Relationship between rest-activity rhythms and cardiorespiratory fitness in middle-aged workers: a cross-sectional study with non-parametric analysis using accelerometers worn on the thigh.

BACKGROUND: Rest-activity rhythms are directly related to health risks, but there are limited objective methods to assess them. This study aimed to investigate the relationship between rest-activity rhythms and cardiorespiratory fitness (CRF) in middle-aged workers. METHODS: Peak oxygen uptake was measured on a treadmill to assess CRF in 254 middle-aged workers who were divided into low, medium, and high-CRF groups based on tertiles. Participants were asked to wear an accelerometer (activPAL) on their thighs for 1 week, and the logarithmically transformed acceleration data were used for the analysis of a 24-hour rest-activity rhythm. Sex, age, body mass index, occupation, smoking status, and alcohol consumption were used as covariates in Model 1, with Model 2 also including walking count on non-workdays. Repeated measures analysis of variance was used to compare time course of rest-activity rhythms changes on workdays between groups, and post-hoc tests were conducted using Bonferroni's correlation. RESULTS: Higher CRF correlated with increased physical activity. In model 1, higher CRF showed improved interdaily stability, but the significant difference disappeared in model 2 after adjusting for non-workday walking counts. A time-course group comparison showed that the high group had significantly higher activity levels than those of the low group from 6:00 to 8:59 and 17:00 to 17:59 and the medium group from 6:00 to 7:59 and 19:00 to 19:59. CONCLUSIONS: Workers who have better rest-activity rhythms and engage in higher levels of physical activity on workdays tend to have higher CRF levels. Regular daily routines, influenced by physical activity during holidays, can positively impact cardiopulmonary endurance.

Characteristics of long working hours and subsequent psychological and physical responses: JNIOSH cohort study.

OBJECTIVES: This study aimed to examine the prospective association among objectively measured average working hours (AWHs), frequency of long working hours (FLWHs; defined as ≥205 working hours/month (≥45 hours/week)) for 6 months, and workers' self-reported psychological and physical health. METHODS: The study included 15 143 workers from 5 Japanese companies. We collected monthly attendance records over 6 months before distributing a questionnaire survey on psychological/physical stress responses and work-related demographics. We then evaluated the associations of those attendance records with psychological/physical measures using analysis of covariance adjusted for sex, age, employment, job type, working conditions, work site and experience of emergency state due to COVID-19. RESULTS: Irritability, anxiety and depression were significantly greater at ≥180 hours (≥45 hours/week), and fatigue and lack of vigour were greater at ≥205 hours than those of the normal working-hour group (140-180 hours/month [35-45 hours/week]). Psychological indices increased significantly with FLWH, with ≥3 times for irritability, depression and fatigue; ≥2 times for lack of vigour; and ≥1 time for anxiety when compared with no long working hours. No significant associations were observed between AWH or FLWH and physical stress responses. CONCLUSIONS: Longer AWH was associated with higher levels of psychological stress responses. The effects of FLWH in the past 6 months varied among the psychological stress responses and did not occur for physical complaints. Under circumstances requiring long hours, workers' mental health should be protected through minimising the frequency of long work hours.

Estimation methods to detect changes in cardiorespiratory fitness due to exercise training and subsequent detraining.

PURPOSE: To determine whether estimated maximal oxygen consumption ([Formula: see text]) can detect cardiorespiratory fitness (CRF) changes by behavioral modifications. This study compared changes in measured [Formula: see text]O2max (m[Formula: see text]O2max) through exercise intervention with e[Formula: see text]O2max using a multiple regression model (MRM) and linear extrapolation method (LEM). METHODS: A cross-sectional analysis involving 173 adults was conducted to establish an MRM by including age, sex, body mass index, questionnaire score, heart rate (HR) from step test, and m[Formula: see text]O2max. Subsequently, 15 men participated in an intervention experiment comprising an 8-week, high-intensity interval training, followed by 8-week detraining, and completed anthropometric measurements, questionnaires, step tests, and m[Formula: see text]O2max tests. m[Formula: see text]O2max changes throughout the intervention were compared to e[Formula: see text]O2max changes calculated using the MRM and LEM. The LEM used the HR during the step test with constant values (predetermined [Formula: see text]O2), such as the Chester step test. RESULTS: Inclusion of the step test HR in a questionnaire-based MRM improved the estimation power, although the MRM underestimated higher m[Formula: see text]O2max values. In the intervention, m[Formula: see text]O2max increased by 20.0 ± 14.1% (P < 0.01) and subsequently decreased by 9.5 ± 6.6% (P < 0.01) after exercise training and detraining, respectively. Significant method × time interactions were observed between m[Formula: see text]O2max and e[Formula: see text]O2max in the MRM but not in the LEM, i.e., an apparent systematic error (underestimation of high values) of the MRM was absent in the LEM, although the correlation between m[Formula: see text]O2max and e[Formula: see text]O2max using the LEM was moderate. CONCLUSION: e[Formula: see text]O2max, particularly using the MRM with HR as an explanatory factor, is not an appropriate method for detecting CRF changes along with behavioral modifications. CLINICAL TRIAL REGISTRATION: Registered number, UMIN000041031; Registered date, 2020/07/08; URL, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046855.

Mediating and Moderating Effects of Psychological Detachment on the Association Between Stressors and Depression: A Longitudinal Study of Japanese Workers.

OBJECTIVES: This study examines the mediating and moderating effects of psychological detachment (PD) based on the stressor-detachment model in the long term. METHODS: Two waves of Web-based surveys, 28 months apart, yielded 3556 responses from Japanese workers. Comparisons between models that included mediating and moderating effects of PD and reverse direction mediating effects (strain → PD → stressor) were made by structural equation modeling. Differences in depression as a strain between combinations of high and low stressors and PD were also examined. RESULTS: The best-fitting model was the moderation/reciprocal partial-mediation model. The effect of PD was significant in the group with stable or decreasing stressor. CONCLUSION: According to the worker's level of stressors, PD, and depression, targeted interventions may effectively prevent physical and mental health problems caused by chronic stress.

Association of sitting time and cardiorespiratory fitness with cardiovascular disease risk and healthcare costs among office workers.

Evidence of the impact of domain-specific sitting time (ST) and cardiorespiratory fitness (CRF) on cardiovascular disease (CVD) risk is currently limited. This study aimed to examine the associations between CRF and domain-specific STs in relation to CVD risk and annual healthcare costs among office workers. This cross-sectional study included 1,749 workers from an insurance company. The Worker's Living Activity-time Questionnaire was used to measure the domain-specific STs, including occupational ST and non-working day ST. Additionally, estimated maximal oxygen uptake as the CRF data was calculated using a validated equation: 59.96 - 0.23 × age + 7.39 × sex - 0.79 × body mass index + 0.33 × physical activity score. The company provided medical checkup results for CVD risk factors and healthcare costs. Multiple logistic regression analyses were used to calculate the odds ratios (ORs) for CVD risk. Significantly lower ORs for CVD risk were seen only with high CRF levels, and it was also associated with low annual healthcare costs. There were no associations between domain-specific STs and annual healthcare costs. Further explorations of domain-specific STs, physical activity, and health risks are warranted, and guidelines should focus on increasing CRF to prevent CVD risk among office workers.

Association of cardiorespiratory fitness with the risk factors of cardiovascular disease: Evaluation using the Japan step test from the National Institute of Occupational Safety and Health.

OBJECTIVE: Cardiorespiratory fitness (CRF) is an important factor for evaluating cardiovascular disease (CVD) risk. We recently developed a novel method (National Institute of Occupational Safety and Health, Japan step test [JST]) for evaluating CRF in workers; its criterion validity has been investigated. However, its association with health risk must be confirmed before its application in the workplace. Therefore, we aimed to determine the association of JST-evaluated CRF with the prevalence of CVD risk among Japanese workers. METHODS: For CRF evaluation, working adults completed the JST, which comprised a 3-minute stepping exercise and a 2-minute recovery period. Data on CVD risk factors and clinical history were collected through medical certification within 1 year from the date of the JST measurements. Participants were divided into three groups for multiple logistic regression analyses based on the JST values (low, moderate, and high). Odds ratios (ORs) for the prevalence of CVD risk were calculated. RESULTS: We recruited 885 working adults (46.4% women). The prevalence of CVD risk in the total population was 18.6%. When compared to the reference group (low CRF), the ORs for CVD risk prevalence after adjustments for lifestyle factors (smoking status, alcohol consumption status, and exercise habits) were 0.42 (95% confidence interval [CI], 0.28-0.63) and 0.29 (95% CI, 0.18-0.45) for the moderate and high groups, respectively. CONCLUSION: An inverse association was noted between the JST-evaluated CRF and CVD risk prevalence. JST may be helpful for identifying workers at risk for CVD development.

Health problems associated with single, multiple, and the frequency of months of objectively measured long working hours: a cohort study by the National Institute of Occupational Safety and Health, Japan.

PURPOSE: We aimed to examine the prospective associations of monthly working hours measured in a month, the 6-month averaged hours, and the frequency of long working hours (≥ 205 h/month) during the past 6 months with health indicators. METHODS: This study included 6,806 Japanese company workers (response rate = 86.6%). Data on the workers' monthly attendance during the second half of fiscal year 2016 and annual health checkups in fiscal years 2016 and 2017 were collected. We evaluated the association of the above three types of monthly working hours with subsequent health checkup data in fiscal year 2017. We adjusted for the corresponding data in fiscal year 2016. RESULTS: Multivariate logistic regression analyses revealed significant associations between monthly working hours and workers' systolic and diastolic blood pressure as well as aspartate aminotransferase, alanine aminotransferase, low-density lipoprotein cholesterol (LDL), and triglyceride levels. However, the associations were not consistent between months. The average monthly working hours were significantly associated with higher LDL levels for the 220-240 h/mo group (OR: 1.49, 95%CI: 1.07-2.08) and lower triglyceride levels for the < 140 h/mo group (OR: 0.15, 95%CI: 0.03-0.77), compared to the 140-180 h/mo group. The frequency of long working hours was significantly associated with higher LDL levels. CONCLUSIONS: Working hours over several months produced various associations with health indicators compared to those measured in a single month. Our present data suggest that the effects of average or frequency of long working hours during the past 6 months are likely to appear in LDL levels.

Prospective changes in sleep problems in response to the daily rest period among Japanese daytime workers: A longitudinal web survey.

The daily rest period (DRP) is the daily inter-work interval and can include a sleep opportunity, leisure time, and other non-work time. A longer DRP may allow workers to increase time in bed (TIB) and adjust sleep timing, and that may reduce sleep problems such as short sleep duration, sleep debt, social jetlag, and poor sleep quality. The present study examined the longitudinal association between the DRP and these sleep problems among Japanese daytime workers. The DRP, TIB on workdays, sleep quality (Pittsburgh Sleep Quality Index [PSQI]), sleep debt and social jetlag were measured in November 2016 (n = 10,000) and February 2019 (n = 3,098). Of these, 955 permanent daytime workers were divided into five groups based on the change in the DRP duration: shortened ≥2 hr, shortened ≥1 hr, no change (<1 hr), extended ≥1 hr and extended ≥2 hr. Linear mixed-model analysis revealed significant interaction (group × time) effects on the TIB, PSQI score and sleep debt (all p < 0.001), but not on social jetlag (p = 0.476). Post hoc comparisons revealed that the TIB was decreased, and the sleep debt was increased in the shortened ≥2 hr group, whereas the TIB was increased and PSQI score was improved in the extended ≥2 hr group (all p < 0.01). These findings suggest that an extension of the DRP improves sleep quantity and quality but not sleep debt and social jetlag. Aside from extending the DRP, ensuring a sufficient sleep duration and adjusting sleep timing during the DRP may also be needed to prevent sleep problems.

Study profile: protocol outline and study perspectives of the cohort by the National Institute of Occupational Safety and Health, Japan (JNIOSH cohort).

How work burden affects physical and mental health has already been studied extensively; however, many issues have remained unexamined. In 2017, we commenced a prospective cohort study of workers at companies in Japan, with a follow-up period of 5-10 years, in order to investigate the current situation of overwork-related health outcomes. From 2017 to 2020, a target population of 150,000 workers across 8 companies was identified. Of these, almost 40,000 workers agreed to participate in the baseline survey. Data on working hours, medical check-up measurements, occupational stress levels, and lifestyle habits were collected. The average age of the participants at baseline was 39.2 ± 11.7 years; 73.1% were men, and 87.7% were regular employees. The most common working hours by self-reported was 41-50 hours per week during normal season, and it increased to more than 50 hours during busy season. Furthermore, more than half of the participants reportedly experienced a form of sleep problem, and the percentage of those who experienced nonrestorative sleep was particularly high.

Improved VO2max Estimation by Combining a Multiple Regression Model and Linear Extrapolation Method.

Maximal oxygen consumption (VO2max) is an important health indicator that is often estimated using a multiple regression model (MRM) or linear extrapolation method (LEM) with the heart rate (HR) during a step test. Nonetheless, both methods have inherent problems. This study investigated a VO2max estimation method that mitigates the weaknesses of these two methods. A total of 128 adults completed anthropometric measurements, a physical activity questionnaire, a step test with HR measurements, and a VO2max treadmill test. The MRM included step-test HR, age, sex, body mass index, and questionnaire scores, whereas the LEM included step-test HR, predetermined constant VO2 values, and age-predicted maximal HR. Systematic differences between estimated and measured VO2max values were detected using Bland-Altman plots. The standard errors of the estimates of the MRM and LEM were 4.15 and 5.08 mL·kg-1·min-1, respectively. The range of 95% limits of agreement for the LEM was wider than that for the MRM. Fixed biases were not significant for both methods, and a significant proportional bias was observed only in the MRM. MRM bias was eliminated using the LEM application when the MRM-estimated VO2max was ≥45 mL·kg-1·min-1. In conclusion, substantial proportional bias in the MRM may be mitigated using the LEM within a limited range.

Validity of Domain-Specific Sedentary Time Using Accelerometer and Questionnaire with activPAL Criterion.

Accelerometers based on the cut-point method are generally the most used in sedentary time (ST) research. However, mixed cut-points are an issue, so an accelerometer based on metabolic equivalents (METs) could be used as an alternative. This study aimed to validate a METs-based accelerometer (HJA-750C, OMRON) and a questionnaire that estimates domain-specific sedentary time measures using activPAL as a criterion value. We also examined whether measurement validity differed according to gender and occupation. We used data from 242 workers in the validation study. Participants wore activPAL on the thigh and OMRON on the waist for seven consecutive days with daily recording logs. The Workers Living Activity-time Questionnaire (WLAQ) was administered once. The domain-specific ST assessed quantities of ST during commuting, working time, non-working time on a workday, and non-workday. Intraclass correlation coefficients (ICC) and Spearman's rho coefficients were then used to conduct analyses. The OMRON accelerometer showed acceptable values (r = 0.67-0.86 and ICC of 0.63-0.87) in the overall domain-specific ST. Additionally, each measurement result suggested that working time is the most accurate domain to measure ST (ICC of 0.87 for OMRON and 0.68 for WLAQ). Moreover, there were no differences in the overall validity of the results according to gender and occupation. The METs-based accelerometer has acceptable validity for ST measurements to be used among workers. Additionally, working time may be the preferred domain for the accurate assessment of ST in both objective and subjective measurements. These results can advance the quality of the sedentary research field.

A favorable metabolic profile in metabolically healthy obesity is associated with physical activity level rather than abdominal fat volume in Japanese males.

[Purpose] To determine the potential factors for difference in metabolic profiles between metabolically healthy obesity and metabolically unhealthy obesity, we investigated the difference in abdominal fat volume, metabolic characteristics, and physical activity levels between metabolically healthy obesity and metabolically unhealthy obesity identified with cardiovascular disease risk factors in Japanese males. [Participants and Methods] Of 305 volunteers recruited, 130 obese males (age: 46.9 ± 8.9 years; body mass index: 29.6 ± 3.5 kg/m2) met the criteria for the study. They were divided into two groups; metabolically healthy obesity and metabolically unhealthy obesity according to cardiovascular disease risk factors including low-density lipoprotein cholesterol. Abdominal fat volumes were measured using magnetic resonance imaging. Cardiovascular disease risk factors and metabolic characteristics were evaluated by blood pressure and blood parameters. Physical activity levels were measured using an accelerometer. [Results] Despite the fact that metabolically healthy obesity had a more favorable metabolic profile than the metabolically unhealthy obesity, no significant differences in visceral and subcutaneous fat volumes were found between the two groups. Moreover, the metabolically healthy obesity had a significantly greater physical activity expenditure and moderate-to-vigorous physical activity level than the metabolically unhealthy obesity. [Conclusion] A more favorable metabolic profile in metabolically healthy obesity may be associated with physical activity level rather than abdominal fat volumes in Japanese males.

Socioeconomic status relates to exercise habits and cardiorespiratory fitness among workers in the Tokyo area.

OBJECTIVES: This survey aims to investigate consciousness regarding habitual exercise among workers in urban areas and to analyze the associations of workers' socioeconomic status with their habitual exercise and cardiorespiratory fitness (CRF). METHODS: Ten thousand participants, who worked in the Tokyo area of Japan, were recruited for the questionnaire-based survey. The questionnaire elicited participant's characteristics, socioeconomic status (eg, employment status and annual income), habitual exercise status, and consciousness regarding exercising. After the data-cleaning procedure, 9406 participants were selected for analyses. CRF was estimated by a validated equation model. RESULTS: Some (32.9%) participants had an exercise habit, and 93% recognized that exercise is good for health. Of the nonexercise habit group (n = 6308), 73% wanted to develop an exercise habit, and "spare time (40%)" and "financial capability (16%)" were the two most necessary conditions for habituating exercise. As socioeconomic statuses increased, the odds ratios (ORs) for engaging in habitual exercise increased among full-time (1.22) versus part-time (reference) employees and those having high (1.76) versus low (reference) incomes, whereas the ORs for low CRF risk decreased among full-time (0.78) versus part-time (reference) employees and those having high (0.53) versus low (reference) incomes. CONCLUSIONS: Although most workers recognized the benefits of exercise, many were unable to develop exercise habits and believed that they could develop exercise habits if they had the time and financial capabilities. The survey suggests that workers with a higher socioeconomic status more likely to obtain favorable physical fitness, indicating a health disparity among workers in urban areas.

Impact of health literacy on health practices in the working life of young Japanese nurses and care workers.

To continue to work healthily, health practices are necessary. This study assessed the impact of health literacy (HL) on health practices in the working life of young Japanese nurses and care workers, occupations with heavy physical and psychological burdens. A web-based survey was conducted with 500 women (330 nurses and 170 care workers) under the age of 30 in 2019. Data regarding their demographic characteristics, HL and health practices in their working life were collected. A significant association was found between high HL and better health practices, such as being likely to rest when tired, working at their own pace maintaining a good work-life balance and regularly performing self-check-ups, which were common to nurses and care workers. In addition, sub-analysis among the high-HL group revealed that the attendance of lectures regarding working life and health for new employees was effective for taking rest when needed, working when not overtired and a good work-life balance. The results of this study suggest that high HL relates to healthy practices in the working life of young Japanese nurses and care workers. Increasing HL or fundamentally enhancing attitudes towards their own health or both may, therefore, have some benefits for healthy working practices.

Daytime Workers with Longer Daily Rest Periods Have Smaller Sleep Debt and Social Jetlag: A Cross-Sectional Web Survey.

Objectives: The work interval duration between the end of one workday and the start of the following workday is referred to as the daily rest period (DRP). The present study examined whether DRP - a proxy for sleep opportunity between work shifts - is associated with indicators of sleep debt and social jetlag among daytime workers. Methods: We used a web-based survey to gather data on demographics, average DRP in the previous month, time in bed (TIB), bedtime, wake-up time, and sleep timing on workdays and non-workdays. The Japanese daytime workers (n = 3,914) were divided into seven DRP groups (hours) as follows: <11, 11, 12, 13, 14, 15, and ≥16. Results: The two-way analyses of covariance (DRP group x day) for TIB, mid-sleep as sleep timing, bedtime, and wake-up time showed significant interactions (all p < .001). Specifically, TIB was significantly shorter, and mid-sleep and wake-up time were significantly earlier on workdays than on non-workdays, across all DRP groups (all p < .001). Additionally, the different values for TIB (sleep debt), sleep timing (social jetlag), bedtime, and wake-up time were calculated by subtracting workdays from non-workdays. The trend analysis showed that workers with longer DRP (sleep opportunity) had smaller differences in TIB, sleep timing, and wake-up time between workdays and non-workdays (all p < .001). Conclusions: Overall, daytime workers reported significant sleep debt and misalignment between work and free sleep-wake periods. However, workers with shorter DRPs (less sleep opportunity between shifts) reported significantly greater amounts of sleep debt and social jetlag than did workers with longer DRPs.

Objective and Subjective Working Hours and Their Roles on Workers' Health among Japanese Employees.

Table 3 of the above paper appeared incorrectly in print. Percentage figures on the table were inadvertently listed as negative values. These errors were corrected in online versions of this paper, as shown below.

Chemical and molecular bases of dome formation in human colorectal cancer cells mediated by sulphur compounds from Cucumis melo var. conomon.

Colorectal cancer was the third most commonly diagnosed malignant tumor and the fourth leading cause of cancer deaths worldwide in 2012. A human colorectal cancer cell line, RCM-1, was established from a colon cancer tissue diagnosed as a well-differentiated rectum adenocarcinoma. RCM-1 cells spontaneously form 'domes' (formerly designated 'ducts') resembling villiform structures. Two sulphur-containing compounds from Cucumis melo var. conomon (Katsura-uri, or Japanese pickling melon), referred to as 3-methylthiopropionic acid ethyl ester (MTPE) and methylthioacetic acid ethyl ester (MTAE), can induce the differentiation of the unorganized cell mass of an RCM-1 human colorectal cancer cell culture into a dome. However, the underlying molecular mechanisms of such dome formation have not been previously reported. Here, we performed a structure-activity relationship analysis, which indicated that methylthioacetic acid (MTA) was the lowest molecular weight compound with the most potent dome-inducing activity among 37 MTPE and MTAE analogues, and the methylthio group was essential for this activity. According to our microarray analysis, MTA resulted in down-regulation of 537 genes and up-regulation of 117 genes. Furthermore, MTA caused down-regulation of many genes involved in cell-cycle control, with the cyclin E2 (CCNE2) and cell division cycle 25A (CDC25A) genes being the most significantly reduced. Pharmacological analysis showed that the administration of two cell-cycle inhibitors for inactivating CDC25A phosphatase (NSC95397) and the cyclin E2/cyclin-dependent kinase 2 complex (purvalanol A) increased the dome number independently of MTA. Altogether, our results indicate that MTA is the minimum unit required to induce dome formation, with the down-regulation of CDC25A and possibly CCNE2 being important steps in this process.

Estimating cardiorespiratory fitness from heart rates both during and after stepping exercise: a validated simple and safe procedure for step tests at worksites.

PURPOSE: Step test protocols are typically based on the heart rate (HR) measured either during exercise or during recovery. This study developed a new step test protocol to estimate maximal oxygen consumption ([Formula: see text]) based on HRs measured during and after exercise, assessed the criterion validity of the model, and evaluated the protocol's test-retest reliability. METHODS: The protocol estimates [Formula: see text] from HR measurements made once a minute during 3 min of step exercise and 2 min of recovery. The model was derived using a group of 118 working adults and cross-validated using a second group of 74 working adults. Furthermore, [Formula: see text] was measured using a conventional treadmill test. While multiple regression analyses were used to develop prediction equations for [Formula: see text], intraclass correlation coefficients (ICCs) were used to examine test-retest reliability. RESULTS: HRs during and after exercise significantly correlated with the measured [Formula: see text]. The highest correlation (r = - 0.61) was for an HR index that combined values of HRs during and after exercise. A model including age, sex, body mass index, and the HR index accounted for 60% of the variance in measured [Formula: see text] (standard error of the estimate, 4.05 mL kg-1 min-1 or 10.5%). Cross-validation analyses demonstrated good stability of the [Formula: see text] prediction models. The ICC for the HR index was 0.65 (0.53-0.74), indicating fair to good reliability. CONCLUSION: The HR index, based on a combination of HR measurements during and after stepping exercise, offers a validated [Formula: see text] estimation procedure suitable for use in the workplace.

Effect of work-related events on depressive symptoms in Japanese employees: a web-based longitudinal study.

While a number of work-related events have been proposed as risk factors for depression, a majority of studies have focused only on a few events in a single study. Therefore, we conducted a web-based longitudinal study to comprehensively investigate the impact of various work-related events on depressive symptoms. Ten thousand Japanese workers representing the Japanese working population were recruited online and questioned on their experiences of 36 work-related events in the past year. Their depressive symptoms were also assessed based on the Center for Epidemiologic Studies Depression Scale. Two years later, 3,098 participants responded to a follow-up study. By excluding 1,030 participants who were classified as being depressed in the baseline survey, data of 2,068 participants were analyzed. Odds ratios (OR) were calculated using multivariate logistic regression to assess the effect of work-related events on depressive symptoms. Sixteen events were found to be risk factors and were sorted into four types as follows: experience of an accident or disaster (OR: 4.78-7.67), excessive responsibility (OR: 3.01-3.62), drastic change in workstyle or workload (OR: 2.38-3.08), and interpersonal conflict (OR: 2.41-11.16). The current results, including magnitude relationship of ORs, should be utilized for promoting psychosocially healthy work environment.

Contribution of Katsura-uri (Japan's Heirloom Pickling Melon, Cucumis melo var. conomon) at the Completely Ripe Stage to Diabetes Control.

The fruit of Katsura-uri (Japan's heirloom pickling melon, Cucumis melo var. conomon) possesses a fruity aroma and moderate sweetness. The fruit juice has potential to minimize human postprandial blood glucose levels. This study provides information regarding the health benefits of Katsura-uri and its utility in treating diabetes. The study methodology involved measuring the color and firmness of Katsura-uri fruit at five ripening stages, and quantitation of the aroma substances, proximate composition, and sugars. Significant changes were detected in the color, firmness, and level of aroma substances with ripening of Katsura-uri fruit, albeit with no major changes in proximate composition, with the exception of dietary fiber, and sugars. To determine the effects of Katsura-uri juice, the blood glucose levels of ten diabetic volunteers aged 46-75 y were monitored after its consumption, and compared with after consumption of muskmelon juice equivalent to the total weight of Katsura-uri juice. The blood glucose area under the curve level was significantly lower after consumption of Katsura-uri juice (16±5 h • mg/dL) than after consumption of muskmelon juice (55±17 h • mg/dL; p<0.05). The level of the glucose spike was also significantly lower after consumption of Katsura-uri juice (22±5 mg/dL) than after consumption of muskmelon juice (64±6 mg/dL; p<0.05). The completely ripe Katsura-uri fruit provides the best results for diabetic subjects, which is the first case of fruits sweetened with the addition of zero-calorie sweeteners.