simple and multiple regression analyses with standard polysomnographical sleep variables as predictors and subjective sleep quality as dependent variables. The results showed that subjective sleep quality (and related variables) was closely related to sleep efficiency, but not sleep stages. At least 87% efficiency was required for ratings of 'rather good' sleep. In addition, sleep quality ratings improved with closeness (of the awakening) to the circadian acrophase (17.00–21.00 hours) of the rectal temperature rhythm. The subjective ease of awakening differed from most other other variables in that it was related to low sleep efficiency. Objective and subjective homologues of sleep length and sleep latency showed high mean intraindividual correlations ( r = 0.55 and 0.64, respectively). It was concluded that objective measures of sleep continuity were closely reflected in perceived sleep quality and that sleep quality essentially means sleep continuity.     

Duration of sleep and breast cancer risk in a large population-based case-control study

One important function of sleep may be its contribution to the maintenance of the immune system and regulation of the circadian rhythms by melatonin. Researchers have speculated that disruption of immune functions involving cortisol levels and natural killer cell activity may increase breast cancer risk whereas increased melatonin exposure may protect against breast cancer. We conducted a multistate population-based case-control study of 4,033 women with invasive breast cancer and 5,314 community women without breast cancer in which we inquired about women's sleep habits in the recent past and during adult lifetime. Relative to women who slept 7.0-7.9 h/night, the multivariate odds ratio for developing breast cancer among women who slept an average of 9 h or more per night approximately 2 years prior to interview was 1.13 (95% CI 0.93-1.37). The multivariate-adjusted odds ratio for the continuous term was 1.06 (95% CI 1.01-1.11), suggesting a 6% increase in risk for every additional hour of sleep. Similar patterns were observed for average lifetime adult sleep duration. We found little evidence that sleeping few hours per night was associated with breast cancer risk. The results of this study suggest that increasing sleep duration is modestly associated with an increased breast cancer risk. In contrast, short duration of sleep (<7 h/night) is not substantially associated with increased risk. Further research in this area is warranted.     

Associations of self-reported obstructive sleep apnea with total and site-specific cancer risk in older women: a prospective study

Background and ObjectivesChronic intermittent hypoxia resulting from obstructive sleep apnea (OSA) may activate multiple carcinogenic pathways and lead to cancer development.MethodsWe prospectively examined the association between OSA and cancer risk among 65,330 women in the Nurses’ Health Study who were free of cancer in 2008 (mean age: 73.3 years). Incident cancer diagnoses were collected until 2016 and confirmed by pathology reports. Clinically diagnosed OSA was self-reported in 2008 and updated in 2012. We used time-dependent Cox regression to estimate hazard ratios (HR) for the associations of OSA with total and site-specific cancer risk.ResultsWe documented 5,257 incident cancer diagnoses during follow-up. In the age-adjusted model, OSA was associated with a 15% (95% CI: 1.03, 1.29) increase in total cancer risk. The association became nonsignificant after adjustment for multiple cancer risk factors (HR: 1.08; 95% CI: 0.96, 1.21). When examining cancer risk by site, OSA was associated with significantly increased risk for lung (fully adjusted HR: 1.52; 95% CI: 1.07, 2.17), bladder (fully adjusted HR: 1.94; 95% CI: 1.12, 3.35), and thyroid cancer (fully adjusted HR: 2.06; 95% CI: 1.01, 4.22) and possibly increased risk for kidney cancer (fully adjusted HR: 1.59; 95% CI: 0.84, 3.01). When grouping cancer sites by risk factor profiles, OSA was positively associated with smoking-related cancers (fully adjusted HR: 1.37; 95% CI: 1.11, 1.67), and this association was stronger in never smokers than ever smokers.ConclusionWhile OSA was not independently associated with overall cancer risk in older women, significant associations were observed for smoking-related cancers, especially in nonsmokers.     

Sleep disorders and work performance: findings from the 2008 National Sleep Foundation Sleep in America poll

Chronic sleep deprivation is common among workers, and has been associated with negative work outcomes, including absenteeism and occupational accidents. The objective of the present study is to characterize reciprocal relationships between sleep and work. Specifically, we examined how sleep impacts work performance and how work affects sleep in individuals not at-risk for a sleep disorder; assessed work performance outcomes for individuals at-risk for sleep disorders, including insomnia, obstructive sleep apnea (OSA) and restless legs syndrome (RLS); and characterized work performance impairments in shift workers (SW) at-risk for shift work sleep disorders relative to SW and day workers. One-thousand Americans who work 30 h per week or more were asked questions about employment, work performance and sleep in the National Sleep Foundation's 2008 Sleep in America telephone poll. Long work hours were associated with shorter sleep times, and shorter sleep times were associated with more work impairments. Thirty-seven percent of respondents were classified as at-risk for any sleep disorder. These individuals had more negative work outcomes as compared with those not at-risk for a sleep disorder. Presenteeism was a significant problem for individuals with insomnia symptoms, OSA and RLS as compared with respondents not at-risk. These results suggest that long work hours may contribute to chronic sleep loss, which may in turn result in work impairment. Risk for sleep disorders substantially increases the likelihood of negative work outcomes, including occupational accidents, absenteeism and presenteeism.     

Sleep quality and the risk of work injury: a Swiss case–control study

Sleep problems are a well‐known risk factor for work injuries, but less is known about which vulnerable populations are most at risk. The aims of this study were to investigate the association between sleep quality and the risk of work injury and to identify factors that may modify the association. A case–control study including 180 cases and 551 controls was conducted at the University Hospital in Basel, Switzerland, from 1 December 2009 to 30 June 2011. Data on work injuries and sleep quality were collected. Adjusted odds ratios and 95% confidence intervals of the association between sleep quality and work injury were estimated in multivariable logistic regression analyses and were stratified by hypothesized effect modifiers (age, gender, job risk, shift work, sleep duration and working hours). Poor sleep quality was associated significantly with work injury of any type (P < 0.05) and with being caught in particular (P < 0.05). The association between poor sleep quality and work injury was significantly higher for workers older than 30 years (odds ratio_>30 1.30 versus odds ratio_≤30 0.91, P < 0.01), sleeping 7 h or less per night (odds ratio_≤7 1.17 versus odds ratio_>7 0.79, P < 0.05) and working 50 h or more per week (odds ratio_≥50 1.79 versus odd ratio_<50 1.10, P < 0.01). Work injury risk increased with increasing severity of sleep problems (P < 0.05). Prior work injury frequency increased with decreasing sleep quality (P < 0.05). Older age, short sleep duration and long working hours may enhance the risk of work injuries associated with sleep quality.     

Sleep Duration and Health-Related Quality of Life among Older Adults: A Population-Based Cohort in Spain

Study Objectives:

The few studies that have addressed the association between sleep duration and health-related quality of life (HRQL) were cross-sectional and small-sized, targeted young and middle-aged persons, and did not adjust for the main confounders. This study sought to examine the cross-sectional and longitudinal relationship between habitual sleep duration and HRQL in older adults.

Design:

Prospective study conducted from 2001 through 2003. Sleep duration was self-reported in 2001, and HRQL was measured using the SF-36 questionnaire in 2001 and 2003. Analyses were adjusted for the main confounders.

Setting:

Community-based study.

Participants:

A cohort of 3834 persons representative of the non-institutionalized Spanish population aged 60 years and over.

Intervention:

None.

Measurement and Results:

In comparison with women who slept 7 hours, those with extreme sleep durations (≤ 5 or ≥ 10 h) reported worse scores on the SF-36 physical and mental scales in 2001. Among men, sleeping ≤ 5 h was associated with a worse score in the role-physical scale in 2001. The magnitude of most of these associations was comparable with the reduction in HRQL associated with aging 10 years. Sleep duration in 2001 failed to predict changes in HRQL between 2001 and 2003.

Conclusion:

Extreme sleep durations are a marker of worse HRQL in the elderly.

Citation:

Faubel R; Lopez-Garcia E; Guallar-Castillón P; Balboa-Castillo T; Gutiérrez-Fisac JL; Banegas JR; Rodríguez-Artalejo F. Sleep duration and health-related quality of life among older adults: a population-based cohort in spain. SLEEP 2009;32(8):1059-1068.     

Aerobic and resistance exercise improve patient-reported sleep quality and is associated with cardiometabolic biomarkers in Hispanic and non-Hispanic breast cancer survivors who are overweight or obese: results from a secondary analysis

Study ObjectivesPoor sleep quality affects nearly one-third of breast cancer survivors and is associated with insulin resistance. The purpose of this secondary analysis was to examine the effects of a 16-week exercise intervention on patient-reported sleep quality among breast cancer survivors and assess whether changes in patient-reported sleep quality were associated with cardiometabolic biomarkers. We explored Hispanic ethnicity as a moderator of the effects of exercise on patient-reported sleep quality.MethodsBreast cancer survivors who were overweight or obese were randomized to exercise (n = 50) or usual care (n = 50). The 16-week intervention included aerobic and resistance exercise. Patient-reported sleep quality (Pittsburgh Sleep Quality Index [PSQI]) and biomarkers of cardiometabolic health were assessed at baseline and post-intervention. Within- and between-group differences were assessed using general linear models repeated-measures analyses of variance and mixed-model repeated-measure analysis, respectively. Associations between changes in PSQI and cardiometabolic biomarkers were computed using Pearson correlations. Linear mixed-models were used to evaluate effect modification by ethnicity.ResultsParticipants were 52 ± 10.4 years old, and over half were of Hispanic ethnicity. As compared to usual care, PSQI global scores improved significantly in the exercise group (mean between-group difference −2.2; 95% CI −3.2 to −0.6). Change in PSQI was inversely associated with changes in all cardiometabolic biomarkers (p < 0.01) among the exercise group. Ethnicity was found to moderate the effects of exercise training on global sleep quality (p < 0.001).ConclusionsAn aerobic and resistance exercise intervention effectively improved patient-reported sleep quality in breast cancer survivors. Hispanic ethnicity as a moderator showed greater improvement in patient-reported sleep indicating Hispanic versus non-Hispanic breast cancer survivors may derive larger sleep benefits.Clinical Trail Information{"type":"clinical-trial","attrs":{"text":"NCT01140282","term_id":"NCT01140282"}}NCT01140282.     

Sleep problems and internet addiction among children and adolescents: a longitudinal study

Although the literature has documented associations between sleep problems and internet addiction, the temporal direction of these relationships has not been established. The purpose of this study is to evaluate the bidirectional relationships between sleep problems and internet addiction among children and adolescents longitudinally. A four‐wave longitudinal study was conducted with 1253 children and adolescents in grades 3, 5 and 8 from March 2013 to January 2014. The sleep problems of the student participants were measured by parental reports on the Sleep Habit Questionnaire, which catalogues early insomnia, middle insomnia, disturbed circadian rhythm, periodic leg movements, sleep terrors, sleepwalking, sleep talking, nightmares, bruxism, snoring and sleep apnoea. The severity of internet addiction was measured by students’ self‐reports on the Chen Internet Addiction Scale. Based on the results of time‐lag models, dyssomnias (odds ratio = 1.31), especially early and middle insomnias (odds ratio = 1.74 and 2.24), sequentially predicted internet addiction, and internet addiction sequentially predicted disturbed circadian rhythm (odds ratio = 2.40), regardless of adjustment for gender and age. This is the first study to demonstrate the temporal relationship of early and middle insomnia predicting internet addiction, which subsequently predicts disturbed circadian rhythm. These findings imply that treatment strategies for sleep problems and internet addiction should vary according to the order of their occurrence.     

Sleep symptomatology is associated with greater subjective cognitive concerns: findings from the community-based Healthy Brain Project

Study ObjectivesTo examine if sleep symptomatology was associated with subjective cognitive concerns or objective cognitive performance in a dementia-free community-based sample.MethodsA total of 1,421 middle-aged participants (mean ± standard deviation = 57 ± 7; 77% female) from the Healthy Brain Project completed the Pittsburgh Sleep Quality Index, Insomnia Severity Index, and Epworth Sleepiness Scale to measure sleep quality, insomnia symptom severity, and daytime sleepiness, respectively. Participants were classified as having no sleep symptomatology (normal scores on each sleep measure), moderate sleep symptomatology (abnormal scores on one sleep measure), or high sleep symptomatology (abnormal scores on at least two sleep measures), using established cutoff values. Analysis of covariance was used to compare objective cognitive function (Cogstate Brief Battery) and subjective cognitive concerns (Modified Cognitive Function Instrument) across groups.ResultsFollowing adjustments for age, sex, education, mood, and vascular risk factors, persons classified as having high sleep symptomatology, versus none, displayed more subjective cognitive concerns (d = 0.24) but no differences in objective cognitive performance (d = 0.00–0.18). Subjective cognitive concerns modified the association between sleep symptomatology and psychomotor function. The strength of the relationship between high sleep symptomatology (versus none) and psychomotor function was significantly greater in persons with high as compared with low cognitive concerns (β ± SE = −0.37 ± 0.16; p = 0.02).ConclusionsMore severe sleep symptomatology was associated with greater subjective cognitive concerns. Persons reporting high levels of sleep symptomatology may be more likely to display poorer objective cognitive function in the presence of subjective cognitive concerns.     

Sleep condition and cognitive decline in Japanese community‐dwelling older people: Data from a 4‐year longitudinal study

This study examined whether sleep duration and excessive daytime sleepiness (EDS) are related to cognitive decline among community‐dwelling older adults with intact cognition at baseline, using 4‐year longitudinal data. A total of 3,151 community‐dwelling older individuals aged ≥65 years were studied. They were assessed for cognitive function, including memory, attention, executive function and processing speed. Cognitive impairment was defined based on a score >1.5 standard deviations below the age‐ and education‐specific mean. Cognitive decline was defined in one or more cognitive tests at follow‐up. Self‐reported sleep duration (short, ≤6.0 hr; medium, 6.1–8.9 hr; long, ≥9.0 hr) and EDS at first‐wave examination were assessed and logistic regression analyses were used to examine the associations of sleep duration and EDS with cognitive status at second‐wave examination. The incidence of cognitive decline differed significantly among the sleep‐duration groups (short, 15.9%; medium, 11.9%; long, 20.1%; p = 0.001). The prevalence of having EDS was 13.1%, which was associated with a higher rate of cognitive decline than having no EDS (18.9% vs. 12.5%, p = 0.004). Long sleep duration compared with medium sleep duration (OR, 1.50; 95% CI, 1.05–2.13) and EDS (1.43; 1.01–2.03) independently impacted the incidence of cognitive decline. The results were similar after multiple imputations (long, 1.68, 1.12–2.52; EDS, 1.55, 1.05–2.29). In conclusion, our study revealed that both long sleep duration and EDS were independent risk factors associated with cognitive decline after 4 years among older adults.     

Sleep quality and body mass index: a co‐twin study

There is a consistent relationship between body mass index and sleep quality. However, the directionality and possible confounding factors of this relationship are unclear. Our aim is to confirm the association between sleep quality and body mass index, independent of possible genetic confounding, as well as to provide some indirect inferences about the directionality of this association. The co‐twin study design was used to analyse the body mass index–sleep relationship in a sample of 2150 twins. We selected two parallel sub‐samples of twins discordant for body mass index (n = 430 pairs), or discordant for sleep quality (n = 316 pairs). Sleep quality and body mass index showed an inverse relationship (b = 0.056, P = 0.032) in the global sample. When twins discordant for body mass index were selected, this association maintained a similar effect size and statistical significance, at all levels of the case–control analysis (all discordant pairs b = 0.173, P < 0.001; dizygotic twins b = 0.174, P = 0.002; monozygotic twins b = 0.173, P = 0.050). Nevertheless, when twin pairs were selected on the basis of their discordance for sleep quality, the association between body mass index and sleep quality appeared weaker and lost significance (b = 0.021, P = 0.508). The analyses including only dizygotic (b = 0.028, P = 0.526) or monozygotic (b = 0.001, P = 0.984) pairs produced similar non‐significant results. Our results confirm the relationship between sleep quality and body mass index, even after applying high levels of control, including genetic factors. Moreover, this study suggests a possible directionality of this relationship, such that sleep quality would strongly affect body mass index, while the opposite would be less robust and consistent in non‐clinical samples.     

Sibling risk of Pediatric Obstructive Sleep Apnea Syndrome and Adenotonsillar Hypertrophy

Objectives:

To estimate sibling risk of hospitalization for children with sleep disordered breathing (SDB), diagnosed with (1) obstructive sleep apnea syndrome (OSAS), or (2) adenotonsillar hypertrophy in the total Swedish population.

Design, Setting, and Participants:

Using the MigMed database at the Karolinska Institute, we divided the population of Sweden aged 0–18 years into sibling groups based on a shared mother and father and presence of a primary hospital diagnosis of OSAS or adenotonsillar hypertrophy for each individual born between 1978 and 1986, during the follow-up period 1997–2004. Individuals with at least one affected sibling were identified and the incidence rates were computed, using standardized incidence ratios (SIRs) with 95% confidence intervals (CIs). Reference groups were boys and girls with unaffected siblings of 2 or more.

Results:

After accounting for socioeconomic status, age, and geographic region, boys with at least one sibling with OSAS had an increased risk of having OSAS (SIR, 33.2; 95% CI, 16.5–64.8), and in girls the SIR was 40.5 (19.4–81.4). For hypertrophy of the tonsils or hypertrophy of the adenoids and tonsils the corresponding SIRs were 4.53 (3.0–6.8) for boys and 4.94 (3.3–7.4) for girls.

Conclusions

The study indicate an increased sibling risk of sleep disordered breathing in children, which may be due to heritable genes and/or shared environment such as increased awareness among family members or referring doctors. Caregivers should ask parents if siblings have similar symptoms, and thus offer them early treatment.

Citation:

Friberg D; Sundquist J; Li X; Hemminki K; Sundquist K. Sibling risk of pediatric obstructive sleep apnea syndrome and adenotonsillar hypertrophy. SLEEP 2009;32(8):1077-1083.     

Sleep and subjective cognitive decline in cognitively healthy elderly: Results from two cohorts

Subjective cognitive decline may reflect a dementia prodrome or modifiable risk factor such as sleep disturbance. What is the association between sleep and subjective cognitive decline? Cross‐sectional design, from two studies of older adults: the WHICAP in the USA and the HELIAD in Greece. A total of 1,576 WHICAP and 1,456 HELIAD participants, without mild cognitive impairment, dementia or severe depression/anxiety, were included. Participants were mostly women, with 12 (WHICAP) and 8 (HELIAD) mean years of education. Sleep problems were estimated using the Sleep Scale from the Medical Outcomes Study. Subjective cognitive decline was assessed using a structured complaint questionnaire that queries for subjective memory and other cognitive symptoms. Multinomial or logistic regression models were used to examine whether sleep problems were associated with complaints about general cognition, memory, naming, orientation and calculations. Age, sex, education, sleep medication, use of medications affecting cognition, co‐morbidities, depression and anxiety were used as co‐variates. Objective cognition was also estimated by summarizing neuropsychological performance into composite z‐scores. Sleep problems were associated with two or more complaints: WHICAP: β = 1.93 (95% confidence interval: 1.59–2.34), p ≤ .0001; HELIAD: β = 1.48 (95% confidence interval: 1.20–1.83), p ≤ .0001. Sleep problems were associated with complaints in all the cognitive subcategories, except orientation for the WHICAP. The associations were noted regardless of objective cognition. At any given level of objective cognition, sleep disturbance is accompanied by subjective cognitive impairment. The replicability in two ethnically, genetically and culturally different cohorts adds validity to our results. The results have implications for the correlates, and potential aetiology of subjective cognitive decline, which should be considered in the assessment and treatment of older adults with cognitive complaints.     

Fatigue and sleep disturbance in adult survivors of childhood cancer: a report from the childhood cancer survivor study (CCSS)

STUDY OBJECTIVE: To examine the prevalence of and risk factors for fatigue and sleep disturbance among adult survivors of childhood cancer. DESIGN: Retrospective cohort of childhood cancer survivors. SETTING: Twenty-six academic institutions treating childhood cancer. PARTICIPANTS: Two thousand six hundred forty-five survivors of childhood acute lymphocytic leukemia, central nervous system tumors, Hodgkin lymphoma, soft-tissue sarcomas, or bone tumors diagnosed before age 21, surviving at least 5 years from diagnosis, and a 500-sibling comparison group. MEASUREMENTS: Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue), Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale. RESULTS: Significant differences were found between survivors and siblings on the Functional Assessment of Chronic Illness Therapy-Fatigue (40.8 vs 42.0, P < 0.02), Pittsburgh Sleep Quality Index (6.1 vs 5.5, P < 0.004), and Epworth Sleepiness Scale (6.2 vs 5.4, P < 0.001). Nineteen percent of survivors were in the most fatigued range, 16.7% reported disrupted sleep, and 14% increased daytime sleepiness. Survivors with a history of radiation therapy were more likely to be fatigued (odds ratio 1.7, 95% confidence interval 1.3-2.3), yet without significantly different mean scores. Female sex, congestive heart failure, pulmonary fibrosis, depression, and being unmarried significantly predicted more fatigue, whereas obesity and an infant in the house predicted more daytime sleepiness. Similar sociodemographic predictors were also identified among the siblings. CONCLUSION: Because of the large sample size, we detected more objectively reported fatigue, sleep disturbance, and daytime sleepiness among adult survivors of childhood cancer. However, the clinical significance of these differences is questionable. Predictors of fatigue and poor sleep were similar in both survivors and the siblings.     

Sleep duration and blood pressure: a longitudinal analysis from early to late adolescence

The aim of this study was to evaluate the association between sleep duration and blood pressure using a cross‐sectional and longitudinal approach. As part of a population‐based cohort, 1403 adolescents were evaluated at 13 and 17 years old. Sleep duration was estimated by the difference between self‐reported usual bedtime and wake‐up time. Blood pressure was measured using the auscultatory method. Regression coefficients (β) and respective 95% confidence intervals were computed to evaluate the association between sleep duration and blood pressure, using linear regression models adjusted for practice of sports and body mass index at 17 years old. The mean (standard deviation) sleep duration at 13 years old was 9.0 (0.76) h per day, and on average it decreased by 46 min up to 17 years old. The median (25th–75th) systolic blood pressure at 17 years old was 110.0 (103.5–119.0) mmHg in females and 114.0 (106.0–122.0)mmHg in males (P < 0.001); for diastolic blood pressure the values were 66.0 (60.0–71.0) and 69.0 (62.0–75.0) mmHg, respectively (P < 0.001). In cross‐sectional analysis, at 17 years old, after adjustment, a positive association was found between sleep duration and blood pressure, significant only for systolic blood pressure among females [β = 0.730 (0.005; 1.455)]. In girls, no significant association was found between sleep duration at 13 years old and blood pressure at 17 years old, but in males an inverse association was found between sleep duration at 13 years old and blood pressure at 17 years old significant only for systolic blood pressure [β = ?1.938 (?3.229; ?0.647)]. This study found no association between sleep duration at 13 years old and blood pressure at 17 years old in girls, but among males an inverse association was found.     

Sleep disturbances in asymptomatic BRCA1/2 mutation carriers: women at high risk for breast–ovarian cancer

This study investigated the association between positive genetic diagnosis for BRCA1/2 mutations and sleep quality in Ashkenazi asymptomatic women. Seventy‐three women, including 17 asymptomatic BRCA1/2 carriers and 20 non‐carriers from the oncogenetic clinic, and 36 community controls, participated in a cross‐sectional design. Women completed sociodemographic, clinical, general psychological distress, cancer‐related worry (CRW), fatigue and sleep questionnaires in their homes, and wore actigraphs for 5–7 nights. Impaired global subjective sleep quality was demonstrated in BRCA1/2 carriers compared to non‐carriers and controls [mean Pittsburgh sleep quality index (PSQI) total scores 7.29 ± 4.34; 3.94 ± 2.49; 4.21 ± 2.80, respectively, P = 0.021] and poor sleep quality (PSQI total score >5) was significantly higher in carriers (53%) compared to non‐carriers (20%) and controls (28%, P = 0.03). Based on actigraphic measures, sleep latency tended to be longer in carriers compared to counterparts, albeit not significantly. Increased sleep disturbance was related significantly to increased fatigue in the entire sample and in the control group; to psychological distress in the entire sample and in non‐carriers; and to CRW in the entire sample. In carriers, sleep disturbance was related strongly but non‐significantly to fatigue, psychological distress and CRW. Fatigue and carrier status were significant predictors of sleep quality, accounting for 15.7% of the variance. In conclusion, asymptomatic BRCA1/2 carriers experience poor sleep quality compared to non‐carriers and controls. Our study design is unique in that it offers insight regarding the nature of being an asymptomatic carrier, and affords the opportunity to examine factors that may contribute to the development of insomnia in women at risk for breast–ovarian cancer.     

A hard day's night: a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue

This prospective four-wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand–control history on the development of sleep quality and fatigue. Based on results of a four-wave complete panel study among 1163 Dutch employees, we found significant effects of job demands and job control on sleep quality and fatigue across a 1-year time lag, supporting the strain hypothesis (Demand–Control model; Karasek and Theorell, Basic Books, New York, 1990). No reversed or reciprocal causal patterns were detected. Furthermore, our results revealed that cumulative exposure to a high-strain work environment (characterized by high job demands and low job control) was associated with elevated levels of sleep-related complaints. Cumulative exposure to a low-strain work environment (i.e. low job demands and high job control) was associated with the highest sleep quality and lowest level of fatigue. Our results revealed further that changes in exposure history were related to changes in reported sleep quality and fatigue across time. As expected, a transition from a non-high-strain towards a high-strain job was associated with a significant increase in sleep-related complaints; conversely, a transition towards a non-high-strain job was not related to an improvement in sleep-related problems.     

Good perceived sleep quality protects against the raised risk of respiratory infection during sleep restriction in young adults

Study ObjectivesProspectively examine the association between sleep restriction, perceived sleep quality (PSQ) and upper respiratory tract infection (URTI).MethodsIn 1318 military recruits (68% males) self-reported sleep was assessed at the beginning and end of a 12-week training course. Sleep restriction was defined as an individualized reduction in sleep duration of ≥2 hours/night compared with civilian life. URTIs were retrieved from medical records.ResultsOn commencing training, approximately half of recruits were sleep restricted (52%; 2.1 ± 1.6 h); despite the sleep debt, 58% of recruits with sleep restriction reported good PSQ. Regression adjusted for covariates showed that recruits commencing training with sleep restriction were more likely to suffer URTI during the course (OR = 2.93, 95% CI 1.29–6.69, p = .011). Moderation analysis showed this finding was driven by poor PSQ (B = −1.12, SE 0.50, p = .023), as no significant association between sleep restriction and URTI was observed in recruits reporting good PSQ, despite a similar magnitude of sleep restriction during training. Associations remained in the population completing training, accounting for loss to follow-up. Recruits reporting poor PSQ when healthy at the start and end of training were more susceptible to URTI (OR = 3.16, 95% CI 1.31–7.61, p = .010, vs good PSQ).ConclusionGood perceived sleep quality was associated with protection against the raised risk of respiratory infection during sleep restriction. Studies should determine whether improvements in sleep quality arising from behavioral sleep interventions translate to reduced respiratory infection during sleep restriction.