Environmental Health and Preventive Medicine最新文献

Background: Exposure to air pollution and adherence to a healthy lifestyle have been identified to be related to sarcopenia. However, the interactive effects between these two factors remain insufficiently elucidated. The present study was designed to investigate the potential interaction exposure to air pollution with healthy lifestyle on the risk of developing sarcopenia.

Methods: In the retrospective cohort study, all data was extracted from China Health and Retirement Longitudinal Study. Household air pollution was assessed based on the utilization of solid fuels for cooking and heating. A lifestyle score was constructed comprising information on physical activity, smoking, drinking and sleeping time. Multivariate logistic regression model was used to assess the effects of household air pollution and healthy lifestyle score on sarcopenia, separately. We further explored the additive interaction between household air pollution and healthy lifestyle score to sarcopenia using the interaction table developed by T Anderson. Relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (SI) were used to evaluate the additive interactive effect.

Results: 2,114 participants were included in this study. The result indicated that exposed to household air pollution [adjusted relative risk (RR) = 1.80, 95% confidence interval (CI): 1.15-2.94] and unhealthy lifestyle (adjusted RR = 1.46, 95%CI: 1.04-2.03) were both significantly associated with increased risk of sarcopenia. Furthermore, participants exposed to both household air pollution and an unhealthy lifestyle exhibited a significantly higher risk of sarcopenia relative to those without household air pollution exposure and maintaining a healthy lifestyle (adjusted RR = 2.44). But RERI, AP, and SI suggested that there is no statistically significant additive interaction between household air pollution exposure and healthy lifestyle factors in relation to sarcopenia risk.

Conclusion: Household air pollution in conjunction with an unhealthy lifestyle confers a significantly higher risk of sarcopenia compared to either factor in isolation, with no evidence of a significant additive interaction between these two risk factors.

Background: The demand for aged-care services in Japan has surged due to the country's aging population. Furthermore, nationwide survey on the current state of aged-care services revealed that the primary reason for the resignation of women working in these sectors was poor interpersonal relationships. Moreover, given that women working in aged-care services work in shifts around the clock to manage the health and safety of the people in their care, they are at high risk of health-related issues including insomnia symptoms. Thus, we aim to examine the association between levels of satisfaction with interpersonal relationships (LSIR) and insomnia symptoms for women working in aged-care services in Japan, as well as the effect of work-life imbalance on the association between LSIR and insomnia symptoms.

Methods: In this cross-sectional study, the participants were 472 women aged 18-60 years who worked in aged-care services in Japan in 2014-2016. Insomnia symptoms were measured using the Athens Insomnia Scale, and scores of 6 or greater indicated the presence of insomnia. LSIR were assessed through self-administered questionnaires and evaluated at three levels. The association between LSIR and insomnia symptoms was evaluated using a multinominal logistic regression model. Path analysis was used to examine the potential effects of LSIR on insomnia symptoms by incorporating covariates such as work-family conflict, marital status, and depressive symptoms.

Results: Compared to high LSIR, the multivariable-adjusted odds ratios (95% confidence interval) of insomnia symptoms were respectively 1.36 (0.81-2.30) and 2.42 (1.11-5.23) for medium and low LSIR. The path analysis showed that low LSIR were significantly associated with having high work-to-family (W-to-F) conflict and being single.

Conclusions: Low LSIR were significantly associated with insomnia symptoms among women working in aged-care services in Japan. High W-to-F conflict exacerbated this relationship. Therefore, enhancing interpersonal relationships may be necessary for preventing insomnia. However, due to the cross-sectional nature of our study, causality cannot be inferred. Further longitudinal research is needed to better understand these associations.

Background: Research has demonstrated that heavy metals and cholesterol are associated with stress urinary incontinence (SUI) in women and that heavy metal exposure can cause dyslipidemia in humans. However, the potential mediating role of cholesterol in the relationship between heavy metals and female SUI remains unexplored.

Methods: The study utilized data from the National Health and Nutrition Examination Survey database from 2013-2018. Blood lead (Pb), cadmium (Cd), total mercury (Hg), manganese (Mn), selenium (Se), and methyl mercury (MeHg) were included in the study. The single and combined effects of the six metals exposure on SUI were examined using logistic analysis, restricted cubic spline (RCS) curves, weighted quantile sum (WQS) regression, and bayesian kernel machine regression (BKMR). The mediating effects of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were investigated through mediation analysis.

Results: The study included 2241 females, with 42.66% experiencing SUI. Initial analysis of six heavy metals revealed the associations between MeHg, Pb, Cd, total Hg, and SUI (all P < 0.05). WQS regression identified that Cd, Se, and Pb were major contributors to the mixed effect causing SUI. BKMR results indicated a positive mixed effect between six heavy metals and SUI. TC partially mediated the relationship of Pb, MeHg, and total Hg with SUI, and LDL-C partially mediated the association of Pb with SUI (all P for mediation < 0.05).

Conclusions: Blood heavy metal concentrations influence the development of female SUI, with blood cholesterol mediating the association between different heavy metals and SUI.

Background: Although many studies have reported the therapeutic effects of hot spring bathing on various diseases, its influence on healthy individuals is not well understood. Myoban Onsen, a sulfur-rich hot spring in Beppu City, Japan, is traditionally believed to improve skin conditions, relieve fatigue, and promote relaxation. However, scientific verification of these effects, particularly their impact on gut microbiota and related metabolic outcomes in healthy individuals, remains scarce. This study aimed to evaluate the effects of Myoban hot spring bathing on gut microbiota composition and SCFA concentrations in healthy individuals.

Methods: In this study, 16 healthy adult males (n = 16) participated in Myoban hot spring bathing four times over two weeks. Fecal samples were collected before and after the intervention, and 16S rRNA sequencing and gas chromatography-mass spectrometry (GC-MS) were performed to analyze gut microbiota composition and organic acid concentrations. The effects of hot spring bathing were evaluated using the Wilcoxon matched-pair signed-rank test to compare pre- and post-intervention.

Results: After Myoban hot spring bathing, there was a significant increase in beneficial gut bacteria, Bifidobacterium, Blautia, and Anaerostipes, compared to pre-bathing (p = 0.0012, p = 0.0103, and p = 0.0017, respectively). Conversely, significant decreases were observed in Parabacteroides, Alistipes, and Oscillibacter (p = 0.0125, p = 0.0215, and p = 0.0125, respectively). Significant increases in SCFAs, including acetic acid, propionic acid, and butyric acid, were observed after Myoban hot spring bathing (p = 0.0067, p = 0.0125, and p = 0.0302, respectively). These findings suggest that Myoban hot spring bathing may benefit healthy adult males.

Conclusions: This study suggests that Myoban hot spring bathing may improve gut health in healthy males. The observed increases in beneficial bacteria and SCFAs indicate a potential contribution to improved health status through modulation of the gut environment.

Trial registration: Registration number: UMIN000055229, retrospectively registered.

Background: Globally, Japan has the highest drowning mortality among older adults, largely because of bathing customs. Although this mortality rate peaks in winter, the nationwide impact of outdoor temperature has not been quantified, and whether specific days carry greater risks for bathtub drowning deaths remains unclear. Therefore, we aimed to address these gaps using nationwide data from Japan.

Methods: We collected daily data on outdoor temperatures and bathtub drowning deaths (from death certificates), along with population data, across 47 prefectures from 1995-2020. A time series regression model incorporating a cyclic spline for day-of-year and a cross-basis function for outdoor temperature was used to estimate seasonality and temperature attributable fractions (AFs). Prefecture-specific estimates were pooled using meta-analysis. National holidays were defined by the Act on National Holidays.

Results: During the study period, 99,930 home bathtub drowning deaths were recorded. The AF for seasonality modelled with a cyclic spline for day-of-year was 77.8% (empirical confidence interval [eCI]: 76.7-78.8%), which decreased to 15.3% (eCI: 13.1-18.0%) after adjusting for outdoor temperature, indicating that outdoor temperature accounted for 80.3% of the seasonal effect. Elevated risks were observed on Sundays (relative risk = 1.16, 95% CI: 1.12-1.20), holidays (1.12, 95% CI: 1.08-1.16), New Year's Day (1.72, 95% CI: 1.61-1.84), and New Year's Eve (1.63, 95% CI: 1.52-1.74) in the adjusted model, which included a cyclic spline for day-of-year and a cross-basis function for outdoor temperature.

Conclusion: Our findings highlight the importance of mitigating the impact of outdoor temperature on bath-related death risk. Identifying high-risk days can be used to help develop targeted preventive strategies.

Background: Subclinical hypothyroidism (SCH) has been reported to be associated with lower endothelial progenitor (CD34-positive) cell count, whereas an inverse association between circulating CD34-positive cell count and height loss is documented. Reports indicate height loss to be associated with all-cause mortality, and a higher CD34-positive cell count has been shown to predict longer life. Therefore, evaluating the association between SCH and height loss provides mechanistic insights underlying the association between height loss and mortality risk.

Methods: A prospective study involving 1,599 participants with normal free triiodothyronine (T3) and free thyroxine (T4) levels was conducted to determine the association between SCH and height loss.Since the free T4 level influences the supply of active thyroid hormone (free T3), the analysis was stratified by the median free T4 level. Height loss was defined as the highest quintile of annual height decrease.

Results: SCH was positively associated with height loss in participants with low-normal free T4 levels (below the median), but not in those with high-normal free T4 levels (at or above the median). After adjusting for sex, age, free T3 level, atherosclerosis, and known cardiovascular risk factors, the adjusted odds ratios (95% confidence interval) for height loss were 1.88 (1.02, 3.47) and 1.92 (1.02, 3.62) in the low-normal free T4 group. The corresponding values in the high-normal free T4 group were 0.37 (0.08, 1.69) and 0.43 (0.09, 1.97).

Conclusion: SCH could influence height loss, and free T4 might influence the association between SCH and height loss in euthyroid individuals. These results clarify the mechanisms underlying the association between height loss and mortality risk.

Background: Changes in socioeconomic inequalities in health behaviours following the COVID-19 pandemic remain unknown, particularly among Japanese school-aged adolescents. Therefore, in this study, we examined changes in socioeconomic inequalities in school-aged adolescents' health behaviours, including physical activity (PA), screen time (ST), sleep duration, breakfast consumption, and bowel movement frequency, before and after the pandemic.

Methods: This three-wave repeated cross-sectional study utilised data from the 2019, 2021, and 2023 National Sports-Life Survey of Children and Young People in Japan, analysing data from 766, 725, and 604 participants aged 12-18 years, respectively. Favourable health behaviours were defined as moderate-to-vigorous PA of ≥60 min/day, ST <2 h/day, sleep duration of 8-10 h, daily breakfast consumption, and bowel movements at least every 3 days. Absolute and relative socioeconomic inequalities were quantified using the slope index of inequality (SII) and the relative index of inequality (RII). Temporal changes were analysed using quadratic trend analyses, employing interaction terms between socioeconomic status and survey year.

Results: Significant quadratic trends indicated that socioeconomic inequalities in breakfast consumption decreased substantially from 2019 (SII: 20.7%, RII: 5.09) to 2021 (SII: -0.1%, RII: 0.95) but resurged in 2023 (SII: 16.2%, RII: 3.70). This resurgence may have been primarily driven by changes among those in the moderately low-income (poverty level II) and higher-income groups, which had a breakfast consumption rate of 81.0, 87.0, and 76.4% in 2019, 2021, and 2023, and 88.7, 82.1, and 87.5%, respectively. Among low-income households, adherence to PA recommendations significantly declined from 18.6% to 5.3%, and ST adherence worsened over the study period. No significant inequalities or trends were observed for sleep duration or bowel movement frequency across survey years.

Conclusions: Socioeconomic disparities in breakfast consumption among Japanese school-aged adolescents resurfaced after initially narrowing during the pandemic, likely driven by changes in moderately low-income and higher-income groups. Among low-income households, adherence to PA and ST guidelines declined over time. However, at the population level, socioeconomic inequalities in PA did not exhibit a consistent trend of widening or narrowing. This study highlights the need for sustained public health initiatives to address these socioeconomic disparities.

Background: Supporting the mental health of researchers is essential to maintaining human resources and advancing science. This study investigated the association between Japanese medical researchers' perceptions of research evaluation processes and their psychological well-being.

Methods: We performed a web-based self-administered questionnaire survey. The questionnaires were distributed to each academic society through the Japanese Association of Medical Sciences from December 2022 to January 2023. These questionnaires targeted medical researchers. Exposure was the medical researchers' perceptions of quantitative indicators for evaluating medical research and researchers. The outcome was psychological well-being, measured using the Japanese version of the World Health Organization-Five Well-Being Index (WHO-5). Multivariable-adjusted logistic regressions were conducted to investigate the association between individual attitudes toward research evaluation and psychological well-being. Stratified analyses by research fields, i.e., clinical, basic, and social medicine, were also performed.

Results: A total of 3,139 valid responses were collected. After excluding 176 responses from research fields of other than clinical, basic, or social medicine, 2,963 researchers (2,185 male, 737 female, and 41 other) were analyzed. Prevalence of poor well-being (WHO-5 score <13) was 28.3% in the researchers. The highest number of medical researchers was in clinical medicine (n = 500) followed by basic medicine (n = 217) and social medicine (n = 121). Medical researchers who considered research funding slightly important/not important for researcher evaluation had poorer psychological well-being than those who considered it especially important (slightly important: adjusted odds ratio (aOR) 1.33, 95% confidence interval (CI) 1.03-1.71; not important: aOR 1.53, 95%CI 1.10-2.12). This tendency was stronger among basic medical researchers than clinical or social medical researchers. The research field significantly modified the relationship between research funding received and interaction with poor psychological well-being both additively (P = 0.030) and multiplicatively (P = 0.024).

Conclusions: The discrepancy between medical researchers' attitudes toward research evaluation and the current state of research evaluation in their research community may worsen their psychological well-being. The influence of this discrepancy differs among clinical, basic, and social medicine. Appropriate evaluation of medical research and researchers in each field can facilitate improving their psychological well-being via the resolution of this discrepancy.

Background: Children's respiratory health demonstrates particular sensitivity to air pollution. Existing evidence investigating the association between short-term ozone (O₃) exposure and childhood pneumonia remains insufficient and inconsistent, especially in low- and middle-income countries (LMICs).

Method: To provide more reliable and persuasive evidence, we implemented a multi-city, time-stratified case-crossover design with a large sample size, using data from seven representative children's hospitals across major geographical regions in China. To avoid the impact of the COVID-19 pandemic, individual-level medical records of inpatient children under 6 years of age diagnosed with pneumonia during 2016-2019 were collected. Conditional logistic regression models were fitted for each city, and city-specific estimates were pooled through a meta-analysis using a random-effects model.

Results: In total, the study included 137,470 pediatric pneumonia hospital admissions. The highest pooled estimate for O₃ occurred at lag0-1, with a 10 µg/m³ increase in O₃ associated with a 1.57% (95% CI: 0.67%-2.48%) higher risk of pediatric pneumonia hospital admissions. Stratified analyses indicated that the effects of O₃ were robust across different sexes, age groups, and admission seasons. We also observed a statistically significant increase in risk associated with O₃ concentrations exceeding the World Health Organization Air Quality Guidelines (WHO-AQGs).

Conclusions: This study revealed a significant positive association between O₃ and pediatric pneumonia hospital admissions. Our findings substantially strengthen the evidence base for the adverse health impacts of O₃, underscoring the importance of O₃ pollution control and management in reducing the public health burden of pediatric pneumonia.

Background: Prior studies have shown that drivers with type 2 diabetes are more likely to be involved in motor vehicle collisions (MVCs) compared to the general population. Certain meteorological factors have been increasingly recognized as contributors to MVC risk. This study aims to examine the association of MVCs with temperature, rainfall, wind speed, and sunshine duration among drivers with type 2 diabetes.

Methods: Using Taiwan's National Health Insurance data (2019-2021), we identified individuals diagnosed with type 2 diabetes and linked their records to the Police-Reported Traffic Accident Registry to obtain daily MVC counts. Meteorological data were sourced from the Central Weather Administration. Associations between daily weather conditions and MVCs were assessed using a Distributed Lag Non-Linear Model.

Results: Over the 1,096-day study period, 170,468 MVC events involving drivers with type 2 diabetes were recorded. A U-shaped association was observed between same-day temperature and MVC rates. Compared with the reference temperature of 17.5 °C, both lower temperatures (≤15 °C; rate ratio [RR] = 1.014-1.053) and higher temperatures (≥30 °C; RR = 1.062) were associated with increased MVC risk. Rainfall showed an inverse relationship with MVCs. Compared with 70 mm of rainfall, the lowest MVC rate occurred at 129 mm (RR = 0.873), while the highest was on rain-free days (0 mm; RR = 1.068). Stronger effects were observed when lag periods up to 14 days were considered. Wind speed and sunshine duration were not significantly associated with MVC risk.

Conclusions: These findings suggest that drivers with type 2 diabetes should exercise greater caution on days with extreme temperatures or in days with lesser rainfall, as these conditions may elevate MVC risk.