Excessive Sleepiness

Self-reported sleep status and influencing factors: a web-based national cross-sectional survey in China

OBJECTIVES

To investigate self-reported sleep duration, sleep timing, sleep status and influencing factors in the Chinese population.

METHODS

This web-based cross-sectional survey was conducted in 2022, covering 31 provinces (91%) in China. 11,000 questionnaires were collected, of which 8970 were valid for analysis. Self-reported sleep habits, problems and quality were investigated. Good or fair sleep ratings, enough duration, regular, with no sleep disturbances and <30 min sleep latency was defined as a composite variable: 'Good sleep'. Factors influencing sleep patterns and 'Good sleep' were analyzed by multivariate logistic regression.

RESULTS

Most participants sleep less than 7 h per night (55.13%), usually go to bed at 10-12 pm (47.99%), wake up at 6-8 am (49.86%), and take less than 30 min to fall asleep (66.30%) with regular sleep schedule (76.01%). Only 12.36% have 'Good sleep'. In the past 3 months, 46.80% of the participants reported symptoms of insomnia, and 21.54% had snoring problems. Among the adults, the young, males, college students, freelancers, and those who resided in urban areas and pandemic-free areas slept later, and the northerners woke up earlier. The adults with low-moderate and moderate income and the minors at elementary and middle school slept earlier and woke up earlier. Mid-aged adults who often napped at noon were more likely to have 'Good sleep' than any other age group, and urban dwellers with the same habit were more likely to have 'Good sleep' than people dwelled in other regions. While people who slept late, woke up too early or too late, slept too little or too much, resided at GMT 7-8 area or pandemic area, had high income, or took up some occupations (entrepreneurs/individuals, professionals, manual and non-manual workers, housewives) were less likely to get a 'Good sleep'.

CONCLUSIONS

The national survey provided a sleep profile of the Chinese population. Both socio-economic status and personal sleep hygiene habits had an impact on 'Good sleep'.

Associations between common sleep disturbances and cardiovascular risk in patients with obstructive sleep apnea: A large-scale cross-sectional study

Objectives

Studies have shown that obstructive sleep apnea (OSA) is inextricably linked with cardiovascular diseases (CVD). However, the roles of certain common sleep disturbances, such as low slow-wave sleep, excessive daytime sleepiness and short sleep duration, in the pathogenesis and progression of CVD in patients with OSA have not been determined. Therefore, we conducted a large cross-sectional study to explore the effect of low slow-wave sleep, excessive daytime sleepiness and short sleep duration on the risk of CVD in patients with OSA.

Methods

Subjects were consecutively enrolled to participate in the sleep center of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital. All OSA patients were diagnosed by standard polysomnography, while controls were all simple snorers. A total of 4,475 participants were strictly recruited. The Framingham Risk Score were employed to assess the 10-year risk of CVD, and logistic regression was used to measure the association between sleep disturbances and the moderate-to-high CVD risk.

Results

In the whole cohort, OSA, excessive daytime sleepiness, and low slow-wave sleep were all risk factors for the moderate-to-high 10-year CVD risk (odds ratio [OR] = 3.012, 95% confidence interval [CI] 2.418–3.751; OR = 1.407, 95% CI: 1.228–1.613, and OR = 0.973,95% CI: 0.967–0.980), but sleep duration did not contribute significantly to that risk. Whether in patients with OSA and controls, low SWS (<12.8%) could increase the risk of CVD. Subjective excessive daytime sleepiness would significantly increase the risk of CVD only in patients with severe OSA.

Conclusion

It is important to pay more attention to the impact of sleep on cardiovascular health. Patients with sleep disturbances should adopt a healthy lifestyle and undergo regular follow-up of cardiovascular indicators to prevent cardiovascular complications.

Trial registration

[http://www.chictr.org.cn/showproj.aspx?proj=43057], identifier [ChiCTr1900025714].

Epigenome-wide association analysis of daytime sleepiness in the Multi-Ethnic Study of Atherosclerosis reveals African-American-specific associations

STUDY OBJECTIVES

Daytime sleepiness is a consequence of inadequate sleep, sleep-wake control disorder, or other medical conditions. Population variability in prevalence of daytime sleepiness is likely due to genetic and biological factors as well as social and environmental influences. DNA methylation (DNAm) potentially influences multiple health outcomes. Here, we explored the association between DNAm and daytime sleepiness quantified by the Epworth Sleepiness Scale (ESS).

METHODS

We performed multi-ethnic and ethnic-specific epigenome-wide association studies for DNAm and ESS in the Multi-Ethnic Study of Atherosclerosis (MESA; n = 619) and the Cardiovascular Health Study (n = 483), with cross-study replication and meta-analysis. Genetic variants near ESS-associated DNAm were analyzed for methylation quantitative trait loci and followed with replication of genotype-sleepiness associations in the UK Biobank.

RESULTS

In MESA only, we detected four DNAm-ESS associations: one across all race/ethnic groups; three in African-Americans (AA) only. Two of the MESA AA associations, in genes KCTD5 and RXRA, nominally replicated in CHS (p-value < 0.05). In the AA meta-analysis, we detected 14 DNAm-ESS associations (FDR q-value < 0.05, top association p-value = 4.26 × 10-8). Three DNAm sites mapped to genes (CPLX3, GFAP, and C7orf50) with biological relevance. We also found evidence for associations with DNAm sites in RAI1, a gene associated with sleep and circadian phenotypes. UK Biobank follow-up analyses detected SNPs in RAI1, RXRA, and CPLX3 with nominal sleepiness associations.

CONCLUSIONS

We identified methylation sites in multiple genes possibly implicated in daytime sleepiness. Most significant DNAm-ESS associations were specific to AA. Future work is needed to identify mechanisms driving ancestry-specific methylation effects.

Hypersomnia and Bipolar Disorder: A systematic review and meta-analysis of proportion

BACKGROUND

Hypersomnia is a common problem amongst individuals with Bipolar Disorder (BD). The objective of this meta-analysis is to estimate the frequency of hypersomnia in individuals with BD, and identify associated factors METHODS: Our search focused on articles documenting the frequency of hypersomnia among individuals with BD indexed in PubMed database and in the Cochrane Library, following the recommendations from the Meta-Analysis Of Observational Studies in Epidemiology (MOOSE) Group. A meta-analysis of proportion was conducted; funnel plot and Egger's test were used for the assessment of publication bias. Subgroups analyses were performed in order to evaluate possible confounders and associated factors.

RESULTS

We identified 10 studies, which included 1824 patients with BD. The overall estimate of the proportion of BD cases that reported hypersomnia was 29.9% [95% confidence interval (CI): 25.8 - 34.1%, I² = 59.2%; p < .05]. The funnel plot and the Egger's test suggest a low risk of publication bias (p = .527). The polarity of mood state, Bipolar Disorder type, use of medication, age, diagnostic criteria and hypersomnia criteria were not significantly related to hypersomnia.

LIMITATIONS

There is a possibility that smaller cross-sectional studies were not included. The high heterogeneity between studies is frequent in meta-analysis of both interventional and observational studies. Hypersomnia was not the primary outcome in some of the included studies.

CONCLUSIONS

To our knowledge, this is the first systematic review and meta-analysis of hypersomnia prevalence in patients with BD. Further studies focused on clinical correlates and implications for health outcomes in BD are warranted.

How Well Do Children Understand the Vocabulary of Sleep?

BACKGROUND

Sleep surveys, such as the Pediatric Daytime Sleepiness Scale (PDSS), are used to determine a variety of concerns associated with sleep, including excessive daytime sleepiness (hypersomnolence), bedtime sleep behaviors, night awakenings, sleep duration, and sleep-disordered breathing. However, the literacy ability of the patient may not be adequate to ensure comprehension of questions and provision of accurate responses.

OBJECTIVE

To assess children's understanding of the sleep-associated vocabulary included in the PDSS.

METHODS

A cross-sectional, open-response survey was developed for use with students age 4 to 12 years. Prior to completing the instrument, each student was asked the meaning of six key sleep-related words used in the PDSS: drowsy, sleepy, alert, awakened, tired, and awake. The parents/caregivers were requested to record their child's definitions of these key words exactly as stated. Identification of words for "suitable" definitions was undertaken through consultation of three online dictionaries. This enabled the qualitative process associated with open-response surveys to be followed: identification of common themes, chunking of information, and criteria for coding responses. The final sample consisted of word definitions from 325 students (152 boys and 173 girls) from a school enrollment of 727 (45%).

KEY RESULTS

A high percentage of children provided "suitable" responses for the words sleepy (84%) and tired (75%). The percentage of "suitable" responses for the words drowsy and awakened gradually increased across the age groups. The words alert and awake were challenging for the children to define, with the sleep-associated definition for alert only being provided by 31% of children overall and awake only being provided by 48% overall. In total, 57% of children were able to provide suitable definitions for at least four words.

CONCLUSIONS

Our findings suggest that the results of many sleep surveys using these terms may not yield results that accurately reflect a child's actual state of daytime sleepiness and sleep/wake behaviors. Prior to administering a sleep survey, physicians need to clearly explain the meanings of sleep-associated words used in the survey and thus gain a more accurate reflection of a child's sleep and daytime behaviors. [HLRP: Health Literacy Research and Practice. 2019;3(1):e53-e69.].

PLAIN LANGUAGE SUMMARY

Sleep surveys are used to identify problems with sleep. Children with poor health literacy due to age may not understand the questions and may not provide adequate answers. Children's understanding of sleep-associated vocabulary was assessed using six words: drowsy, sleepy, alert, awakened, tired, and awake. Many of these words were found to be difficult for the children to define.

The cholinergic system may play a role in the pathophysiology of residual excessive sleepiness in patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) is a prevalent condition characterized by momentary cessations in breathing during sleep due to intermittent obstruction of the upper airway. OSA has been frequently associated with a number of medical comorbidities. CPAP (continuous positive airway pressure) is the gold standard treatment and is known to improve OSA symptoms, including excessive sleepiness. However, 12-14% of CPAP-treated patients continue to complain of sleepiness despite normalization of ventilation during sleep, and 6% after exclusion of other causes of EDS. This is of great concern because EDS is strongly associated with systemic health disorders, lower work performance, and a high risk of accidents. We hypothesized that decreased central cholinergic activity plays a role in the pathophysiology of residual excessive sleepiness in patients with OSA treated with CPAP. Acetylcholine (Ach) plays a large role in wakefulness physiology, and its levels are reduced in sleepiness. Herein, we discuss the potential role of the cholinergic system in this new clinical condition.

Sleep-related collisions in United Arab Emirates

INTRODUCTION

Road traffic collisions (RTC) are a major health problem in UAE. Sleep as a contributing factor to RTC is not well-studied in the Middle East.

OBJECTIVE

We aimed to study to the proportion of RTC caused by sleep behind the wheel and the factors contributing to sleep related collisions (SRC).

METHODS

Data of all hospitalized drivers who were involved in RTC in Al-Ain city were prospectively collected during the period of April 2006-October 2007. Variables studied included, driver's demographic data, time, date, location, mechanism of collision, speed at collision and whether sleepiness was a contributing factor as reported by the drivers. A direct logistic regression model was performed to define factors related to sleep while driving.

RESULTS

444 drivers (92% males) were involved in RTC during the study period. Sleepiness of drivers was a contributing factor in 5%. Most of the drivers experiencing SRC (79%) reported speeds of 100km/h or more during the collision. SRC was strongly over-represented during the month of Ramadan (42%) and in driving on highways (83%). A logistic regression model has shown that driving during the lunar month of Ramadan (p<0.0001, OR=6.36) and on highways (p=0.037, OR=3.75) were the most significant independent contributors to increasing the odds of SRC.

CONCLUSION

Sleep is an important contributing factor to RTC in UAE. Drivers should be advised to discontinue driving when feeling sleepy especially during the lunar month of Ramadan and while driving on highways.

The association between sleep problems and perceived health status: a Japanese nationwide general population survey

OBJECTIVE

Sleep problems in humans have been reported to impact seriously on daily function and to have a close association with well-being. To examine the effects of individual sleep problems on physical and mental health, we conducted a nationwide epidemiological survey and examined the associations between sleep problems and perceived health status.

METHODS

Cross-sectional surveys with a face-to-face interview were conducted in August and September, 2009, as part of the Nihon University Sleep and Mental Health Epidemiology Project (NUSMEP). Data from 2559 people aged 20 years or older were analyzed (response rate 54.0%). Participants completed a questionnaire on perceived physical and mental health statuses, and sleep problems including the presence or absence of insomnia symptoms (i.e., difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], and early morning awakening [EMA]), excessive daytime sleepiness (EDS), poor sleep quality (PSQ), short sleep duration (SSD), and long sleep duration (LSD).

RESULTS

The prevalence of DIS, DMS, and EMA was 14.9%, 26.6%, and 11.7%, respectively, and 32.7% of the sample reported at least one of them. At the complaint level, the prevalence of EDS, PSQ, SSD, and LSD was 1.4%, 21.7%, 4.0%, and 3.2%, respectively. Multiple logistic regression analyses revealed that DMS, PSQ, SSD, and LSD were independently associated with poor perceived physical health status; DIS, EDS, and PSQ were independently associated with poor perceived mental health status.

CONCLUSIONS

This study has demonstrated that sleep problems have individual significance with regard to perceived physical or mental health status.