REM Sleep: An Unknown Indicator of Sleep Quality

Standard polysomnographic analysis of sleep has not provided evidence of an objective measure of sleep quality; however, factors such as sleep duration and sleep efficiency are those more consistently associated with the subjective perception of sleep quality. Sleep reduction as currently occurs in our 24/7 society has had a profound impact on sleep quality; the habitual sleep period should fit within what is a limited nighttime window and may not be sufficient to satisfy the whole sleep process; moreover, the use of artificial light during the evening and early night hours can delay and disturb the circadian rhythms, especially affecting REM sleep. The correct phase relationship of the sleep period with the circadian pacemaker is an important factor to guarantee adequate restorative sleep duration and sleep continuity, thus providing the necessary background for a good night’s sleep. Due to the fact that REM sleep is controlled by the circadian clock, it can provide a window-like mechanism that defines the termination of the sleep period when there is still the necessity to complete the sleep process (not only wake-related homeostasis) and to meet the circadian end of sleep timing. An adequate amount of REM sleep appears necessary to guarantee sleep continuity, while periodically activating the brain and preparing it for the return to consciousness.

A pilot feasibility trial of cognitive–behavioural therapy for insomnia in people with inflammatory bowel disease

ObjectivePoor sleep is common in inflammatory bowel disease (IBD), associated with worse overall disease course and predominantly attributable to insomnia. While cognitive–behavioural therapy for insomnia (CBT-I) is the recommended first-line treatment for chronic insomnia, it is untested in IBD. It is unclear if CBT-I will be as effective in this group given the extent of night-time symptoms people with IBD experience. Thus, we evaluated the feasibility and preliminary efficacy of CBT-I in IBD.DesignWe comprehensively assessed sleep in people with mild-to-moderately active IBD using questionnaires, daily diaries and actigraphy. People with significant insomnia symptoms were allocated to a single-arm, uncontrolled pilot feasibility study of gold-standard CBT-I treatment. They were then reassessed post-treatment.Results20 participants with IBD completed a baseline assessment. 10 were experiencing insomnia and were allocated to CBT-I. All participants who were offered CBT-I elected to complete it, and all completed 5/5 sessions. Participants rated treatment acceptability highly and daily diary and actigraphy completion rates were >95%. At baseline, participants with insomnia evidenced significantly worse sleep than participants without insomnia. Following CBT-I, participants reported significant improvements in diary and actigraphy measures of sleep continuity, dysfunctional sleep-related beliefs and IBD disease activity.ConclusionCBT-I was feasible and acceptable and demonstrated a signal for efficacy in the treatment of insomnia in IBD. Importantly, the improvements in sleep continuity were consistent with the extant literature. Future fully powered randomised controlled studies should evaluate whether treatment of insomnia can improve other aspects of IBD, including pain and inflammation.Trial registration numberNCT04132024.

P020 Reduced duration and continuity of N3 sleep is associated with excessive daytime sleepiness in suspected obstructive sleep apnea patients

Introduction Excessive daytime sleepiness (EDS) is a common but not universal-accompanying symptom of obstructive sleep apnea (OSA). The mechanisms explaining the presence of EDS in OSA subjects are not fully understood. We hypothesised that characteristic differences in sleep architecture can be quantified with more comprehensive descriptors of sleep continuity in those with and without severe-EDS according to the Multiple Sleep Latency Test (MSLT). Methods 2111 participants with suspected OSA and complaints of daytime sleepiness underwent in-lab diagnostic polysomnography (PSG) and next-day MSLT. Sleep continuity was quantified by calculating the cumulative-frequency relationship of continuous sleep-state duration against proportion of sleep time; and continuous sleep-state duration against absolute sleep time. Results Study contained 368 severe-EDS participants (MSLT≤5min) and 385 non-EDS participants (MSLT>15min). Severe-EDS participants had less Wake After Sleep Onset (48.1±37.7 vs. 68.1±44.2-minutes, p<0.05 [mean±SD]), and greater Total Sleep Time (366.5±50.3 vs. 336.2±58.2-minutes, p<0.05). While total NREM sleep time was similar between groups, severe-EDS participants had less N3 sleep (67.7±38.0 vs. 78.6±32.0-minutes, p<0.05) and more N2 sleep (230.7±59.3 vs. 178.4±45.9-minutes, p<0.05). Moreover, severe-EDS participants had both less cumulative N3 sleep (36.9±2.9 vs. 60.0±3.3-minutes, p<0.05) and a lower proportion of N3 sleep (66.8±5.3% vs. 77.2±4.2%, p<0.05) occurring in periods ≥10mins duration. Discussion Whilst OSA participants with severe EDS have similar NREM sleep time to non-EDS participants; they have less N3 sleep, and N3 sleep periods are less consolidated. These preliminary results suggest that individuals with OSA which disturbs both the quantity and consolidation of N3 sleep are at greater risk of severe EDS.

P129 A substantial percentage of patients with Chronic Insomnia do not appreciably increase Total Sleep Time after Cognitive Behavioural Therapy for Insomnia

Introduction Total sleep time (TST) does not exceed baseline for the majority of patients after CBT-I. However by follow-up, TST increases by almost 1 hour on average. The current study investigated the extent to which this TST improvement is common and assessed for baseline predictors of increased TST after CBT-I. Methods This study is an archival analysis of data from a randomised clinical trial comparing acute CBT-I to acute CBT-I plus maintenance therapy (N = 80). The percent of patients that exceeded baseline TST by ≥30 minutes was assessed at post treatment and 3, 6, 12, and 24 months following treatment. Linear mixed models were conducted to assess the effect of patient demographics (age, sex, ethnicity, marital status), and baseline Sleep Diary-reported sleep continuity and Insomnia Severity Index (ISI) scores on changes in TST. Results 17% of patients achieved an appreciable increase in TST by treatment end, and this proportion only increased to 58% over time. Sleep Diary-reported sleep latency, wake after sleep onset, early morning awakenings, total wake time, TST, and sleep efficiency at baseline were associated with greater increases in TST after CBT-I (interaction ps < .03). Demographics and ISI scores were not significant predictors (interaction ps > .07). Conclusion A substantial proportion of patients do not appreciably increase TST after CBT-I, but patients with more severe sleep continuity disturbances at baseline exhibited the largest improvements. Whether all patients could increase their TST even further after CBT-I is a topic for further investigation.

368 Durability of Tx Response to Zolpidem using a Partial Reinforcement Regimen: Does this strategy require contingent reinforcement?

Introduction In 2015, partial reinforcement (PR) was assessed as an alternative approach to maintenance therapy with zolpidem. The method being: once a treatment response is obtained over the course of 1-month’s Tx with QHS dosing (Phase-1), Tx response can maintained over time with a PR regimen (Phase-2 [nightly pill/capsule use with 50% of capsules having medication and 50% having only inert filler]). In that study, it was assumed that Phase1 QHS dosing was required 1) to maximize treatment responding and 2) for the conditioning of pharmacologic responses to the medication vehicle (capsule). In the present study, these assumptions were tested by including both QHS and PR arms into Phase-1. Methods In Phase-1 (1 month), subjects were randomized to the QHS or PRS conditions (2QHS:1PRS). In Phase-2 (3 months), the PRS group continued forward without a change in the treatment regimen (variable dose [VD-VD]) and the QHS group was re-randomized to either continued QHS Tx (full dose [FD-FD]) or to PRS Tx [FD-VD]). Both study phases were evaluated for treatment responses rates and for average change in TWT (SL+WASO+EMA). Results 55 subjects (age 61.2+/-8.1, 64% female, & 73% white) were enrolled into Phase-1; 39 were randomized to the QHS condition and 16 to the PRS condition. In Phase-1, 77% (QHS) and 50% (PRS) exhibited treatment responses (p=0.09) where the average change in TWT was similar by group (QHS was -43min [CI -76,-9] and PRS was -76min [CI -138,-14];p=0.35). In Phase-2, 73% (FD-FD), 57% (FD-VD), and 88% (VD-VD) exhibited continued treatment responses (p=0.22) where the average improvement of TWT continued with FD-FD and remained stable for FD-VD and VD-VD (p<0.01). Conclusion These data, while preliminary, suggest that QHS (vs. PRS) dosing produces more treatment responders and similar initial effects on sleep continuity during Phase-1, comparable maintenance of treatment response over time, and continued improvement on sleep continuity during Phase-2. These results suggest that partial reinforcement can maintain effects but cannot allow for the additional clinical gains afforded by continuous treatment. Given this, it may be the case that the partial reinforcement technique could be improved upon by extending phase from 1 to 2–4 months. Support (if any):

259 Tracking naturalistic sleep over the menstrual cycle with a wearable in healthy young women

Introduction A woman’s menstrual cycle is characterized by hormonal changes that might affect sleep and therefore daily functionality. While some studies using self-reports have shown a lower sleep quality in the peri-menstruation phase, objective – in lab – studies have not found significant differences in sleep continuity during the menstrual cycle, but are limited by only a few recordings across the cycle. The aim of this study is to examine changes in sleep during the healthy menstrual cycle using a multi-sensory wearable, allowing continuous, objective, reliable and ecologically valid measurement. Methods 12 healthy young women (28.14 ± 2.33) were monitored using Oura ring – a sleep and activity tracker – during an entire menstrual cycle. Participants also reported mood, readiness, and sleep quality using a diary. Four phases of the menstrual cycle were compared (menstruation, periovulation, mid-luteal, and late-luteal). Ovulation day was determined using a urinary luteinizing hormone test. Results Ovulatory cycles were confirmed by the Oura ring, which showed a significant increase in average nocturnal heart rate and skin temperature during the post-ovulatory luteal phase relative to menstruation and periovulation. Oura ring measures of sleep continuity (Sleep Onset Latency, Wake After Sleep Onset) and self-reported sleep quality did not change across the 4 menstrual phases. We observed a trend for objective sleep duration, which tended to be shorter in the mid-luteal and late-luteal phases. We also observed a small reduction in perceived readiness and mood during these two phases. Conclusion Physiological changes (increase in heart rate and body temperature) in the postovulatory phase of the menstrual cycle are detectable with the Oura ring. Sleep features remain quite stable during the healthy, ovulatory menstrual cycle, apart from a trend for slightly shorter sleep duration in the post-ovulatory phases. In comparison to self-reports, which rely on retrospective memory and might be biased by perception and mood, wearable technologies seem to be a sensitive and informative tool to track sleep and physiological changes during the menstrual cycle. Support (if any) Supported by RF1AG061355 (Baker/Mednick)

774 Insomnia precedes suicidal ideation in a national longitudinal study of sleep continuity (NITES)

Introduction Suicide is the 10th leading cause of death among US adults, and disrupted sleep significantly increases suicide risk. It is unclear, however, how quickly changes in sleep can affect suicidal thoughts and behaviors. Therefore, the present study explored whether insomnia, sleep continuity, and nightmares predicted subsequent suicidal thinking. Methods Data were drawn from N=1,248 individuals 35 years and older who were part of a 1-year prospective study of the natural history of insomnia. Suicidal ideation was measured biweekly from the Patient Health Questionnaire – 9 and dichotomized (Score = 0, No; Score > 0, Yes). The primary predictors were Insomnia Severity Index (ISI) score and total wake time, total sleep time, difficulty initiating/maintaining sleep, and nightmares (from daily sleep diaries). Predictors were averaged over the previous 2 weeks and measured 2 nights prior to measuring suicidal ideation. Data were modeled using generalized estimating equations to account for within-subject correlations and adjusted for age, sex, and race/ethnicity. Results A total of N=124 individuals (65% female) reported suicidal ideation during the study. In unadjusted models, no sleep variable was associated with subsequent suicidal ideation. However, after adjusting for age, sex, and race/ethnicity, insomnia severity was associated with subsequent suicidal ideation when averaged over the preceding 2 weeks (OR 1.09 per point on the ISI, 95% CI [1.03–1.16]) and measured 2 days prior (OR 1.11 per point on the ISI, 95% CI [1.01–1.22]). Stratified analyses showed that this effect was driven by age, with insomnia predicting suicidal ideation in individuals 55–64 and 65 and older. Conclusion Insomnia is a significant, proximal risk factor for suicidal ideation, particularly in older adults. Consequently, treatment of insomnia may represent an effective suicide risk reduction strategy. Support (if any) K24AG055602 R01AG041783