Menstrual Cycle Effects on Sleep

Menstrual-Cycle Symptoms and Sleep Characteristics in Elite Soccer Players

PURPOSE

To determine whether menstrual-cycle symptoms are associated with sleep in elite female athletes.

METHODS

Sleep was assessed for a minimum of 25 nights (range = 25-31) using activity monitoring and sleep diaries. Menstrual-cycle symptoms were collected over the same duration in 12 elite female professional soccer players. Generalized estimating equations were used to examine the relationship between the day of the menstrual cycle (from day 1) and total menstrual-cycle symptoms on sleep characteristics.

RESULTS

There was a significant relationship between sleep duration and the day of the menstrual cycle (P = .042) and total symptoms reported that day (P < .001), with sleep duration increasing by 21 minutes for every symptom reported. There was a negative day × symptom interaction on sleep duration (P = .004), indicating that with increased symptoms, the day of the menstrual cycle had a smaller relationship with sleep duration. Sleep efficiency (P = .950), wake after sleep onset (P = .217), and subjective sleep quality (P = .080) were not related to the day of the menstrual cycle. The total symptoms reported had no relationship with sleep efficiency (P = .220), subjective sleep quality (P = .502), or sleep latency (P = .740) but did significantly relate to wake after sleep onset (P < .001), with a significant day × symptom interaction (P < .001).

CONCLUSIONS

Sleep duration increased from day 1 of the menstrual cycle and was associated with the number of menstrual-cycle symptoms reported. All other sleep metrics remained unchanged; however, total symptoms reported were related to wake after sleep onset. Monitoring and managing menstrual-cycle symptoms should be encouraged due to a potential relationship with sleep characteristics.

Menstrual cycle patterns and their relationship with measures of well-being and perceived performance metrics in competitive and recreational resistance-trained athletes

BACKGROUND

There is mixed evidence on how the menstrual cycle (MC) affects sports performance, with many studies showing variations in performance during different phases of the MC, while other evidence shows that the MC's effects on performance may be trivial. Therefore, this exploratory longitudinal monitoring study was designed to investigate MC characteristics and symptoms in a resistance-trained (RT) population to look for associations between measures of well-being and perceived performance metrics across the MC.

METHODS

RT females reported their workout habits, perceived performance metrics, and measures of well-being while tracking their MC with detailed methods via daily check-ins in an app.

RESULTS

Most MC characteristics and symptoms in the present RT population aligned with previous research on the general population. However, the frequency of irregular cycles was higher than in previous research on the general population. The amount of individual variation and within-subject cycle-to-cycle variation in MC characteristics and MC symptoms was also high. All measures of well-being were significantly associated with specific days of the MC, demonstrating a change in well-being based on the timing of the MC. Several perceived performance metrics were significantly associated with changes across the MC, while others were not.

CONCLUSIONS

Overall, with the current evidence as it stands, a highly individualized approach should be taken for any training or performance considerations surrounding the MC due to the high levels of individual variation.

How do phases of the menstrual cycle affect sleep? A polysomnographic study of the EPISONO database

PURPOSE

Our study aimed to evaluate the impact of the menstrual cycle stages, especially menses, on sleep, inflammatory mediators, fatigue, anxiety, depression, and quality of life.

METHODS

We used data from the EPISONO study cohort, selecting 96 women who had undergone one-night polysomnography. The women were distributed in three groups according to the time point of the menstrual cycle on the polysomnography night: menses, mid/late follicular phase, and luteal phase. The volunteers completed questionnaires related to sleep quality, daytime sleepiness, insomnia, fatigue, anxiety, depression, and quality of life. Blood samples were collected to analyze interleukin 6, tumor necrosis factor-alpha, and C-reactive protein.

RESULTS

Sleep efficiency was statistically higher in women in the mid/late follicular group (89.9% ± 9.6) compared to menstrual (83.0% ± 10.8) and luteal (83.7% ± 12.7) groups. The mid/late follicular group presented a statistically significant reduction in sleep onset latency (7.1 ± 7.1 min) compared to the menstrual (22.3 ± 32.4 min) and luteal groups (15.9 ± 14.7 min). No statistical differences among the three groups were observed in other polysomnographic parameters, inflammatory mediators, daytime sleepiness, insomnia, fatigue, anxiety, depression, and quality of life.

CONCLUSIONS

Our findings demonstrate that the mid/late follicular phase might be beneficial for women's sleep, although there were no statistically changes in inflammatory mediators among the groups.

Impact on health outcomes associated with changing the clock 1 hour during fall and spring transitions in the Southern Hemisphere

STUDY OBJECTIVES

Changing the clocks seasonally is potentially harmful because it interferes with normal daytime activities. Studies aimed at quantifying this association are scant. The objective of this study was to determine the effects of 1 year's worth of changing the clocks (fall and spring transitions) on healthy young men located in the Southern Hemisphere in South America.

METHODS

We performed an observational prospective study. Thirty healthy male university students were evaluated from 2 weeks before to 2 weeks after both the fall and spring transitions. We administered an overall sleep questionnaire, assessed quality of life, recorded 7-day wrist actigraphy, and had participants perform a psychomotor vigilance task. We defined the 1-hour clock change as the primary exposure and the change in psychomotor vigilance task lapses of 500 milliseconds or more in response time as our primary outcome. Changes were evaluated by the Wilcoxon rank test (significance: P < .05).

RESULTS

After the fall transition, we found a significant worsening in psychomotor vigilance task performance (median [interquartile range], 9.9 [6.0-14.3] lapses of ≥ 500 milliseconds in response time at baseline vs 16.8 [8.2-28.0] after transition; P < .002). Additionally, we found a median loss of about 1 hour of total sleep time and time in bed after the fall transition. Furthermore, participants presented with insomnia. Performance on the psychomotor vigilance task was also affected after the spring transition (16.7 [10-23] vs 23 [12.2-32.2]; P < .001).

CONCLUSIONS

A decrease in performance in neurocognitive tests was found after both time transitions. The transition led to insomnia and a significant worsening of sleep variables.

CITATION

Labarca G, Henriquez-Beltrán M, Sanhueza R, et al. Impact on health outcomes associated with changing the clock 1 hour during fall and spring transitions in the Southern Hemisphere. J Clin Sleep Med. 2024;20(6):887-893.

The prevalence of menstrual cycle symptoms and their association with mental health and sleep in German exercising women and athletes

OBJECTIVES

Menstrual cycle symptoms are very common in female athletes. However, more evidence about the association between menstrual cycle characteristics and symptoms with sleep and mental health in athletes needs to be gathered. This study aimed to examine this association in German exercising women and athletes.

DESIGN

322 women (mean age: 23.13 ± 4.36) participated in a cross-sectional study. The survey included the Menstrual Symptom index (MSi), the Depression Anxiety Stress Scales (DASS-21), the Pittsburgh Sleep Quality Index (PSQI), and the Athletes Sleep Behavior Questionnaire (ASBQ). Additionally, demographic, sport-specific data and further menstrual cycle characteristics were examined. Multiple regression models were used for the statistical analyses.

RESULTS

The MSi score demonstrated a highly significant (p < 0.001) positive association with Depression, Anxiety, Stress, PSQI, and ASBQ. The most prevalent menstrual cycle symptoms were cravings/increased appetite, mood changes/anxiety, and tiredness/fatigue. A difference between individual and team sport athletes could not be found. Moreover, there was no association between the constructs and menses length, irregularity, or heaviness of bleeding.

CONCLUSIONS

Menstrual cycle symptoms occur very frequently in female athletes. In this study, they were related to mental health, sleep quality, and sleep behavior, regardless of the cycle phase. This evidence demonstrates the relevance of considering the menstrual cycle and menstrual symptoms in future studies with female athletes and in sport practice.

Assessing sleep quality in elite and junior cyclists

In the pursuit of optimal recovery, the significance of sleep cannot be overstated for elite cyclists, including high-level cyclists within the junior category. This study aims to assess the sleep quality of elite athletes of different categories and disciplines, including junior. The sleep quality of 112 high-level cyclists (males n = 80; females n = 32) participating in endurance and sprint disciplines was evaluated using the Pittsburgh Sleep Quality Index (PSQI). A noteworthy 41% of both elite and junior cyclists displayed poor sleep quality. No significant differences were observed between elite and junior cyclists in terms of sleep quality, but there was a medium effect size, indicating greater sleep efficiency in junior cyclists [0.36 (0.16, 0.53)]. Gender differences were found, with females exhibiting worse PSQI scores (males = 4.00 [2.25]; females 5.00 [3.00]; p = 0.035). Endurance cyclists spent more time in bed compared to cyclists from sprinting disciplines (8:30 [1.00] and 8:00 [1:03], respectively; p = 0.019). These findings reveal poor sleep habits, even among individuals classified as good sleepers by the PSQI, emphasizing the importance of preventing sleep disorders in cyclists. This study provides valuable insights into athlete sleep quality, encompassing various categories, genders, and cycling disciplines. In conclusion, elite cyclists demonstrate suboptimal sleep quality, suggesting the potential for interventions utilizing the PSQI. These findings advocate for the incorporation of sleep quality assessments into routine evaluations for athletes.

Changes in the Objective Measures of Sleep in Association with Menses Among Female Athletes with Poor Subjective Sleep Quality: Female Athletes with Poor Subjective Sleep Quality Have More Sleep Arousals During Menses

Purpose

Female athletes with menstrual abnormalities have poor sleep quality. However, whether female athletes with poor sleep quality based on subjective assessment have distinctive changes in objective measures of sleep in association with menses remains unclear. This study aimed to compare changes in objective sleep measurements during and following menses between collegiate female athletes with and without poor subjective sleep quality.

Patients and Methods

Female collegiate athletes (age range/mean ± standard deviation: 18-22/ 22.2±1.1) with regular menstrual cycles were recruited. The participants underwent home electroencephalogram monitoring during the first and second nights after the onset of menses and one night between the seventh and 10th nights after menses onset (mid-follicular phase). The Pittsburgh Sleep Quality Index (PSQI) was used to assess the subjective sleep quality. Interactions between the presence of poor subjective sleep quality (ie, PSQI ≥6) and changes in objective measures of sleep in association with menses were analyzed.

Results

Data of 45 athletes, including 13 with poor subjective sleep quality, showed that changes in arousal index in athletes with poor subjective sleep quality were distinctive from those in athletes without poor subjective sleep quality (p = 0.036 for interaction). In athletes with poor subjective sleep quality, the arousal index was significantly increased in menses (p for analysis of variance, 0.015), especially on the first night after the onset of menses compared with during the mid-follicular phase (p = 0.016).

Conclusion

Collegiate female athletes with regular menstrual cycles are likely to have poor subjective sleep quality in association with more frequent arousal during the first night after the onset of menses than during the mid-follicular phase.

Interaction of sleep and emotion across the menstrual cycle

Menstruating individuals experience an increased risk for sleep and affective disorders, attributed in part to monthly oscillations in sex hormones. Emotional functioning and sleep continuity worsens during the perimenstrual phase of the menstrual cycle. This study examined the interactive effects of sleep, menstrual phase, and emotion in healthy women. Participants (N = 51, 43% Caucasian) aged 18-35 (m = 24 years) completed actigraphy and daily sleep/emotion diaries over two menstrual cycles (m days = 51.29). Diary and actigraphic total wake time at night (TWT) and daily ratings of positive and negative affect were compared across four phases of the menstrual cycle: perimenstrual, mid-follicular, periovulatory, and mid-luteal. Relationships between phase, sleep, and emotion were estimated using multistep hierarchical linear modelling. Mean menstrual cycle length was 28.61 ± 2.69 days. Perimenstrual phase positively predicted anger (p < 0.001) but no other emotions. Additionally, the perimenstrual phase predicted higher rates of TWT, such that diary TWT was 8-16 min longer during the perimenstrual (m = 67.54, SE = 3.37) compared to other phases (p < 0.001). Actigraphic TWT was also increased by 4-7 min (m = 61.54, SE = 3.37) in the perimenstrual phase (p < 0.001). Positive emotions were 0.05-0.10 points lower (p = 0.006-0.02) when TWT was greater in the perimenstrual phase. Greater rates of anger and sleep disruption were seen during the perimenstrual phase compared with other phases. When poor sleep occurred during the perimenstrual phase individuals reported reduced positive emotions. Reducing perimenstrual sleep disruptions may be an important intervention target for those at risk for affective disorders.

Menstruation-related symptoms are associated with physical activity and midpoint of sleep: a pilot study

Introduction

Menstruation-related symptoms (MRSs) significantly impact women's health and contribute to economic burdens worldwide. Current interventions, primarily pharmacological ones, have limitations and side effects that underscore the need for alternative management strategies. This study explores the association between MRSs and lifestyle factors, specifically physical activity and sleep timing across menstrual cycle phases, to inform non-pharmacological intervention development.

Methods

Fourteen female students from Ritsumeikan University, Japan, with regular menstrual cycles (25-38 days), not on hormonal treatment or engaged in shift work, participated in this observational study. Using a Fitbit Inspire 2, total daily energy expenditure (TDEE) and sleep timing were monitored over a complete cycle. Menstrual cycle phases were defined based on ovulation day, predicted using home luteinizing hormone tests. Participants completed daily electronic questionnaires rating MRSs using a modified menstrual distress questionnaire. Data were analyzed using a generalized linear mixed model with a gamma distribution and logarithmic link function, examining the relationship of TDEE and the midpoint of sleep time (MS time) with MRS severity.

Results and discussion

The following observations were noted: first, MRS severity, except for behavioral change symptoms, significantly increased during the menstrual and luteal phases compared to the follicular phase. Second, delayed MS time was associated with reduced pain, concentration symptoms, water retention, and negative affect during the menstrual phase and reduced negative affect during the luteal phase. Finally, an increase in TDEE was associated with reduced concentration symptoms, autonomic reaction symptoms, and negative affect during the menstrual and luteal phases and reduced water retention only during the luteal phase. This study provides insights into the relationship between MRSs and TDEE/MS time, suggesting potential non-therapeutic approaches for symptom management, though further research is needed to substantiate these findings for practical applications.

L. M, Narawa Y, Srinath R, Kanitkar M. Improved sleep, cognitive processing and enhanced learning and memory task accuracy with Yoga nidra practice in novices

Complementary and Alternative medicine is known to have health benefits. Yoga nidra practice is an easy-to-do practice and has shown beneficial effects on stress reduction and is found to improve sleep in insomnia patients. Effect of yoga nidra practice on subjective sleep is known but its effect on sleep and cognition objectively is not documented. The aim of the study was to study the effect of yoga nidra practice on cognition and sleep using objective parameters. 41 participants were enrolled, and baseline sleep diary (SD) collected. Participants volunteered for overnight polysomnography (PSG) and cognition testing battery (CTB) comprising of Motor praxis test, emotion recognition task (ERT), digital symbol substitution task, visual object learning task (VOLT), abstract matching (AIM), line orientation task, matrix reasoning task, fractal-2-back test (NBACK), psychomotor vigilance task and balloon analog risk task. Baseline CTB and after one and two weeks of practice was compared. Power spectra density for EEG at central, frontal, and occipital locations during CTB was compared. Repeat SD and PSG after four weeks of practice were done. After yoga nidra practice, improved reaction times for all cognition tasks were seen. Post intervention compared to baseline (95%CI; p-value, effect size) showed a significant improvement in sleep efficiency of +3.62% (0.3, 5.15; p = 0.03, r = 0.42), -20min (-35.78, -5.02; p = 0.003, d = 0.84) for wake after sleep onset and +4.19 μV2 (0.5, 9.5; p = 0.04, r = 0.43) in delta during deep sleep. Accuracy increased in VOLT (95% CI: 0.08, 0.17; p = 0.002, d = 0.79), AIM (95% CI: 0.03, 0.12; p = 0.02, d = 0.61) and NBACK (95% CI: 0.02, 0.13; p = 0.04, d = 0.56); ERT accuracy increased for happy, fear and anger (95% CI: 0.07, 0.24; p = 0.004, d = 0.75) but reduced for neutral stimuli (95% CI: -0.31, -0.12; p = 0.04, r = 0.33) after yoga nidra practice. Yoga Nidra practice improved cognitive processing and night-time sleep.

The Menstrual Cycle and Sleep

Aspects of sleep change across the menstrual cycle in some women. Poorer sleep quality in the premenstrual phase and menstruation is common in women with premenstrual symptoms or painful menstrual cramps. Although objective sleep continuity remains unchanged across the regular, asymptomatic menstrual cycle, activity in the sleep electroencephalogram varies, with a prominent increase in sleep spindle activity in the postovulatory luteal phase, when progesterone is present, relative to the follicular phase. Menstrual cycle phase, reproductive stage, and menstrual-related disorders should be considered when assessing women's sleep complaints.

The Relationship Between Mood and Sleep in Different Female Reproductive States

Mood and sleep are tightly interrelated. Mood and sleep symptoms and disorders are more common in women than in men and often associated with reproductive events. This article reviews the current literature on the reciprocal relationships between mood and sleep across reproductive phases in women, such as menstrual cycle and related disorders, pregnancy, climacteric, and use of hormonal contraception and hormone replacement therapy. Mood and sleep symptoms seem to covary in relation to physiologic and pathologic reproductive conditions, although the relationship seems more clear for subjective than objective sleep.

Good sleep is a mood buffer for young women during menses

STUDY OBJECTIVES

We sought to elucidate the interaction between sleep and mood considering menstrual cycle phase (menses and non-menses portions of the cycle) in 72 healthy young women (18-33 years) with natural, regular menstrual cycles and without menstrual-associated disorders. This work fills a gap in literature of examining mood in context of sleep and menstrual cycle jointly, rather than individually.

METHODS

Daily subjective measures of sleep and mood, and date of menses were remotely, digitally collected over a 2-month period. Each morning, participants rated their sleep on the previous night, and each evening participants rated the extent of positive and negative mood for that day. Objective sleep was tracked with a wearable (ŌURA ring) during month 2 of the study. Time-lag cross-correlation and mixed linear models were used to analyze the significance and directionality of the sleep-mood relationship, and how the interaction between menstrual cycle status and sleep impacted mood levels.

RESULTS

We found that menstrual status alone did not impact mood. However, subjective sleep quality and menstrual status interacted to impact positive mood (p < .05). After a night of perceived poor sleep quality, participants reported lower positive mood during menses compared to non-menses portions of the cycle, while after a night of perceived good sleep quality participants reported equivalent levels of positive mood across the cycle.

CONCLUSIONS

We suggest that the perception of good sleep quality acts as a mood equalizer, with good sleep providing a protective buffer to positive mood across the menstrual cycle.

The Menstrual Cycle's Influence on Sleep Duration and Cardiovascular Health: A Comprehensive Review

The menstrual cycle, a fundamental biological process in women, extends its influence beyond reproduction, impacting sleep duration and cardiovascular health. This comprehensive review delves into the intricate connections that bind these three vital aspects of women's health. Beginning with thoroughly exploring the menstrual cycle, we uncover its phases and the dynamic hormonal fluctuations that underlie each stage. We pay special attention to estrogen and progesterone, the primary sex hormones orchestrating the menstrual cycle. With their rhythmic rise and fall, these hormones orchestrate events, affecting sleep duration, sleep patterns, and various indicators of cardiovascular well-being. The review examines how the menstrual cycle influences sleep patterns, exploring the nuanced changes in sleep duration observed throughout menstrual phases. We elucidate the contributing factors, encompassing hormonal fluctuations, the impact of pain and discomfort, and the significance of emotional and psychological factors. All of these elements collectively contribute to variations in sleep quality. Shifting our focus to the cardiovascular system, we investigate the bidirectional relationships between sleep disturbances and cardiovascular conditions, emphasizing the need to address sleep-related issues in the context of cardiovascular risk. The menstrual cycle is analyzed as a pivotal mediator in these intricate connections, exploring how hormonal fluctuations across menstrual phases can influence sleep patterns and cardiovascular health. This analysis provides valuable insights into the complex causality web. As clinical implications emerge, we emphasize the importance of tailoring healthcare strategies for individuals with irregular menstrual cycles. We explore potential interventions, from personalized care and hormone management to lifestyle adjustments, to improve sleep and cardiovascular well-being. In conclusion, this comprehensive review sheds light on the interplay between the menstrual cycle, sleep duration, and cardiovascular health. It underscores the urgent necessity for personalized healthcare approaches and preventive strategies, empowering women to navigate these intricate relationships. Ultimately, through a nuanced understanding of these interactions, we can work towards enhancing women's overall well-being and reducing cardiovascular risk within the context of menstrual cycle-related influences.

The Role of Meeting Exercise and Nutrition Guidelines on Sleep during Pregnancy

Sleep disturbances are common during pregnancy. This study determined whether meeting physical activity or dietary guidelines during pregnancy was associated with improved sleep. Third trimester pregnant women (n = 49, 31.9 ± 4.1 years) completed physical activity and sleep questionnaires and then wore a wrist actigraph 24 h/day and completed three 24 h dietary recalls across two weeks. Participants who reported meeting physical activity guidelines (>150 min moderate-to-vigorous physical activity [MVPA]/week, n = 23) or dietary guidelines (≥1.1 g protein/kg body weight/day, n = 26 or ≥25 g fiber/day, n = 16) were compared to those who were physically inactive (<90 min/week) or did not meet dietary guidelines, respectively. Multivariate ANOVAs and Mann-Whitney U tests compared groups and correlations were conducted between physical activity, diet, and sleep variables. Physical activity groups did not differ in objective sleep measures (ps > 0.05); however, the active group reported better sleep quality (p = 0.049). Those who met protein guidelines exhibited longer sleep duration and less wake-after-sleep-onset (ps < 0.05). Across all participants, higher weekly MET mins/week of MVPA associated with better sleep quality (p = 0.02), and a diet higher in fat and lower in carbohydrates associated with longer sleep duration (ps < 0.05). Meeting physical activity and nutrition guidelines positively associates with improved sleep, with protein associated with objective measures and physical activity with subjective measures.

Sleep and Women's Mental Health

Women have increased risks for both sleep disturbances and disorders and for mental health issues throughout their lives, starting in adolescence. Women have a higher prevalence of insomnia disorder and restless legs syndrome (RLS) versus men, and obstructive sleep apnea (OSA) is more likely as women age. Hormonal transitions are important to consider in women's sleep. For women, insomnia, OSA, and RLS are predictive of depression, and insomnia and sleep-disordered breathing are predictive of Alzheimer disease. These findings underscore the importance of assessment, treatment, and future research examining sleep and mental health in women, given their unique and increased vulnerability.

The stress of losing sleep: Sex-specific neurobiological outcomes

Sleep is a vital and evolutionarily conserved process, critical to daily functioning and homeostatic balance. Losing sleep is inherently stressful and leads to numerous detrimental physiological outcomes. Despite sleep disturbances affecting everyone, women and female rodents are often excluded or underrepresented in clinical and pre-clinical studies. Advancing our understanding of the role of biological sex in the responses to sleep loss stands to greatly improve our ability to understand and treat health consequences of insufficient sleep. As such, this review discusses sex differences in response to sleep deprivation, with a focus on the sympathetic nervous system stress response and activation of the hypothalamic-pituitary-adrenal (HPA) axis. We review sex differences in several stress-related consequences of sleep loss, including inflammation, learning and memory deficits, and mood related changes. Focusing on women's health, we discuss the effects of sleep deprivation during the peripartum period. In closing, we present neurobiological mechanisms, including the contribution of sex hormones, orexins, circadian timing systems, and astrocytic neuromodulation, that may underlie potential sex differences in sleep deprivation responses.

A Survey of the Menstrual Status of Female College Students

Education about menstruation is a sensitive topic for young female students; providing appropriate knowledge is essential for maintaining and improving their health. The present study was conducted to collect data corresponding to different factors affecting health among young individuals; the menstrual status, exercise habits, sleep status, and body composition of these individuals as well as the relationships among these factors, were evaluated. Altogether, 200 female students responded to the survey; 129 completed all the physical measurement items. As a case study, face-to-face interviews regarding menstrual symptoms were conducted. Results showed that 49/200 (25%) and 120/200 (60%) participants experienced moderate or severe pain before and during menstruation, respectively. The degree of pain one week before menstruation and during menstruation were significantly positively correlated (r = 0.573, p < 0.01). When analyzed as group data, it was difficult to identify the relationship between menstrual status, exercise habits, and sleep status; these were found to be intricately associated with various factors. The case study analysis confirmed that some individuals experienced physical and psychological symptoms, such as irregular menstrual cycles, premenstrual syndrome, and severe menstrual cramps.

A weighted blanket increases pre-sleep salivary concentrations of melatonin in young, healthy adults

Weighted blankets have emerged as a potential non-pharmacological intervention to ease conditions such as insomnia and anxiety. Despite a lack of experimental evidence, these alleged effects are frequently attributed to a reduced activity of the endogenous stress systems and an increased release of hormones such as oxytocin and melatonin. Thus, the aim of the present in-laboratory crossover study (26 young and healthy participants, including 15 men and 11 women) was to investigate if using a weighted blanket (~12% of body weight) at bedtime resulted in higher salivary concentrations of melatonin and oxytocin compared with a light blanket (~2.4% of body weight). We also examined possible differences in salivary concentrations of the stress hormone cortisol, salivary alpha-amylase activity (as an indicative metric of sympathetic nervous system activity), subjective sleepiness, and sleep duration. When using a weighted blanket, the 1 hour increase of salivary melatonin from baseline (i.e., 22:00) to lights off (i.e., 23:00) was about 32% higher (p = 0.011). No other significant differences were found between the blanket conditions, including subjective sleepiness and total sleep duration. Our study is the first to suggest that using a weighted blanket may result in a more significant release of melatonin at bedtime. Future studies should investigate whether the stimulatory effect on melatonin secretion is observed on a nightly basis when frequently using a weighted blanket over weeks to months. It remains to be determined whether the observed increase in melatonin may be therapeutically relevant for the previously described effects of the weighted blanket on insomnia and anxiety.

Association between night pain and quality of life in women: A general population sleep study

BACKGROUND

Women with pain present decreased sleep duration and quality of life, but little is known about the consequences of nighttime pain on overall health. Our goal was to compare levels of anxiety, depression and fatigue in women with pain during the night with those without pain. We hypothesized that pain perception is associated with the worsening of fatigue and mood.

METHODS

In total, 244 women aged 20-80 years who took part in the Epidemiologic Sleep Study (EPISONO) met the inclusion criteria, 85 in the self-reported pain group and 171 in the control group. Participants were assigned to the pain group if they both responded (i) they generally had pain, according to Pre-Sleep Questionnaire (PSQ) and (ii) their pain generally interfered with their sleep 3 or more times a week, according to Pittsburg Sleep Quality Index (PSQI). Those who answered negatively to both questions were allocated to the control group. All participants underwent a full night laboratory polysomnography, and completed questionnaires related to fatigue, depression, anxiety and quality of life.

RESULTS

Pain group participants had a significantly lower perception of quality of life, and significantly higher levels of fatigue (5.4 times), anxiety and depression. Pain perception was also correlated to levels of anxiety and depression in the psychological (r_s  = -0.463, -0.607, respectively) and social (r_s  = -0.423, -0.438, respectively) quality of life domains.

CONCLUSIONS

Nighttime pain in women was associated with decreased quality of life, worsening mood and fatigue. Our data shows the importance of investigating pain and its deleterious effects on women's health.

SIGNIFICANCE

Our study highlights that women experiencing nighttime pain also reported worse mood outcomes and decreased quality of life, regardless of the level and type of pain. Our data, based on association analysis and not investigating causality, suggest it is important to consider nighttime pain in clinical care to improve quality of life and general health.

Factors Affecting Sleep Quality of College Students during the Coronavirus Disease 2019 Pandemic: A Cross-Sectional Study

Background and Objectives: The purpose of this study was to identify the correlation between college students' fear of coronavirus disease 2019 (COVID-19), intolerance of uncertainty, and sleep quality during the COVID-19 pandemic, and to identify factors affecting sleep quality. Materials and Methods: Data were collected through an online survey of 310 college students from three universities located in three regions in Korea. Results: The average sleep quality score of college students was 4.76 ± 2.86 points, the average fear of COVID-19 was 14.01 ± 5.05 points, and the average intolerance of uncertainty was 31.50 ± 7.92 points. Fear of COVID-19 and intolerance of uncertainty were positively correlated (r = 0.302, p < 0.001). Sleep quality was positively correlated with fear of COVID-19 (r = 0.246, p < 0.001). Sleep quality was positively correlated with intolerance of uncertainty (r = 0.212, p < 0.001). Health status was the most powerful factor that affected sleep quality (β = 0.377, p < 0.001). The next most powerful factors that affected sleep quality were fear of COVID-19 (β = 0.164, p = 0.003) and intolerance of uncertainty (β = 0.122, p = 0.027), respectively. Conclusions: These results are expected to be used as basic data for the development of health intervention programs to protect and improve the psychological well-being of college students by improving their sleep quality.

Determinants of Sleep Quality: A Cross-Sectional Study in University Students

When entering the university setting, poor sleep quality is reportedly prevalent among students and has been linked to a range of adverse health outcomes, including reduced academic performance. Moreover, determinants of sleep quality are not yet fully understood. This study was designed to (1) assess the prevalence of poor sleep quality and (2) identify determinants of sleep quality in German university students. In total, 1,684 undergraduate and graduate students (50.6% female, mean age 22.87 ± 3.15 years) from multiple academic disciplines completed a cross-sectional online survey assessing socio-demographic, health, and study-related indicators and sleep quality using the Pittsburgh Sleep Quality Index (PSQI). In our sample, 820 (48.7%) met the PSQI cut-off score (>5) for poor sleep quality. Multiple regression analysis showed that older age, being a business student, lower subjective social status, poorer self-rated health, stress, exhaustion, and poor academic performance significantly predicted poor sleep quality. Our findings document a high prevalence of poor sleep quality among university students and suggest that business students, especially, might be exposed to a greater risk for poor sleep quality. Furthermore, the results of this study are valuable for academic staff to develop tailored interventions to promote healthy sleep-in university students.

Women's mood at high altitude. sexual dimorphism in hypoxic stress modulation by the tryptophan-melatonin axis

Sexual (and gender)-dimorphism in tolerance to hypobaric hypoxia increasingly matters for a differential surveillance of human activities at high altitude (HA). At low altitudes, the prevalence of anxiety and depression in women has already been found to double when compared with men; it could be expected to even increase on exposure to HA. In purposefully caring for the health of women at HA, the present work explores the potential involvement of the tryptophan (Trp)-melatonin axis in mood changes on exposure to hypobaric hypoxia. The present work highlights some already known anxiogenic effects of HA exposure. Hypoxia and insomnia reduce serotonin (5-HT) availability; the latter defect being expressed as failure of brown adipose tissue (BAT) activation and mood disorders. Rapid eye movement (REM) sleep organization and synapsis restoration that are additionally affected by hypoxia impair memory consolidation. Affective complaints may thus surge, evolving into anxiety and depression. Sex-related differences in neural network organization and hormonal changes during the menstrual cycle, and certainly also during the life cycle, underscore the possibility of 5-HT-related mood alterations, particularly in women on HA exposure. The mean brain rate of 5-HT synthesis at sea level is already 1.5-fold higher in males than in females. sexual dimorphism also evidences the overexpression effects of SERT, a 5-HT transporter protein. Gonadal and thyroid hormones, as influenced by HA exposure, further modulate 5-HT availability and its effects in women. Besides caring for adequate oxygenation and maintenance of one's body core temperature, special precautions concerning women sojourning at HA should include close observations of hormonal cycles and, perhaps, also trials with targeted antidepressants.

Nocturnal Hot Flashes, but Not Serum Hormone Concentrations, as a Predictor of Insomnia in Menopausal Women: Results from the Midlife Women's Health Study

Background: Sleep disruptions are among the most common symptoms experienced during menopause and can be associated with depression, hot flashes, and fluctuating hormones. However, few studies have examined how such risk factors influence sleep in midlife women in a network-based approach that will establish the complex relationship between variables. Materials and Methods: We used a Bayesian network (BN) to examine the relationship between multiple factors known to influence sleep and depression in midlife women, including hormone concentrations, hot flashes, and menopause status among participants of the longitudinal Midlife Women's Health Study. In year 1, 762 women (45-54 years of age) answered questions regarding the frequency of insomnia, hot flashes, and depression; 389 of the same women answered similar questions at year 4. We measured serum hormones and calculated free estradiol index, free testosterone index, and ratios of estradiol:progesterone, and estradiol:testosterone. For our model, we calculated the change in frequency of insomnia, depression, and covariates (body mass index, menopause status, hot flashes at night, and present quality of life) from year 1 to 4. Results: Using a BN, we found that self-reported hot flashes at night, and no other factors, were direct predictors of self-reported insomnia in year 1. Surprisingly, we did not identify an association between hormone concentrations and self-reported insomnia. Frequency of insomnia in year 4 was only predicted by frequency of insomnia in year 1, whereas frequency of depression in year 4 was predicted by year 4 insomnia and frequency of depression in year 1. No other factors were direct predictors of insomnia or depression in our model. Conclusions: Therefore, hot flashes at night, previous insomnia, and depression are stronger predictors of how women will self-report frequency of sleep disruptions and treatment may reduce menopausal sleep complaints.

Menstrual cycle and hormonal contraceptive phases' effect on elite rowers' training, performance and wellness

Objectives: To investigate the effect of menstrual cycle (MC) and hormonal contraception (HC) phases in elite rowers training, performance and wellness monitoring. Methods: Twelve French elite rowers were follow-up for 4,2 cycles on average in their final preparation for the Olympics and Paralympics Games in Tokyo 2021 through an on-site longitudinal study based on repeated measures. Daily self-reported evaluation using Likert rating scales of wellness (sleep quality, fitness, mood, injuries' pain), menstrual symptoms and training parameters (perceived exertion and self-assessment of performance) were collected (n = 1,281) in parallel to a coach evaluation of rowers' performance (n = 136), blinded to theirs MC and HC phases. Salivary samples of estradiol and progesterone were collected in each cycle to help to classify the MC into 6 phases and HC into 2-3 phases depending on the pills' hormone concentration. A chi-square test normalized by each rower was used to compare the upper quintile scores of each studied variable across phases. A Bayesian ordinal logistic regression was applied to model the rowers' self-reported performance. Results: Rowers with a natural cycle, n = 6 ( + 1 amenorrhea) evaluate their performance and wellness with significant higher score indices at the middle of their cycle. Top assessments are rarer at the premenstrual and menses phases, when they more frequently experience menstrual symptoms which are negatively correlated with their performance. The HC rowers, n = 5, also better evaluate their performance when taking the pills and more frequently experience menstrual symptoms during the pill withdrawal. The athletes self-reported performance is correlated with their coach's evaluation. Conclusion: It seems important to integrate MC and HC data in the wellness and training monitoring of female athletes since these parameters vary across hormonal phases affecting training perception of both athlete and coach.

Expression deregulation of matrix metalloproteinases and vasoconstriction related genes in Pakistani females with abnormal uterine bleeding

BACKGROUND

Abnormal uterine bleeding (AUB) is irregular menstrual bleeding which has great impact on female health and life style. Various genetic factors are involved in etiology and pathology of AUB. Present study was designed to explore the association of PTGFR, MMP9, MMP2, TGFB3 and VEGFB with AUB.

METHODS

Blood samples of 212 females with AUB were collected along with age-matched healthy control. Expression variation of targeted genes was evaluated using qPCR. Present study cohort was divided into different groups based on demographic parameters and all targeted genes were correlated with study demographics.

RESULTS

Expression of targeted genes was significantly (P < 0.001) downregulated in females with AUB compared to control. Reduced (P < 0.01) expression of targeted genes was observed in all age groups (21-30, 31-40, 41-50 year) of AUB patients compared to respective control. Expression of VEGFB increased (P < 0.05) in AUB females with > 9 days bleeding compared to AUB patient had < 9 days bleeding. AUB women with miscarriage history showed upregulation in MMP2, TGFB3 (P < 0.05), and downregulation in MMP9 and VEGFB (P < 0.05) expression compared to AUB group with no miscarriage history. Expression of MMP2 increased (P < 0.05) in AUB females with > 60 kg body weigh compared to AUB patient with < 60 kg weight.

CONCLUSION

Present study open a new window for diagnosis of AUB at early stages and suggested a possible involvement of PTGFR, MMP9, MMP2, TGFB3 and VEGFB as candidate biomarkers in AUB.

Gender differences in narcolepsy: What are recent findings telling us?

Three papers currently published in SLEEP using two different mouse models of narcolepsy, including either Hcrt-tTa;TetO diptheria toxin-A (DTA) or Hypocretin knock-out (Hcrt-KO) mice, suggest important gender differences in narcolepsy expression. Specifically, these recent data corroborate previous findings in mice demonstrating that females show more cataplexy events and more total cataplexy expression than males. Moreover, in the neurotoxic DTA mouse model, females show earlier onset of cataplexy expression than males during active Hcrt cell loss. Finally, females show a doubling of cataplexy during estrous compared to other phases of the estrous cycle. These findings are reviewed in the broader context of prior published literature, including reported gender differences in Hcrt expression and hormonal influences on sleep and wakefulness. Although similar findings have not been reported in humans, a systematic evaluation of gender differences in human narcolepsy has yet to be performed. Taken together, these animal data suggest that more research exploring gender differences in human narcolepsy is warranted.

Sleep quality and pain in adolescents and young adults with sickle cell disease

STUDY OBJECTIVES

This study evaluated sleep quality in relation to pain and pain-related impairment in adolescents and young adults with sickle cell disease. The purpose was to examine whether increased age was associated with poorer sleep quality and pain and to examine the sleep quality-pain association in this age group.

METHODS

Eighty-nine adolescents and young adults with sickle cell disease between the ages of 13 and 25 completed ratings of sleep quality, overall pain, and 2 measures of pain-related impairment (pain impact and pain burden) as part of their clinical care. Retrospective chart reviews were completed to match ratings to demographic and medical characteristics. Correlations and multiple regression were used to examine associations between age, sleep quality, and pain variables, including an exploratory analysis of the sleep-pain association by age.

RESULTS

Increased age was associated with poorer sleep quality, worse overall pain, and higher pain burden. Poorer sleep quality was also associated with worse overall pain and pain burden. Using multiple regression, a small, but not statistically significant trend was observed for the interaction of increased age and strengthening of the sleep quality-pain burden association.

CONCLUSIONS

Sleep quality and pain are important challenges for adolescents and young adults with sickle cell disease that may persist or worsen with increased age. Early identification of these difficulties in pediatric populations as well as continued screening and intervention as adolescents transition into adult care is important. Additional longitudinal research is needed to better understand the progression of the sleep-pain relationship over time.

CITATION

Schlenz AM, Thomas SJ, Gloston G, Lebensburger J, Maxwell SL, Kanter J. Sleep quality and pain in adolescents and young adults with sickle cell disease. J Clin Sleep Med. 2022;18(12):2845-2853.

Sustained Sleep Restriction Reduces Resistance Exercise Quality and Quantity in Females

INTRODUCTION

Female athletes sleep less and report more sleep problems than their male counterparts. Inadequate sleep reduces maximal strength in male athletes; however, little is known about the impact of sleep restriction (SR) on the quantity and quality of resistance exercise performed by female athletes. This study investigated the effect of nine nights of moderate SR on repeated resistance exercise performance, hormonal responses, and perceived fatigue in females.

METHODS

Ten healthy, resistance-trained, eumenorrheic females age 18-35 yr underwent nine nights of SR (5-h time in bed) and normal sleep (NS; ≥7-h time in bed) in a randomized, crossover fashion with a minimum 6-wk washout. Participants completed four resistance exercise sessions per trial, with blood samples collected before and after exercise. Exercise performance was assessed using volume load, reactive strength index, and mean concentric velocity with rating of perceived exertion recorded after exercise. Participants completed awakening saliva sampling and the Multi-component Training Distress Scale daily.

RESULTS

Volume load decreased trivially (<1%, P < 0.05) with SR. Mean concentric velocity per set was slower during SR for the lower-body (up to 15%, P < 0.05), but not the upper-body, compound lifts. Intraset velocity loss was up to 7% greater during SR for back squats ( P < 0.05). SR increased salivary cortisol area under the curve (by 42%), total training distress (by 84%), and session perceived exertion (by 11%).

CONCLUSIONS

Sustained SR reduces markers of resistance exercise quality (bar velocity) more than quantity (volume load) and increases perceived effort at the same relative intensity in resistance-trained females. Markers of exercise quality and internal load may be more sensitive than volume load, to advise coaches to the decline in lifting performance for female athletes experiencing SR.

Effect of sleep and fatigue on cardiovascular performance in young, healthy subjects

Physical performance could be negatively affected by sleep deficiency and fatigue. The present study assesses the role of sleep quality, fatigue and motivation on cardiovascular performance (VO₂peak, Wmax, and HRmax) in a sample of active young subjects. The current study is a cross-sectional design. Ninety-six university students (males 54.2%; 21.5 ± 2.9 yrs) completed an incremental exercise test on a bicycle ergometer. Sleep, fatigue, and motivation were assessed with the Pittsburgh Sleep Quality Index and two visual analogue scales, respectively. Differences in VO₂peak, Wmax, HRmax, self-perceived fatigue and motivation were compared between good and bad sleepers and sleep duration >/<7.5 h, while regression analysis defined the predictors of VO₂peak, Wmax, and HRmax_. In the male sample, good and bad sleepers' differences were significant only for self-perceived fatigue (p = 0.04). The female sample showed no statistically significant differences between good and bad sleepers and different sleep durations. In the male sample, linear regression analysis showed a significant inverse correlation between Wmax and the PSQI score (-0.4, p = 0.004). The stepwise regression model indicated that sleep (β = -0.3, p = 0.02) was a significant predictor of VO₂peak in males accounting for 20% of the variance, whereas physical performance seems more affected by fatigue (β = -0.4, p = 0.03) in females. In conclusion, chronic inadequate and self-reported sleep quality seems to be one of the factors compromising cardiovascular performance in males.

Human circadian rhythm studies: Practical guidelines for inclusion/exclusion criteria and protocol

As interest in circadian rhythms and their effects continues to grow, there is an increasing need to perform circadian studies in humans. Although the constant routine is the gold standard for these studies, there are advantages to performing more naturalistic studies. Here, a review of protocols for such studies is provided along with sample inclusion and exclusion criteria. Sleep routines, drug use, shift work, and menstrual cycle are addressed as screening considerations. Regarding protocol, best practices for measuring melatonin, including light settings, posture, exercise, and dietary habits are described. The inclusion/exclusion recommendations and protocol guidelines are intended to reduce confounding variables in studies that do not involve the constant routine. Given practical limitations, a range of recommendations is provided from stringent to lenient. The scientific rationale behind these recommendations is discussed. However, where the science is equivocal, recommendations are based on empirical decisions made in previous studies. While not all of the recommendations listed may be practical in all research settings and with limited potential participants, the goal is to allow investigators to make well informed decisions about their screening procedures and protocol techniques and to improve rigor and reproducibility, in line with the objectives of the National Institutes of Health.

Environmental exposure to per- and polyfluoroalkyl substances and sleep disturbance in pregnant women: A prospective cohort study

Previous studies on the association between exposure to per- and polyfluoroalkyl substances (PFAS) and sleep patterns in pregnant women are limited. This cohort study aims to assess the associations between PFAS and sleep quality in pregnant women. Of the 4127 women who participated in the Shanghai Birth Cohort, 3174, 3070, and 2887 women in their first, second, and third trimesters of gestation, respectively, were included in our analysis. Sleep measures were taken using the Pittsburgh Sleep Quality Index questionnaire. Ten PFAS were measured in blood samples collected in early pregnancy. We first evaluate the associations between individual PFAS and sleep quality in the three trimesters. Weighted quantile sum (WQS) regression models were performed to test the overall effect of the PFAS mixture on sleep quality during the three trimesters. Longitudinal analyses throughout pregnancy were performed with generalized estimating equation models. Furthermore, the effect of the PFAS mixture on longitudinal sleep patterns was examined using longitudinal latent class analyses combined with WQS models. The single pollutant analysis suggested that most PFAS were associated with increased sleep disturbance risk, lower sleep efficiency, and shorter sleep duration in the three trimesters. Similarly, the WQS models revealed a significant association between the PFAS mixtures and elevated sleep disturbance risk in pregnant women, with perfluorobutane sulfonate acting as the predominant risk factor. Additionally, the longitudinal analysis confirmed the effects of PFAS exposure on increased sleep disturbance over time. The PFAS mixture was positively associated with higher risks of poor sleep quality and sleep medicine use [adjusted odds ratio (aOR) = 1.10; 95 % confidence interval (95%CI): 1.01, 1.20; and aOR = 1.25 (95%CI: 1.04, 1.50) respectively] throughout the three trimesters. Our study suggests that PFAS may increase the risk of sleep disturbance in pregnant women. Further studies are needed to confirm our results and elucidate potential mechanisms.

The effects of morning/afternoon surgeries on the early postoperative sleep quality of patients undergoing general anesthesia

Objective

This study aimed to investigate the effects of morning and afternoon surgeries on the early postoperative sleep function in patients undergoing general anesthesia.

Methods

Fifty nine patients, aged 18–60 years, American society of anaesthesiologists (ASA) grade I or II, Body mass index of 18.5–28 kg/m², undergoing laparoscopic myomectomy under total intravenous anesthesia, were included in the study. These patients were divided into two groups according to the start time of anesthesia: morning surgery group (group A, 8:00–12:00) and afternoon surgery group (group P, 14:00–18:00). The sleep conditions of the two groups of patients were evaluated by the Athens Insomnia Scale (AIS) one day before and one day after the operation. A total score of > 6 was regarded as postoperative sleep disturbance. The incidences of sleep disturbance one day after the operation in two groups were compared. The bispectral Index assessed the patient’s total sleep duration, sleep efficiency, and overall quality of sleep from 21:00 to 6:00 on the first night after surgery. Plasma concentrations of melatonin and cortisol at 6:00 am 1 day before surgery, 1 day after surgery were measured by ELISA, and rapid random blood glucose was measured.

Results

The total AIS score, overall quality of sleep, total sleep duration, and final awakening earlier than desired scores of the two groups of patients on the first night after surgery were significantly increased compared with preoperative scores (P < 0.01). In group P, the sleep induction and the physical and mental functioning during the day scores increased significantly after surgery compared with preoperative scores (P < 0.05). The postoperative AIS scores in group P increased significantly compared with those in group A (P < 0.01). The incidence of postoperative sleep disturbances (70.0%) in group P was significantly higher than that in group A (37.9%) (P < 0.05). Compared with group A, the total sleep duration under BIS monitoring in group P was significantly shorter, the sleep efficiency and the overall quality of sleep was significantly reduced (P < 0.01). Compared with those in group A, the level of melatonin on 1 d after surgery in group P was significantly decreased, and the level of cortisol in group P was significantly increased. There were no significant differences between the two groups in the levels of postoperative blood glucose and pain.

Conclusion

Both morning and afternoon surgeries have significant impacts on the sleep function in patients undergoing general anesthesia, while afternoon surgery has a more serious impact on sleep function.

Trial registration

ClinicalTrials, NCT04103528. Registered 24 September 2019—Retrospectively registered, http://www.ClinicalTrials.gov/ NCT04103528.

The space-time profiles of sleep spindles and their coordination with slow oscillations on the electrode manifold

Sleep spindles are important for sleep quality and cognitive functions, with their coordination with slow oscillations (SOs) potentially organizing cross-region reactivation of memory traces. Here, we describe the organization of spindles on the electrode manifold and their relation to SOs. We analyzed the sleep night EEG of 34 subjects and detected spindles and SOs separately at each electrode. We compared spindle properties (frequency, duration, and amplitude) in slow wave sleep (SWS) and Stage 2 sleep (S2); and in spindles that coordinate with SOs or are uncoupled. We identified different topographical spindle types using clustering analysis that grouped together spindles co-detected across electrodes within a short delay (±300 ms). We then analyzed the properties of spindles of each type, and coordination to SOs. We found that SWS spindles are shorter than S2 spindles, and spindles at frontal electrodes have higher frequencies in S2 compared to SWS. Furthermore, S2 spindles closely following an SO (about 10% of all spindles) show faster frequency, shorter duration, and larger amplitude than uncoupled ones. Clustering identified Global, Local, Posterior, Frontal-Right and Left spindle types. At centro-parietal locations, Posterior spindles show faster frequencies compared to other types. Furthermore, the infrequent SO-spindle complexes are preferentially recruiting Global SO waves coupled with fast Posterior spindles. Our results suggest a non-uniform participation of spindles to complexes, especially evident in S2. This suggests the possibility that different mechanisms could initiate an SO-spindle complex compared to SOs and spindles separately. This has implications for understanding the role of SOs-spindle complexes in memory reactivation.

Sex Hormones, Sleep, and Memory: Interrelationships Across the Adult Female Lifespan

As the population of older adults grows, so will the prevalence of aging-related conditions, including memory impairments and sleep disturbances, both of which are more common among women. Compared to older men, older women are up to twice as likely to experience sleep disturbances and are at a higher risk of cognitive decline and Alzheimer's disease and related dementias (ADRD). These sex differences may be attributed in part to fluctuations in levels of female sex hormones (i.e., estrogen and progesterone) that occur across the adult female lifespan. Though women tend to experience the most significant sleep and memory problems during the peri-menopausal period, changes in memory and sleep have also been observed across the menstrual cycle and during pregnancy. Here, we review current knowledge on the interrelationships among female sex hormones, sleep, and memory across the female lifespan, propose possible mediating and moderating mechanisms linking these variables and describe implications for ADRD risk in later life.

Evening Caffeine Did Not Improve 100-m Swimming Time Trials Performed 60 Min Post-Ingestion or the Next Morning After Sleep

The potential ergogenic benefits of caffeine (CAF) are well known within the athletic community, often leading to its use in adolescent swimming cohorts to enhance their performance. However, it has previously been reported that CAF has sleep-disturbing effects, which could be detrimental to performance over consecutive days in multiday competitions. Moreover, the effects that evening CAF ingestion has on sleep, side effects, and next-day performances are yet to be researched in trained adolescents. In a double-blind, randomized, crossover design, eight national-level swimmers (age: 18 ± 1 years, height: 1.76 ± 0.06 cm, body mass [BM]: 69.4 ± 6.4 kg) ingested a capsule containing 3 mg/kg BM CAF or a placebo 60 min before an evening 100-m swimming time trial. The next morning, sleep was analyzed (Core Consensus Sleep Diary) and 100-m time trials were repeated. Side effects were analyzed via visual analog scales throughout the study. No differences were found for swimming performance (p = .911) in the evening (CAF: 59.5 ± 7.8 s, placebo: 59.9 ± 7.9 s, g = 0.06) or morning (CAF: 59.7 ± 7.7 s, placebo: 60.2 ± 7.9 s, g = 0.07). In addition, no group differences were found for any subjective side effects (e.g., anxiety: p = .468, tachycardia: p = .859, alertness: p = .959) or sleep parameters (e.g., sleep latency: p = .395, total sleep time: p = .574). These results question the use of a standardized 3 mg/kg BM CAF ingestion strategy for 100-m swimming time trials in trained adolescents, although objective measures may be needed to confirm that CAF does not affect sleep within this cohort.

Effects of sex and estrous cycle on sleep and cataplexy in narcoleptic mice

Narcolepsy type 1 (NT1) is a rare neurology disorder caused by the loss of orexin/hypocretin neurons. NT1 is characterized by excessive daytime sleepiness, sleep and wake fragmentation, and cataplexy. These symptoms have been equally described in both women and men, although influences of gender and hormonal cycles have been poorly studied. Unfortunately, most studies with NT1 preclinical mouse models, use only male mice to limit potential variations due to the hormonal cycle. Therefore, whether gender and/or hormonal cycles impact the expression of narcoleptic symptoms remains to be determined. To address this question, we analyzed vigilance states and cataplexy in 20 female and 17 male adult orexin knock-out narcoleptic mice, with half of the females being recorded over multiple days. Mice had access to chocolate to encourage the occurrence of cataplectic episodes. A vaginal smear was performed daily in female mice to establish the state of the estrous cycle (EC) of the previous recorded night. We found that vigilance states were more fragmented in males than females, and that females had less paradoxical sleep (p = 0.0315) but more cataplexy (p = 0.0375). Interestingly, sleep and wake features were unchanged across the female EC, but the total amount of cataplexy was doubled during estrus compared to other stages of the cycle (p = 0.001), due to a large increase in the number of cataplexy episodes (p = 0.0002). Altogether these data highlight sex differences in the expression of narcolepsy symptoms in orexin knock-out mice. Notably, cataplexy occurrence was greatly influenced by estrous cycle. Whether it is due to hormonal changes would need to be further explored.

Adult Female Sleep During Hypoxic Bed Rest

Purpose

Hypobaric hypoxic habitats are currently being touted as a potential solution to minimise decompression procedures in preparation for extra vehicular activities during future space missions. Since astronauts will live in hypoxic environments for the duration of such missions, the present study sought to elucidate the separate and combined effects of inactivity [simulated with the experimental bed rest (BR) model] and hypoxia on sleep characteristics in women.

Methods

Twelve women (Age = 27 ± 3 year) took part in three 10-day interventions, in a repeated measures cross-over counterbalanced design: (1) normobaric normoxic BR (NBR), (2) normobaric hypoxic BR (HBR; simulated altitude of 4,000 m), and (3) normobaric hypoxic ambulatory (HAMB; 4,000 m) confinement, during which sleep was assessed on night 1 and night 10 with polysomnography. In addition, one baseline sleep assessment was performed. This baseline assessment, although lacking a confinement aspect, was included statistically as a fourth comparison (i.e., pseudo normobaric normoxic ambulatory; pNAMB) in the present study.

Results

Hypoxia decreased sleep efficiency (p = 0.019), increased N1% sleep (p = 0.030), decreased N3 sleep duration (p = 0.003), and increased apnea hypopnea index (p < 0.001). BR impaired sleep maintenance, efficiency, and architecture [e.g., N2% sleep increased (p = 0.033)]. Specifically, for N3% sleep, the effects of partial pressure of oxygen and activity interacted. Hypoxia decreased N3% sleep both when active (pNAMB vs HAMB; p < 0.001) and inactive (NBR vs HBR; p = 0.021), however, this decrease was attenuated in the inactive state (–3.8%) compared to the active state (–10.2%).

Conclusion

A 10-day exposure to hypoxia and BR negatively impacted sleep on multiple levels as in macrostructure, microstructure and respiratory functioning. Interestingly, hypoxia appeared to have less adverse effects on sleep macrostructure while the participants were inactive (bed ridden) compared to when ambulatory. Data were missing to some extent (i.e., 20.8%). Therefore, multiple imputation was used, and our results should be considered as exploratory.

Tracking Sleep, Temperature, Heart Rate, and Daily Symptoms Across the Menstrual Cycle with the Oura Ring in Healthy Women

Background and Objective

The ovulatory menstrual cycle is characterized by hormonal fluctuations that influence physiological systems and functioning. Multi-sensor wearable devices can be sensitive tools capturing cycle-related physiological features pertinent to women’s health research. This study used the Oura ring to track changes in sleep and related physiological features, and also tracked self-reported daily functioning and symptoms across the regular, healthy menstrual cycle.

Methods

Twenty-six healthy women (age, mean (SD): 24.4 (1.1 years)) with regular, ovulatory cycles (length, mean (SD): 28.57 (3.8 days)) were monitored across a complete menstrual cycle. Four menstrual cycle phases, reflecting different hormone milieus, were selected for analysis: menses, ovulation, mid-luteal, and late-luteal. Objective measures of sleep, sleep distal skin temperature, heart rate (HR) and vagal-mediated heart rate variability (HRV, rMSSD), derived from the Oura ring, and subjective daily diary measures (eg sleep quality, readiness) were compared across phases.

Results

Wearable-based measures of sleep continuity and sleep stages did not vary across the menstrual cycle. Women reported no menstrual cycle-related changes in perceived sleep quality or readiness and only marginally poorer mood in the midluteal phase. However, they reported moderately more physical symptoms during menses (p < 0.001). Distal skin temperature and HR, measured during sleep, showed a biphasic pattern across the menstrual cycle, with increased HR (p < 0.03) and body temperature (p < 0.001) in the mid- and late-luteal phases relative to menses and ovulation. Correspondingly, rMSSD HRV tended to be lower in the luteal phase. Further, distal skin temperature was lower during ovulation relative to menses (p = 0.05).

Conclusion

The menstrual cycle was not accompanied by significant fluctuations in objective and perceived measures of sleep or in mood, in healthy women with regular, ovulatory menstrual cycles. However, other physiological changes in skin temperature and HR were evident and may be longitudinally tracked with the Oura ring in women over multiple cycles in a natural setting.

Sex Differences Across the Life Course: A Focus On Unique Nutritional and Health Considerations among Women

In the United States, women, while having a longer life expectancy than men, experience a differential risk for chronic diseases and have unique nutritional needs based on physiological and hormonal changes across the life span. However, much of what is known about health is based on research conducted in men. Additional complexity in assessing nutritional needs within gender include the variations in genetics, body compositions, hormonal milieus, underlying chronic diseases, and medication usage, with this list expanding as we consider these variables across the life course. It is clear women experience nutrient shortfalls during key periods of their lives, which may differentially impact their health. Consequently, as we move into the era of precision nutrition, understanding these sex- and gender-based differences may help optimize recommendations and interventions chosen to support health and weight management. Recently, a scientific conference was convened with content experts to explore these topics from a life-course perspective at biological, physiological, and behavioral levels. This publication summarizes the presentations and discussions from the workshop and provides an overview of important nutrition and related lifestyle considerations across the life course. The landscape of addressing female-specific nutritional needs continues to grow; now more than ever, it is essential to increase our understanding of the physiological differences between men and women, and determine how these physiological considerations may aid in optimizing nutritional strategies to support certain personal goals related to health, quality of life, sleep, and exercise performance among women.

Associations between sleep duration and Mediterranean diet score in Costa Rican adults

Both insufficient and excessive sleep duration have been associated with lower-quality diets in adult populations. However, investigations in Latin America, where different sleep norms may exist (e.g., daily napping), are scarce. Therefore, we examined whether weekday sleep duration and inconsistencies between weekday and weekend sleep duration were related to adherence to the Mediterranean diet among Costa Rican adults. The study population included 2169 controls (74% men) from a population-based case-control study. Usual sleep duration (weekday versus weekend) was self-reported and defined as short, recommended, and long (<7 h, 7-9 h, >9 h, respectively). Inconsistent weekday-weekend sleep duration was defined as >1-h difference. Diet was assessed with a food frequency questionnaire, and adherence to the Mediterranean diet was calculated with the Alternative Mediterranean Diet Score (AMED). Sex-stratified linear regression models were conducted with AMED score as a continuous outcome and sleep variables as categorical or dichotomous exposures (in separate models). Models were adjusted for age, area of residence, education, napping, caffeine intake, smoking status, type 2 diabetes mellitus, hypertension, and physical activity. Average (SD) hours of sleep per night reported were 7.0 (1.4) on weekdays and 7.3 (1.6) on weekends for men, and 7.0 (1.5) on weekdays and 7.2 (1.6) on weekends for women. Among women, sleep duration <7-h per night was associated with a lower AMED score compared to those with recommended sleep duration (β: -0.35, CI: -0.63 to -0.07). Unstratified models showed a suggestive association between inconsistent weekday-weekend sleep and lower AMED scores that did not vary by sex (β: -0.08, CI: -0.16, 0.006; P, interaction with sex = 0.93). Lastly, the napping frequency was not associated with AMED scores in any model. In conclusion, short and inconsistent sleep duration may affect the dietary patterns of Costa Ricans.

Sex differences in childhood sleep and health implications

CONTEXT

Sleep is critical for optimal childhood metabolic health and neurodevelopment. However, there is limited knowledge regarding childhood sex differences in sleep, including children with neurodevelopmental disorders, and the impact of such differences on metabolic health.

OBJECTIVE

To evaluate if sex differences in childhood sleep exist and if sleep associates with metabolic health outcomes equally by sex. Using autism spectrum disorder (ASD) as a case study, we also examine sleep sex differences in children with a neurodevelopmental disorder.

METHODS

A narrative review explored the literature focussing on sex differences in childhood sleep.

RESULTS

Sex differences in sleep were not detected among pre-adolescents. However, female adolescents were more likely to report impaired sleep than males. Childhood obesity is more common in males. Shorter sleep duration may be associated with obesity in male pre-adolescents/adolescents; although findings are mixed. ASD is male-predominant; yet, there was an indication that pre-adolescent female children with ASD had more impaired sleep.

CONCLUSION

Sex differences in sleep appear to emerge in adolescence with more impaired sleep in females. This trend was also observed among pre-adolescent female children with ASD. Further research is needed on sex differences in childhood sleep and metabolic health and the underlying mechanisms driving these differences.

Melatonin for premenstrual syndrome: A potential remedy but not ready

Premenstrual syndrome (PMS), a recurrent and moderate disorder that occurs during the luteal phase of the menstrual cycle and quickly resolves after menstruation, is characterized by somatic and emotional discomfort that can be severe enough to impair daily activities. Current therapeutic drugs for PMS such as selective serotonin reuptake inhibitors are not very satisfying. As a critical pineal hormone, melatonin has increasingly been suggested to modulate PMS symptoms. In this review, we update the latest progress on PMS-induced sleep disturbance, mood changes, and cognitive impairment and provide possible pathways by which melatonin attenuates these symptoms. Moreover, we focus on the role of melatonin in PMS molecular mechanisms. Herein, we show that melatonin can regulate ovarian estrogen and progesterone, of which cyclic fluctuations contribute to PMS pathogenesis. Melatonin also modulates gamma-aminobutyric acid and the brain-derived neurotrophic factor system in PMS. Interpreting the role of melatonin in PMS is not only informative to clarify PMS etiology but also instructive to melatonin and its receptor agonist application to promote female health. As a safe interaction, melatonin treatment can be effective in alleviating symptoms of PMS. However, symptoms such as sleep disturbance, depressive mood, cognitive impairment are not specific and can be easily misdiagnosed. Connections between melatonin receptor, ovarian steroid dysfunction, and PMS are not consistent among past studies. Before final conclusions are drawn, more well-organized and rigorous studies are recommended.

Relationship between hormonal contraceptives and sleep among women of reproductive age: a systematic review protocol

INTRODUCTION

The aetiology of sleep disruptions is unknown, but hormonal fluctuations during the menstrual cycle, pregnancy and menopause have been shown to potentially affect how well a woman sleeps. The aim of this systematic review was to investigate whether hormonal contraceptives are associated with a decreased quality of sleep and increased sleep duration in women of reproductive age.

METHODS

This review will analyse data from randomised controlled trials or non-randomised comparative studies investigating the association between hormonal contraceptives and sleep outcomes among women of reproductive age. Reviews addressing the same research question with similar eligibility criteria will be included. A literature search will be performed using the MEDLINE, Embase and Cochrane Central Register of Controlled Trials databases from inception to 7 March 2021. The Cochrane Collaboration's Risk of Bias for Randomised Trials V.2.0 and The Risk of Bias for Non-randomised Studies of Interventions tool will be used to assess risk of bias for each outcome in eligible studies. Two reviewers will independently assess eligibility of studies and risk of bias and extract the data. All extracted data will be presented in tables and narrative form. For sleep measures investigated by two or more studies with low heterogeneity, we will conduct random-effects meta-analysis to estimate the magnitude of the overall effect of hormonal contraceptives. If studies included in this systematic review form a connected network, a network meta-analysis will be conducted to estimate the comparative effect of different contraceptives. The Grading of Recommendations, Assessment, Development, and Evaluation approach will be used to summarise the quality of evidence. Our protocol follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols 2015 guidelines.

ETHICS AND DISSEMINATION

Ethics approval is not required as data were sourced from previously reported studies. The findings of this review will be published in a peer-reviewed journal and presented at relevant conferences.

PROSPERO REGISTRATION NUMBER

CRD42020199958.

Subjective sleep quality and characteristics across the menstrual cycle in women with and without Generalized Anxiety Disorder

OBJECTIVE

Past studies have found that various psychiatric symptoms fluctuate over the menstrual cycle. Sleep disturbance is a transdiagnostic feature of psychiatric conditions and is associated with several symptoms that exhibit menstrual fluctuations. Although some evidence indicates that subjective sleep quality changes over the menstrual cycle in healthy women, no studies have investigated whether sleep fluctuates over the menstrual cycle in psychiatric populations, other than premenstrual dysphoric disorder.

METHODS

The present study used a mixed between- within-groups design to compare self-reported sleep characteristics (sleep onset latency, number and duration of night-time awakenings, and total sleep time), sleep quality, insomnia symptoms, and daytime sleepiness in women with (n = 31) and without (n = 32) generalized anxiety disorder (GAD) at two time points within a single menstrual cycle - the early-follicular (low ovarian hormones) and mid-luteal (high ovarian hormones) phases.

RESULTS

Women with GAD reported lower sleep quality, more insomnia symptoms, and more daytime sleepiness (η_p² = 0.13-0.14), but comparable sleep characteristics, compared to women without GAD. In both groups, sleep variables remained stable over the menstrual phases examined. Within-person changes in estradiol and progesterone between the two menstrual phases were mostly not associated with within-person changes in sleep variables, except that larger increases in estradiol were associated with a reduction in the number of night-time awakenings from the early-follicular to mid-luteal phases (β = -0.26).

CONCLUSION

These findings indicate that subjective sleep disturbance, unlike other psychiatric symptoms, may not be modulated by the menstrual cycle and ovarian hormones during the phases examined in this study.

Menstrual regularity and bleeding is associated with sleep duration, sleep quality and fatigue in a community sample

Female menstrual health and its relationship with sleep is an understudied subject. The aim of this investigation was to determine the association between the two in a community sample. Data were obtained from n = 579 menstruating females who participated in the Sleep and Health Activity, Diet, Environment, and Socialization (SHADES) study, a community-based sample of adults aged 22-60 years. Participants were asked, "How regular is your period?", with response choices of "very regular", "mostly regular", "fairly regular" and "not regular". They were also asked, "How much bleeding do you usually experience during your period?" Response choices were: "very heavy", "heavy", "medium", "light" or "very light". These were evaluated as ordinal outcomes. Sleep-related predictors included sleep duration (in hr; ≤ 6 [short], 7-9 [normal] and ≥ 9 [long]), Insomnia Severity Index score, Pittsburgh Sleep Quality Index score, Epworth Sleepiness Scale score and Fatigue Severity Scale score. Covariates included age, education, income, race/ethnicity and body mass index. Short sleep duration was associated with heavier bleeding (odds ratio = 1.46, p = 0.026) and greater cycle irregularity (odds ratio = 1.44, p = 0.031) as compared with normal sleep. Higher Pittsburgh Sleep Quality Index score was associated with greater cycle irregularity (odds ratio = 1.05, p = 0.022). Higher Fatigue Severity Scale score was associated with heavier bleeding (odds ratio = 1.02, p = 0.003) and greater cycle irregularity (odds ratio = 1.02, p = 0.008). Long sleep, Insomnia Severity Index and Epworth Sleepiness Scale were not associated with either outcome. These results demonstrate an association between short sleep duration, poor sleep quality, fatigue, stress and depression with heavier bleeding and menstrual cycle irregularity, highlighting the need for further studies to improve treatment options.

Sex, drugs, and anaesthesia research

In this issue of the British Journal of Anaesthesia, Joksimovic and colleagues report significant sex differences in sensitivity to the behavioural and neurophysiological effects of 3β-OH, a novel neurosteroid anesthetic. Female rats were more sensitive to the effects of 3β-OH than male rats, although the mechanims remain unclear. Sex differences have been understudied in anaesthesia research, and this article by Joksimovic and colleagues emphasizes the need to devote more effort to understanding these differences.

Patterns of endogenous and exogenous ovarian hormone modulation on recovery metrics across the menstrual cycle

Introduction

As the number of female athletes competing rises globally, training methodologies should reflect sex differences across critical metrics of adaptation to training. Surrogate markers of the autonomic nervous system (ANS) used for monitoring training load are heart rate variability (HRV) and resting heart rate (RHR). The aim was to investigate ovarian hormone effects on standard recovery metrics (HRV, RHR, respiratory rate (RR) and sleep duration) across a large population of female athletes.

Methods

A retrospective study analysed 362 852 days of data representing 13 535 menstrual cycles (MC) from 4594 respondents (natural MC n=3870, BC n=455, progestin-only n=269) for relationships and/or differences between endogenous and exogenous ovarian hormones on ANS.

Results

HRV and return to baseline (recovery) decreased as resting HR and RR increased (p<0.001) from the early follicular to the late luteal phase of the MC. Patterning was paradoxical across phases for users of combined hormonal contraception (BC) as compared with the patterning of the MC. HRV and recovery start elevated and drop off quickly during the withdrawal bleed, rising through the active pill weeks (p<0.001). Progestin-only users had similar patterning as the MC. The relationship between normalised recovery and previous day strain is modulated by birth control type. BC exhibited steeper declines in recovery with additional strain-normalised recovery decreases by an additional 0.0055±0.00135 (p<0.001) per unit of strain; with no significant difference between MC and progestin-only (p=0.19).

Conclusion

The patterning of ANS modulation from ovarian hormones is significantly different between naturally cycling women and those on BC, with the patterning dependent on the type of contraception used.