Environmental Health and Preventive Medicine最新文献

Background and aim: The association between physical activity (PA) and sarcopenia has mostly been investigated in older people, with few studies focused on earlier life stages. The present study aimed to determine whether higher PA levels are associated with a lower sarcopenia risk in middle-aged and early older people.

Methods: This was an 8-year follow-up study. Participants were 6,500 community-dwelling adults aged 40-74 years who participated in the baseline questionnaire survey conducted in 2011-2014 in Japan. Levels of total and leisure-time PAs at baseline were assessed using validated metabolic equivalent scores. Multi-frequency bioelectrical impedance analysis and handgrip strength measurement were performed in 2021-2022, and participants with low height-adjusted appendicular lean mass (<20th percentile) and low grip strength were diagnosed as having sarcopenia (outcome). Covariates were demographics, body size, lifestyle, and disease history at baseline.

Results: The prevalence of sarcopenia was 137/2926 (4.7%) for men and 127/3574 (3.6%) for women. Higher total PA levels were associated with lower odds of sarcopenia (P for trend = 0.0278), with the second highest group having a significantly lower OR (0.51) than the lowest group (reference) in women, but not in men. Regarding leisure-time PA, those engaged in leisure-time vigorous PA had a lower OR of sarcopenia than those who did not (OR = 0.67, P = 0.0625).

Conclusion: Higher levels of total PA are associated with a lower risk of sarcopenia in women but not in men, suggesting a sex difference in this association. In addition, high levels of vigorous leisure-time PA may be effective for preventing sarcopenia.

Background: Meals are provided at nursery schools for Japanese preschool children, and this may result in different energy and nutrient intakes on weekdays and weekends. The purpose of this study was to obtain basic information for public nutrition policies in early childhood by examining differences in energy and nutrient intakes of preschool children between weekdays and weekends using meal categories such as breakfast, lunch, dinner, and snacks.

Methods: Energy and nutrient intakes were examined in 761 Japanese preschool children (423 boys, 338 girls) aged 3-6 years attending childcare facilities in seven regions in Japan. Data collection was based on non-consecutive four-day dietary records (two weekdays, two weekend days) in 2019 or 2020. Energy and nutrient intake by meal category were compared using a generalized linear mixed model adjusted for demographic factors.

Results: Total energy intake was significantly higher on weekdays for boys (1,478 vs. 1,415 kcal) and girls (1,349 vs. 1,296 kcal) (both P < 0.001). Weekday lunches had higher protein content and essential micronutrients such as potassium, iron, vitamins, and lower fat, saturated fatty acids, and salt, compared to weekend lunches. Similarly, weekday snacks also had significantly higher nutritional consumption for most nutrients compared to weekend equivalents.

Conclusion: These findings suggest that meals at nursery schools, particularly lunch and snacks, result in more desirable nutrient intake in preschool children. On weekdays, children consume meals with higher nutrient density, possibly due to the role of dietitians in menu planning. However, some children still fail to meet the Dietary Reference Intakes for Japanese, indicating a need for improvements in nursery school and home meals. More communication is needed between nursery schools and families, including sharing menus and recipes is essential. The results of this study are of value for development of public health nutrition strategies targeting early childhood.

Background: The protective effectiveness of an N95 respirator depends on the filtration efficiency of the material from which the N95 respirator is made of, as well as the wearers' facial fit. The facial fit of an N95 respirator mainly depends on the degree of matching between the wearers' facial dimension characteristics and the N95 respirator. Quantitative fit testing objectively evaluates the fit of N95 respirators; however, it is not easy to promote because of the limitations of testing conditions. The aim of this study is to establish a fit prediction model of N95 respirator based on facial images.

Methods: Facial images and fit factor (FF) value of 5 N95 respirators were gathered from 299 medical staffs in 10 hospitals in Beijing. Face geometry measurement was based on 3D face modelling, and the American TSI-8038 Porta Count Pro+ was used to conduct quantitative fit test. Multiple linear regression analysis was employed to identify facial dimensional features that significantly influenced the fit of N95 respirators. Through matching training of facial image and FF values, a fit prediction model has been established, enabling rapid recommendation of N95 respirators meeting the fit standard via facial image recognition.

Results: A fit prediction model for N95 respirators based on facial images has been developed, which enables the rapid recommendation of N95 respirators with acceptable FF value for healthcare personnel. The model demonstrated an accuracy of 55.93%, a precision of 98.43%, a recall of 51.65%, and an F1 score of 0.68.

Conclusions: It is feasible to utilize computer-based facial recognition technology to rapidly recommend N95 respirators for medical personnel. Given the high level of accuracy achieved, the model demonstrates significant potential for practical application.

Under the background of climate change, the escalating air pollution and extreme weather events have been identified as risk factors for chronic respiratory diseases (CRD), causing serious public health burden worldwide. This review aims to summarize the effects of changed atmospheric environment caused by climate change on CRD. Results indicated an increased risk of CRD (mainly COPD, asthma) associated with environmental factors, such as air pollutants, adverse meteorological conditions, extreme temperatures, sandstorms, wildfire, and atmospheric allergens. Furthermore, this association can be modified by factors such as socioeconomic status, adaptability, individual behavior, medical services. Potential pathophysiological mechanisms linking climate change and increased risk of CRD involved pulmonary inflammation, immune disorders, oxidative stress. Notably, the elderly, children, impoverished groups and people in regions with limited adaptability are more sensitive to respiratory health risks caused by climate change. This review provides a reference for understanding risk factors of CRD in the context of climate change, and calls for the necessity of adaptive strategies. Further interdisciplinary research and global collaboration are needed in the future to enhance adaptability and address climate health inequality.

In Japan, during the high economic growth period (1950-1960s), air pollution due to sulfur dioxide (SO₂) and dust derived from large-scale factories and power plants was apparent in many industrial districts, and it caused serious health problems such as the so-called "Yokkaichi Asthma." Many epidemiological studies have revealed the relationship between air pollution and respiratory diseases, and have provided scientific evidence for the regulatory control of air pollution. The concentration of SO₂ has markedly decreased since the 1970s, and its adverse health effects have improved. In contrast, increased automobile traffic has caused considerable traffic-related air pollution, including nitrogen oxides (NOx) and particulate matter (PM). Epidemiological studies in Chiba and Tokyo revealed that the prevalence and incidence of asthma were significantly higher among individuals living in roadside areas than among those living in other areas. Large-scale epidemiological studies conducted in urban districts have revealed an association between traffic-related air pollution and the onset of asthma in schoolchildren and persistence of asthmatic symptoms in preschool children. Thereafter, the concentrations of NOx and PM gradually decreased due to the control measures based on the Automobile NOx/PM Law enforced in 2001. Thus, epidemiological studies have contributed to a reduction in air pollution caused by automobile exhaust emissions. Recently, the adverse health effects of ambient fine PM (PM_2.5) and ozone (O₃) at ground level have become an international concern. Our epidemiological studies showed that short-term exposure to considerably low concentrations of PM_2.5 and O₃ was associated with a decrease in pulmonary function among asthmatic children and increased airway inflammation in healthy adolescents. The effects of exposure to PM_2.5 during pregnancy and early childhood on children's development have also been reported. These air pollutants consist of not only emissions from primary sources but also secondary formations in the atmosphere. They are affected by climate change and spread worldwide. Air quality control measures and climate change adaptation and mitigation strategies are synergistic, and will have co-benefits on human health. Therefore, global efforts are required to protect populations from the health risks posed by these air pollutants.

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.