0016 Changes in Alertness Over Consecutive Workdays for Internal Medicine Interns: A Secondary Analysis of the iCOMPARE Trial

Introduction

Little is known about the impact of cumulative workdays on medical residents' alertness. The purpose of this study was to examine changes in alertness over consecutive workdays following a day off for internal medicine interns.

Methods

This is a secondary report of a randomized non-inferiority trial of 12 internal-medicine residency programs assigned to either standard duty-hour (80h workweek/16h shifts) or flexible (80h workweek/no shift-length limit) policies. Interns were followed for 2 weeks during inpatient rotations. Each morning, alertness (number of Brief Psychomotor Vigilance Test [PVT-B] lapses) was assessed, and interns selected the type of shift worked (day-off, days, nights, beginning/ending extended overnights, or other). Sleep duration (actigraphy) was averaged each 24h day. For this analysis, interns were included if they had ≥1 day-off followed by at least 3 workdays, and had no flagged PVT-B results for non-adherence. To examine the longitudinal effect of consecutive workdays on alertness, a generalized linear mixed model with random intercept and slope, and Poisson distribution was used to determine the rate of PVT-B lapses for up to 4 work days following a day off, controlling work shift type, sleep duration, and policy, with sleep and shift type interaction, and linear spline to account for the change in slope after the 2nd workday.

Results

N=328 interns were included (mean age 27.8±2.2y, 49% males). Mean±SD number of PVT-B lapses were 3.4±4.5, 4.2±5.6, 5.3±6.6, 4.8±5.8, and 4.7±6.0, and mean±SD sleep duration was 9.0±1.9, 6.9±1.3, 6.5±2.1, 6.6±1.8, and 6.9±1.7 hours for a day off and workdays 1-4 respectively. Rate of lapses increased by 1.1 lapse/day from a day off to the 2nd workday (p=0.004; 95%CI: 1.03-1.18), and then significantly decreased from days 2-4 at a rate of 0.89 lapses/day (p<0.0001; 95%CI: 0.85-0.92). Patterns of change in the rate of lapses were similar to changes in sleep duration, where, from baseline, every 1h longer sleep duration was associated with 0.91 fewer PVT-B lapses (p<0.0001; 95%CI: 0.93-0.97).

Conclusion

Both sleep and subsequent alertness were negatively impacted when returning to work following a day off for interns in this study. After two workdays, sleep duration appeared to increase again, with observed improvements in alertness.

Support (If Any)

Funded by the NHLBI and American Council for Graduate Medical Education. M.C. is supported by NIH/NINR (K99 NR019862).

Impaired Vigilant Attention Partly Accounts for Inhibition Control Deficits After Total Sleep Deprivation and Partial Sleep Restriction

PURPOSE

Sleep loss impairs a range of neurobehavioral functions, particularly vigilant attention and arousal. However, the detrimental effects of sleep deprivation on inhibition control and its relationship to vigilant attention impairments remain unclear. This study examined the extent to which vigilant attention deficits contribute to inhibition control performance after one night of total sleep deprivation (TSD) and two nights of partial sleep restriction (PSR).

PARTICIPANTS AND METHODS

We analyzed data from N = 49 participants in a one-night of TSD experiment, N=16 participants in a control experiment without sleep loss, and N = 16 participants in a two-nights of PSR experiment (time in bed, TIB = 6 h for each night). Throughout waking periods in each condition, participants completed the psychomotor vigilance test (PVT), which measures vigilant attention, and the Go/No-Go task, which measures inhibition control.

RESULTS

After TSD and PSR, participants displayed significantly slower reaction times (RT) and more lapses in PVT performance, as well as slower Go RT and more errors of omission during the Go/No-Go task. PVT deficits accounted for 18.0% of the change in Go RT and 12.4% of the change in errors of omission in the TSD study, and 23.7% of the change in Go RT and 20.3% of the change in errors of omission in the PSR study.

CONCLUSION

Both TSD and PSR impaired inhibition control during the Go/No-Go task, which can be partly accounted for by vigilant attention deficits during the PVT. These findings support the key role of vigilant attention in maintaining overall neurobehavioral function after sleep loss.

670 Changes in Childhood Sleep Patterns in an Intervention Study Prior to and During COVID19 Restrictions

Introduction

We conducted a childhood sleep promotion study between March 2019 and December 2020 in Philadelphia. COVID19 was first detected in Pennsylvania in March 2020 and non-essential services were strictly curtailed (including school closures), with easing of curtailments by the fall 2020 (including hybrid schooling in some districts). We determined if changes in sleep duration were consistent during pre-, earlier, and later COVID19 periods.

Methods

Typically developing children (9-12y) with sleep duration <8.5 hours per weeknight were enrolled. Sleep was measured using Fitbit devices during a baseline week and a 7-week intervention period. A factorial design was used to test five candidate intervention components: 1) sleep goal; 2) electronic device reduction messaging; 3) daily routine messaging; 4) child-directed financial incentive; and 5) parent-directed financial incentive. Sleep data were transmitted to a mobile health platform that automated delivery of the intervention components. We categorized participants when they completed the study: 1) Spring-Fall 2019 semesters (pre-COVID19); 2) Spring 2020 semester (started pre-COVID19, with strict restrictions impacting intervention periods); or 3) Fall 2020 semester (easing of COVID19 restrictions). Mixed effect modelling determined sleep changes.

Results

Mean age of participants was 11.6y (51% female and 29% Black participants). Pre-COVID19 (N=59), average sleep duration increased from baseline by 21 (95% CI: 10, 30) minutes per weeknight during the intervention. In spring 2020 (N=18), the average sleep duration increase was two times larger in magnitude at 41 (95% CI: 25, 59) minutes per weeknight. For fall 2020 (N=20), the average sleep duration increase was 24 (95% CI: 7, 40) minutes per weeknight. Changes in sleep timing from baseline during the intervention were consistent pre-COVID19 and in the fall 2020 (e.g., ≈15 minutes earlier sleep onset throughout the intervention period), whereas sleep timing changes were dynamic in the spring 2020 (e.g., 41 minutes earlier for week 1, and 44 minutes later for week 7).

Conclusion

This sleep intervention demonstrated increases in sleep duration pre-COVID19, with marked duration increases and dynamic timing changes coinciding with COVID19 restrictions during earlier (Spring 2020), but not later (Fall 2020), weeks of the COVID19 pandemic in Pennsylvania.

Support (if any)

K0 1 HL1 2 3 6 1 2 and CHOP

215 Sleep duration, quality and timing during confinement amid the COVID-19 Pandemic

Introduction

As of March 2020, most U.S. states and territories issued statements advising people “stay at home” to avoid spreading the novel Coronavirus (COVID-19). This resulted in an unprecedented number of people practicing physical confinement and social distancing. This study examined self-reported changes in sleep duration, quality and timing in response to confinement and isolation.

Methods

We developed the “Anonymous Survey on Confinement during the COVID-19 Pandemic” to collect information on the American population practicing social distancing and some level of confinement. The survey collected information on demographics, duration and degree of confinement, and sleep-wake dynamics. The online survey was available for completion by any individual ≥18 years of age through the Penn Medicine Clinical Research page from May 16th to November 11th 2020. Descriptive statistics characterized the nature of confinement and non-parametric correlations evaluated the relationships between confinement and sleep-wake dynamics.

Results

N=226 participants completed the survey (n=176 female [77.8%]; n=47 male [20.8%]). The average age was 44.9±17.4 years. N=215[95.1%] reported confinement since March 2020 for an average of 89.3±41.7 days in confinement. Surveyed participants in confinement reported sleeping more than before confinement [40.0%], taking the same amount of time to fall asleep [56.6%], and felt that they were getting enough sleep [66.3%]. However, 36.3% of participants reported going to bed earlier and waking up earlier. Participants that engaged in naps prior to confinement reported taking more naps in confinement [50.8%]. Participants reported more daytime sleepiness [42.9%] and more disturbed sleep quality during confinement relative to before confinement [42.5%]. There were no significant correlations between time in confinement and sleep outcomes.

Conclusion

During the confinement amid the COVID-19 pandemic, participants responded by sleeping more and at different times, which could reflect circadian disruption of sleep. Changes in sleep amount and sleeping timing were accompanied by increased daytime sleepiness and a reduction in sleep quality. These changes may have been due to age, stressors experienced during the pandemic, social isolation, and/or a change in behavioral routines in response to changing demands and schedules. Our findings suggest that attention to changes in sleep-wake dynamics due to prolonged confinement is likely important to maintain healthy behaviors.

Support (if any):

613 Variation in Sleep Beliefs and Behaviors Among Caregiver-Child Dyads Participating in a Sleep Extension Intervention

Introduction

Given the high prevalence and poor outcomes of insufficient child sleep, effective interventions for the pediatric primary care setting are needed. Collecting family perspectives on intervention strategies is critical to understand and enhance outcomes, particularly among children who do not experience improvements. This study examined variation in qualitative family sleep beliefs and behaviors by quantitative child sleep outcomes of a sleep extension intervention.

Methods

A total of 24 caregiver-child dyads (child age 9–12 years, M age 11.3 (SD:1.0) years; 46% male; 50% non-Latinx White; 29% Black) participated in a mobile health sleep extension intervention, between March-December 2019, and completed post-intervention semi-structured telephone interviews to solicit intervention perceptions. The intervention used a 25 factorial design consisting of sleep duration goals and weekly performance feedback, with random assignment to sleep health promotion messaging and financial incentive conditions. Sleep duration was assessed via Fitbit Flex 2 devices during 2-week baseline and 7-week intervention periods. We developed a codebook using a grounded theory approach and conducted coding in NVivo. We compared preliminary qualitative themes among children who showed a >=30-minute improvement in sleep duration (‘responders’) versus those who did not (‘non-responders’).

Results

Of the 24 dyads, 38% (N=9 dyads) were classified as non-responders. Preliminary qualitative themes included: family beliefs about sleep and electronics usage; the study impact on sleep behaviors; and an enhanced awareness of child sleep. Intervention responder and non-responder dyads similarly described family restrictions on evening electronics usage (e.g., electronic parental controls; physical removal of devices) to benefit child sleep. However, more children classified as intervention responders described the benefits of these restrictions and expressed beliefs about the negative impacts of electronics on sleep. Whereas caregivers of both responders and non-responders described efforts to remind their child to go to bed earlier during the intervention, caregivers in the responder group described being more focused on and active in child sleep extension strategies. These included setting bedtime reminders and adjusting family activities to ensure an extended sleep schedule.

Conclusion

Addressing caregiver-child beliefs about sleep behaviors and engagement in sleep extension strategies could augment sleep extension intervention outcomes in future research.

Support (if any)

K01HL123612 (JAM), CHOP (JAM), K23HD094905 (AAW)

219 Comparing Sleep Amount and Quality for People Working from Home with and Without Minor Dependents during the COVID-19 Pandemic

Introduction

The global pandemic due to the novel coronavirus (COVID-19) has had unprecedented effects on society, in particular for those who are also working with children in the household. The aim of this analysis was to evaluate sleep amount and sleep quality during the COVID-19 pandemic compared to before COVID-19 for those working from home with minor household dependents.

Methods

We developed the “Anonymous Survey on Confinement during the COVID-19 Pandemic”, a national survey for individuals ≥18 years of age hosted on the Penn Medicine Clinical Research website from May 16th to November 11th, 2020. This 200 question survey captured demographics and multiple dimensions of health and well-being, including stress, sleep, eating behaviors, and coping activities. Respondents who indicated they were working from home were stratified by whether they were living with ≥1 minor dependent vs no dependents. Separate ordinal logistic regression models were used to evaluate associations between living with a minor dependent and sleep amount (less, same, more) and disturbed quality (none, less, same, more) during, compared to before, COVID-19 controlled for age, sex, ethnicity, and annual income.

Results

A total of 232 respondents (n=182 no dependents, n=50 dependents, 84.9% Caucasian) reported working from home, the majority of which had been in confinement (95.7%). Respondents with dependents were younger (mean age 38.9±13.5 vs 47.4±18.0, p=0.002) and mostly female (86% vs 76.9%, p=0.03). On average, reported days worked/week (3.5±2.4 days) and hours worked/day (5.5±4.17 hours) were similar regardless of dependents. Comparing those without to those with minor dependents, there were no significant differences in log odds of getting enough sleep (β=-0.38, p=0.25) or worse sleep quality (β=0.41, p=0.22) during the COVID-19 pandemic compared to before COVID-19. Respondents with dependents reported a higher log odds of taking longer to fall asleep during COVID-19 (β=0.71, p=0.045), and higher stress (β=-0.65, p=0.04).

Conclusion

In this mostly Caucasian female sample of people working from home, having minor dependents in the household did not significantly impact sleep amount or quality compared to no minor household dependents. However, respondents with dependents reported longer time to fall asleep and were more stressed.

Support (if any)

MC/CJ are supported by NHLBI (T32 HL007713).

226 Changes in sleep amount and sleep quality due to the COVID-19 pandemic confinement associate with ratings of health and stress

Introduction

In March 2020, an unprecedented number of individuals were confined to their homes in an effort to stem the spread of the novel Coronavirus (Covid-19), however the impact of this confinement on health and behavior is unknown. Long-duration confinement studies have found effects on homeostatic biology and neurobehavioral functions, including reduced sleep durations. This study evaluated how confinement due to Covid-19 has impacted health and stress through changes in sleep.

Methods

The Anonymous Survey on Confinement during the COVID-19 Pandemic was available online to any individual ≥18 years of age through the Penn Medicine Clinical Research webpage on May 14, 2020 and the data presented are through October 24, 2020. The survey collected self-reported information on demographics, the amount and quality of sleep, as well as ratings of health and stress. To determine the impact of confinement on these domains, participants were asked to answer questions relative to pre-confinement levels. To test associations between sleep amounts and sleep quality on health and stress, generalized linear models were used and adjusted for age, sex, and race.

Results

N=228 participants (n=180 female [79.0%]) were on average 45.0±17.1 years of age. During confinement relative to pre-confinement, 41.7% of participants reported sleeping more, 37.3% reported sleeping the same amount, and 21.0% reported less sleep, while 14.0% reported better sleep quality, 47.4% the same, and 38.6% worse quality of sleep relative to pre-confinement. Ratings of worse health during confinement were associated with both reduced sleep amount (β=0.695; P<0.0001) and worse sleep quality (β=0.532; P=0.0002). Lower stress ratings were associated with increased sleep amount (β=0.734; P=0.034), better sleep quality (β=1.396; P=0.0002), better health ratings (β=-0.079; P=0.0045). Conversely, worse sleep quality was associated with higher stress ratings (β=-1.086; P=0.0007).

Conclusion

The confinement resulting from the COVID-19 pandemic has impacted the amount and quality of sleep and good sleep may help to reduce stress and maintain health. These findings highlight the need to further examine how long-term confinement influences human health and behavior and warrant examining what factors or life-style behaviors promote resilience to the negative effects of confinement.

Support (if any)

CWJ supported by NHLBI NRSA (T32 HL007713).

1100 Self-Monitoring Of PVT Performance In Healthy Adults And Individuals With MDD

Introduction

Negativity bias in depression has been repeatedly demonstrated in the judgment and decision-making literature. Research investigating the impact of sleep deprivation on self-evaluation of performance in healthy or depressed populations is limited. We examined 1) whether individuals with Major Depressive Disorder (MDD) exhibit a negativity bias in subjective ratings of performance on the Psychomotor Vigilance Task (PVT) as compared with healthy adults, and 2) the impact of total sleep deprivation (TSD) on these ratings.

Methods

N=33 individuals with MDD and n=9 healthy adults completed a 5-day study protocol including two baseline nights (B1-B2, 9h TIB), 36 hours of TSD, and one night of recovery sleep opportunity (Rec). The PVT was administered every 2-4 hours. A brief questionnaire was administered immediately prior to (PRE) and following (POST) the PVT, asking participants to estimate their average reaction time (RT) using a 9-point Likert-type scale. Mixed-effects models examined the impact of group (MDD, Control), protocol day (B1, B2, SD, Rec), and their interaction on objective PVT performance (mean RT) and subjective performance estimates (PRE and POST ratings).

Results

Mean RT was significantly slower during TSD (p&lt;0.001) for all participants. Individuals with MDD and healthy adults did not differ in objective PVT performance (p=0.25) across days. There was no significant interaction between group and protocol day (p=0.96). Both groups predicted slower RTs during TSD as compared with baseline or recovery days (PRE-PVT, p=0.006). Individuals with MDD anticipated slower RTs as compared with healthy adults (p=0.001). On POST-PVT estimates, all participants reported subjective poorer performance during TSD (p&lt;0.008). Individuals with MDD reported slower RTs as compared with healthy adults (p=0.002). Interaction effects between group and protocol day on PRE- and POST- performance ratings were not significant.

Conclusion

This project is the first to investigate subjective estimates of PVT performance in healthy and depressed individuals. Individuals with MDD subjectively reported slower response times as compared with control participants, despite similar objective performance. Depressive symptoms may be a potential confounder of subjective, but not objective, PVT performance.

Support

5R01MH107571

0294 Baseline Response Speed Predicts Locus Coeruleus Integrity Change After Sleep Deprivation

Introduction

Locus coeruleus (LC) is the major source of norepinephrine (NE) in the brain, which plays a key role in maintaining arousal and alertness. Sleep loss significantly impairs arousal and alertness. However, it is unknown whether sleep loss disrupts LC integrity, which can be measured non-invasively by diffusion tensor imaging (DTI). In the current study, we used DTI to examine the effects of one night of acute total sleep deprivation (TSD) on fractional anisotropy (FA), an index reflecting fiber density, axonal diameter and myelination.

Methods

We analyzed DTI and psychomotor vigilance test (PVT) data from N=54 health adults (23 females, age range 21–50 years) from a well controlled in-laboratory sleep deprivation study. Participants were randomized to either a TSD condition (n=40) without sleep on night 2, or a control condition (n=14) with no sleep loss. Standard DTI scans were conducted on the morning of day 2 and day 3 between 0700h-1000h. The PVT reciprocal response time (RRT) was used to measure individual’s response speed at baseline without sleep loss. LC regions-of-interest (ROI) were defined by standard templates from Keren et al. (2009). Imaging data were analyzed using FSL toolbox.

Results

For the whole TSD group, no differences were found in the LC FA values before and after sleep deprivation (p &gt; .2). However, when dividing the TSD group to a slow group and a fast group based on their baseline PVT response speed, significantly increased LC FA were found in the slow group (p = .007) but not in the fast group (p &gt; .4). The PVT RRT negatively correlated with LC FA value changes after TSD (r = -.44, p = .004). No correlations were found between the PVT RRT and LC FA changes in the control group.

Conclusion

Our results showed that baseline vigilance response speed correlated with LC integrity change after sleep deprivation, with slower response exhibiting greater changes in LC integrity. These findings support the key role of LC-NE system in the regulation of alertness and arousal.

Support

Supported in part by NIH grants R01-HL102119, R01-MH107571, R21-AG051981. CTRC UL1RR024134, and P30-NS045839.

0060 Morning Locus Coeruleus Activation During the PVT Predicts Later-Day Sleepiness

Introduction

The locus coeruleus (LC) plays a key role in the regulation of arousal and autonomic function. Homeostatic sleep pressure refers to the drive for sleep that increases as a saturating exponential when we stay awake and decreases exponentially when we sleep. The current study used arterial spin labeling (ASL) functional magnetic resonance imaging (fMRI) to investigate the relationship between homeostatic sleep pressure (sleepiness) and LC activity during the psychomotor vigilance test (PVT).

Methods

We analyzed sleepiness and ASL imaging data from N=70 health adults (40 males, age range 21–50 years) who participated in a controlled in-laboratory sleep study. All participants were scanned at rest and during the PVT on the morning between 0700h-1000h after 9 hour time-in-bed (TIB) baseline sleep. LC regions-of-interest (ROI) were defined by standard templates from Keren et al. (2009). Sleepiness was assessed by the Karolinska Sleepiness Scale (KSS) every two hours from 10:30 am to 10:30 pm.

Results

Sleepiness scores gradually increased over wakefulness time and reached its peak in the evening at about 10:20pm. PVT-induced CBF changes did not correlate with sleepiness scores on the morning (p &gt; 0.05), but showed significant negative correlations with sleepiness scores on later day when sleep pressure became higher, especially during the night-time (r = -0.41, p &lt; 0.001). Specifically, LC CBF showed significant increases during the PVT scan as compared to the resting scan (p = 0.04) in individuals with less nigh-time sleepiness (KSS &lt; 4), but no differences (p &gt; 0.1) in individuals with greater nigh-time sleepiness (KSS ≥ 5). After controlling for age, gender, and total sleep time, PVT-induced regional CBF difference in the LC still negatively predicted sleepiness (β = -0.325, p = 0.005).

Conclusion

Our findings showed that individuals with greater LC CBF increases during the PVT were less sleepy during the night, supporting the key role of LC activity in promoting wakefulness and maintaining sleep homeostasis. PVT-induced LC activation may provide a non-invasive bio-marker of homeostatic sleep pressure in healthy adults.

Support

Supported in part by NIH grants R01-HL102119, R01-MH107571, R21-AG051981. CTRC UL1RR024134, and P30-NS045839.

Short-Term Variability in Apnea-Hypopnea Index during Extended Home Portable Monitoring

STUDY OBJECTIVES

Apnea-hypopnea index (AHI) is the primary measure used to confirm a diagnosis of obstructive sleep apnea (OSA). However, there may be significant night-to-night variability (NNV) in AHI, limiting the value of AHI in clinical decision-making related to OSA management. We examined short-term NNV in AHI and its predictors during home portable monitoring (PM).

METHODS

Single center prospective observational study of patients (n = 84) with newly diagnosed OSA by polysomnography (PSG) AHI ≥ 5/h. All participants underwent 2 to 8 consecutive nights of PM.

RESULTS

Participants (n = 84) were middle-aged (47 ± 8.3 y, mean ± standard deviation; SD), including 28 women, with mean AHI on baseline PSG (AHIPSG) of 30.1 ± 31.8. Mean AHI on PM (AHIPM) was 27.4 ± 23.7. Intraclass correlation coefficient (ICC) for AHIPM in the entire sample was 0.73 (95% CI 0.66-0.8), indicating that 27% of the variability in AHIPM was due to intra-individual factors. Mild severity of OSA, defined by AHIPSG 5-15/h, was associated with higher NNV (likelihood ratio, -0.4 ± 0.14; p = 0.006) and absence of comorbidity showed a trend towards higher NNV (-0.54 ± 0.27, p = 0.05) on AHIPM.

CONCLUSIONS

The intraindividual short-term NNV in AHIPM is higher in mild versus moderately severe OSA, even in the home setting, where first-night effect is not expected. Larger studies of NNV focused on patients with mild OSA are needed to identify characteristics that predict need and timing for repeated diagnostic testing and treatment.

COMMENTARY

A commentary on this article appears in this issue on page 787.

Early Blood Lead Levels and Sleep Disturbance in Preadolescence

STUDY OBJECTIVES

Little is known about the effect of lead exposure on children's sleep. This study examined the association between blood lead levels (BLL) and sleep problems in a longitudinal study of children.

SETTING

Four community-based elementary schools in Jintan City, China.

PARTICIPANTS

1,419 Chinese children.

MEASUREMENT AND RESULTS

BLL were measured when children were aged 3-5 y, and sleep was assessed at ages 9-13 y. Sleep was assessed by both parents' report, using the Children's Sleep Habits Questionnaire (CSHQ), and children's report, using an adolescent sleep questionnaire. A total of 665 children with complete data on BLL and sleep at both ages were included in the current study. Mean age of the sample at BLL assessment was 4.74 y (standard deviation [SD] = 0.89) and at sleep assessment was 11.05 y (SD = 0.88). Mean BLL was 6.26 μg/dL (SD = 2.54). There were significant positive correlations between BLL and 3 CSHQ subscales: Sleep onset delay (r = 0.113, P < 0.01), sleep duration (r = 0.139, P < 0.001), and night waking (r = 0.089, P < 0.05). Excessive daytime sleepiness (EDS) (26.1% versus 9.0%, P < 0.001) and use of sleeping pills (6.5% versus 1.8%, P = 0.03) were more prevalent in children BLL ≥ 10.0 μg/dL than in those children BLL < 10.0 μg/dL. After adjusting for demographics, BLL ≥ 10.0 μg/dL was significantly associated with increased risk for insomnia symptoms (odds ratio [OR] = 2.01, 95% confidence interval [CI] = 1.03-3.95) and EDS (OR = 2.90, 95% CI = 1.27-6.61).

CONCLUSION

The findings indicate that elevated blood lead levels in early childhood are associated with increased risk for sleep problems and excessive daytime sleepiness in later childhood.

Predictors of continuous positive airway pressure use during the first week of treatment

This study aimed to identify pre-treatment and immediate early treatment factors predicting continuous positive airway pressure (CPAP) use during the first week of therapy, when the pattern of non-adherence is established. Four domains of potential predictors were examined: pre-treatment demographic and clinical factors, patients' perceived self-efficacy, treatment delivery (mask leak and bothering side effects) and immediate disease reduction (residual respiratory events and flow limitation). The Autoset™ Clinical System objectively documented daily CPAP use, mask leak, residual respiratory events and flow limitation. Ninety-one CPAP-naive patients with newly diagnosed obstructive sleep apnea were followed for 1week after treatment initiation. Mean CPAP daily use during the first week was 3.4±2.7h, with significantly lower use observed in black than non-black participants (2.7 versus 4.4h, respectively, P=0.002). Less intimacy with partners caused by CPAP was the only treatment side effect correlated with CPAP use (r=-0.300, P=0.025). Reduced CPAP use during the first week was associated simultaneously with being black, higher residual apnea-hypopnea index and the treatment side effect of less intimacy with partners. The three factors together accounted for 25.4% of the variance in the CPAP use (R(2) =0.254, P<0.01). These data suggest the need to assess the impact of CPAP on intimacy and troubleshooting aspects of the treatment that interfere with sexual relationships. Assessing the presence of residual respiratory events may be important in promoting CPAP adherence. The association of race and CPAP use needs to be explored further by including more socioeconomic information.

Emotional expressiveness in sleep-deprived healthy adults

The purpose of this study was to evaluate the influence of sleep deprivation on emotional expression and subjective emotional experience in a highly controlled, laboratory setting. Twenty-three healthy adult participants watched positive (amusing) and negative (sad) film clips before and after they were randomly assigned to a night of sleep deprivation or a normal sleep control condition. The intensity of their facial expressiveness while viewing the films was coded by human judges and compared to their subjective emotional responses. Relative to the control group, sleep-deprived participants demonstrated less expressiveness, especially in response to positive stimuli. Subjective responses were not significantly different between the sleep-deprived and control groups. These preliminary results suggest that sleep deprivation is associated with attenuated emotional expressiveness in healthy adults.

Sleep, fatigue, and medical training: setting an agenda for optimal learning and patient care

The difficult issues surrounding discussions of sleep, fatigue, and medical education stem from an ironic biologic truth: physicians share a common physiology with their patients, a physiology that includes an absolute need for sleep and endogenous circadian rhythms governing alertness and performance. We cannot ignore the fact that patients become ill and require medical care at all times of the day and night, but we also cannot escape the fact that providing such care requires that medical professionals, including medical trainees, be awake and functioning at times that are in conflict with their endogenous sleep and circadian physiology. Finally, we cannot avoid the reality that medical education requires long hours in a constrained number of years. Solutions to the problem of sleep and fatigue in medical education will require the active involvement of numerous parties, ranging from trainees themselves to training program directors, hospital administrators, sleep and circadian scientists, and government funding and regulatory agencies. Each of these parties can be informed by previous laboratory and field studies in a variety of operational settings. including medical environments. Education regarding the known effects of sleep. circadian rhythms, and sleep deprivation can help to elevate the general level of discourse and point to potential solutions. Empiric research addressing the effects of sleep loss on patient safety, education outcomes, and resident health is urgently needed: equally important are the development and assessment of innovative countermeasures to maximize performance and learning. Addressing the economic realities of any changes in resident work hours is an essential component of any discussion of these issues. Finally, work-hour regulations may serve as one component of improved sleep and circadian health for medical trainees. but they should not be seen as substitutes for more original solutions that rely less on enforcement and more on collaboration. By working together to address the problems of sleep and fatigue in its own trainees, the medical field can provide a valuable legacy to patients and to future generations of healthcare providers--a legacy or optimal medical education, healthy doctors, and healthy patients.

Behavioral and neuroendocrine characteristics of the night-eating syndrome

CONTEXT

Investigators first described the night-eating syndrome (NES), which consists of morning anorexia, evening hyperphagia, and insomnia, in 1955, but, to our knowledge, this syndrome has never been subjected to careful clinical study.

OBJECTIVE

To characterize NES on the basis of behavioral characteristics and neuroendocrine data.

DESIGN AND SETTING

A behavioral observational study was conducted between January 1996 and June 1997 in a weight and eating disorders program at the University of Pennsylvania. A neuroendocrine study was conducted from May through August 1997 at the Clinical Research Center of the University Hospital, Tromso, Norway.

SUBJECTS

The behavioral study included 10 obese subjects who met criteria for NES and 10 matched control subjects. The neuroendocrine study included 12 night eaters and 21 control subjects. Behavioral study subjects were observed for 1 week on an outpatient basis, and neuroendocrine study subjects were observed during a 24-hour period in the hospital.

MAIN OUTCOME MEASURES

The behavioral study measured timing of energy intake, mood level, and sleep disturbances. The neuroendocrine study measured circadian levels of plasma melatonin, leptin, and cortisol.

RESULTS

In the behavioral study, compared with control subjects, night eaters had more eating episodes in the 24 hours (mean [SD], 9.3 [0.6] vs 4.2 [0.2]; P<.001) and consumed significantly more of their daily energy intake at night than did control subjects (56% vs 15%; P<.001). They averaged 3.6 (0.9) awakenings per night compared with 0.3 (0.3) by controls (P<.001). In night eaters, 52% of these awakenings were associated with food intake, with a mean intake per ingestion of 1134 (1197) kJ. None of the controls ate during their awakenings. In the neuroendocrine study, compared with control subjects, night eaters had attenuation of the nocturnal rise in plasma melatonin and leptin levels (P<.001 for both) and higher circadian levels of plasma cortisol (P = .001).

CONCLUSION

A coherent pattern of behavioral and neuroendocrine characteristics was found in subjects with NES.