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.

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.

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]O_2max (m[Formula: see text]O_2max) through exercise intervention with e[Formula: see text]O_2max 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]O_2max. 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]O_2max tests. m[Formula: see text]O_2max changes throughout the intervention were compared to e[Formula: see text]O_2max 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]O_2max values. In the intervention, m[Formula: see text]O_2max 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]O_2max and e[Formula: see text]O_2max 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]O_2max and e[Formula: see text]O_2max using the LEM was moderate.

CONCLUSION

e[Formula: see text]O_2max, 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.

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

Maximal oxygen consumption (VO_2max) 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 VO_2max 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 VO_2max 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 VO_2max 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 VO_2max 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.

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.

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.

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.

OPERA tau neutrino charged current interactions

The OPERA experiment was designed to discover the vτ appearance in a vμ beam, due to neutrino oscillations. The detector, located in the underground Gran Sasso Laboratory, consisted of a nuclear photographic emulsion/lead target with a mass of about 1.25 kt, complemented by electronic detectors. It was exposed from 2008 to 2012 to the CNGS beam: an almost pure vμ beam with a baseline of 730 km, collecting a total of 1.8·1020 protons on target. The OPERA Collaboration eventually assessed the discovery of vμ→vτ oscillations with a statistical significance of 6.1 σ by observing ten vτ CC interaction candidates. These events have been published on the Open Data Portal at CERN. This paper provides a detailed description of the vτ data sample to make it usable by the whole community.

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.

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.

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.

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.

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.

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.

Expression profiles of four BES1/BZR1 homologous genes encoding bHLH transcription factors in Arabidopsis

Arabidopsis bHLH-type transcription factors-BRASSINOSTEROID INSENSITIVE 1-EMS-SUPPRESSOR 1 (BES1) and BRASSINAZOLE RESISTANT 1 (BZR1)-play key roles in brassinosteroid (BR) signaling. By contrast, the functions of the other four BES1/BZR1 homologs (BEH1-4) remain unknown. Here, we describe the detailed expression profiles of the BES1/BZR1 family genes. Their expressions were distinct regarding growth-stage dependence and organ specificity but exhibited some overlaps as well. Furthermore, their mRNA levels mostly remained unchanged responding to seven non-BR phytohormones. However, BEH1 and BEH2 were downregulated by brassinolide, suggesting a close association with the BR function. Additionally, BEH4 was ubiquitously expressed throughout the life of the plant but displayed some expression preference. For instance, BEH4 expression was limited to guard cells and the adjacent pavement cells in the leaf epidermis and was induced during growth progression in very young seedlings, suggesting that BEH4 is specifically regulated in certain contexts, although it is almost constitutively controlled.

Association of abdominal fat with metabolic syndrome components in overweight women: effect of menopausal status

BACKGROUND

The association between abdominal fat distribution and metabolic syndrome (MetSyn) components by menopausal status has yet to be explicated. The purpose of this study was to examine a cross-sectional association between abdominal fat compartments and MetSyn components in pre- and post-menopausal overweight Japanese women.

METHODS

Of 212 overweight Japanese women, 76 pre-menopausal overweight (BMI ≥ 25) women (PreM age, 42.1 ± 5.9 years) and 87 post-menopausal overweight women (PostM: age, 56.2 ± 4.5 years) were analyzed in this study. Measurements were taken for body mass index (BMI), abdominal compartments [visceral fat (VF), subcutaneous fat (SF), superficial subcutaneous fat (SSF), and deep subcutaneous fat (DSF)], serum high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol, triglycerides (TG), and fasting plasma glucose (FPG). Abdominal compartments were assessed using computed tomography.

RESULTS

No significant differences were found for BMI, SF, SSF, or DSF between the PreM and PostM. Despite this, the PreM had a significantly smaller VF area than that of the PostM. However, the difference in VF area disappeared when age was adjusted for. VFA significantly correlated with HDLC, TG, and FPG independently of menopause status.

CONCLUSIONS

These results suggest that the effect of menopause status on the association between VF and MetSyn components is negligible. Abdominal subcutaneous fat compartments were not associated with MetSyn components in overweight women regardless of menopausal status.

Workers' physical activity data contribute to estimating maximal oxygen consumption: a questionnaire study to concurrently assess workers' sedentary behavior and cardiorespiratory fitness

Background

Sedentary behavior (SB) and cardiorespiratory fitness (CRF) are important issues in occupational health. Developing a questionnaire to concurrently assess workers’ SB and CRF could fundamentally improve epidemiological research. The Worker’s Living Activity-time Questionnaire (WLAQ) was developed previously to assess workers’ sitting time. WLAQ can be modified to evaluate workers’ CRF if additional physical activity (PA) data such as PA frequency, duration, and intensity are collected.

Methods

A total of 198 working adults (93 women and 105 men; age, 30–60 years) completed anthropometric measurements, a treadmill exercise test for measuring maximal oxygen consumption (VO_2max), and modified WLAQ (m-WLAQ, which included questions about PA data additional to the original questions). Multiple regression analyses were performed to develop prediction equations for VO_2max. The generated models were cross-validated using the predicted residual error sum of squares method. Among the participants, the data of 97 participants who completed m-WLAQ twice after a 1-week interval were used to calculate intraclass correlation coefficient (ICC) for the test–retest reliability analyses.

Results

Age (r = − 0.29), sex (r = 0.48), body mass index (BMI, r = − 0.20), total sitting time (r = − 0.15), and PA score (total points for PA data, r = 0.47) were significantly correlated with VO_2max. The models that included age, sex, and BMI accounted for 43% of the variance in measured VO_2max [standard error of the estimate (SEE) = 5.04 ml·kg^− 1·min^− 1]. These percentages increased to 59% when the PA score was included in the models (SEE = 4.29 ml·kg^− 1·min^− 1). Cross-validation analyses demonstrated good stability of the VO_2max prediction models, while systematic underestimation and overestimation of VO_2max were observed in individuals with high and low fitness, respectively. The ICC of the PA score was 0.87 (0.82–0.91), indicating excellent reliability.

Conclusions

The PA score obtained using m-WLAQ, rather than sitting time, correlated well with measured VO_2max. The equation model that included the PA score as well as age, sex, and BMI had a favorable validity for estimating VO_2max. Thus, m-WLAQ can be a useful questionnaire to concurrently assess workers’ SB and CRF, which makes it a reasonable resource for future epidemiological surveys on occupational health.

Interleukin-18 is associated with the presence of interstitial lung disease in rheumatoid arthritis: a cross-sectional study

OBJECTIVE

Serum interleukin-18 (IL-18) levels are increased in patients with interstitial lung disease (ILD). In addition, IL-18 levels are increased in patients with rheumatoid arthritis (RA) and are associated with arthritis activity. We determined whether increased IL-18 levels are associated with ILD in RA.

METHOD

RA patients were enrolled using an RA cohort database. Plasma IL-18 levels were measured by enzyme-linked immunosorbent assay. ILD was determined by a pulmonologist and a radiologist based on chest radiography and computed tomography findings. IL-18 levels for RA with ILD and RA without ILD were compared. Associations between ILD and various markers including IL-18 and confounding factors (e.g. smoking history) were investigated by logistic regression analysis. Diagnostic values of IL-18 for the presence of ILD were investigated using receiver operating characteristics curve analysis.

RESULTS

ILD was complicated in 8.2% (n = 26) of the study population (N = 312). Plasma IL-18 levels were higher for RA patients with ILD than for RA patients without ILD (721.0 ± 481.4 vs 436.8 ± 438.9 pg/mL, p < 0.001). IL-18, Krebs von den Lungen-6, and anti-cyclic citrullinated peptide antibody titre and glucocorticoid doses were independently associated with the presence of ILD during multivariate logistic regression analysis. Sensitivity and specificity of IL-18 levels for the detection of ILD in RA patients were 65.3% and 76.3%, respectively (area under the curve = 0.73).

CONCLUSION

Plasma IL-18 levels were higher for RA patients with ILD than for those without ILD. Increased IL-18 levels were associated with the presence of ILD.

Final Results of the OPERA Experiment on ν_{τ} Appearance in the CNGS Neutrino Beam

The OPERA experiment was designed to study ν_{μ}→ν_{τ} oscillations in the appearance mode in the CERN to Gran Sasso Neutrino beam (CNGS). In this Letter, we report the final analysis of the full data sample collected between 2008 and 2012, corresponding to 17.97×10^{19} protons on target. Selection criteria looser than in previous analyses have produced ten ν_{τ} candidate events, thus reducing the statistical uncertainty in the measurement of the oscillation parameters and of ν_{τ} properties. A multivariate approach for event identification has been applied to the candidate events and the discovery of ν_{τ} appearance is confirmed with an improved significance level of 6.1σ. |Δm_{32}^{2}| has been measured, in appearance mode, with an accuracy of 20%. The measurement of the ν_{τ} charged-current cross section, for the first time with a negligible contamination from ν[over ¯]_{τ}, and the first direct evidence for the ν_{τ} lepton number are also reported.

Cross-sectional Internet-based survey of Japanese permanent daytime workers' sleep and daily rest periods

Objectives:

This study aimed to describe the sleep quantity, sleep quality, and daily rest periods (DRPs) of Japanese permanent daytime workers.

Methods:

Information about the usual DRP, sleep quantity, and sleep quality (Japanese version of the Pittsburgh Sleep Quality Index: PSQI-J) of 3,867 permanent daytime workers in Japan was gathered through an Internet-based survey. This information was analyzed and divided into the following eight DRP groups: <10, 10, 11, 12, 13, 14, 15, and ≥16 h.

Results:

The sleep durations for workers in the <10, 10, 11, 12, 13, 14, 15, and ≥16 h DRP groups were found to be 5.3, 5.9, 6.1, 6.3, 6.5, 6.7, 6.7, and 6.9 h, respectively. The trend analysis revealed a significant linear trend as the shorter the DRP, the shorter was the sleep duration. The PSQI-J scores for the <10, 10, 11, 12, 13, 14, 15, and ≥16 h DRP groups were 7.1, 6.7, 6.7, 6.3, 6.0 (5.999), 5.6, 5.2, and 5.2, respectively. The trend analysis revealed a significant linear trend as the shorter the DRP, the lower was the sleep quality.

Conclusions:

This study described sleep quantity, sleep quality, and DRP in Japanese daytime workers. It was found that a shorter DRP was associated with poorer sleep quantity as well as quality.

[Evaluation of Worker's Living Activity-time Questionnaire (JNIOSH-WLAQ) primarily to assess workers' sedentary behavior]

OBJECTIVES

The National Institute of Occupational Safety and Health, Japan (JNIOSH) developed a new Worker's Living Activity-time Questionnaire (JNIOSH-WLAQ) which primarily evaluates workers' sedentary behavior. The purpose of this study was to investigate the test-retest reliability and criterion validity of the WLAQ.

METHODS

One hundred and thirty eight workers completed the WLAQ twice in one week. During the week, they wore a thigh-worn inclinometer (activPAL) and maintained a daily log as criteria measurements. The WLAQ measures working time, commuting time, daily rest period (DRP), sleeping time, and time spent sitting within the four typical domains of a worker's life: (a) working time, (b) commuting time, (c) non-working time on a workday, and (d) non-workday. We calculated intraclass correlation coefficients (ICC) as a reliability value and Spearman's ρ as a validity value. Bland-Altman plots were used to assess any bias.

RESULTS

The analysis of WLAQ indicated favorable ICCs (0.72-0.98) for all living activity-times. The WLAQ had "strong" ρ values for working time (0.80) and DRP (0.83), a "very strong" ρ value for commuting time (0.96), and "moderate" ρ values for sleeping time during a workday (0.69) and a non-workday (0.53). As for the sitting time, the WLAQ had "moderate" ρ values for working time (0.67) and non-working time on a workday (0.59), a "strong" ρ value for commuting time (0.82), and a "low" ρ value for a non-workday (0.40). Bland-Altman plots showed a significant fixed bias for sitting time during working time and significant fixed and proportional biases for sitting time on a non-workday.

CONCLUSIONS

The study showed that the WLAQ has acceptable measurement features, which makes this questionnaire a reliable resource for future epidemiological surveys.

Evaluation of the effectiveness of the potent bis-quaternary ammonium compound, 4,4'-(α,ω-hexametylenedithio) bis (1-octylpyridinium bromide) (4DTBP-6,8) on Pseudomonas aeruginosa

AIMS

Quaternary ammonium compounds (QACs), including benzalkonium chloride (BAC) and cetylpyridinium chloride (CPC) are cationic surfactants and have been used widely as general disinfectants in the medical field due to their strong antibacterial effects and low cytotoxicity to human cells. 4,4'-(α,ω-hexametylenedithio) bis (1-octylpyridinium bromide) (4DTBP-6,8) is one of the potent bis-QACs synthesized to improve the antimicrobial activities of mono-QACs such as BAC. This study aimed to assess the effectiveness of 4DTBP-6,8 against Pseudomonas aeruginosa, a prevalent hospital pathogen.

METHODS AND RESULTS

The minimum inhibitory concentrations of 4DTBP-6,8, CPC and BAC against P. aeruginosa were measured. 4DTBP-6,8 exhibited strong antibacterial activity. We assessed the bactericidal effects of QACs against P. aeruginosa under certain conditions and their cytotoxicities in human epithelial cells using lactate dehydrogenase (LDH) release. 4DTBP-6,8 exerted excellent bactericidal effects against high concentrations of bacteria, biofilm cells and even in the presence of contaminated proteins. Cellular LDH was not released by the treatment with 4DTBP-6,8.

CONCLUSIONS

4DTBP-6,8 exhibited the strongest bactericidal activity against P. aeruginosa among the three QACs tested without any cytotoxicity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The potent bis-QAC, 4DTBP-6,8 has the potential to be an effective disinfectant in preventing hospital infections caused by P. aeruginosa.

Novel reuterin-related compounds suppress odour by periodontopathic bacteria

OBJECTIVE

Halitosis is caused by volatile sulphur compounds including methyl mercaptan (CH₃ SH) in the oral cavity and is a serious problem that limits interpersonal social communication. The aim of study was to evaluate the effects of reuterin-related compounds (RRCs) on halitosis-related periodontopathic bacteria in vitro.

MATERIALS AND METHODS

RRC-01, RRC-02 and RRC-03 (32 and 64 μg ml^-1 ) in culture media containing Fusobacterium nucleatum JCM8523 and Porphyromonas gingivalis ATCC33277 were used. The effects of RRCs on CH₃ SH production and detectable odour by F. nucleatum and P. gingivalis were examined by CH₃ SH production assay and organoleptic test, respectively. The number of bacterial cells was also measured using an ATP assay. In P. gingivalis treated with RRCs, the expression of mgl gene, which is responsible for CH₃ SH production, was examined by qRT-PCR.

RESULTS

CH₃ SH production and the score of detectable odour from F. nucleatum and P. gingivalis culture media containing RRCs were significantly lower than that without RRCs (P < 0.05). The expression of mgl gene in P. gingivalis was significantly downregulated by RRC-01 (P < 0.01), but not by RRC-02 or RRC-03.

CONCLUSIONS

RRCs are potent oral care products for preventing halitosis via reducing CH₃ SH production.

Caries-related Bacteria and Cytokines Induce CXCL10 in Dental Pulp

Marked infiltration of inflammatory cells, such as activated T-cells, is observed in the progression of pulpitis; however, little is known about the mechanism of their recruitment into pulpal lesions. It has been recently demonstrated that CXC chemokine ligand 10 (CXCL10) chemoattracts CXC chemokine receptor 3 (CXCR3)-positive activated T-cells. We therefore examined whether CXCL10 is involved in the pathogenesis of pulpitis. CXCL10 mRNA expression levels in clinically inflamed dental pulp were higher than those in healthy dental pulp. Immunostaining results revealed that CXCL10 was detected in macrophages, endothelial cells, and fibroblasts in inflamed dental pulp, and that CXCR3 expression was observed mainly on T-cells. Moreover, cultured dental pulp fibroblasts produced CXCL10 after stimulation with live caries-related bacteria, peptidoglycans, and pro-inflammatory cytokines. In contrast, heat-killed bacteria did not induce CXCL10 secretion. These findings suggest that CXCL10-CXCR3 may play an important role in the pulpal immune response to caries-related bacterial invasion. Abbreviations: CXCL10, CXC chemokine ligand 10; CXCR3, CXC chemokine receptor 3; IFN, interferon; FBS, fetal bovine serum; LTA, lipoteichoic acid; PGN, peptidoglycan; IL, interleukin; TNF, tumor necrosis factor; PBS, phosphate-buffered saline; ELISA, enzyme-linked immunosorbent assay; CCL, C-C chemokine ligand; TLR, Toll-like receptor; NOD, nucleotide oligomerization domain; HDPF, human dental pulp fibroblasts.

Pathogenic factors in Candida biofilm-related infectious diseases

Candida albicans is a commonly found member of the human microflora and is a major human opportunistic fungal pathogen. A perturbation of the microbiome can lead to infectious diseases caused by various micro-organisms, including C. albicans. Moreover, the interactions between C. albicans and bacteria are considered to play critical roles in human health. The major biological feature of C. albicans, which impacts human health, resides in its ability to form biofilms. In particular, the extracellular matrix (ECM) of Candida biofilm plays a multifaceted role and therefore may be considered as a highly attractive target to combat biofilm-related infectious diseases. In addition, extracellular DNA (eDNA) also plays a crucial role in Candida biofilm formation and its structural integrity and induces the morphological transition from yeast to the hyphal growth form during C. albicans biofilm development. This review focuses on pathogenic factors such as eDNA in Candida biofilm formation and its ECM production and provides meaningful information for future studies to develop a novel strategy to battle infectious diseases elicited by Candida-formed biofilm.

Chondroitin Sulfate Iron Colloid as MR Contrast Agent in Differentiation between Hepatocellular Carcinoma and Adenomatous Hyperplasia

Using a 1.5 T MR imaging unit, T1- and T2-weighted images were obtained before and after i.v. administration of chondroitin sulfate iron colloid (CSIC) in order to differentiate hepatocellular carcinoma (n = 20) from adenomatous hyperplasia without atypia (n = 16). Differentiation was made from the tumor-liver contrast to noise ratio (CNR) and visual evaluation of the nodule, with reference to signal intensity relative to that of the surrounding liver. The CNR of adenomatous hyperplasia was on T1-weighted images significantly decreased after CSIC administration (p < 0.01). On T2-weighted images, there was no significant difference in CNR after CSIC administration. On the other hand, the CNR of hepatocellular carcinoma was significantly increased after CSIC administration on both T1- and T2-weighted images (p < 0.01). CSIC reflects intratumor reticuloendothelial cellular functions, and is therefore useful in differentiating hepatocellular carcinoma from adenomatous hyperplasia without atypia.

A comparison of the prevalence of the metabolic syndrome and its components among native Japanese and Japanese Brazilians residing in Japan and Brazil

Background

This study investigated the prevalence of risk factors associated with the metabolic syndrome (MetSyn) among individuals of Japanese descent exposed to different cultural environments.

Design

A cross-sectional study to assess component risk factors for the diagnosis of MetSyn was undertaken in urban areas in Japan and Brazil. A total of 773 men and women aged 35 years or over were included in three groups: 249 native Japanese, 269 Brazilian individuals of Japanese ancestry residing in Japan, and 255 Brazilian individuals of Japanese ancestry residing in Brazil.

Results

Higher rates of metabolic abnormalities with respect to central obesity and serum lipid profiles were observed among Brazilian individuals of Japanese ancestry residing in Brazil compared with those residing in Japan and native Japanese. Likewise, an increased risk of hypertension was observed among Japanese Brazilian individuals residing in Japan. The prevalence of MetSyn in men was significantly higher among Brazilians of Japanese ancestry residing in Brazil (37.5%) compared with those residing in Japan (25.3%) or native Japanese (21.4%), whereas no significant difference was observed among women. In the logistic model, Brazilian individuals of Japanese ancestry residinginBrazil weretwice as likely to develop MetSyn compared with native Japanese, whereas no significant differences were found among those residing in Japan.

Conclusions

These findings underscore the significant heterogeneity in risk factors among communities of Japanese ancestry residing in Brazil and Japan, and suggest that immigrants exposed to the Brazilian cultural environment are more susceptible to the development of risk factors associated with MetSyn than native Japanese.

Percentage-Method Improves Properties of Workers' Sitting- and Walking-Time Questionnaire

Background

Does asking for the percentage of time spent sitting during work (P-method) instead of asking for the absolute length of time spent sitting (T-method) improve properties of the workers’ sitting- and walking-time questionnaire (WSWQ)? The purpose of this study was to investigate whether questioning technique influences test-retest reliability and criterion validity of the WSWQ.

Methods

Sixty-five Japanese workers completed each version of the WSWQ in random order. Both questionnaires assessed quantities of time spent sitting or walking (including standing) during work time, non-working time on a workday, and anytime on a non-workday. Participants wore the thigh-worn inclinometer (activPAL) as criterion measure. Intraclass correlation coefficients (ICC) and Spearman’s ρ were used for the analyses.

Results

For all three domains, values of reliability and validity with the P-method tended to be higher than with the T-method: ICC values ranged from 0.48–0.85 for the T-method and from 0.71–0.85 for the P-method; Spearman’s ρ values ranged from 0.25–0.58 for the T-method and from 0.42–0.65 for the P-method. The validities with both methods on a workday (0.51–0.58 for the T-method and 0.56–0.65 for the P-method) were higher than validities on a non-workday (0.25–0.45 for the T-method and 0.42–0.60 for the P-method). In post-survey interviews, 48 participants (77%) chose the P-method as their preferred questioning style.

Conclusions

The study revealed that the P-method WSWQ had better reliability, validity, and ease of answering than the T-method, suggesting that the P-method can improve properties of the WSWQ and consequently advance the quality of epidemiological surveys in this field.

IDENTICAL TWIN SISTERS WITH CLOSE ONSET OF GRAVES' DISEASE AND WITH MULTIPLE HLA SUSCEPTIBILITY ALLELES FOR GRAVES' DISEASE

CONTEXT

Autoimmune thyroid disease is considered a multifactorial disorder in which autoimmunity against thyroid antigens is facilitated by exposure to endogenous and environmental factors. We present here a rare case of identical female twins who developed consecutively Graves' disease within a few months and had three HLA susceptibility alleles for the development of Graves' disease.

SUBJECTS

A 28-year-old woman was referred to our hospital complaining of thirst, sweating, palpitations, tremor and skin rash. Laboratory data showed hyperthyroidism with antibodies against the thyroid stimulating hormone receptor and ultrasonography of the thyroid revealed enlargement with hypervascularity. Her identical twin was referred to our hospital because of similar symptoms.

RESULT

We diagnosed them with Graves' disease and both were treated with methimazole. Human leukocyte antigen genotyping showed that both twins possessed the DRB1*04:05, DQB1*04:01:01, DPB1*05:01 haplotype, which confers susceptibility to Graves' disease.

CONCLUSIONS

This case supports the hypothesis that interaction of multiple human leukocyte antigen susceptibility alleles as well as genetic background and environmental factors might synergistically contribute the close timing in Graves' disease onset.

Discovery of τ Neutrino Appearance in the CNGS Neutrino Beam with the OPERA Experiment

The OPERA experiment was designed to search for ν_{μ}→ν_{τ} oscillations in appearance mode, i.e., by detecting the τ leptons produced in charged current ν_{τ} interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the ν_{μ}→ν_{τ} appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ν_{τ} candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of ν_{μ}→ν_{τ} oscillations in appearance mode with a significance larger than 5σ.

Effect of aerobic exercise training followed by a low-calorie diet on metabolic syndrome risk factors in men

BACKGROUND AND AIMS

Whether low-volume, high-intensity, interval training (HIIT) is an adequate exercise method for improving metabolic risk factors is controversial. Moreover, it is not known if performing a short-term, low-calorie diet intervention (LCDi) after a HIIT program affects risk factors. This study investigated how an 8-week, 3 times/week exercise intervention (EXi) incorporating either HIIT or moderate-intensity continuous training (MICT) followed by a 4-week LCDi affects risk factors.

METHODS AND RESULTS

Twenty-six male workers with metabolic risk factors (47.4 ± 7.1 years; cardiorespiratory capacity (VO2peak) of 28.5 ± 3.9 ml/kg/min) were randomly assigned to either the HIIT (3 sets of 3-min cycling with a 2-min active rest between sets, 180 kcal) or MICT (45 min, 360 kcal) group. After the EXi, all subjects participated in a 4-week LCDi (4 counseling sessions). During the EXi, VO2peak improved more (P < 0.05) through HIIT (25.4 ± 14.6%) than through MICT (14.9 ± 12.8%), whereas improvements in body fat and HDL cholesterol were similar. During the LCDi, some risk factors improved further (P < 0.05) without any group differences, while VO2peak in the HIIT group decreased (P < 0.05) to the same level as in the MICT group.

CONCLUSION

VO2peak increased more with HIIT than with MICT during the EXi despite HIIT having a lower exercise volume than MICT, but this advantage of HIIT promptly disappeared through detraining. An intervention strategy consisting of 8 weeks of either HIIT or MICT followed by a 4-week LCDi has a positive effect on metabolic risk factors.

CLINICAL TRIAL REGISTRATION

UMIN11352.