Subjective–objective sleep discrepancy in patients with insomnia during and after cognitive behavioural therapy: An actigraphy study

Although patients with insomnia often show a discrepancy between self‐reported and objective sleep parameters, the role of and change in this phenomenon during treatment remain unclear. The present study aimed to assess the effect of cognitive behavioural therapy for insomnia on subjective and objective sleep discrepancy of total sleep time, sleep‐onset latency and wake after sleep onset. The total sleep time discrepancy was also assessed across the entire therapy. The second aim was to examine the treatment outcome of two insomnia groups differing in sleep perception. Thirty‐six adults with insomnia (mean age = 46.7 years, SD = 13.9; 22 females) were enrolled in the final analyses. Patients underwent a 6‐week group cognitive behavioural therapy for insomnia programme. Sleep diary and actigraphy measurements were obtained during the therapy. Patients who underestimated total sleep time (n = 16; underestimating group) were compared with patients who accurately perceived or overestimated total sleep time (n = 20; accurate/overestimating group). After cognitive behavioural therapy for insomnia, a significant decrease of total sleep time and sleep‐onset latency discrepancy was observed without a change in wake after sleep onset discrepancy in the total sample. Only the underestimating group reported decreased sleep‐onset latency discrepancy after the treatment, whereas total sleep time discrepancy significantly changed in both groups. The underestimating group showed a significant decrease of total sleep time discrepancy from Week 1 to Week 2 when the sleep restriction was implemented, whereas the accurate/overestimating group showed the first significant change at Week 4. In conclusion, both groups differing in sleep perception responded similarly to cognitive behavioural therapy for insomnia, although different In conclusion, both groups differing in sleep perception responded similarly to cognitive behavioural therapy for insomnia, although different therapeutic components could play important roles in each group. components could play important roles in each group.     

Subjective–objective sleep discrepancy among older adults: associations with insomnia diagnosis and insomnia treatment

Discrepancy between subjective and objective measures of sleep is associated with insomnia and increasing age. Cognitive behavioural therapy for insomnia improves sleep quality and decreases subjective–objective sleep discrepancy. This study describes differences between older adults with insomnia and controls in sleep discrepancy, and tests the hypothesis that reduced sleep discrepancy following cognitive behavioural therapy for insomnia correlates with the magnitude of symptom improvement reported by older adults with insomnia. Participants were 63 adults >60 years of age with insomnia, and 51 controls. At baseline, participants completed sleep diaries for 7 days while wearing wrist actigraphs. After receiving cognitive behavioural therapy for insomnia, insomnia patients repeated this sleep assessment. Sleep discrepancy variables were calculated by subtracting actigraphic sleep onset latency and wake after sleep onset from respective self‐reported estimates, pre‐ and post‐treatment. Mean level and night‐to‐night variability in sleep discrepancy were investigated. Baseline sleep discrepancies were compared between groups. Pre–post‐treatment changes in Insomnia Severity Index score and sleep discrepancy variables were investigated within older adults with insomnia. Sleep discrepancy was significantly greater and more variable across nights in older adults with insomnia than controls, P ≤ 0.001 for all. Treatment with cognitive behavioural therapy for insomnia was associated with significant reduction in the Insomnia Severity Index score that correlated with changes in mean level and night‐to‐night variability in wake after sleep onset discrepancy, P < 0.001 for all. Study of sleep discrepancy patterns may guide more targeted treatments for late‐life insomnia.     

CBT for late‐life insomnia and the accuracy of sleep and wake perceptions: Results from a randomized‐controlled trial

Subjective and objective estimates of sleep are often discordant among individuals with insomnia who typically under‐report sleep time and over‐report wake time at night. This study examined the impact and durability of cognitive‐behavioural therapy for insomnia on improving the accuracy of sleep and wake perceptions in older adults, and tested whether changes in sleep quality were related to changes in the accuracy of sleep/wake perceptions. One‐hundred and fifty‐nine older veterans (97% male, mean age 72.2 years) who met diagnostic criteria for insomnia disorder were randomized to: (1) cognitive‐behavioural therapy for insomnia (n = 106); or (2) attention control (n = 53). Assessments were conducted at baseline, post‐treatment, 6‐months and 12‐months follow‐up. Sleep measures included objective (via wrist actigraphy) and subjective (via self‐report diary) total sleep time and total wake time, along with Pittsburgh Sleep Quality Index score. Discrepancy was computed as the difference between objective and subjective estimates of wake and sleep. Minutes of discrepancy were compared between groups across time, as were the relationships between Pittsburgh Sleep Quality Index scores and subsequent changes in discrepancy. Compared with controls, participants randomized to cognitive‐behavioural therapy for insomnia became more accurate (i.e. minutes discrepancy was reduced) in their perceptions of sleep/wake at post‐treatment, 6‐months and 12‐months follow‐up (p < .05). Improved Pittsburgh Sleep Quality Index scores at each study assessment preceded and predicted reduced discrepancy at the next study assessment (p < .05). Cognitive‐behavioural therapy for insomnia reduces sleep/wake discrepancy among older adults with insomnia. The reductions may be driven by improvements in sleep quality. Improving sleep quality appears to be a viable path to improving sleep perception and may contribute to the underlying effectiveness of cognitive‐behavioural therapy for insomnia.     

Disturbed sleep in attention‐deficit hyperactivity disorder (ADHD) is not a question of psychiatric comorbidity or ADHD presentation

Attention‐deficit hyperactivity disorder (ADHD) is a heterogeneous psychiatric disorder with three different presentations and high levels of psychiatric comorbidity. Serious sleep complaints are also common, but the role of the presentations and comorbidity in sleep is under‐investigated in ADHD. Consequently, the goal of the study was to investigate sleep problems in medicine‐naive school‐aged children (mean age = 9.6 years) with ADHD compared to controls using objective methods and to examine the role of comorbidity and presentations. Ambulatory polysomnography results suggested that children with ADHD (n = 76) had significantly more sleep disturbances than controls (n = 25), including a larger percentage of rapid eye movement (REM) sleep and more sleep cycles, as well as lower mean sleep efficiency, mean non‐REM (NREM) sleep stage 1 and mean NREM sleep stage 3. No significant between‐group differences were found on the multiple sleep latency test. Stratifying for comorbidity in the ADHD group did not reveal major differences between groups, but mean sleep latency was significantly longer in children with ADHD and no comorbidity compared to controls (36.1 min; SD = 30.1 versus 22.6 min; SD = 15.2). No differences were found between ADHD presentations. Our results support the presence of night‐time sleep disturbances in children with ADHD. Poor sleep does not appear to be attributable to comorbidity alone, nor do sleep disturbances differ within ADHD presentations.     

Resistance training does not alter same‐day sleep architecture in institutionalized older adults

Sleep disturbance is a common symptom in institutionalized older adults that reduces their quality of life and may contribute to progression of cognitive impairment. While we found that a 7‐week combination of resistance training, walking and social activity significantly improved sleep in institutionalized older adults compared with a usual care control group, no one to our knowledge has determined the acute effects of resistance training on same‐day sleep in this population. Given the effort required to promote exercise adherence in institutionalized older adults and to obtain a positive training effect, understanding of the acute effects of resistance training on same‐day sleep architecture should be elucidated, especially with respect to unintended consequences. This secondary data analysis assessed if resistance training altered the same‐day sleep architecture in institutionalized older adults. Forty‐three participants (age 81.5 ± 8.1 years, male = 17, female = 26) had two attended overnight polysomnography tests in their rooms for sleep architecture analysis; one polysomnography with same‐day resistance training, one without any resistance training. Resistance training consisted of chest and leg press exercises (three sets, eight repetitions, 80% predicted one‐repetition maximum). There were no significant changes in sleep architecture between either polysomnography nights; sleep efficiency (P = 0.71), time in non‐rapid eye movement stages (P = 0.50), time in rapid eye movement stages (P = 0.14), time awake (P = 0.56), time until sleep onset (P = 0.47), total sleep stage shifts (P = 0.65) or rapid eye movement sleep stage latency (P = 0.57). Our results show no acute same‐day effects of resistance training on sleep architecture in institutionalized older adults. Clinical Trial Registration ClinicalTrials.gov Identifier: NCT00888706.     

Endothelial function and sleep: associations of flow‐mediated dilation with perceived sleep quality and rapid eye movement (REM) sleep

Endothelial function typically precedes clinical manifestations of cardiovascular disease and provides a potential mechanism for the associations observed between cardiovascular disease and sleep quality. This study examined how subjective and objective indicators of sleep quality relate to endothelial function, as measured by brachial artery flow‐mediated dilation (FMD). In a clinical research centre, 100 non‐shift working adults (mean age: 36 years) completed FMD testing and the Pittsburgh Sleep Quality Index, along with a polysomnography assessment to obtain the following measures: slow wave sleep, percentage rapid eye movement (REM) sleep, REM sleep latency, total arousal index, total sleep time, wake after sleep onset, sleep efficiency and apnea–hypopnea index. Bivariate correlations and follow‐up multiple regressions examined how FMD related to subjective (i.e. Pittsburgh Sleep Quality Index scores) and objective (i.e. polysomnography‐derived) indicators of sleep quality. After FMD showed bivariate correlations with Pittsburgh Sleep Quality Index scores, percentage REM sleep and REM latency, further examination with separate regression models indicated that these associations remained significant after adjustments for sex, age, race, hypertension, body mass index, apnea–hypopnea index, smoking and income (Ps < 0.05). Specifically, as FMD decreased, scores on the Pittsburgh Sleep Quality Index increased (indicating decreased subjective sleep quality) and percentage REM sleep decreased, while REM sleep latency increased (Ps < 0.05). Poorer subjective sleep quality and adverse changes in REM sleep were associated with diminished vasodilation, which could link sleep disturbances to cardiovascular disease.     

Sleep deprivation increases formation of false memory

Retrieving false information can have serious consequences. Sleep is important for memory, but voluntary sleep curtailment is becoming more rampant. Here, the misinformation paradigm was used to investigate false memory formation after 1 night of total sleep deprivation in healthy young adults (N = 58, mean age ± SD = 22.10 ± 1.60 years; 29 males), and 7 nights of partial sleep deprivation (5 h sleep opportunity) in these young adults and healthy adolescents (N = 54, mean age ± SD = 16.67 ± 1.03 years; 25 males). In both age groups, sleep‐deprived individuals were more likely than well‐rested persons to incorporate misleading post‐event information into their responses during memory retrieval (P < 0.050). These findings reiterate the importance of adequate sleep in optimal cognitive functioning, reveal the vulnerability of adolescents' memory during sleep curtailment, and suggest the need to assess eyewitnesses' sleep history after encountering misleading information.     

Accurate scoring of the apnea–hypopnea index using a simple non‐contact breathing sensor

Sleep apnea is a serious condition that afflicts many individuals and is associated with serious health complications. Polysomnography, the gold standard for assessing and diagnosing sleep apnea, uses breathing sensors that are intrusive and can disrupt the patient's sleep during the overnight testing. We investigated the use of breathing signals derived from non‐contact force sensors (i.e. load cells) placed under the supports of the bed as an alternative to traditional polysomnography breathing sensors (e.g. nasal pressure, oral‐nasal thermistor, chest belt and abdominal belt). The apnea–hypopnea index estimated using the load cells was not different than that estimated using standard polysomnography leads (t₄₄ = 0.37, P = 0.71). Overnight polysomnography sleep studies scored using load cell breathing signals had an intra‐class correlation coefficient of 0.97 for the apnea–hypopnea index and an intra‐class correlation coefficient of 0.85 for the respiratory disturbance index when compared with scoring using traditional polysomnography breathing sensors following American Academy of Sleep Medicine guidelines. These results demonstrate the feasibility of using unobtrusive load cells installed under the bed to measure the apnea–hypopnea index.     

Sleep‐related attentional bias in poor versus good sleepers is independent of affective valence

Contradictory evidence exists relating to the presence of an attention bias to sleep‐related stimuli in poor sleepers/insomnia using the emotional Stroop task (EST). These inconsistencies may be due to methodological issues related to the affective valence of the sleep‐related stimuli. Thus, individuals may attend differentially to sleep‐related stimuli not because of their ‘sleep’ properties, but their negativity. The current study addresses this by controlling the affective valence of sleep‐related words. A total of 107 participants [mean age = 33.22 years, standard deviation (SD) = 12.31 years; 61.7% female] were recruited during an evening event at the Newcastle Science Festival. Participants completed the Pittsburgh Sleep Quality Index (PSQI) and a computerized EST containing 20 non‐affective sleep‐related, 20 neutral and 20 negatively valenced threat words. Good and poor sleepers were categorized using the PSQI. There were no significant differences between groups on response latency to sleep‐related words (t₍₁₀₅₎ = –0.30, P = 0.76). However, the interaction between good versus poor sleepers and word‐type on response latency was significant (F_(2,210) = 3.06, P < 0.05). Poor sleepers took longer to respond to sleep‐related words (mean = 723.35, SD = 172.55) compared to threat words (mean = 694.63, SD = 162.17) than good sleepers (mean = 713.20, SD = 166.32; and mean = 716.65, SD = 181.14). The results demonstrate the presence of an attention bias towards sleep‐related stimuli compared to threat stimuli in poor sleepers. Accordingly, poor sleepers may be consumed by stimuli relevant to their specific difficulties, as well as being more highly attuned to negative cues that signal anxious states. Thus, the present research suggests that there are two opposing forces at play: one which facilitates performance (non‐specific threats) and one which hinders performance (personally relevant threats).     

Assessment of a hearing protection device on infant sleep in the neonatal intensive care unit

Premature infants often require prolonged hospitalisation in the neonatal intensive care unit (NICU) where they are exposed to adverse noise that may disrupt sleep and further compromise recovery and developmental outcomes. This single-session trial assessed the effects of a novel circumaural hearing protection device (DREAMIES®; NEATCAP Medical LLC) on sleep in 10 premature infants (mean 34.1 weeks GA) in a Level III NICU. Using polysomnography (PSG), the infant's sleep was compared between three interfeed periods throughout which DREAMIES® was ON or OFF. Each infant received the same condition order, OFF1-ON-OFF2. The PSG 30 s epochs were scored by a rater masked to the condition as Quiet Sleep, Active Sleep, Indeterminate Sleep, and Wake. There was a 14.1% increase in sleep from OFF1 to ON (p = 0.05) and an 18.4% decrease in sleep from ON to OFF2 (p = 0.02); an analogous inverse effect was observed for wake (χ² = 5.03, p = 0.08). There was a main effect of DREAMIES on active sleep (χ² = 7.4, p = 0.025) due to more active sleep for ON1 (46%) compared with OFF2 (32%; p = 0.074). No significant effect was observed for quiet sleep or indeterminate sleep. On average, the sound level was 51 dBA (range 36–113 dBA) and did not differ significantly among the three periods. The strongest relationship between the minute-by-minute maximum sound level and movement actigraphy was observed for the OFF1 condition (ρ0.301, p < 0.001). These findings suggest that DREAMIES® may augment sleep in premature infants by reducing acute episodes of adverse noise in the NICU.     

Psychological interventions to improve sleep in college students: A meta‐analysis of randomized controlled trials

Sleep disturbances and insomnia are common in college students, and reduce their quality of life and academic performance. The aim of this meta‐analysis was to evaluate the efficacy of psychological interventions aimed at improving sleep in college students. A meta‐analysis was conducted with 10 randomized controlled trials with passive control conditions (N = 2,408). The overall mean effect size (Hedges’ g) of all sleep‐related outcomes within each trial was moderate to large (g = 0.61; 95% confidence interval: 0.41?0.81; numbers‐needed‐to‐treat = 3). Effect sizes for global measures of sleep disturbances were g = 0.79; 95% confidence interval: 0.52?1.06; and for sleep‐onset latency g = 0.65; 95% confidence interval: 0.36?0.94. The follow‐up analyses revealed an effect size of g = 0.56; 95% confidence interval: 0.45?0.66 for the combined sleep‐related outcomes based on three studies. No significant covariates were identified. These results should be interpreted cautiously due to an overall substantial risk of bias, and in particular with regard to blinding of participants and personnel. Nevertheless, they provide evidence that psychological interventions for improving sleep are efficacious among college students. Further research should explore long‐term effects and potential moderators of treatment efficacy in college students.     

Age affects sleep microstructure more than sleep macrostructure

It is well known that the quantity and quality of physiological sleep changes across age. However, so far the effect of age on sleep microstructure has been mostly addressed in small samples. The current study examines the effect of age on several measures of sleep macro‐ and microstructure in 211 women (22–71 years old) of the ‘Sleep and Health in Women’ study for whom ambulatory polysomnography was registered. Older age was associated with significantly lower fast spindle (effect size f² = 0.32) and K‐complex density (f² = 0.19) during N2 sleep, as well as slow‐wave activity (log) in N3 sleep (f² = 0.21). Moreover, total sleep time (f² = 0.10), N3 sleep (min) (f² = 0.10), rapid eye movement sleep (min) (f² = 0.11) and sigma (log) (f² = 0.05) and slow‐wave activity (log) during non‐rapid eye movement sleep (f² = 0.09) were reduced, and N1 sleep (f² = 0.03) was increased in older age. No significant effects of age were observed on slow spindle density, rapid eye movement density and beta power (log) during non‐rapid eye movement sleep. In conclusion, effect sizes indicate that traditional sleep stage scoring may underestimate age‐related changes in sleep.     

Apnea‐related sleep fragmentation and poor vigilance in children with well‐controlled asthma

It has been reported that sleep problems and neurocognitive deficit in asthmatic children is prevalent. However, systematic studies on these problems in stable asthma using polysomnography have rarely been performed. We therefore investigated sleep and neurocognitive functioning in children with well‐controlled asthma. Forty‐three children with well‐controlled, stable asthma and 31 controls (age range: 6–9 years) were enrolled in the study. Subjects were questioned for daytime sleepiness using the Paediatric Daytime Sleepiness Scale. Complete overnight polysomnography and neurocognitive function tests were performed on all subjects. Children with stable asthma had lower pulmonary function in comparison to their age‐matched controls. Asthmatic children had a higher apnea–hypopnea index (P < 0.001) and apnea–hypopnea‐related arousal index (P < 0.001) as compared with non‐asthmatics. Deep sleep was decreased in asthmatics (P = 0.001). In the vigilance test, the mean number of correct answers was lower (P = 0.005) and the mean reaction time was slower (P = 0.002) in asthmatic children. A hierarchical multiple linear regression showed that deep sleep and apnea–hypopnea‐related arousal index were significant predictors of vigilance. The data suggest that the prevalence of paediatric sleep‐disordered breathing and sleep fragmentation could be very high among children with well‐controlled asthma. Moreover, vigilance, the ability to maintain attention and alertness, was worse in stable asthmatic children when compared with healthy controls. Sleep‐disordered breathing should be checked even in stable asthmatic children as they are at risk for developing neurobehavioural deterioration associated with frequent arousals during sleep. Furthermore, early treatment for asthma may be required in order to prevent airway remodelling that could cause sleep problems.     

Discrepancies in sleep diary and actigraphy assessments in adults with fibromyalgia: Associations with opioid dose and age

Sleep diary and actigraphy assessments of insomnia symptoms in patients with fibromyalgia (FM) are often discrepant. We examined whether opioid dose and age interact in predicting magnitude or direction of discrepancies. Participants (N = 199, M = 51.5 years, SD = 11.7) with FM and insomnia completed 14 days of diaries and actigraphy. Multiple regressions determined whether average opioid dose and its interaction with age predicted magnitude or direction of diary/actigraphy discrepancies in sleep onset latency (SOL), wake after sleep onset (WASO) and sleep efficiency (SE), controlling for sex, use of sleep medication, evening pain and total sleep time. Higher opioid dose predicted greater magnitude of discrepancy in SOL and SE. Opioid dose interacted with age to predict direction but not magnitude of discrepancy in SOL and SE. Specifically, higher opioid use was associated with better subjective (shorter SOL, higher SE) than objective reports of sleep among younger adults, and longer subjective than objectively measured SOL among older adults. Opioid dose did not predict magnitude or direction of WASO discrepancies. In FM, a higher opioid dose increases diary/actigraphy SOL and SE discrepancies, and direction of discrepancies may depend on age. We speculate that increased opioid use combined with age‐related factors, such as slow wave sleep disruption, increased awakenings and/or cognitive decline, may impact perceived sleep.     

Self‐reported sleep quantity,quality and sleep hygiene in elite athletes

Sleep is essential for recovery and performance in elite athletes. While actigraphy‐based studies revealed suboptimal sleep in athletes, information on their subjective experience of sleep is scarce. Relatively unexplored is also the extent to which athletes’ sleep is adversely affected by environmental conditions and daytime behaviours, that is sleep hygiene. This study aimed to provide insight in sleep quantity, quality and its putative association with sleep hygiene. Participants were 98 elite (youth) athletes competing at the highest (inter‐)national level. Sleep quantity, quality and sleep hygiene were assessed once covering a 1‐month period by using established (sub)clinical questionnaires, and repeatedly during 7 consecutive days. Sleep quality was generally healthy, although 41% of all athletes could be classified as ‘poor sleeper’, and 12% were identified as having a sleep disorder. Daily self‐monitoring revealed sleep durations of 8:11 ± 0:45 h, but elevated wake after sleep onset of 13 ± 19 min. Sleep quality, feeling refreshed, and morning vigor were moderate at best. Regarding sleep hygiene, general measures revealed irregular sleep–wake patterns, psychological strain and activating pre‐sleep behaviours. At the daily level, blue‐light exposure and late‐evening consumption of heavy meals were frequently reported. General sleep hygiene revealed significant associations with sleep quality (0.45 < r > 0.50; P < 0.001). Results indicate that there is ample room for optimization, specifically in onset latency and in wake after sleep onset. Subtle improvements in sleep seem possible, and optimizing sleep hygiene, such as regular sleep–wake patterns and reducing psychological strain, may facilitate this sleep upgrading process.     

Associations between quantitative sleep EEG and subsequent cognitive decline in older women

The pathophysiological processes of Alzheimer's dementia predate its clinical manifestation. Sleep disturbances can accelerate the aging process and are common features of dementia. This study examined whether quantitative sleep electroencephalogram changes predate the clinical development of mild cognitive impairment and/or incident dementia. We collected data from a nested case‐control sample of women (mean age 83 years) from the Sleep and Cognition Study, an ancillary study to the longitudinal Study of Osteoporotic Fractures, who were characterized as cognitively normal at the time of a baseline polysomnography study (Study of Osteoporotic Fractures visit 8) based on a Mini‐Mental Status Exam (MMSE) score >24. Cases (n = 85) were women who developed new mild cognitive impairment or dementia by objective cognitive testing 5 years after polysomnography. Controls were women with no mild cognitive impairment/dementia (n = 85) at baseline or at follow‐up. Differences in electroencephalogram absolute and relative power density were observed between the two groups. Specifically, higher electroencephalogram power values were found in the dementia/mild cognitive impairment group, for the alpha (p = .01) and theta bands (p = .04) in non‐rapid eye movement sleep, as well as alpha (p = .04) and sigma (p = .04) bands in rapid eye movement sleep. In contrast, there were no group differences in traditional polysomnography measures of sleep architecture and sleep stage distribution, as well as sleep apnea and periodic limb movement indices. Our results provide evidence for quantitative electroencephalogram changes, which precede the clinical onset of cognitive decline and the diagnosis of dementia in elderly women, and support the application of quantitative sleep electroencephalogram analysis as a promising biomarker for imminent cognitive decline.     

Contactless detection of periodic leg movements during sleep: A 3D video pilot study

In clinical practice, the quality of polysomnographic recordings in children and patients with neurodegenerative diseases may be affected by sensor displacement and diminished total sleep time due to stress during the recording. In the present study, we investigated if contactless three‐dimensional (3D) detection of periodic leg movements during sleep was comparable to polysomnography. We prospectively studied a sleep laboratory cohort from two Austrian sleep laboratories. Periodic leg movements during sleep were classified according to the standards of the World Association of Sleep Medicine and served as ground truth. Leg movements including respiratory‐related events (A1) and excluding respiratory‐related events (A2 and A3) were presented as A1, A2 and A3. Three‐dimensional movement analysis was carried out using an algorithm developed by the Austrian Institute of Technology. Fifty‐two patients (22 female, mean age 52.2 ± 15.1 years) were included. Periodic leg movement during sleep indexes were significantly higher with 3D detection compared to polysomnography (33.3 [8.1–97.2] vs. 30.7 [2.9–91.9]: +9.1%, p = .0055/27.8 [4.5–86.2] vs. 24.2 [0.00–88.7]: +8.2%, p = .0154/31.8 [8.1–89.5] vs. 29.6 [2.4–91.1]: +8.9%, p = .0129). Contactless automatic 3D analysis has the potential to detect restlessness mirrored by periodic leg movements during sleep reliably and may especially be suited for children and the elderly.     

Discrepancy between wrist‐actigraph and polysomnographic measures of sleep in patients with stable heart failure and a novel approach to evaluating discrepancy

Wrist‐actigraphy is often used to measure sleep characteristics in a variety of populations, but discrepancies between actigraphic and polysomnographic measures have been noted in populations experiencing poor sleep quality. The purpose of this study is to examine the discrepancy between these measures and risk factors for discrepancy in people with heart failure using a novel index. We used sleep measures simultaneously recorded by actigraphy and polysomnography, and clinical data from a cross‐sectional study of 155 patients with heart failure (age = 60.5 [16.1] years; 65.2% male) recruited from evidence‐based heart failure disease management programmes. The discrepancy and consistency between the two measures were evaluated using Bland–Altman plots, intra‐class correlations and a newly developed index that represents activity counts in wake episodes. Overall, participants had short total sleep time (327.7 [95.9] min) and poor sleep efficiency (71.3 [16.0]%) on polysomnography. The discrepancies between sleep measures were small in patients less than 60 years old, and there was excellent consistency (intra‐class correlation = 0.81) compared with older patients who had poorer consistency (intra‐class correlation = 0.53) on total sleep time. Higher daytime motor activity, poor sleep quality and more severe insomnia were associated with smaller discrepancies in older, but not younger, patients, and associations were more sensitively detected by the new index. These findings suggest the importance of aging, disability and co‐morbidity that may influence motor activity from which sleep estimates are scored with actigraphy. The new index may be useful in identifying factors associated with the correspondence between actigraphy and polysomnography.     

Sleep quality is negatively related to video gaming volume in adults

Most literature on the relationship between video gaming and sleep disturbances has looked at children and adolescents. There is little research on such a relationship in adult samples. The aim of the current study was to investigate the association of video game volume with sleep quality in adults via face‐to‐face interviews using standardized questionnaires. Adults (n = 844, 56.2% women), aged 18–94 years old, participated in the study. Sleep quality was measured using the Pittsburgh Sleep Quality Index, and gaming volume was assessed by asking the hours of gaming on a regular weekday (Mon–Thurs), Friday and weekend day (Sat–Sun). Adjusting for gender, age, educational level, exercise and perceived stress, results of hierarchical regression analyses indicated that video gaming volume was a significant predictor of sleep quality (β = 0.145), fatigue (β = 0.109), insomnia (β = 0.120), bedtime (β = 0.100) and rise time (β = 0.168). Each additional hour of video gaming per day delayed bedtime by 6.9 min (95% confidence interval 2.0–11.9 min) and rise time by 13.8 min (95% confidence interval 7.8–19.7 min). Attributable risk for having poor sleep quality (Pittsburgh Sleep Quality Index > 5) due to gaming >1 h day was 30%. When examining the components of the Pittsburgh Sleep Quality Index using multinomial regression analysis (odds ratios with 95% confidence intervals), gaming volume significantly predicted sleep latency, sleep efficiency and use of sleep medication. In general, findings support the conclusion that gaming volume is negatively related to the overall sleep quality of adults, which might be due to underlying mechanisms of screen exposure and arousal.     

Validity,potential clinical utility,and comparison of consumer and research‐grade activity trackers in Insomnia Disorder I: In‐lab validation against polysomnography

Consumer activity trackers claiming to measure sleep/wake patterns are ubiquitous within clinical and consumer settings. However, validation of these devices in sleep disorder populations are lacking. We examined 1 night of sleep in 42 individuals with insomnia (mean = 49.14 ± 17.54 years) using polysomnography, a wrist actigraph (Actiwatch Spectrum Pro: AWS) and a consumer activity tracker (Fitbit Alta HR: FBA). Epoch‐by‐epoch analysis and Bland?Altman methods evaluated each device against polysomnography for sleep/wake detection, total sleep time, sleep efficiency, wake after sleep onset and sleep latency. FBA sleep stage classification of light sleep (N1 + N2), deep sleep (N3) and rapid eye movement was also compared with polysomnography. Compared with polysomnography, both activity trackers displayed high accuracy (81.12% versus 82.80%, AWS and FBA respectively; ns) and sensitivity (sleep detection; 96.66% versus 96.04%, respectively; ns) but low specificity (wake detection; 39.09% versus 44.76%, respectively; p = .037). Both trackers overestimated total sleep time and sleep efficiency, and underestimated sleep latency and wake after sleep onset. FBA demonstrated sleep stage sensitivity and specificity, respectively, of 79.39% and 58.77% (light), 49.04% and 95.54% (deep), 65.97% and 91.53% (rapid eye movement). Both devices were more accurate in detecting sleep than wake, with equivalent sensitivity, but statistically different specificity. FBA provided equivalent estimates as AWS for all traditional actigraphy sleep parameters. FBA also showed high specificity when identifying N3, and rapid eye movement, though sensitivity was modest. Thus, it underestimates these sleep stages and overestimates light sleep, demonstrating more shallow sleep than actually obtained. Whether FBA could serve as a low‐cost substitute for actigraphy in insomnia requires further investigation.