The Statin Target HMG-Coenzyme a Reductase (Hmgcr) Regulates Sleep Homeostasis in Drosophila

Statins, HMG Coenzyme A Reductase (HMGCR) inhibitors, are a first-line therapy, used to reduce hypercholesterolemia and the risk for cardiovascular events. While sleep disturbances are recognized as a side-effect of statin treatment, the impact of statins on sleep is under debate. Using Drosophila, we discovered a novel role for Hmgcr in sleep modulation. Loss of pan-neuronal Hmgcr expression affects fly sleep behavior, causing a decrease in sleep latency and an increase in sleep episode duration. We localized the pars intercerebralis (PI), equivalent to the mammalian hypothalamus, as the region within the fly brain requiring Hmgcr activity for proper sleep maintenance. Lack of Hmgcr expression in the PI insulin-producing cells recapitulates the sleep effects of pan-neuronal Hmgcr knockdown. Conversely, loss of Hmgcr in a different PI subpopulation, the corticotropin releasing factor (CRF) homologue-expressing neurons (DH44 neurons), increases sleep latency and decreases sleep duration. The requirement for Hmgcr activity in different neurons signifies its importance in sleep regulation. Interestingly, loss of Hmgcr in the PI does not affect circadian rhythm, suggesting that Hmgcr regulates sleep by pathways distinct from the circadian clock. Taken together, these findings suggest that Hmgcr activity in the PI is essential for proper sleep homeostasis in flies.

The Association Between Dry Eye Disease With Depression, Anxiety and Sleep Disturbance During COVID-19

Objective: This study aimed to investigate the relationship between dry eye disease (DED) with anxiety and depression. Additionally, the mediating effect of sleep quality on this relationship was explored.Methods: 321 patients with DED were recruited from Tianjin Medical University Eye Hospital clinic and surveyed using demographic questionnaires, the Ocular Surface Disease Index (OSDI), Hospital Anxiety and Depression Scale (HADS), and Pittsburgh Sleep Quality Index (PSQI). Regression analysis and the bootstrap method were used to investigate the influence of sleep on the relationship between DED, anxiety and depression.Results: Among the patients with DED, 86 (26.79%), 85 (26.48%), and 54 (16.82%) patients presented with anxiety, depression, and both anxiety and depression respectively. The OSDI and PSQI score were positively correlated with depression and anxiety (all p < 0.01). The direct effects of OSDI on depression and anxiety were significant (P < 0.01). Additionally, the bootstrap test showed significant mediating effects of subjective sleep quality [95% CI [0.003–0.016] (depression); [0.001–0.011] (anxiety)] and sleep latency [95% CI [0.001–0.010] (depression); [0.001–0.008] (anxiety)]. These results indicated that the severity of DED symptoms, as measured by the OSDI score, affected anxiety and depression through a direct and an indirect pathway mediated by subjective sleep quality and sleep latency.Conclusions: The results indicated that there was a significant correlation between DED and anxiety and depression. Moreover, subjective sleep quality and sleep latency were a mediator of the relationship between DED symptoms and anxiety and depression.

Influence of Pair-housing on Sleep Parameters Evaluated with Actigraphy in Female Rhesus Monkeys

Rhesus monkeys are naturally social animals, and behavioral management strategies have focused on promoting pairhousingin laboratory settings as an alternative to individual or group housing. In humans, co-sleeping can have a major impact on bed partners’ sleep, raising the possibility that pair-housing also may influence sleep parameters in monkeys. In the present study, we investigated if pair-housing would impact home-cage partner’s sleep in female rhesus monkeys, and if nighttime separation using socialization panels would alter this pattern. Sleep parameters of 10 experimentally naïve adult female rhesus monkeys (5 pairs) were evaluated for 7 consecutive days using actigraphy monitors attached to primate collars. Paired animals then were separated by socialization panels during the night, and sleep-associated measures were evaluated for 7 consecutive days. The data showed that sleep efficiency was significantly lower when monkeys were pairhoused as compared with when they were separated. On the nights when subjects were pair-housed, a positive correlation was detected for sleep measures (both sleep latency and efficiency) of both members of a pair (R2’s = 0.16–0.5), suggesting that pair-housing influences sleep quality. On nights when subjects were separated, no correlations were observed for sleep measures between members of the pairs (R2’s = 0.004–0.01), suggesting that when separated, the home-cage partner’s sleep no longer influenced the partner’s sleep. Our results indicate that pair-housing has a strong impact on the home-cage partner’s sleep, and that this pattern can be prevented by nighttime separation using socialization panels. Studies evaluating sleep in pair-housed monkeys should consider the effects that the partner’s sleep may have on the subject’s sleep. Sleep is a biologic phenomenon and experimental outcome that affects physical and behavioral health and altered sleep due to pair-housing may affect a range of research outcomes.

Exploring the clinical usefulness of an electronic diary in fibromyalgia patients: A pilot study

This study examines the usefulness of an electronic diary (ED) in the monitoring of clinical manifestations of fibromyalgia (FM), compared to traditional pencil-and-paper self-reports. Fourteen women with FM completed an interview, several questionnaires, and an ED for a week (several times a day) recording pain, fatigue, sleep, difficulty in thinking, emotional distress, difficulty in daily functioning, and coping with the disease, and stress. There were no differences in the symptoms throughout the moments of the day, observing a sleep latency of 45.36 minutes and sleep duration of 6.25 hours. Significant correlations were found between ED measures depending on the time of day, and between ED measures and questionnaires. The ED showed to be useful for the evaluation of FM symptomatology, and can be a key component in psychological intervention programs.

Relationshp Between Sleep Quality, Mood State, and Performance of Elite Air-Rifle Shooters

Background To evaluate the impact of pre-competition sleep quality on the mood and performance of elite air-rifle shooters. Methods This study included 23 elite air-rifle shooters who participated in an air-rifle shooting-competition from April 2019 to October 2019. Sleep time, sleep efficiency, sleep latency, and wake-up time after sleep onset were monitored using actigraphy. The Pittsburgh sleep quality index and Profile of Mood State were used to assess sleep quality. Competitive State Anxiety Inventory-2 was used to evaluate mood state. Results The average time to fall asleep, sleep time, sleep efficiency, and subjective sleep quality were 20.6 ± 14.9 min, 7.0 ± 0.8 h, 85.9 ± 5.3%, and 5.2 ± 2.2, respectively. Sleep quality decreased as the competition progressed. Pre-competition sleep time in female athletes was significantly higher than that on the competition day (P = 0.05). Pre-competition sleep latency was significantly longer in women than in men (P = 0.021). During training and pre-competition, the tension, fatigue, depression, and emotional disturbance were significantly lower in athletes with good sleep quality than in athletes with poor sleep quality. Athletes with good sleep quality had significantly more energy. The PSQI total score was positively correlated with positive emotion, TMD, cognitive anxiety, and somatic anxiety POMS scores, and negatively correlated with energy and self-confidence scores. Race scores and depression and somatic anxiety scores were negatively correlated. Conclusion Poor sleep quality negatively impacted the mood of athletes; however, sleep indices and competition performance of athletes during competitions were not significantly correlated.

Correlation between Serum Levels of Sympathetic Nerve Activity Markers and Sleep Quality and Cognitive Function in Patients with Chronic Insomnia Disorder

Objectives: To explore the changes of the serum levels of copeptin and α-amylase and the correlations with sleep quality and cognition function in the patients with chronic insomnia disorder (CID). Methods: Fifty-seven CID patients and thirty healthy controls were enrolled continuously. Pittsburgh Sleep Quality Index (PSQI), polysomnography (PSG) and Pre-Sleep Arousal Scale (PSAS) were used to assess the insomnia severity and cognitive and somatic manifestations of arousal experienced at bedtime. Montreal Cognitive Assessment scale (MoCA) and Nine-Box Maze were used to respectively assess general cognition and memories. The serum levels of copeptin and α-amylase were detected using Enzyme-Linked ImmunoSorbent Assay. Results: Compared to the controls, the CID patients had increased PSQI and PSAS scores (Z=‒7.678 and ‒7.350; Ps<0.001), decreased MoCA score (t=‒4.625, P<0.001), increased numbers of errors in the object working, spatial working and object recognition (Z=‒2.099, ‒3.935 and ‒2.266; Ps<0.05) memories, and elevated serum levels of copeptin and α-amylase (t=5.414 and 5.597, P <0.001). In the CID patients，the level of copeptin positively correlated with PSQI and PSAS scores (r=0.338 and 0.316; Ps<0.05), and PSG sleep latency, wake time and N1% (r=0.324, 0.325 and 0.278, Ps<0.05), and negatively correlated with PSG N 2% (r=‒0.279, Ps<0.05). Alpha-amylase was positively correlated with waking numbers in PSG (r=0.293, P< 0.05). Multiple linear regression analysis showed that copeptin level affected PSQI score and PSG sleep latency (P<0.05). Conclusions: The serum levels of copeptin and α-amylase elevated in the CID patients, and the serum levels of copeptin may be associated with the poor sleep quality, especially in the individuals of initial sleep difficulties.

The effect of wind turbine noise on polysomnographically-measured and self-reported sleep latency in wind turbine noise naïve participants

Study Objectives Wind turbine noise exposure could potentially interfere with the initiation of sleep. However, effects on objectively assessed sleep latency are largely unknown. This study sought to assess the impact of wind turbine noise on polysomnographically-measured and sleep diary-determined sleep latency compared to control background noise alone in healthy good sleepers without habitual prior wind turbine noise exposure. Methods Twenty-three wind turbine noise naïve urban residents (mean±standard deviation age: 21.7±2.1 years, range 18-29, 13 females) attended the sleep laboratory for two polysomnography studies, one week apart. Participants were blind to noise conditions and only informed that they may or may not hear noise during each night. During the sleep onset period, participants were exposed to counterbalanced nights of wind turbine noise at 33 dB(A), the upper end of expected indoor values; or background noise alone as the control condition (23 dB(A)). Results Linear mixed model analysis revealed no differences in log10 normalized objective or subjective sleep latency between the wind turbine noise versus control nights (median [interquartile range] objective 16.5 [11.0 to 18.5] versus 16.5 [10.5 to 29.0] minutes, p = 0.401; subjective 20.0 [15.0 to 25.0] versus 15.0 [10.0 to 30.0] minutes, p = 0.907). Conclusions Although undetected small effects cannot be ruled out, these results do not support that wind turbine noise extends sleep latency in young urban dwelling individuals without prior wind turbine noise exposure.

Insomnia with physiological hyperarousal is associated with lower weight: a novel finding and its clinical implications

Previous studies on the association of insomnia with body mass index (BMI) have been controversial. Physiological hyperarousal, the key pathological mechanism of insomnia, may be an important reason for different findings. We explored whether insomnia with physiological hyperarousal measured by the multiple sleep latency test (MSLT) is associated with body-weight differences. A total of 185 normal sleepers and 440 insomniacs were included in this study. Insomnia was defined by standard diagnostic criteria with symptoms lasting ≥6 months. All subjects underwent one night of laboratory polysomnography followed by a standard MSLT. We used the median MSLT value (i.e., ≥14 min) to define physiological hyperarousal. BMI was based on measured height (cm) and weight (kg) during the subjects’ sleep laboratory visit. BMI > 25 kg/m2 was defined as overweight, while BMI < 18.5 kg/m2 was defined as underweight. After controlling for confounders, the odds of lower weight rather than overweight were significantly increased among insomnia patients with increased MSLT: insomnia with MSLT 14–17 min and MSLT > 17 min increased the odds of lower weight by approximately 89% (OR = 1.89, 95% CI 1.00–4.85) and 273% (OR = 3.73, 95% CI 1.51–9.22) compared with normal sleepers, respectively. In contrast, insomnia in patients with MSLT 11–14 min and 8–11 min was not different from normal sleepers in terms of body weight. Insomnia associated with physiological hyperarousal, the most severe phenotype of chronic insomnia, is associated with higher odds of lower weight and underweight compared with normal sleepers. This is a novel finding consistent with previous physiologic data and has significant clinical implications.