Epidemiology of insomnia in korean adults: prevalence and associated factors

Elevated prevalence and treatment of sleep disorders from 2011 to 2020: a nationwide population-based retrospective cohort study in Korea

OBJECTIVES

This study used National Health Insurance claims data from Korea to report the prevalence of sleep disorders and treatment status, including traditional Korean medicine, in the last 10 years.

METHODS

This is a retrospective cohort study in Korea. All diagnosis and prescription data, including herbal medicine claims, from the Health Insurance Review and Assessment Service from 2011 to 2020 were reviewed. Prevalence estimation, direct medical expenses and prescribed amounts for sleep disorders were recorded.

RESULTS

The prevalence of sleep disorders increased from 3 867 975 (7.62%) in 2011 to 7 446 846 (14.41%) in 2020, nearly doubling over 10 years. Insomnia was observed in 91.44% (n=9 011 692) of the patients. The mean number of hospital visits per patient for sleep disorders was 11.5 (±26.62). Benzodiazepines are the most commonly prescribed medications for sleep disorders, and gamma-isoyosan is the most frequently prescribed herbal medicine.

CONCLUSIONS

Sleep disorders are continuously increasing, as is the use of medical services-personal and social medical expenses are also increasing accordingly. Sleep disorders should be recognised as a significant health problem that needs to be actively addressed to improve quality of life.

Insomnia during coronavirus disease 2019 pandemic in Korea: a National sleep survey

Coronavirus disease 2019 (COVID-19) pandemic has caused widespread increase in stress and affected sleep quality and quantity, with up to 30% prevalence of sleep disorders being reported after the declaration of the pandemic. This study aimed to assess perceived changes due to the pandemic in the prevalence of insomnia and excessive daytime sleepiness (EDS) in Korea, and identify the associated factors. An online survey was conducted among 4000 participants (2035 men and 1965 women) aged 20-69 years enrolled using stratified multistage random sampling according to age, sex, and residential area, between January, 2021 and February, 2022. The questionnaire included various items, such as socio-demographics, Insomnia Severity Index, and Epworth Sleepiness Scale (ESS). Insomnia was defined as difficulty falling asleep and difficulty maintaining sleep more than twice a week. EDS was classified as an ESS score ≥ 11. Insomnia was reported by 32.9% (n = 1316) of the participants (37.3% among women and 28.6% among men). Multivariate logistic regression revealed that insomnia was associated with female sex [odds ratio (OR) = 1.526, 95% confidence interval (CI) = 1.297-1.796], night workers (OR 1.561, 95% CI 1.160-2.101), and being unmarried (OR 1.256, 95% CI 1.007-1.566). EDS was reported by 12.8% (n = 510) of the participants (14.7% among men and 10.7% among women). EDS was associated with male sex (OR 1.333, 95% CI 1.062-1.674), and being employed (OR 1.292, 95% CI 1.017-1.641). During the COVID-19 pandemic, the prevalence of insomnia increased in Korea, while there was no significant change in EDS compared with pre-pandemic evidence.

Association between discrimination in the workplace and insomnia symptoms

Background

In Korea, little research has focused on the relationship between discrimination in the workplace and sleep health. Thus, this study aims to investigate the association between such discriminatory experiences and insomnia, a common sleep disorder, using Korean employees' data.

Methods

This study used data from the 6th Korea Working Conditions Survey. Discrimination experiences due to age, ethnic background, nationality, race, sex, religion, disability, sexual orientation, educational level, hometown, and employment status were investigated. The Minimal Insomnia Symptom Scale estimated insomnia symptoms. The association between discrimination experience and insomnia symptoms were analyzed using survey-weighted logistic regression analysis.

Results

Based on experiences of discrimination over the past 12 months, insomnia symptoms were associated with discrimination experience due to religion (odds ratio [OR]: 3.70; 95% confidential interval [CI]: 1.58-8.69), sex (OR: 2.51; 95% CI: 1.87-3.37), age (OR: 2.30; 95% CI: 1.88-2.81), hometown (OR: 2.07; 95% CI: 1.44-2.97), employment status (OR: 1.69; 95% CI: 1.37-2.10), and educational level (OR: 1.67; 95% CI: 1.31-2.14). Furthermore, the prevalence of insomnia symptoms increased with the number of discrimination experiences.

Conclusions

In this study, discrimination experiences due to religion, sex, age, hometown, employment status, and educational level were significantly associated with insomnia symptoms. Furthermore, as the number of discrimination experiences increased, so did the prevalence of insomnia. Preventing workplace discrimination may improve workers' sleep health.

Association between Occupational Noise Exposure and Insomnia among Night-Shift Production Workers: A 4-Year Follow-up Study

Objectives

This study aimed to investigate whether occupational noise exposure is a risk factor for insomnia among male night-shift production workers.

Methods

This study followed 623 male night-shift production workers at a tire manufacturing factory without insomnia for 4 years. Insomnia was evaluated based on the insomnia severity index at baseline and at 4-year follow-up. A score of ≥15 was defined as insomnia. The higher occupational noise exposure group was defined as those individuals exposed to 8-hour time-weighted-average noise above 80 dB (A).

Results

Participants' mean age was 46.3 ± 5.6 years. Of the 623 participants, 362 (58.1%) were in the higher occupational noise exposure group. At 4-year follow-up, insomnia occurred in 3.2% (n = 20) of the participants. In a multiple logistic regression analysis, the odds ratio of insomnia was 3.36 (95% confidence interval 1.083-10.405, P = 0.036) in the higher occupational noise exposure group when compared with the lower noise exposure group after adjusting for confounders.

Conclusion

Our findings suggested that occupational noise exposure affected insomnia in male night-shift production workers. To prevent insomnia, efforts are required to reduce workplace noise exposure levels. Alternatively, moving to a less noisy work environment should be considered for workers with severe insomnia.

A novel sleep aid device to reduce sleep latency using air-CO2 mixed gas

Introduction

Sleep is an indispensable component of human life. However, in modern times, the number of people suffering from sleep disorders, such as insomnia and sleep deprivation, has increased significantly. Therefore, to alleviate the discomfort to the patient due to lack of sleep, sleeping pills and various sleep aids are being introduced and used. However, sleeping drugs are prescribed only to a limited extent due to the side effects posed by them and resistance to such drugs developed by patients in the long term, and the majority of sleep aids are scientifically groundless products. This study aimed to develop a device that induced sleep by spraying a mixed gas of carbon dioxide and air to create an environment that could induce sleep, similar to the inside of a sealed vehicle, to control oxygen saturation in the body.

Methods

Based on the stipulated safety standards and the human tidal volume, the target concentration of carbon dioxide was determined to be of three types: 15,000, 20,000, and 25,000 ppm. After analyzing diverse structures for safely mixing gases, the most appropriate shape, the reserve tank, was selected as the best suited structure. Various variables, such as spraying angle and distance, flow rate, atmospheric temperature, and nozzle length, were comprehensively measured and tested. Furthermore based on this aspect, diffusion simulation of carbon dioxide concentration and actual experiments were conducted. To secure the stability and reliability of the developed product, an accredited test was performed to investigate the error rate of carbon dioxide concentration. Furthermore, clinical trials comprising polysomnography and questionnaires confirmed the effectiveness of the developed product not only in reducing sleep latency but also in enhancing the overall sleep quality.

Results

When the developed device was put to use in reality, sleep latency was decreased by 29.01%, on average, for those with a sleep latency of 5 min or more, compared to when the device was not in use. Moreover, the total sleep time was increased by 29.19 min, WASO was decreased by 13.17%, and sleep efficiency was increased by 5.48%. We also affirmed that the ODI and 90% ODI did not decrease when the device was used. Although different questions may be raised about the safety of using a gas such as carbon dioxide (CO₂), the result that tODI was not reduced shows that sleep aids using CO₂ mixtures do not adversely affect human health.

Discussion

The results of this study suggest a new method that can be used to treat sleep disorders including insomnia.

Mediation effect of insomnia symptoms between positive psychotic like experiences and suicidal ideation among Lebanese young adults

BACKGROUND

Psychotic symptoms reported by healthy individuals in the general population are referred to as psychotic-like experiences (PLEs) and have been proven to increase the risk of suicidal ideation (SI) in these individuals. As it is well established that PLEs and insomnia share a bidirectional association and also that insomnia is linked to SI, we hypothesized that insomnia may represent a mediator underlying the relationship between PLEs and SI. Our aim was to validate this hypothesis among Lebanese young adults.

METHODS

A total of 3103 young adults (mean age 21.73 ± 3.80 years; 63.6% females) recruited from all Lebanese governorates completed a self-administered online questionnaire. PLEs were assessed using the CAPE-42 scale, SI using the Columbia Suicide Rating Scale, and insomnia using the Insomnia Severity Index). We conducted a mediation analysis using SPSS PROCESS v3.4 model 4 with three pathways. Variables that showed a p < 0.25 in the bivariate analysis were entered in the path analysis.

RESULTS

A total of 1378 participants (44.4%) had insomnia; 18.8% had SI; 42.5% reported at least one positive PE 'nearly always', and 30.5% reported at least one negative PE with this frequency. The results of the mediation analysis showed that insomnia severity partially mediated the association between positive dimension and SI; higher positive dimension was significantly associated with more insomnia severity, which was, in turn, significantly associated with more SI. Finally, more positive dimension was significantly and directly associated with more SI.

CONCLUSION

These preliminary findings might encourage the implementation of new preventive measures to reduce SI among PLEs patients. Treating symptoms of insomnia might help reduce the risk of suicide.

Improving mental health and daytime function in adult insomnia patients predict cognitive behavioral therapy for insomnia effectiveness: A case-control study

Objective

This study investigated demographic, sleep related symptoms and mental health status as predictors of clinically significant treatment responses to cognitive behavioral therapy in adults who have good adherence for the cognitive behavioral therapy for insomnia (CBT-I) program in primary insomnia.

Methods

A total of 42 adults with primary insomnia disorder were treated with CBT-I at a university hospital from June 2020 to January 2021. Demographic variables were surveyed and sleep-related symptoms were measured using self-reported questionnaires before and after the intervention, comprising a 6-week interval. The treatment responder group was defined as patients with an Insomnia Severity Index change score >7 compared to baseline. Logistic regression and paired t-test examined whether these factors predicted treatment outcomes for CBT-I.

Results

Demographic variables did not predict treatment outcomes. Higher levels of anxiety were associated with a higher likelihood of treatment response (odds ratio [OR] = 1.234; confidence interval [CI]: 1.008-1.511). More severe insomnia at baseline was associated with a greater likelihood of treatment response (OR = 1.450; CI: 1.121-1.875). The lesser the dysfunctional beliefs and attitudes about sleep, the more effective the treatment response (OR = 0.943; CI: 0.904-0.984). Unlike the group of treatment responders, daytime function, depressive mood, and anxiety status did not improve in the group of treatment non-responders after CBT-I intervention.

Conclusions

Patients with severe insomnia and anxiety at baseline should be treated more aggressively with CBT-I. During treatment, patients' mental health problems and daytime activities should be continuously monitored, in order to help improve these problems which might strengthen the effectiveness of CBT-I.

Socioeconomic status and sleep health: a narrative synthesis of 3 decades of empirical research

STUDY OBJECTIVES

This review aims to assess the association between socioeconomic status (SES) and sleep health in the general population and the mediating effects of lifestyle and mental and physical health in this relationship.

METHODS

Observational studies testing the independent association between objective or subjective SES indicators and behavioral/physiological or clinical sleep health variables in the general population were included. PubMed/MEDLINE was searched for reports published from January 1990 to December 2019. The direction of effect was used as the primary effect measure, testing the hypothesis that low SES is associated with poor sleep health outcomes. Results are presented in the form of direction effect plots and synthesized as binomial proportions.

RESULTS

Overall, 336 studies were identified. A high proportion of effects at the expected direction was noted for measures of sleep continuity (100% for sleep latency, 50-100% for awakenings, 66.7-100% for sleep efficiency), symptoms of disturbed sleep (75-94.1% for insomnia, 66.7-100% for sleep-disordered breathing, 60-100% for hypersomnia), and general sleep satisfaction (62.5-100%), while the effect on sleep duration was inconsistent and depended on the specific SES variable (92.3% for subjective SES, 31.7% for employment status). Lifestyle habits, chronic illnesses, and psychological factors were identified as key mediators of the SES-sleep relationship.

CONCLUSIONS

Unhealthy behaviors, increased stress levels, and limited access to health care in low-SES individuals may explain the SES-sleep health gradient. However, the cross-sectional design of most studies and the high heterogeneity in employed measures of SES and sleep limit the quality of evidence. Further research is warranted due to important implications for health issues and policy changes.

CITATION

Papadopoulos D, Etindele Sosso FA. Socioeconomic status and sleep health: a narrative synthesis of 3 decades of empirical research. J Clin Sleep Med. 2023;19(3):605-620.

Insomnia is a key risk factor for persistent anxiety and depressive symptoms: A 12-month longitudinal cohort study during the COVID-19 pandemic

BACKGROUND

Insomnia is a risk factor for affective disorders. This study examined whether individuals with insomnia symptoms early in the pandemic, either pre-existing or new-onset, were more vulnerable to anxiety and depressive symptoms over time than those who maintained normal sleep. Additionally, sleep-related factors such as pre-sleep arousal were assessed for their influence on clinically significant anxiety and depression risk.

METHODS

Using a global online survey with 3-, 6-, and 12-month follow-ups between April 2020 and May 2021, data from 2069 participants (M = 46.16 ± 13.42 years; 75.3 % female) with pre-existing, new-onset, or no insomnia symptoms was examined using mixed-effects and logistic regression models.

RESULTS

New-onset and pre-existing insomnia predicted persistent anxiety and depressive symptoms longitudinally (p's < 0.001), over other known risk factors, including age, sex, and previous psychiatric diagnoses. Anxiety and depressive symptoms in both insomnia groups remained above clinically significant thresholds at most time points, whereas normal sleepers remained subclinical. Pre-sleep arousal was found to increase the risk of clinically significant anxiety (OR = 1.05) and depressive symptoms (OR = 1.09) at 12-months. Sleep effort contributed to anxiety (OR = 1.06), whereas dysfunctional sleep-related beliefs and attitudes predicted clinically significant depression (OR = 1.22).

LIMITATIONS

Insomnia group categorization was based on self-report at baseline supported by a validated measure. High participant attrition was observed at 3-months (53 %; n = 971), but retention remained steady till 12-months (63 %, n = 779).

CONCLUSIONS

Insomnia is a modifiable risk factor for persistent anxiety and depressive symptoms that needs to be addressed in mental healthcare. Additionally, pre-sleep arousal may be an important transdiagnostic process linking insomnia with affective disorders.

Sleep state of the elderly population in Korea: Nationwide cross-sectional population-based study

Objective

Interest in sleep disorders among the elderly, especially those in Korea, has increased. We aimed to describe the overall sleep status of the elderly population in Korea using survey data and to determine the risk factors concerning different aspects of sleep status.

Methods

We conducted a cross-sectional survey on 271 respondents aged 65-86 years old. We performed multistage clustered random sampling according to the population and socioeconomic distribution of all Korean territories. The survey questionnaire was used to perform a structural assessment of sociodemographic characteristics; medical comorbidities; psychiatric comorbidities; and sleep status, including sleep duration, sleep quality, presence of insomnia, excessive daytime sleepiness, sleep apnea, and restless legs syndrome.

Results

Approximately 12.5, 22.%, and 51.3% of the elderly population had poor sleep quality, excessive daytime sleepiness, and insomnia, respectively. Hypertension, dyslipidemia, insomnia, anxiety, and depression predicted poor sleep quality. Female sex, insomnia, and sleep apnea predicted excessive daytime sleepiness. Poor sleep quality and depression predicted insomnia.

Conclusion

A substantial proportion of the elderly Korean population have sleep problems, including poor sleep quality, excessive daytime sleepiness, and insomnia. Sleep status is influenced by various factors, including age, sex, and metabolic and psychiatric comorbidities.

Pharmacopuncture Effects on Insomnia Disorder: Protocol for a Multi-Site, Randomized, Acupuncture-Controlled, Clinical Trial

Insomnia is a common health problem that can lead to various diseases and negatively impact quality of life. Pharmacopuncture is a new type of acupuncture that involves applying herbal medicine extracts to acupoints. Korean medicine doctors frequently use it to treat insomnia disorder. However, there is insufficient evidence to support the effectiveness and safety of pharmacopuncture for insomnia disorder. We designed a pragmatic randomized controlled trial to compare the effectiveness of pharmacopuncture and acupuncture for insomnia disorder. This multi-site, randomized, acupuncture-controlled trial will enroll 138 insomnia patients. The subjects will be randomly assigned to one of two groups, pharmacopuncture or acupuncture, at a 2:1 ratio. For 4 weeks, the participants will receive ten sessions of pharmacopuncture or acupuncture treatment and will be followed up for 4 weeks after the treatment ends. The Pittsburgh Sleep Quality Index score is the primary outcome measure. Insomnia severity index score, sleep parameters recorded using actigraphy and sleep diaries, physical symptoms associated with insomnia, emotions, quality of life, medical costs, and safety are the secondary outcome measures. The findings of this trial willprovide evidence that will be useful in clinical decision-making for insomnia treatment strategies.

Melatonin and melatonergic drugs in sleep disorders

Melatonin is an endogenous chronobiological regulator secreted mainly from the pineal gland, which has been used as a dietary supplement in the treatment of sleep problems, including insomnia, parasomnia, and circadian rhythm sleep disorders. However, the short half-life and rapid metabolism of melatonin limit its suitability as a drug. There are many melatonergic drugs used in the treatment of sleep disorders and several drugs are under investigation for approval. Ramelteon was the first melatonergic agonist approved as hypnotic agent by U.S. Food and Drug Administration for the treatment of insomnia. It exhibits higher selective affinity for melatonin 1a (MT₁) receptor than melatonin 1b (MT₂) receptor. This selectivity suggests that it targets sleep onset with no significant adverse effect or dependency. Agomelatin, naphtahalenic compound, act as a potent MT₁/MT₂ melatonergic receptor agonist and serotonergic receptor antagonist was approved for treatment of depression in 2009. This dual action drug is the first melatonergic agent used in depression. Another melatonergic agonist, tasimelteon has high affinity for the MT₁/MT₂ receptors in humans. It was approved for the treatment of non-24 hours sleep-wake rhythm disorder. The newly developed melatonin and melatonergic drugs have the potential to be used extensively in various clinical situations and substitute the old benzodiazepine and its derivatives in the treatment of insomnia. However, the efficacy and safety of newly developed melatonergic drugs should be elucidated through long-term clinical trials.

Sleep-related healthcare use prevalence among adults with insomnia symptoms in Hebei, China: a population-based cross-sectional study

OBJECTIVE

This study investigated the prevalence of sleep-related healthcare use and the factors associated with it among adults with different insomnia symptoms.

DESIGN AND SETTING

This was a population-based study with a cross-sectional design conducted in Hebei province, China.

PARTICIPANTS

Participants were community residents aged 18 years and above; a total of 21 376 valid questionnaires were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

The Athens Insomnia Scale (AIS) was used to evaluate participants' insomnia symptoms. Variables such as sleep-related healthcare use, chronic disease, living alone and sociodemographics were assessed for all the participants.

RESULTS

Among adults with any insomnia symptoms, only 2.1% used sleep-related healthcare in the past year. Even for adults with insomnia, the prevalence of sleep-related healthcare use was only 6.2%. Furthermore, the prevalence rates of sleep-related healthcare use among adults with sleep induction, night awakenings, earlier awakening, sleep duration, sleep quality, daytime well-being, daytime functioning, and daytime sleepiness were 3.1%, 2.9%, 3.6%, 3.4%, 3.9%, 4.9%, 4.6% and 2.8%, respectively. The following factors were associated with sleep-related healthcare use among adults with insomnia: male (adjusted OR (aOR)=0.52, p<0.01), younger age (aOR=1.02, p<0.01), rural region (aOR=0.45, p<0.001) and AIS score (aOR=1.23, p<0.001). The same factors were also associated with sleep-related healthcare use among adults with insomnia symptoms.

CONCLUSIONS

The prevalence of sleep-related healthcare use among adults with insomnia symptoms is very low. Young men from rural areas with insomnia symptoms tend not to use healthcare. As such, it is necessary to form policies and strategies to promote sleep-related healthcare use among rural young men with insomnia symptoms.

The Combination of Sleep Disorders and Depression Significantly Increases Cancer Risk: A Nationwide Large-Scale Population-Based Study

Introduction: Sleep disorders, depression, and cancer have become increasingly prevalent worldwide. However, it is unknown whether coexistence of sleep disorders and depression influences the risk of cancer development. Therefore, we conducted a nationwide population-based study to examine this association among patients in Taiwan. Materials and Methods: A total of 105,071 individuals diagnosed with cancer and 420,284 age- and sex-matched patients without a diagnosis of cancer between 2000 and 2015 were identified from Taiwan’s National Health Insurance Research Database. The underlying chronic diseases of patients that may developed cancer were gathered and studied as the predictor. A multivariate Cox proportional odds model was used to estimate the crude and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) to estimate the interaction effect between sleep disorders and depression on the risk of cancer. Results: After adjusting for age, sex, comorbidities, and other covariates, the cancer group was associated with increased exposure to sleep disorders than the non-cancer group (aOR = 1.440, 95% CI = 1.392−1.489, p < 0.001). In addition, patients with both sleep disorders and depression were at an even higher risk for cancer than the general population (aOR = 6.857, p < 0.001). Conclusions: This retrospective cohort study shows that patients with both sleep disorders and depression are at a higher risk of cancer. Clinically, a meticulous cancer risk evaluation is recommended for patients with both sleep disorders and depression.

Mediation Effect of Insomnia Symptoms on Relation Between Stress and Quality of Life

OBJECTIVE

Among various causes of insomnia, stress is the most common and representative cause. Insomnia is also known to negatively affect the quality of life (QoL). The objective of this study was to explore the effect of stress on QoL and the mediating role of insomnia symptoms in the relationship between stress and QoL.

METHODS

In this study, the mediating effect of insomnia symptoms on the relationship between stress and QoL was analyzed by enrolling 3,714 participants from the Ansung and Ansan cohorts of the Korea Association Resource project from 2001 to 2004. These cohort participants were asked about how much they felt stressed during their everyday life. Insomnia symptoms were evaluated by asking participants whether they had trouble sleeping such as difficulty in falling asleep, disrupted sleep, and early morning awakening due to the lack of a validated questionnaire for this cohort. QoL was evaluated using the World Health Organization QoL Scale Brief Version.

RESULTS

In total, stress was positively associated with insomnia symptoms, which in turn predicted QoL. The same result could be derived from subgroup analysis according to sex, and it was confirmed that insomnia symptoms acted as a mediating factor more significantly in female than in male.

CONCLUSION

In this study, insomnia symptoms were confirmed to act as a significant mediating factor between stress and QoL, suggesting that insomnia symptoms should be actively identified and controlled to alleviate the negative effect of stress on QoL in clinical practice.

A Randomized Controlled Trial Comparing Neurofeedback and Cognitive-Behavioral Therapy for Insomnia Patients: Pilot Study

Insomnia is a common disease that negatively affects patients both mentally and physically. While insomnia disorder is mainly characterized by hyperarousal, a few studies that have directly intervened with cortical arousal. This study was conducted to investigate the effect of a neurofeedback protocol for reducing cortical arousal on insomnia compared to cognitive-behavioral treatment for insomnia (CBT-I). Seventeen adults with insomnia, free of other psychiatric illnesses, were randomly assigned to neurofeedback or CBT-I. All participants completed questionnaires on insomnia [Insomnia Severity Index (ISI)], sleep quality [Pittsburgh Sleep Quality Index (PSQI)], and dysfunctional cognition [Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-16)]. The neurofeedback group showed decreases in beta waves and increases in theta and alpha waves in various areas of the electroencephalogram (EEG), indicating lowered cortical arousal. The ISI and PSQI scores were significantly decreased, and sleep efficiency and sleep satisfaction were increased compared to the pre-treatment scores in both groups. DBAS scores decreased only in the CBT-I group (NF p = 0.173; CBT-I p = 0.012). This study confirmed that neurofeedback training could alleviate the symptoms of insomnia by reducing cortical hyperarousal in patients, despite the limited effect in reducing cognitive dysfunction compared to CBT-I.

External Auditory Stimulation as a Non-Pharmacological Sleep Aid

The increased demand for well-being has fueled interest in sleep. Research in technology for monitoring sleep ranges from sleep efficiency and sleep stage analysis to sleep disorder detection, centering on wearable devices such as fitness bands, and some techniques have been commercialized and are available to consumers. Recently, as interest in digital therapeutics has increased, the field of sleep engineering demands a technology that helps people obtain quality sleep that goes beyond the level of monitoring. In particular, interest in sleep aids for people with or without insomnia but who cannot fall asleep easily at night is increasing. In this review, we discuss experiments that have tested the sleep-inducing effects of various auditory stimuli currently used for sleep-inducing purposes. The auditory stimulations were divided into (1) colored noises such as white noise and pink noise, (2) autonomous sensory meridian response sounds such as natural sounds such as rain and firewood burning, sounds of whispers, or rubbing various objects with a brush, and (3) classical music or a preferred type of music. For now, the current clinical method of receiving drugs or cognitive behavioral therapy to induce sleep is expected to dominate. However, it is anticipated that devices or applications with proven ability to induce sleep clinically will begin to appear outside the hospital environment in everyday life.

The association between laryngopharyngeal reflux and insomnia

OBJECTIVES

To evaluate the prevalence of insomnia in patients with laryngopharyngeal reflux (LPR) and to analyze the relationship between the severity of insomnia and LPR-related symptoms.

METHODS

We analyzed 69 patients with LPR and 61 healthy controls. The LPR was confirmed via the 24-h hypopharyngeal-esophageal multichannel intraluminal impedance pH monitoring. Reflux symptoms and sleep disturbances were assessed using the Reflux Symptom Index and Insomnia Severity Index. We compared the prevalence of insomnia between the two groups. We analyzed the relationship between reflux symptoms and severity of insomnia.

RESULTS

The prevalence of insomnia was significantly higher in patients with LPR than in healthy controls (46.3% vs. 29.5%; p = 0.049). The severity of reflux-related symptoms was correlated with insomnia severity (rho = 0.44; p < 0.001). Patients with LPR with nighttime reflux were more likely to have sleep disturbances than patients with LPR without nighttime reflux.

CONCLUSION

Patients with LPR are more likely to experience insomnia than healthy controls, and the severity of reflux symptoms was related to the severity of insomnia.

Association between insomnia and constipation: A multicenter 3-year cross-sectional study using shift workers’ health check-up data

Background

Although insomnia and constipation are highly prevalent worldwide, studies examining a possible association between them are lacking. We examined the relationship between insomnia and constipation in shift workers who have a high prevalence of insomnia and other diseases.

Methods

This study had a multicenter cross-sectional design and conducted using health examination data including self-reported questionnaires. In total, 12,879 and 4,650 shift workers were enrolled in Severance Hospital and Wonju Severance Hospital, respectively, during 2015-2017. Multivariate logistic regression models and subgroup analysis were performed in each center with the same protocol, using a common data model.

Results

The mean age of the total population was 44.35 (standard deviation = 8.75); the proportion of males was 56.9%. Female sex, being underweight and non-smoker were strongly associated with an increased risk of constipation symptom (p < 0.001). Pooled odds ratios (ORs) were calculated using ORs of both centers with weights; there was a significant dose–response relationship (sub-threshold 1.76 [95% confidence interval [CI] 1.62–1.91]; moderate 2.28 [95% CI 2.01–2.60]; severe 4.15 [95% CI 3.18–5.41] in the final model, p for trend < 0.001). Subgroup analysis performed by stratifying sex and pooled ORs showed a similar trend to that of the entire group.

Conclusion

We observed a strong correlation between insomnia and constipation in this population. Our findings may help in formulating guidelines and policies to improve quality of life in shift workers through the management of sleep quality and proper bowel function. This study is the first to report this relationship among people working in shifts.

Analysis of Medical Services for Insomnia in Korea: A Retrospective, Cross-Sectional Study Using the Health Insurance Review and Assessment Claims Data

This study aimed to analyze current trends in healthcare utilization and medication usage in patients with insomnia. We reviewed the National Patient Sample data from the Health Insurance Review and Assessment Service to determine healthcare utilization in patients diagnosed with insomnia (International Classification of Diseases-10 codes G470, F510) between January 2010 and December 2016. There were 87,470 patients enrolled in this study who utilized healthcare services at least once during the 7-year period. Healthcare utilization trends, Korean and Western medicine (KM and WM, respectively) therapies utilized, comorbidities, and socioeconomic data were analyzed. The number of patients seeking WM or KM care for insomnia increased annually. Adults aged ≥45 years accounted for 73% of the cohort, and there were more female than male patients. KM treatment including acupuncture was the most common in KM (65.29%), while examination was the most common WM treatments (49.31%). In pharmacological therapy, sedatives and hypnotics were the most common (41.08%), followed by antianxiety (19.50%), digestive system and metabolism-related drugs (7.77%). The most common comorbidities were mental health disorders (50.56%) in WM but musculoskeletal disorders in KM (35.67%). Code G470 was used more frequently than code F510, and the difference was more evident in KM than in WM. The findings will provide valuable information for both clinicians and researchers.

Impact of Insomnia Symptoms on the Clinical Presentation of Depressive Symptoms: A Cross-Sectional Population Study

Objective: Insomnia and depression are prevalent disorders that often co-occur. This study aimed to investigate the impact of clinically significant insomnia symptoms on the prevalence and clinical presentation of clinically significant depressive symptoms and vice versa. Methods: This study used data from the Korean Headache-Sleep Study (KHSS), a nationwide cross-sectional population-based survey regarding headache and sleep. Clinically significant insomnia symptoms were defined as Insomnia Severity Index (ISI) scores ≥ 10 and clinically significant depressive symptoms were defined as Patient Health Questionnaire-9 (PHQ-9) scores ≥ 10, respectively. We referred clinically significant insomnia symptoms and clinically significant depressive symptoms as insomnia symptoms and depressive symptoms, respectively. Results: Of 2,695 participants, 290 (10.8%) and 116 (4.3%) were classified as having insomnia and depressive symptoms, respectively. The prevalence of depressive symptoms was higher among participants with insomnia symptoms than in those without insomnia symptoms (25.9 vs. 1.7%, respectively, P < 0.001). Among participants with depressive symptoms, the PHQ-9 scores were not significantly different between participants with and without insomnia symptoms (P = 0.124). The prevalence of insomnia symptoms was significantly higher among participants with depressive symptoms than in those without depressive symptoms (64.7 vs. 8.3%, respectively, P < 0.001). The ISI scores were significantly higher among participants with insomnia and depressive symptoms than in participants with insomnia symptoms alone (P < 0.001). Conclusions: Participants with depressive symptoms had a higher risk of insomnia symptoms than did those without depressive symptoms. The severity of depressive symptoms did not significantly differ based on insomnia symptoms among participants with depressive symptoms; however, the severity of insomnia symptoms was significantly higher in participants with depressive symptoms than in those without depressive symptoms.

Association between socioeconomic status and longitudinal sleep quality patterns mediated by depressive symptoms

STUDY OBJECTIVES

We aimed to examine whether associations between socioeconomic status (SES) and longitudinal sleep quality patterns are mediated by depressive symptoms.

METHODS

We utilized data on 3347 participants in the Korean Genome and Epidemiology Study aged 40-69 years at baseline from 2001 to 2002 who were followed up for 16 years. A group-based modeling approach was used to identify sleep quality trajectories using the Pittsburgh Sleep Quality Index (years 2, 6, 8, 10, and 12). Educational attainment (college graduated or less), monthly household income (≥$2500 or less), and occupation (unemployed, manual labor, and professional labor) at baseline (year 0) were used for analyses. Depressive symptoms were assessed using Beck's Depression Inventory at year 4. Associations between SES and sleep quality patterns were examined using a multinomial logistic regression model. The mediation effect of depressive symptoms was further examined using PROC CAUSALMED.

RESULTS

We identified five distinct sleep quality trajectories: "normal-stable" (n = 1697), "moderate-stable" (n = 1157), "poor-stable" (n = 320), "developing to poor" (n = 84), and "severely poor-stable" (n = 89). Overall, associations between SES levels and longitudinal sleep patterns were not apparent after full adjustment for sociodemographic and lifestyle factors measured at baseline. Depressive symptoms, however, tended to fully mediate associations between SES levels and sleep quality patterns (odds ratio range for indirect effects of depressive symptoms: for education, 1.05-1.17; for income, 1.05-1.15).

CONCLUSION

A significant mediating role for depressive symptoms between SES levels and longitudinal sleep quality warrants consideration among mental healthcare professionals.

Prevalence of Insomnia in Various Industries and Associated Demographic Factors in Night-Shift Workers Using Workers' Specific Health Examination Data

This study aimed to investigate the prevalence of insomnia in various industries and the associated demographic factors. We searched the nationwide night-shift Workers’ Specific Health Examination (nsWSHE) data extracted in 2015 information on factors associated with insomnia, including sex, age, and the number of workers in the workplace. The prevalence of moderate insomnia in the total industry was 4.6%. Industries with a high prevalence of insomnia included the arts, sports, and recreation-related services industry, followed by the activities of household as employers industry, financial and insurance activities industry, human health and social welfare industry, and accommodation and food services activities industry. The prevalence of insomnia was higher in women. Age was a significant factor. In general, insomnia was highest among those aged ≥60 years. Insomnia was highest in small-sized companies with fewer than five employees compared to large enterprises with more than 1000 employees. This study is the first to analyze the prevalence of insomnia among night-shift workers who participated in the WSHEs. The findings of this study can be used to prioritize intervention policies for insomnia among night-shift workers.

The association between sleep quality and quality of life: a population-based study

OBJECTIVES

This study aimed to evaluate the association between sleep quality and quality of life (QoL).

METHODS

This cross-sectional study included 225,541 adults (101,133 men, 124,408 women) who participated in the 2018 Korean Community Health Survey. Multiple sociodemographic and psychosocial variables were evaluated and compared between participants with poor (n = 67,619) and good sleep quality (n = 157,922); sleep quality was subjectively determined using the Pittsburgh Sleep Quality Index (PSQI). The EuroQol five-dimension (EQ-5D) index scores were adjusted for multiple confounding factors and compared between the good and poor sleep quality groups. A logistic regression analysis was used to identify determinants of the lowest quartile of QoL.

RESULTS

The mean EQ-5D index scores were significantly lower in the poor sleep quality group (score 0.85) than in the good sleep quality group (score 0.92; p < 0.001). The multivariate odds ratio (OR) for the lowest quartile of the EQ-5D index scores in the poor sleep quality group versus that in the good sleep quality group was 1.95 (95% confidence interval [CI], 1.89-2.00). Participants with poor sleep quality were more likely than those with good sleep quality to have some or severe problems with physical activity (OR, 1.46; 95% CI, 1.41-1.51), self-control (OR, 1.35; 95% CI, 1.29-1.42), daily activity (OR, 1.44; 95% CI, 1.39-1.50), pain (OR, 1.81; 95% CI, 1.77-1.86), and anxiety/depression (OR, 2.24; 95% CI, 2.17-2.31).

CONCLUSION

Poor sleep quality is associated with impaired QoL, particularly if some or severe problems with anxiety/depression are present.

The Herbal Formula CWBSD Improves Sleep Quality Dependent on Oral Microbial Type and Tongue Diagnostic Features in Insomnia

Cheonwangbosim-dan (CWBSD) is a traditional Korean herb formula that has been widely prescribed for insomnia patients with a heart-yin deficiency (HYD) pattern. Several studies have reported that heart function and insomnia are interrelated, and few have explored associations between insomnia, oral microbiota, and tongue diagnosis. This study aimed to evaluate the effects of CWBSD on primary insomnia, tongue diagnosis, and oral microbiota. At baseline, 56 patients with primary insomnia were assigned to two groups, a HYD group and a non-HYD (NHYD) group and they took CWBSD for 6 weeks. During the study, Pittsburgh Sleep Quality Indices (PSQIs) and Insomnia Severity Indices (ISIs) decreased significantly in both groups. However, the PSQI reduction observed in the HYD group was greater than in the NHYD group and sleep times increased only in the HYD group. As sleep quality improved, the amount of tongue coating increased at the posterior tongue, where heart function appears. At baseline, the HYD and NHYD group had a specific oral microbiota (Veillonella at genus level), but no significant change was observed after taking CWBSD. Additionally, subjects were divided into two oral microbiota types ("orotypes"). The genera Prevotella, Veillonella, or Neisseria were abundant in each orotype. The reduction in PSQI in orotype 1 during the 6-week treatment period was greater than in orotype 2. In conclusion, this study shows that CWBSD could be used to treat primary insomnia in patients with a HYD pattern as determined using tongue diagnosis and oral microbiota distributional patterns.

Irregular Work Hours and the Risk of Sleep Disturbance Among Korean Service Workers Required to Suppress Emotion

Although a necessity in a modern society, irregular work schedule can lead to sleep problems. We investigated the effect of work schedule irregularity on sleep disturbance of 17,846 Korean service workers using the fifth Korean Working Conditions Survey. The odds ratio (OR) and 95% confidence interval (CI) for sleep disturbance occurrence were calculated through a multiple logistic regression model. The adjusted ORs for moderate and severe sleep disturbances for those with irregular work hours were 2.11 (95% CI 1.90–2.33) and 3.10 (95% CI 2.62–3.66), respectively. Work schedule irregularity and emotion suppression at work showed synergistic effect on both moderate and severe sleep disturbances. Sleep disturbances can lead to brain function deterioration and work-related injuries; therefore, appropriate measures should be addressed for the vulnerable population.

Worry and insomnia as risk factors for depression during initial stages of COVID-19 pandemic in India

The biggest nationwide COVID-19 pandemic lockdown worldwide was enforced in India for an initial period of 21-days. Emerging evidence suggests that pandemic situations and associated lockdowns have an adverse impact on sleep and mental health. However, prediction of sleep health from sociodemographic characteristics and the public’s worry during the initial stages of the COVID-19 pandemic has not been extensively explored so far. It’s also unclear whether sleep outcomes mediate the association between worry and mental health during pandemic situations. A web-survey (N = 391) on sociodemographic characteristics, COVID-19 related worry, sleep health (insomnia and daytime sleepiness), and depression was conducted during the initial 21-days of the COVID-19 stringent lockdown in India. Multiple regression analyses showed that variables, including sex, age, income level, and worry score, contributed to the significant regression equation for insomnia but not for daytime sleepiness. Specifically, the female, younger, lower income, and highly worried populations contributed significantly more than the male, elderly, higher income, and less worried populations, respectively, to the prediction of insomnia. Mediation analyses showed that insomnia, but not daytime sleepiness, fully mediated the relationship between worry score and severity of depressive symptoms. We provide evidence that the female, younger, lower income, and worried populations may be at higher risk for insomnia during pandemic situations. Current evidence gives hope that improving sleep may reduce depressive symptoms during a pandemic situation. This underscores the importance of the implementation of effective public health policies in conjunction with strategical responses to the COVID-19 pandemic.

Association of sleep duration and quality with elevated hs-CRP among healthy Korean adults

This study aimed to investigate the association of sleep duration and quality with high-sensitivity C-reactive protein (hs-CRP) among middle-aged and elderly Koreans. Among a total of 74,867 participants (25,069 men and 49,798 women) recruited for the Health Examinees (HEXA) study, adjusted geometric means of hs-CRP level were compared across categories of sleep duration (<6, 6–7, 8–9, and ≥10 hours) and sleep quality (difficulty in initiating sleep and maintaining sleep) using ANCOVA models. Odds ratios (ORs) and 95% confidence intervals (CIs) for elevated hs-CRP (>3 mg/L) associated with sleep characteristics were estimated using multivariable-adjusted logistic regression models. Men who slept ≥10 hours per day were significantly associated with elevated hs-CRP (OR = 1.47, 95% CI 1.11–1.95). Whereas in women, difficulty in initiating sleep (OR = 1.28, 95% CI 1.04–1.57 for “Always”), and maintaining sleep was significantly associated with elevated hs-CRP levels (OR = 1.13, 95% CI 1.02–1.26 for “Often”; OR = 1.11, 95% CI 0.97–1.28 for “Always”). Additionally, women who experienced poor sleep quality presented an elevated level of hs-CRP (OR = 1.13, 95% CI 1.03–1.23). Our findings suggest that excessive sleep duration and poor sleep quality are significantly associated with the elevated inflammatory marker, specifically hs-CRP. Further research is needed to examine the effect of sleep interventions focused on these factors.

The Prevalence and Incidence of Insomnia in Korea during 2005 to 2013

OBJECTIVE

The aim of this study was to estimate the progress of insomnia prevalence and incidence over the past several years. Also, this study compared survival rates between individuals with and without insomnia.

METHODS

The National Health Insurance Service-National Sample Cohort (NHIS-NSC) from 2002-2013 was used for this study. Prevalent cases of insomnia were defined using ICD-10 codes F51.0 or G47.0, or a prescription of sedatives. Cox's proportional hazard analysis was conducted to compare survival rates between insomnia patients and people without insomnia.

RESULTS

In 2013, there were 46,167 (5.78%) insomnia patients over 20 years old in this cohort. Insomnia was more common among women and the elderly. Annual incidence over the past several years remained steady but the prevalence increased. The survival of insomnia patients was lower than that of people without insomnia, and the hazard ratio for overall mortality was 1.702 (p<0.001).

CONCLUSION

This large-scale population-based cohort study provided current epidemiologic indicators of insomnia in the Korean general population.

Sleep Disturbance and Its Clinical Implication in Patients with Adult Spinal Deformity: Comparison with Lumbar Spinal Stenosis

Purpose

The purpose of this study was to investigate the prevalence of sleep disturbance and its clinical implication in patients with ASD.

Methods

A total of 44 patients with ASD and 137 patients with lumbar spinal stenosis (LSS) were enrolled in the study. Forty four patients were selected from the LSS group after propensity score matching. Global Pittsburgh Sleep Quality Index (PSQI) score, demographic data, visual analog scale (VAS) score for back and leg pain, Oswestry Disability Index (ODI), and EuroQol 5-dimension questionnaire (EQ-5D) were compared between both groups. Multiple regression analysis was performed with VAS for back pain as the dependent variable and age, sex, PSQI, and VAS for leg pain as the independent variables in the ASD group.

Results

33 (75.0%) and 32 (72.7%) patients were classified as poor sleepers in the ASD group and the LSS group, respectively. In the ASD group, the VAS score for back pain was 7.7 ± 1.7 in the poor sleeper group and 5.6 ± 2.2 in the nonpoor sleeper group. In the LSS group, poor sleep quality was associated with the ODI score, ODI score without a sleep component, and EQ-5D. The regression model for predicting VAS for back pain in the ASD group suggested that poor sleep quality and increased leg pain were associated with increased back pain.

Conclusions

Because sleep quality is a critical factor in augmenting back pain in patients with ASD, this study underlines the need to investigate sleep quality during the routine examination of patients with ASD.

Sleep Disturbance in Patients With Lumbar Spinal Stenosis: Association With Disability and Quality of Life

STUDY DESIGN

This was a cross-sectional cohort study.

OBJECTIVE

The objective of this study was to identify the prevalence of sleep disturbance in patients with symptomatic lumbar spinal stenosis (LSS) and to establish the relationship between sleep disturbance and both functional disability and health-related quality of life in patients with symptomatic LSS.

SUMMARY OF BACKGROUND DATA

Despite the possible association between LSS and poor sleep quality, there has been no study regarding the relationship between LSS and sleep disturbance.

MATERIALS AND METHODS

A total of 148 patients with LSS were divided into the poor sleeper and nonpoor sleeper groups according to Global Pittsburgh Sleep Quality Index (PSQI) score. Demographic data, Visual Analog Scale (VAS) score for back and leg pain, Oswestry Disability Index (ODI), and EuroQol 5-dimension questionnaire (EQ-5D) were compared between both groups. Multiple regression analysis was performed with ODI or ODI without sleep component as the dependent variable and age, sex, PSQI, VAS for back pain, VAS for leg pain as independent variables.

RESULTS

Of the 148 patients who participated in this study, 54 (36.5%) and 94 (63.5%) patients were classified into nonpoor sleeper and poor sleeper groups. Although there were no differences in demographic data or VAS for back or leg pain between the nonpoor sleeper and poor sleeper groups, poor sleepers demonstrated significantly higher ODI scores, and lower EQ-5D than nonpoor sleepers (P=0.003 and 0.004, respectively). There were significant correlations between the global PSQI score and both the ODI score and EQ-5D. Although the surgical treatment group showed significantly higher VAS for back pain, VAS for leg pain, ODI scores, and lower EQ-5D than the conservative treatment group, the ratio of poor to nonpoor sleepers was not different between both groups (P=0.733). In the surgical treatment group, the percent of poor sleeper decreased from 65.1% to 47.6% 6 months after surgery (P<0.001).

CONCLUSIONS

The present study demonstrated that 'poor sleep quality' is a prevalent condition (63.5%) in patients with symptomatic LSS. Poor sleep quality has an adverse effect on functional disability and health-related quality of life in symptomatic LSS patients.

Temporal association between zolpidem medication and the risk of suicide: A 12-year population-based, retrospective cohort study

There have been concerns about abuse and unnecessary chronic administration of zolpidem, and zolpidem's relation to suicide risk. To investigate the temporal association of zolpidem with the risk of suicide, we conducted a 12-year, population-based, retrospective cohort study on the National Health Insurance Service-National Sample Cohort (NHIS-NSC), South Korea. Data were collected from 2002 to 2013 from the NHIS-NSC, and data cleaning was performed for 1,125,691 subjects. Cox proportional hazards regression analysis was used to investigate the correlation over time between zolpidem medication and suicide. Over intervals commencing after 80 months of observation, the adjusted hazard ratio of suicides associated with the use of the zolpidem was 2.01 (95% CI: 1.58-2.56; p < 0.001). The mean cumulative number of days of zolpidem prescription was significantly longer in the suicide group than in the non-suicide group after log-transformation (p = 0.005). Cases of chronic use of zolpidem (over six months or one year) were significantly more common in the suicide group compared to the non-suicide group (p = 0.002 and 0.005, respectively). Subjects who received zolpidem medication had a significantly higher risk of suicide after at least 80 months of observation, suggesting a long-term increased suicide risk associated with insomnia exposed to zolpidem medication.

Electroacupuncture for treatment-resistant insomnia: study protocol for a randomised, controlled, assessor-blinded, pilot clinical trial

INTRODUCTION

A considerable number of insomnia patients experience sleep disturbance even with long-term use of hypnotic medication. Previous studies have indicated that electroacupuncture (EA) could be an efficacious treatment for managing insomnia. However, few trials have been conducted to evaluate the effectiveness and safety of EA for treatment-resistant insomnia. This pilot study aims to explore the feasibility and preliminary effectiveness and safety of EA as an adjunct treatment for treatment-resistant insomnia.

METHODS AND ANALYSIS

This is a multicentre, randomised, usual care controlled and assessor-blinded pilot study protocol. Fifty patients presenting with sleep problems who have been taking hypnotic medication for more than 3 months will be randomly allocated to either an EA group or a usual care group at a 1:1 ratio. The EA group will undergo 12 EA treatment sessions twice a week for 6 weeks whereas the usual care group will not receive EA treatment. All the participants will receive a brochure containing educational information on sleep hygiene. The primary outcome will be the measured mean change of the total score of the Insomnia Severity Index from the baseline to week 7. The secondary outcome regarding sleep quality will be measured using the Pittsburgh Sleep Quality Index, a sleep diary and actigraphy. Moreover, we will assess the quality of life, the direct and indirect cost of treating insomnia for economic evaluation. After 4 weeks, the subjects will visit the research sites for a follow-up assessment.

ETHICS AND DISSEMINATION

Ethical approval of this study protocol was established by the institutional review boards of the each involved study site. All potential subjects will be provided written informed consent. The results of this study will be accessible in peer-reviewed publications and be presented at academic conference.

TRIAL REGISTRATION NUMBER

KCT0003235.

Relationship between sleep and obesity among U.S. and South Korean college students

Background

Little is known about the relationship between sleep and obesity in young adults, particularly college students. This study examined the relationship between sleep (i.e., sleep duration and quality) and obesity in a large and diverse binational sample of college students.

Methods

Analyses were based on a 40-item paper survey from 2016/2017 to 2017/2018 academic years, with a 72% response rate. The samples were 1578 college students aged 18–25 years from five universities (two in the U.S. and three in South Korea). Weight and height were measured objectively; other measures (e.g., health behaviors) were self-reported. Multinomial logistic regression was used to assess the association between sleep duration and independent variables (race/nationality, gender, and BMI). Poisson regression was used to examine the relationship between sleep quality and independent variables.

Results

Overall, blacks had a higher adjusted odds ratio (AOR) of short sleep (< 7 h/night) than whites (AOR = 1.74, P < .01); overweight participants had a higher AOR of short sleep than normal weight participants (AOR = 1.52, P < .01); and obese participants had a higher AORs of both short and long sleep (> 9 h/night) (AOR = 1.67, P < .01; AOR = 1.79, P < .05, respectively). Among men, being black, overweight, and obesity were associated with short sleep (P < .05), whereas only obesity was related to short sleep among women (P < .05). In analyses stratified by race and nationality, overweight and obesity were related to short sleep among blacks only (P < .05). Overall, sleep quality (getting enough sleep to feel rested in the morning in the past 7 days) was worse in blacks and South Koreans than whites (P < .05), worse in women than men (P < .05), and worse in participants with obesity than normal weight participants (P < .05).

Conclusions

Obesity was associated with both short (< 7 h/night) and long sleep duration (> 9 h/night) and poor sleep quality among all participants. In comparison with whites, blacks were more like to have short sleep, and blacks and South Koreans had worse sleep quality. Further investigations using a larger sample of college students in multiple countries may be helpful to identify target populations who are at a greater risk of obesity and sleep problems.

Gender Differences With Regard to Perceived Job Insecurity and Insomnia in a Working Population

OBJECTIVES

Insomnia is one of the most prevalent disorders, and it is associated with various factors. Therefore, this study aimed to examine the association between perceived job insecurity and insomnia.

METHODS

Multiple logistic regression analysis was used to examine the association between three levels of perceived job insecurity and insomnia using the 2017 Korean Working Conditions Survey.

RESULTS

Approximately 10.2% of the total study population has insomnia. The higher the perception of job insecurity, the greater the chance for insomnia in both men (odds ratio = 4.03, 95% confidence interval [CI] = 3.18 to 5.11) and women (odds ratio = 4.44, 95% CI = 3.41 to 5.77).

CONCLUSION

These findings reveal the sex differences in insomnia, thus suggesting the need to implement different approaches to deal with perceived job insecurity based on sex.

Sleep, Sleep Disorders, and Sexual Dysfunction

Good sleep is necessary for good health. Sleep health is increasingly recognized as important for physical and mental health by both the medical profession and the general public, and there is great interest in how to avoid and treat sleep disorders and problems. Recent research indicates that insufficient sleep, disrupted sleep, and sleep disorders affect many aspects of human health including sexual function. In fact, patients with urological disorders or erectile dysfunction (ED) may have a sleep disorder that contributes to their urological or sexual dysfunction. Obstructive sleep apnea, insomnia, shift work disorder, and restless legs syndrome are all common sleep disorders and are associated with ED and/or other urological disorders. Therefore, careful attention should be paid to the diagnosis and treatment of concomitant sleep disorders in patients with sexual dysfunction. In this review, we provide an overview of what sleep is and how it is assessed in the clinic or laboratory; our current understanding of the functions of sleep and sleep health; a description of common sleep disorders, as well as how they are diagnosed and treated; and how sleep and its disorders are associated with male sexual dysfunction. Sleep is considered to be a 'third pillar of health', along with diet and exercise. With an understanding of common sleep disorders and how they can impact male sexual function, the urologist can ensure that sleep disorders are considered as a contributor to sexual dysfunction in their patients in order to provide them with the optimal treatment for overall health.

Rice bran extract supplement improves sleep efficiency and sleep onset in adults with sleep disturbance: A randomized, double-blind, placebo-controlled, polysomnographic study

We previously reported that rice bran extract supplement (RBS) administration to mice decreased sleep latency and induced non-rapid eye movement (NREM) sleep via inhibition of the histamine H₁ receptor. Based on this, we performed the first clinical trial to investigate whether RBS would be beneficial to subjects with disturbed sleep. We performed a randomized, double‐blinded, placebo‐controlled, 2-week study. Fifty subjects with sleep disturbance were enrolled and received either RBS (1,000 mg/day) or placebo. Polysomnography was performed, and Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale (ESS), and Fatigue Severity Scale were administered at the initiation and termination of the study. Compared with the placebo, RBS led to significant polysomnographic changes, including decreased sleep latency (adjusted, P = 0.047), increased total sleep time (P = 0.019), and improved sleep efficiency (P = 0.010). Additionally, the amount of stage 2 sleep significantly increased in the RBS group. When adjusted for caffeine intake, wakefulness after sleep onset, total wake time, and delta activity tended to decrease in the RBS group. RBS administration decreased ESS scores. There were no reported serious adverse events in both groups. RBS improved sleep in adults with sleep disturbance. Trial registration: WHO ICTRP, KCT0001893.

The Effect of Anxiety and Depression on Sleep Quality of Individuals With High Risk for Insomnia: A Population-Based Study

Introduction: One of the most common sleep disorders, insomnia is a significant public health concern. Several psychiatric disorders, such as anxiety disorders and depression, have shown strong relationships with insomnia. However, the clinical impact of the combination of these two conditions on insomnia severity and sleep quality remains unknown. We investigated the relationship between sleep disturbance and psychiatric comorbidities in subjects with high risk for insomnia.

Methods: We analyzed data from a nation-wide cross-sectional survey of Korean adults aged 19 ~ 69 years conducted from November 2011 to January 2012. The survey was performed via face-to-face interviews using a structured questionnaire. We used the insomnia severity index (ISI) to evaluate insomnia and defined respondents with ISI scores of ≥10 were considered to be at high risk for insomnia. To diagnose anxiety and depression, we used the Goldberg anxiety scale (GAS) and Patient Health Questionnaire-9 (PHQ-9), respectively.

Results: Of the 2,762 respondents, 290 (10.5%) were classified as subjects with high risk for insomnia; anxiety [odds ratio (OR), 9.8; 95% confidence interval (CI), 7.3–13.1] and depression (OR, 19.7; 95% CI, 13.1–29.6) were more common in this population than in participants without insomnia. Of the participants with insomnia, 152 (52.4%) had neither anxiety nor depression, 63 (21.7%) only had anxiety, 21 (7.2%) only had depression, and 54 (18.6%) had both anxiety and depression. The group with both anxiety and depression was associated with worse scores on sleep-related scales than the other groups [high ISI, Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale]. The relationship between outcome measures (ISI and PSQI) and psychiatric problems was significant only when anxiety and depression were present. The PSQI has a significant mediation effect on the relationship between psychiatric comorbidities and insomnia severity.

Conclusion: Among the respondents with insomnia, psychiatric comorbidities may have a negative impact on daytime alertness, general sleep quality, and insomnia severity, especially when the two conditions are present at the same time. Clinicians should, therefore, consider psychiatric comorbidities when treating insomnia.

A Double-Blind, Randomized, Placebo-Controlled Crossover Clinical Study of the Effects of Alpha-s1 Casein Hydrolysate on Sleep Disturbance

This study evaluated the effects of alpha-s1 casein hydrolysate (ACH; Lactium^®) on the subjective and objective sleep profiles of a community-based sample of Koreans with poor sleep quality. We performed a double-blind, randomized crossover trial with 48 participants (49.0 ± 1.7 years old, 65% female) who exhibited a mild to moderate degree of sleep disturbance. Either ACH or placebo was administered for the initial four weeks, and the counterpart was administered in precisely the same manner after a four-week washout period. Sleep disturbance scales, daytime functioning, and psychiatric aspects showed a similar tendency to improve during both ACH and placebo phases without significant group differences. Overall perceived sleep profiles in sleep diaries were significantly improved during the ACH phase, represented by increased total sleep time and sleep efficiency (SE), as well as decreased sleep latency and wake after sleep onset (WASO). Interestingly, actigraphy demonstrated significantly increased SE after continuous use of ACH for four weeks, clearly more improved when compared to two weeks of use. The polysomnography measures showed a similar tendency without statistically significant group differences. Our findings suggest that refined ACH was well tolerated and could improve sleep quality, with possible cumulative beneficial effects with long-term administration.

Insomnia among Town Residents in Ethiopia: A Community-Based Cross-Sectional Survey

Background

Insomnia is one of the most common sleep problems throughout the world and a major public health concern among adults in the general population. The aim of this study was to assess the prevalence of insomnia and its associated factors among town adult residents in Ethiopia.

Methods

Community-based cross-sectional study was done among 840 randomly selected adult participants by using standardized and pretested Athens insomnia scale (AIS) to assess insomnia. Systematic random sampling technique was used to get samples of the study participants. Data were entered into Epi-Info and analyzed using SPSS version 20. Descriptive, bivariate, and multivariate logistic regression models were used for analysis. Adjusted odds ratio (AOR) with 95% Confidence Interval (CI) was used to show the odds, and P value < 0.05 was considered as statistically significant.

Results

The prevalence of insomnia was found to be 42.9%. Sleep problems were associated with female sex [AOR =2.74, 95% CI; (1.77, 4.24)], age above 48 years [AOR=4.67, 95% CI: (2.32, 9.40)], being single [AOR=2.81, 95% CI (1.59, 4.95)] and widowed [AOR=4.20, 95% CI; (1.60, 11.01)], khat chewing [AOR=1.76,95% CI; (1.19, 2.60)], current tobacco smoking [AOR=3.13, 95% CI; (1.64, 5.95)], caffeinated beverage use [AOR=1.67, 95% CI; (1.12, 2.49)], comorbid medical-surgical disorders [AOR=2.03, 95% CI; (1.18, 3.48)], common mental disorders [AOR=8.92, 95% CI; (5.93,13.44)], and noise at bed time [AOR=2.13 95% CI; (1.20, 3.78)].

Conclusion

The prevalence of insomnia has to be found high and associated with many area related factors. It is important to pay attention in urban settings and large scale studies recommended.

Trends in prescriptions for sedative-hypnotics among Korean adults: a nationwide prescription database study for 2011-2015

PURPOSE

This study investigated prescriptions for sedative-hypnotics via data obtained from the Health Insurance Review and Assessment (HIRA) service.

METHODS

Data on sedative-hypnotic prescriptions from the HIRA service of the Republic of Korea were analyzed from 2011 to 2015. We included prescriptions for subjects > 18 years of age from hospitals and community healthcare centers. In addition, subgroup analyses with a subsample restricted to prescriptions from patients with diagnostic codes F510 (nonorganic insomnia) or G470 (insomnia) were performed. After analyzing the number of prescriptions by individual pharmacy items, the prescription codes were grouped as: (1) benzodiazepines; (2) non-benzodiazepines, including zolpidem; (3) antidepressants; and (4) antipsychotics. We calculated the monthly percent change in the number of prescriptions by drug group using Joinpoint regression.

RESULTS

Among the sedative-hypnotic groups, benzodiazepines were the most commonly prescribed drugs in Korea during the study period. As a single sedative-hypnotic item, zolpidem was the most frequently prescribed medication for patients with insomnia. Prescriptions for all groups of sedative-hypnotics increased significantly during the study period. When stratified by age group, antipsychotic prescriptions increased significantly by 0.19-0.21% per month among men and women aged 50-59 years and > 70 years. Prescriptions for antidepressants in 30-39-year-old men increased significantly by 0.20%.

CONCLUSIONS

Benzodiazepine prescriptions as well as those for antipsychotics and antidepressants to treat insomnia increased during 2011-2015 in Korea. Monitoring the use of sedative-hypnotics at the national level is necessary, especially in the elderly population.

Genome-wide analysis of insomnia in 1,331,010 individuals identifies new risk loci and functional pathways

Insomnia is the second most prevalent mental disorder, with no sufficient treatment available. Despite substantial heritability, insight into the associated genes and neurobiological pathways remains limited. Here, we use a large genetic association sample (n = 1,331,010) to detect novel loci and gain insight into the pathways, tissue and cell types involved in insomnia complaints. We identify 202 loci implicating 956 genes through positional, expression quantitative trait loci, and chromatin mapping. The meta-analysis explained 2.6% of the variance. We show gene set enrichments for the axonal part of neurons, cortical and subcortical tissues, and specific cell types, including striatal, hypothalamic, and claustrum neurons. We found considerable genetic correlations with psychiatric traits and sleep duration, and modest correlations with other sleep-related traits. Mendelian randomization identified the causal effects of insomnia on depression, diabetes, and cardiovascular disease, and the protective effects of educational attainment and intracranial volume. Our findings highlight key brain areas and cell types implicated in insomnia, and provide new treatment targets.

Sleepless from the Get Go: Sleep Problems Prior to Initiating Cancer Treatment

PURPOSE

Cancer patients are likely to experience sleep problems. Understanding their perception of sleep problems is important as subjective symptom experience is associated with treatment-seeking behavior. We explored the prevalence of sleep problems and its correlates in a large sample of cancer patients at an important but understudied stage of their cancer journey: prior to initiating treatment.

METHODS

Cancer patients (5702) (67.5% female; 76.9% White; 23.0% Hispanic), following diagnosis and prior to initiating cancer treatment, completed an electronic screening instrument. Patients across eight different cancer diagnoses (breast, gastrointestinal, gynecological, head and neck, hematological, lung, prostate, urinary) rated their sleep problems on a five-point scale, with those reporting "severe" or "very severe" sleep problems classified as having high sleep problems.

RESULTS

Overall, 12.5% of patients reported high sleep problems. Across diagnoses, the proportion of patients reporting high sleep problems ranged from 4.3 to 13.8%, with prostate cancer patients least likely and gastrointestinal cancer patients most likely to report high sleep problems. Older age, having a partner, higher education, and higher household income were associated with a lower likelihood of experiencing sleep problems. Being female, Black, Hispanic, and reporting anxiety or depression was associated with an increased likelihood of sleep problems.

CONCLUSIONS

A sizeable proportion of cancer patients experience significant problems with their sleep before any treatment has occurred. This clinical issue cannot be ignored as treatment is likely to worsen existing sleep problems. Oncology providers should routinely screen for sleep-related problems. Identifying and treating patients for sleep problems during a vulnerable period early in their cancer trajectory should be an essential component of clinical care.

The impact of stress on sleep: Pathogenic sleep reactivity as a vulnerability to insomnia and circadian disorders

Sleep reactivity is the trait-like degree to which stress exposure disrupts sleep, resulting in difficulty falling and staying asleep. Individuals with highly reactive sleep systems experience drastic deterioration of sleep when stressed, whereas those with low sleep reactivity proceed largely unperturbed during stress. Research shows that genetics, familial history of insomnia, female gender and environmental stress influence how the sleep system responds to stress. Further work has identified neurobiological underpinnings for sleep reactivity involving disrupted cortical networks and dysregulation in the autonomic nervous system and hypothalamic-pituitary-adrenal axis. Sleep reactivity is most pathologically and clinically pertinent when in excess, such that high sleep reactivity predicts risk for future insomnia disorder, with early evidence suggesting high sleep reactivity corresponds to severe insomnia phenotypes (sleep onset insomnia and short sleep insomnia). High sleep reactivity is also linked to risk of shift-work disorder, depression and anxiety. Importantly, stress-related worry and rumination may exploit sensitive sleep systems, thereby augmenting the pathogenicity of sleep reactivity. With the development of cost-effective assessment of sleep reactivity, we can now identify individuals at risk of future insomnia, shift-work disorder and mental illness, thus identifying a target population for preventive intervention. Given that insomniacs with high sleep reactivity tend to present with severe insomnia phenotypes, patient sleep reactivity may inform triaging to different levels of treatment. Future research on sleep reactivity is needed to clarify its neurobiology, characterize its long-term prospective associations with insomnia and shift-work disorder phenotypes, and establish its prognostic value for mental illness and other non-sleep disorders.

Factors related with quality on sleep of daytime workers

Background

This study was conducted to identify the sleep status of daytime workers who do not work in shifts. This study analyzed factors affecting sleep duration and sleep quality.

Methods

This study was conducted on 1171 daytime workers at a manufacturing workshop. We used a self-administered questionnaire to investigate demographic variables, work type, working period, musculoskeletal symptoms and the Pittsburgh Sleep Quality Index to assess sleep. Regular health checkup was conducted for the worker’s clinical examination.

Results

The mean sleep duration was 6.36 h and the mean score on the Pittsburgh Sleep Quality Index was 4.46. Work type and obesity were related to sleep duration. Age, obesity and musculoskeletal pain were significantly related to sleep quality. The prevalence ratio of researcher group for short sleep duration was 1.27 (95% confidence interval: 1.02–1.58). The prevalence ratio of those aged 50 years and over was 0.47 (0.25–0.91) and of those in their 40s was 0.56 (0.35–0.91) for poor sleep quality compared to those in their 20s. The prevalence ratio of the obesity group for poor sleep quality was 1.53 (1.10–2.12). The prevalence ratio of musculoskeletal pain group for poor sleep quality was 1.92 (1.29–2.84).

Conclusions

Age, obesity and musculoskeletal pain were factors affecting the poor quality on sleep of daytime workers. In addition, work type related to short sleep duration.

Low Income as a Vulnerable Factor to the Effect of Noise on Insomnia

OBJECTIVE

The present study aimed to examine the potential mediating effect of income level on the association between noise exposure and insomnia.

METHODS

706 individuals were evaluated in conjunction with 2014 noise map data from Seoul, South Korea. Cross-sectional analysis was performed to examine differences in noise level according to household income, while three separate logistic regression models were used to examine factors influencing insomnia. Odds ratios (ORs) were calculated after adjusting for depression, anxiety, auditory acuity and noise sensitivity in the first model. Analyses were adjusted for sociodemographic variables in the second model, lifestyle factors and medical illnesses in the third model.

RESULTS

Noise level was significantly associated with an increased risk of insomnia in the low-income group, although no such association was observed in the high-income group. Groups exposed to >60 dB of noise (Lden; day-evening-night equivalent) exhibited a 1.79-fold increase in the incidence of insomnia relative to those exposed to <50 dB. The result was significant after adjusting sociodemographic variables, although not significant when adjusted for lifestyle factors and medical illnesses.

CONCLUSION

Individuals with low income may be more vulnerable to the deleterious effects of noise exposure on health. Various aspects including income should be considered to ascertain the influence of noise on insomnia.

Insomnia as an independent predictor of suicide attempts: a nationwide population-based retrospective cohort study

BACKGROUND

Numerous studies have verified that insomnia is associated with suicidal ideation, suicide attempts, and death by suicide. Limited population-based cohort studies have been conducted to examine the association. The present study aimed to analyze whether insomnia increases the risk of suicide attempts and verify the effects of insomnia on suicide risk.

METHODS

This study is a cohort study using 2000-2013 hospitalization data from the National Health Insurance Research Database (NHIRD) to track the rate of suicide attempts among insomnia patients aged 15 years or older. In addition, a 1:2 pairing based on sex, age, and date of hospitalization was conducted to identify the reference cohort (patients without insomnia). Cox proportional hazard model was used to assess the effects of insomnia on suicide risk.

RESULTS

The total number of hospitalized patients aged 15 years or older was 479,967 between 2000 and 2013 (159,989 patients with insomnia and 319,978 patients without insomnia). After adjusting for confounders, suicide risk in insomnia patients was 3.533-fold that of patients without insomnia (adjusted hazard ratio [HR] = 3.533, 95% confidence interval [CI] = 3.059-4.080, P < 0.001). Suicide risk in low-income patients was 1.434-fold (adjusted HR = 1.434, 95% CI = 1.184-1.736, P < 0.001) that of non-low-income patients. Suicide risk in patients with drug dependence and with mental disorders was 1.592-fold (adjusted HR = 1.592, 95% CI = 1.220-2.077, P < 0.001) and 4.483-fold (adjusted HR = 4.483, 95% CI = 3.934-5.109, P < 0.001) that of patients without drug dependence and without mental disorders, respectively. In the female population, suicide risk in insomnia patients was 4.186-fold (adjusted HR = 4.186, 95% CI = 3.429-5.111, P < 0.001) that of patients without insomnia. Among patients aged 25-44 years, suicide risk in insomnia patients was 5.546-fold (adjusted HR = 5.546, 95% CI = 4.236-7.262, P < 0.001) that of patients without insomnia. Furthermore, the suicide risk of insomnia patients with mental disorders was 18.322-fold that of patients without insomnia and mental disorders (P < 0.001).

CONCLUSION

Insomnia, low income, drug dependence, and mental disorders are independent risk factors for suicide attempts. Female patients and those aged 25-44 years are at high risk of suicide due to insomnia. Insomnia, mental disorders, and low income exhibit a synergistic effect on suicide attempts. Clinicians should pay attention to mental status and income level of insomnia patients.