Association between commuting and mental health among Japanese adolescents.

AIM: Mental health issues in adolescence contribute to various disease burdens later in life and are associated with violence, crime, and suicide. Activities such as sleep, diet, exercise, and time spent using electronic devices are related to declining mental health. However, few studies have examined the association between commuting times to school and mental health. This study tested the hypothesis that high school students' long commuting times are associated with poor mental health. METHOD: A cross-sectional study was conducted between October and December 2022 among 2067 students at two private high schools. Survey items included participant information (sex, grade, school), commuting time, mental health status (Patient Health Questionnaire 9 [PHQ-9]: depressive symptoms, and Generalized Anxiety Disorder 7 [GAD-7]: anxiety symptoms), lifestyle factors, and sleep-related factors. RESULTS: Data from 1899 high school students were analyzed. The prevalence of depressive and anxiety symptoms was 17.3% and 19.0%, respectively. A commuting time of ≥1 h was significantly associated with depressive symptoms (adjusted odds ratio: 1.60 [95% confidence interval]: 1.14-2.24) and anxiety symptoms (adjusted odds ratio: 1.51 [95% confidence interval]: 1.09-2.10). Sex, grade, use of ≥8 h/day of electronic devices, and chronotype were significantly associated with depressive symptoms, while sex, grade, use of ≥8 h/day of electronic devices, and insomnia were significantly associated with anxiety symptoms. CONCLUSION: It is suggested that long commuting times are associated with poor mental health in high school students. Parents and schools should consider commuting time when advising students on school selection to maintain their mental health.

Awareness, Attitudes, and Concerns Regarding Heated Tobacco Products Among Physicians in Japan.

BACKGROUND: New tobacco products, particularly heated tobacco products (HTPs), have been introduced across several international markets as alternatives to combustible products, such as cigarettes. However, there are limited studies on physicians' perceptions of HTPs. This study analyzes the awareness of HTPs among physicians and assesses their concerns and attitudes toward patients using HTPs. METHODS: A self-administered questionnaire was sent to a sample of 7,500 member physicians (6,000 male and 1,500 female) from the Japan Medical Association (JMA). The smoking status of physicians was categorized as never smokers, ever HTP smokers, current HTP smokers, and ever and current smokers of other products. Physicians' awareness and attitudes toward patients using HTPs were analyzed using descriptive statistics. The correlation between the outcomes was examined using logistic regression models, whereas physicians' concerns about HTPs were analyzed using descriptive statistics. RESULTS: Data were obtained from 5,492 physicians (21.9% women; aged 60.4; standard deviation, 12.1 years) with a response rate of 74.6%. Overall, 76.7% of the physicians had awareness of HTP, and about half of whom asked patients about using HTPs. Physicians who took longer to discuss cessation were more likely to discourage patient use. Smoking status was associated with discouraging HTP use in patients. Physicians who had experience with HTP use were primarily concerned about the products' long-term safety and less about product regulation. CONCLUSION: Japanese physicians do not have sufficient information and knowledge about HTPs. Therefore, evidence-based guidelines are required to support physicians in advising patients against HTP use.

Association and dose-response relationship between exposure to alcohol advertising media and current drinking: a nationwide cross-sectional study of Japanese adolescents.

BACKGROUND: Underage drinking is a public health concern. However, few studies have examined the association between alcoholic beverage advertising and underage drinking, particularly in countries with low underage drinking rates, such as Japan. Therefore, we aimed to investigate the relationship between exposure to advertising in various media and alcohol drinking among Japanese adolescents. METHODS: We conducted a cross-sectional study involving 15,683 adolescents (51% girls) using data from a nationwide lifestyle survey in 2021 among junior and senior high schools across Japan. Media types were websites, stores, and public transportation. We defined current drinking as alcohol consumption of ≥1 day in the 30 days preceding the survey. Multivariable logistic regression was used to examine the association between exposure to alcohol advertisements and current drinking, adjusting for sex, grades, school area, lifestyle (bedtime and having fun at school), and addictive behaviors (smoking status and parents' alcohol consumption). RESULTS: The prevalence of current drinking was 2.2% (2.3% of boys and 2.0% of girls). Students who were exposed to any alcohol advertising media had higher odds of current drinking compared with those who were not (odds ratio, 1.48; 95% confidence interval [CI], 1.18-1.87). Students who were exposed to web, in-store, and public transportation advertisements had odds ratios of 1.44 (95% CI, 1.14-1.81), 1.62 (1.28-2.05), and 1.45 (1.06-1.98) of current drinking, respectively, compared with those who were not. The association of exposure to alcohol advertising media with the prevalence of current drinking was similar among boys and girls (all p for sex interaction >0.1), except for that of exposure to web advertisements; its association with current drinking was more pronounced in girls (p for sex interaction = 0.046). Exposure to a larger cumulative number of different alcohol advertising media was independently associated with a higher prevalence of current drinking among all students, boys, and girls (p-values for trend <0.001, 0.031, and <0.001, respectively; p for sex interaction = 0.085). CONCLUSIONS: We found an association with a dose-response relationship between exposure to alcohol advertisements and current drinking among adolescents in junior and senior high schools across Japan. Our findings highlight the need for further advertising regulations to prevent underage drinking.

Effectiveness of nurse-delivered screening and brief alcohol intervention in the workplace: A randomized controlled trial at five Japan-based companies.

BACKGROUND: Excessive alcohol use is a leading cause of global morbidity and premature mortality. This study evaluated the effectiveness of two types of nurse-delivered interventions to reduce excessive alcohol consumption among screened participants using the alcohol use disorders identification test (AUDIT) in the workplace. METHODS: A randomized controlled trial involving AUDIT-positive employees of five Japan-based companies was conducted. A total of 351 participants were randomized into groups that received a patient information leaflet (PIL), 5 min of brief advice, or 15 min of brief advice and counseling. Outcomes (weekly alcohol consumption and drinking and binge drinking frequency in the previous 30 days) were evaluated at 6 and 12-month follow-up. RESULTS: The follow-up rates were 96.3% (n = 338) and 94.9% (n = 333) at 6 and 12 months, respectively. At 6 months, the mean change in weekly alcohol consumption was -38.1 g (-1.64 US fluid oz/week) in the 15-min brief advice and counseling group, which differed significantly from the PIL group. The reduction in the advice and counseling group persisted at 12-month follow-up but was no longer significantly different from the PIL group. There was no significant change in alcohol consumption observed in the 5-min brief advice group. Improvement in drinking and binge drinking frequency was observed in all three groups. CONCLUSIONS: Nurse-delivered 15-min brief advice and counseling was effective over a 6-month period in reducing alcohol consumption in a workplace setting. This finding suggests that the implementation of workplace screening and brief intervention could play a useful role in preventing the burden of harmful alcohol use.

Association between nighttime urinary frequency and sleep problems among Japanese adolescents.

OBJECTIVE: To conduct a cross-sectional study to investigate the relationship between nighttime urinary frequency and sleep problems in Japanese adolescents. METHODS: A self-administered questionnaire survey was conducted among 1757 adolescents (mean age 15.6 ± 1.1 years; 49.0% boys). The survey assessed sleep problems (sleep duration, sleep quality, and insomnia symptoms), nighttime urinary frequency, eating habits (breakfast, late-night eating, energy drink consumption), problematic internet use, engagement in club activities, and mental health. We analyzed the association between nighttime urinary frequency and sleep problems using descriptive statistics and logistic regression models. RESULTS: The response rate was 99.6% (1699 students). The prevalence of nighttime urinary frequency ≥2 was 5.6% in boys and 4.6% in girls. The prevalence rates of sleep problems were: insomnia, 16.4%; difficulty initiating sleep, 11.8%; difficulty maintaining sleep, 5.9%; early-morning awakening, 5.4%; and poor sleep quality, 19.9%. Analysis of the relationship with sleep problems differentiating between zero, one, and two nighttime urinations showed that an increase in nighttime urinary frequency corresponded to an increase in the prevalence of insomnia, difficulty initiating sleep, and difficulty maintaining sleep. Logistic regression analysis also showed that insomnia, difficulty initiating sleep, and difficulty maintaining sleep had a linear, significant relationship with increased nighttime urinary frequency. CONCLUSION: This study suggests that adolescents with high nighttime urinary frequency experience increased sleep problems. Consideration of urinary frequency is required when tackling adolescent sleep problems.

Heat-not-burn tobacco, electronic cigarettes, and combustible cigarette use among Japanese adolescents: a nationwide population survey 2017.

BACKGROUND: From among the global public health concerns, smoking remains one of the most crucial challenges. Especially for adolescents, the increase in the use of electronic cigarettes is controversial, as its use may lead to established smoking. In Japan, where a unique tobacco regulation system exists, the heat-not-burn tobacco market has been growing. However, the prevalence and association of combustible cigarettes and new tobacco-related products have not yet been closely investigated among Japanese adolescents. This study aimed to clarify the prevalence of smoking among adolescents, including new types of tobacco-related products, and to compare the characteristics of their users. METHODS: The 2017 Lifestyle Survey of Adolescents is a nationally-representative survey collected in Japan. From the national school directory, 98 junior high schools and 86 high schools were randomly sampled throughout Japan. The students completed an anonymous questionnaire at school. We calculated the prevalence of use for each type of tobacco product. Then, the use of a combination of products and the characteristics of different types of products were examined. RESULTS: In total, 64,152 students from 48 junior high schools and 55 high schools were included the analysis (school response rate = 56%, Mage = 15.7 years, 53.9% boys). The age-adjusted rate of ever (current) use of electronic cigarettes was 2.1% (0.7%) in junior high school and 3.5% (1.0%) in high school; that of combustible cigarettes was 2.6% (0.6%) in junior high school and 5.1% (1.5%) in high school. The rate of heat-not-burn tobacco use was lower relative to other products: 1.1% (0.5%) in junior high school and 2.2% (0.9%) in high school. An examination of the combined use of the three products identified a high number of dual users. Comparisons between different types of users indicated different backgrounds for combustible cigarette users and new product users. CONCLUSIONS: The prevalence of new tobacco-alternative products is growing in popularity among Japanese adolescents. Dual use is common, and many adolescents use new products only. Moreover, e-cigarettes might attract a broader range of groups to smoking. Continuous monitoring and research are needed to investigate their influence as a possible gateway to tobacco smoking.

Relationship between internet addiction and sleep disturbance in high school students: a cross-sectional study.

BACKGROUND: The increase in the number of Internet users has increased Internet dependence worldwide. In adolescents, this dependence may interfere with sleep, which is important for the development of psychophysiological capabilities. However, few large-scale surveys have described the relationship between Internet addiction (IA) and sleep disturbance using standardized questionnaires. We conducted a survey in one prefecture in Japan to determine the relationship between sleep disturbance and IA in adolescents based on the categories of the Young Diagnostic Questionnaire (YDQ). METHODS: In 2016, high school students (N = 10,405, age range: 15-16 years) in all 54 daytime high schools in the selected prefecture were surveyed using a self-administered questionnaire. Participants with scores > 5.5 points on the Japanese version of the Pittsburgh Sleep Quality Index were defined as having a sleep disturbance. IA was evaluated using the YDQ: Participants with five to eight YDQ items present were classified as having IA; those with three or four items present were classified as "at risk of IA"; and those with two or less YDQ items were classified as "non-IA". Multiple logistic regression analysis was performed with sleep disturbance as the dependent variable, IA as the explanatory variable, and adjustments for eight other variables. RESULTS: High YDQ scores were associated with a high prevalence of sleep disturbance in boys and girls. These findings persisted after controlling for other factors in the multiple regression model. CONCLUSIONS: Among Japanese adolescents, there was a significant independent relationship between IA and sleep disturbance.

Factors Associated with the Development of Childhood Asthma in Japan: A Nationwide Longitudinal Study.

INTRODUCTION: Many environmental factors are related to the development of asthma. However, the key factors of childhood asthma onset have not been sufficiently elucidated. Further, low-weight births have increased in Japan. The aim of this study was to examine the risk factors for the incidence of childhood asthma and to evaluate whether these risk factors differ according to birth weight in Japan. METHODS: We used the National Longitudinal Survey from 2001 to 2010. Multiple logistic regression analyses were conducted to determine the effects of gender, birth weight, single vs. multiple births, birth order, nutrition, keeping pets in the home, place of residence, annual household income, and parent ages, smoking behaviors, and educational backgrounds on asthma-related hospital visits. RESULTS: Overall, 45,060 children were analyzed. The rate of cumulative hospital visits until age 10 was 18.9%. Birth weight < 2500 g (adjusted odds ratio [AOR] = 1.14, 95% confidence interval [CI] 1.03-1.26), being a boy (AOR = 1.27, 95% CI 1.21-1.33), having older siblings (AOR = 1.07, 95% CI 1.02-1.14), parental smoking behavior, mother`s age, and low household income (AOR = 1.17, 95% CI 1.10-1.24) were associated with asthma-related hospital visits. DISCUSSION: Parental smoking behavior is a key risk factor for the development of asthma. Among low birth weight infants, being a boy, having older siblings, and father`s smoking behavior were predictive factors for the development of asthma. However, low birth weight was not associated with the development of asthma after 6 years of age.

The association between alcohol use and problematic internet use: A large-scale nationwide cross-sectional study of adolescents in Japan.

BACKGROUND: This study aimed to clarify the associations between the frequency and amount of alcohol consumption and problematic Internet use, such as Internet addiction and excessive Internet use. METHODS: A self-administered questionnaire survey was administered to students enrolled in randomly selected junior and senior high schools throughout Japan, and responses from 100,050 students (51,587 males and 48,463 females) were obtained. Multiple logistic regression analyses were performed in order to examine the associations between alcohol use and problematic Internet, use such as Internet addiction (Young Diagnostic Questionnaire for Internet Addiction ≥5) and excessive Internet use (≥5 h/day). RESULTS: The results of multiple logistic regression analyses indicated that the adjusted odds ratios for Internet addiction (YDQ ≥5) and excessive Internet use (≥5 h/day) became higher as the number of days in which alcohol had been consumed during the previous 30 days increased. In addition, the adjusted odds ratio for excessive Internet use (≥5 h/day) indicated a dose-dependent association with the amount of alcohol consumed per session. CONCLUSIONS: This study revealed that adolescents showing problematic Internet use consumed alcohol more frequently and consumed a greater amount of alcohol than those without problematic Internet use. These findings suggest a close association between drinking and problematic Internet use among Japanese adolescents.

The Association Between Alcohol-Flavoured Non-Alcoholic Beverages and Alcohol Use in Japanese Adolescents.

AIMS: There are no legal regulations in Japan governing minors' consumption of alcohol-flavoured non-alcoholic beverages (AFNAB); therefore, we examined if their consumption could lead to increased alcohol use among adolescents in Japan. METHODS: This cross-sectional study used a nonclinical, nationally representative sample of 38,494 junior (19,662 boys) and 61,556 senior (31,925 boys) high school students recruited in 2012. We measured AFNAB consumption rates and the order that adolescents first consumed AFNAB and alcohol. RESULTS: The AFNAB consumption was strongly associated with alcohol use in high school students. Among all age groups, alcohol was more commonly consumed before AFNAB for both males and females. CONCLUSIONS: Consumption of AFNAB is more prevalent among minors than alcohol consumption and it has a strong association with alcohol consumption. However, concerns that AFNAB use would lead to increased alcohol use were not supported because AFNAB consumption usually started after adolescents began consuming alcohol. SHORT SUMMARY: Consumption of AFNAB is more prevalent among high school students than alcohol consumption and it has a strong association with alcohol consumption. However, concerns that AFNAB use would lead to increased alcohol use were not supported because AFNAB consumption usually started after adolescents began consuming alcohol.

Prevalence, knowledge, and concerns regarding the use of heated tobacco products and electronic cigarettes among young Japanese physicians.

INTRODUCTION: Heated tobacco products (HTPs) and e-cigarettes (ECs) have gained traction as alternatives for harm reduction, especially in Japan. In particular, the use of HTPs is rapidly gaining popularity among young adults in Japan, with a prevalence of 10.9% in 2020. Despite uncertainties regarding the health effects of HTPs and ECs, concerns regarding nicotine and carcinogens persist. Although physicians play a vital role in smoking cessation, they lack awareness and concerns regarding HTPs. This study aimed to assess the prevalence, knowledge, and concerns regarding HTPs and ECs among young Japanese physicians. METHODS: A cross-sectional online survey was conducted in 2021 with 529 young Japanese physicians aged 24-39 years. Parameters assessed included awareness, smoking status, knowledge of HTPs and ECs, and concerns related to HTPs. Statistical analyses were conducted to assess prevalence, knowledge, and concerns by smoking status using the chi-squared test and logistic regression. RESULTS: Most participants were aware of HTPs (89.0%) and ECs (71.3%). Young male physicians preferred HTPs, while females favored ECs. Primary sources of information included newspapers and stories (56.8%), and TV (37.4%). Non-smokers (89.0%) demonstrated limited knowledge of these products. Concerns were highest and lowest among non-smokers and HTP users, respectively, with safety concerns being the most prevalent. CONCLUSIONS: Young physicians exhibited lower smoking rates than the general population, but HTP use was prominent among young male physicians. Concerns varied based on smoking status, indicating the need to address these issues among healthcare professionals. Despite high awareness, knowledge gaps, particularly among non-smokers, highlight the importance of public health and educational campaigns to disseminate knowledge among physicians, regardless of medical specialty.

A School-Based Program for Problematic Internet Use for Adolescents in Japan.

Despite the serious influence of problematic Internet use on mental health among Japanese adolescents, no randomized clinical trials have investigated universal school-based interventions for this potential health challenge. Therefore, this study aimed to assess the efficacy of a school-based educational program. This two-armed, parallel, cluster-based randomized clinical trial included 5312 students from 13 high schools situated in a mid-sized Japanese city. The students in the intervention arm received 10 weekly standardized sessions, including a combination of information provision and interactive sessions by schoolteachers. The students in the control group followed a standard school curriculum. A generalized estimating equation model was applied to assess the primary (Korean Scale for Internet Addiction [K-scale] score) and secondary (behavioral change status according to changes in the transtheoretical model smartphone addiction score and Internet usage time) outcomes two months after intervention completion. The intention-to-treat analysis included 2597 (97.2%) and 2504 (94.9%) students in the intervention and control groups, respectively. Nevertheless, a significant discrepancy emerged regarding the behavioral change status. Therefore, this school-based program did not improve the Internet or smartphone addiction scores among Japanese adolescents. Further studies are needed to develop appropriate interventions for adolescents.

Development and validation of the Work Style Reform Scale.

In Japan, the "Act on the Arrangement of Related Acts to Promote Work Style Reform" was enforced in 2019 to reduce long working hours. However, work style reforms largely depend on workers' and companies' awareness and abilities. This study aimed to develop the Work Style Reform scale to assess the competencies required for work style reform and to examine its validity and reliability. This study was conducted with a diverse sample of 1,641 Japanese workers, and 17 questions across three subscales-Work Style, Personal Style, and Work Environment-were developed. After a response bias analysis, some items were discarded based on an exploratory factor analysis; the reliability coefficients were calculated; and a confirmatory factor analysis was performed. The convergent and discriminant validity were evaluated through a multi-trait multi-method analysis. Finally, nine questions remained. Construct validity, reliability and convergent validity were sufficient for all Subscales, and discriminant validity was sufficient only for Work Style. In conclusion, while Work Style was sufficient, issues remained in other subscales. To improve the accuracy of them in the future, it is necessary to examine the validation of discriminant validity using different indicates and the addition of new items to the smallest subscale; Personal Style.

Optimal telework frequency in terms of sleep and labor productivity depends on the workers' psychological distress: A cross-sectional study in Tokyo, Japan.

OBJECTIVES: This study aimed to determine that workers' sleep and labor productivity differ with the telework frequency and that the optimal telework frequency depends on workers' psychological distress. METHODS: A cross-sectional study using an online-based questionnaire was conducted with 2,971 workers employed by Japanese companies from October to December 2021. We used the 6-item Kessler Scale, K6, as a nonspecific psychological distress scale to screen mental health conditions. A score of ≤ 4 was defined as low psychological distress (LPD), and a score of ≥ 5 was defined as high psychological distress (HPD). We used the Athens Insomnia Scale (AIS) as a measure of sleep quality. The Utrecht Work Engagement (UWES) and Work Functioning Impairment (WFun) scales were used as measures of labor productivity. Series of analysis of covariance (ANCOVA) was used for the data analysis. RESULTS: The analysis included 2,013 participants (1,390 men and 623 women; mean age 43.2 years, standard deviation 11.3). Multiple comparison tests showed that among the participants categorized HPD (HPD type), the AIS estimates were lowest in the 1-2 d/wk group, with significant differences between the 0-3 d/m and ≥ 5 d/wk groups. UWES estimates were lowest in the 3-4 d/wk group with significant differences between the participants categorized LPD (LPD type) and HPD type, while no significant differences were observed among the LPD type. The WFun estimates among the LPD type decreased significantly with increasing telework frequency, while no significant differences were observed among the HPD type. CONCLUSIONS: The optimal telework frequency for sleep and labor productivity may depend on the workers' psychological distress. The finding of this study could make a great contribution to occupational health activities and health promotion for teleworkers, which is necessary to make teleworking a sustainable work style.

Relationship between Telework Jetlag and Perceived Psychological Distress among Japanese Hybrid Workers.

Social jetlag is associated with physical and mental health problems. With the increased popularity of telework, we investigated a specific form of social jetlag that we termed "telework jetlag". This study aimed to clarify the relationship between telework jetlag-the difference in sleep and wake-up times between in-office and telework days-and mental health problems among Japanese hybrid workers. A cross-sectional study was conducted with 1789 participants from October to December 2021 using an online-based questionnaire. Telework jetlag, defined as the difference in the midsleep point between in-office and telework days, was investigated using two groups according to telework jetlag-those lagging <1 h versus ≥1 h. We used the six-item Kessler Scale as a nonspecific psychological distress scale for the outcome. Telework jetlag was significantly associated with psychological distress, and the ≥1 h group had a higher risk (odds ratio: 1.80) of developing high psychological distress (HPD) than the <1 h group in the multivariate analysis. Since most teleworkers are forced to have a hybrid work style that mixes going to work and teleworking, telework jetlag must be addressed to maintain the health of teleworkers.

Longitudinal assessment of lifestyle factors associated with nonrestorative sleep in Japan.

OBJECTIVE: Nonrestorative sleep (NRS) is common in the general global population. This study surveyed the incident/remission rate of NRS and identified related lifestyle factors in a general Japanese adult cohort. METHODS: Data from a Japanese health check-based cohort between the fiscal years 2011 and 2018 were obtained. NRS was assessed through a single item question, and socio-demographic and clinical data were assessed through self-reports. To identify potential correlates of NRS incidence/remission, Cox regression analysis (or survival analysis) was performed. RESULTS: Among the 135 609 individuals surveyed at baseline, data from 93 548 were considered for analysis. NRS exhibited incidence and remission rates of 11.3% and 15.4%, respectively. New NRS incidence was predicted by eating fast (hazard ratio [HR]: 1.07, 95% confidence interval [CI]: 1.04-1.10), dining close to bedtime (HR: 1.33, 95% CI: 1.27-1.38), midnight snacking (HR: 1.09, 95% CI: 1.04-1.13), skipping breakfast (HR: 1.16, 95% CI: 1.10-1.22), non-regular exercise (HR: 1.12, 95% CI: 1.07-1.17), lower levels of physical activity (HR: 1.19, 95% CI: 1.14-1.24), and slow walking speed (HR: 1.34, 95% CI: 1.29-1.39), while heavy drinking was less predictive of NRS. However, the same factors (except for heavy drinking) were found to predict NRS remission. CONCLUSIONS: We found that unhealthy lifestyle behaviors, particularly dining close to bedtime and slow walking speed, were positively associated with NRS incidence, while they were negatively associated with NRS remission. These results can be useful in developing more effective health promotion policies to achieve good sleep.

Impact of chronotype, insomnia symptoms, sleep duration, and electronic devices on nonrestorative sleep and daytime sleepiness among Japanese adolescents.

OBJECTIVES: Nonrestorative sleep (NRS) and excessive daytime sleepiness (EDS) are important indicators of daytime dysfunction. Electronic media use before bedtime greatly affects adolescent sleep quality. However, few studies have examined factors associated with these symptoms. Therefore, we aimed to investigate the impact of chronotype, electronic device use before bedtime, and insomnia symptoms on NRS and EDS in Japanese adolescents. METHODS: A web-based cross-sectional survey of 2067 adolescents was conducted in 2022 to mainly assess sleep-related issues (sleep duration, chronotype, insomnia symptoms, NRS, and EDS), time spent using electronic devices, physical activity, and mental health. RESULTS: We analyzed data of 1880 adolescents (age, 16.4 ± 0.8 years; males, 56.7%). NRS and EDS prevalence rates were 54.9% and 39.4%, respectively. In multivariate analysis, evening chronotype [odds ratio (OR): 2.14, 95% confidence interval (CI): 1.58-2.89], difficulty initiating sleep (OR: 1.94, 95% CI: 1.43-2.64), <5 h sleep (OR: 1.77, 95% CI: 1.24-2.54), 5-6 h sleep (OR: 1.52, 95% CI: 1.20-1.93), and using electronic devices just before bedtime (OR: 1.48, 95% CI: 1.08-2.04) were associated with NRS. Evening chronotype (OR: 1.40, 95% CI: 1.07-1.82), early morning awakening (OR: 1.60, 95% CI: 1.02-2.50), using electronic devices just before bedtime (OR: 2.08, 95% CI: 1.48-2.93), and using electronic devices 30 min before bedtime (OR: 1.57, 95% CI: 1.07-2.29) were associated with EDS. CONCLUSION: Chronotype may be an important factor influencing NRS and EDS. Discontinuing electronic device use at least 30 min before bedtime could benefit affected adolescents.

Trends and socioeconomic inequities in insomnia-related symptoms among Japanese adults from 1995 to 2013.

BACKGROUND: Although insomnia prevalence is increasing in developed countries, little is known about trends in sleep problems among Japanese adults according to socioeconomic status. Therefore, we aimed to determine trends and socioeconomic inequalities in insomnia-related symptom (IRS) in Japan using nationally representative data. METHODS: The IRSs were based on past subjective sleeping difficulty. Using data from the Comprehensive Survey of Living Conditions for every 3 years from 1995 to 2013, we built multivariable Poisson regression models, with IRS as an outcome and survey year and socioeconomic status variables as explanatory variables. RESULTS: Data from 513,223 Japanese adults were analyzed. Age- and sex-adjusted IRS prevalence was the lowest in 1995, highest in 2007, and decreased from 2007 to 2013. The IRSs were more frequently reported in unemployed or self-employed individuals aged 20-64 years; those with the lowest household expenditure level, except among women aged ≥65 years; and those divorced, separated, or single, especially among women aged 20-64 years. LIMITATIONS: First, the repeated cross-sectional study design prevented the exclusion of the possibility of reversal of causality between factors. Second, data on insomnia-related lifestyle behaviors were unavailable. Third, the IRSs examined did not meet established clinical criteria for clinical insomnia. Fourth and fifth, information and selection biases could exist because of self-reported data and a small sample size, respectively. CONCLUSIONS: These results could aid in developing more effective prevention strategies for sleep problems and provide benchmarks for monitoring sleep health trends in Japan and other East Asian countries.

Nonrestorative sleep is a risk factor for metabolic syndrome in the general Japanese population.

BACKGROUND: This longitudinal study aimed to investigate the effects of nonrestorative sleep on developing metabolic syndrome (MetS) and related diseases in a general Japanese middle-aged population. METHODS: Overall, 83,224 adults without MetS (mean age: 51.5 ± 3.5 years) from the Health Insurance Association in Japan were followed up for a maximum of 8 years between 2011 and 2019. The Cox proportional hazard method was used to determine whether nonrestorative sleep, assessed using a single-item question, was significantly associated with the respective development of MetS, obesity, hypertension, diabetes, and dyslipidemia. The MetS criteria were adopted by the Examination Committee for Criteria of Metabolic Syndrome in Japan. RESULTS: The mean follow-up duration was 6.0 years. The incidence rate of MetS was 50.1 person-years/1,000 during the study period. Data suggested that nonrestorative sleep was associated with MetS (hazard ratio [HR]: 1.12, 95% confidence interval [CI]: 1.08-1.16) and other disorders, such as obesity (HR: 1.07, 95% CI: 1.02-1.12), hypertension (HR: 1.07, 95% CI: 1.04-1.11), and diabetes (HR: 1.07, 95% CI: 1.01-1.12) but not with dyslipidemia (HR: 1.00, 95% CI: 0.97-1.03). CONCLUSIONS: Nonrestorative sleep is associated with the development of MetS and many of its core components in the middle-aged Japanese population. Therefore, assessing nonrestorative sleep may help identify individuals at a risk of MetS development.

Comparison of the responses of cross-sectional web- and paper-based surveys on lifestyle behaviors of Japanese adolescents.

Objective: In Japan, paper-based surveys are currently more effective than web-based surveys. This study compared the response rates and lifestyle behaviors between paper- and web-based surveys conducted among Japanese junior and senior high schools. Methods: In total, there were 42 and 64 junior and senior high schools, respectively, for the web-based surveys and 20 and 27 junior and senior high schools, respectively, for the paper-based surveys. The questionnaire covered lifestyle behaviors (e.g., alcohol consumption, smoking, exercise, eating, and sleep status), mental health, and plans to attend college. School- and student-level response rates by survey method were assessed, and so was the effect on the reporting of each lifestyle behavior using logistic regression models. Results: The school response rates were 16.0% and 38.3% for web- and paper-based surveys, respectively. The student response rates were 88.7% and 77.2%, respectively. The web-based group had significantly more female participants and lower response rates for higher grades in senior high schools. The odds of lifetime and current alcohol consumption and poor mental health were lower, whereas those of lifetime use of conventional cigarettes, shorter sleep duration, and plans to continue attending college were higher among web-based (vs. paper-based) participants. Conclusions: The school response rate was poor in the web-based survey. However, whether the differences in lifestyle behavior are attributed to selection bias or the survey method remains unclear.