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Background Despite the impact of heat exposure caused by global warming, few studies have investigated the hourly effects of heat exposure and the risk of cardiovascular disease (CVD) in the elderly. We examined the associations between short-term heat exposure and the risk of CVD in the elderly in Japan and evaluated possible effect-measure modifications by rainy seasons that occur in East Asia. Methods and Results We conducted a time-stratified case-crossover study. The study included 6527 residents in Okayama City, Japan, aged ≥65 years who were transported to emergency hospitals between 2012 and 2019 for the onset of CVD during and a few months after the rainy seasons. We examined the linear associations between temperature and CVD-related emergency calls for each year and for hourly preceding intervals before the emergency call during the most relevant months. Heat exposure during 1 month after the end of the rainy season was associated with CVD risk; the odds ratio (OR) for a 1° C increase in temperature was 1.34 (95% CI, 1.29-1.40). When we further explored the nonlinear association by using the natural cubic spline model, we found a J-shaped relationship. Exposures 0 to 6 hours before the case event (preceding intervals 0-6 hours) were associated with CVD risk, particularly for the preceding interval 0 to 1 hour (OR, 1.33 [95% CI, 1.28-1.39]). For longer periods, the highest risk was at preceding intervals 0 to 23 hours (OR, 1.40 [95% CI, 1.34-1.46]). Conclusions Elderly individuals may be more susceptible to CVD after heat exposure during the month after the rainy season. As shown by finer temporal resolution analyses, short-term exposure to increasing temperature can trigger CVD onset.

Background: Many epidemiological studies have reported the association between exposure to particulate matter and mortality, but long-term prospective studies from Asian populations are sparse. Furthermore, associations at low levels of air pollution are not well clarified. Here, we evaluated associations between long-term exposure to particulate matter <2.5 µg/m 3 (PM 2.5 ) and mortality in a Japanese cohort with a relatively low exposure level., Methods: The Japan Public Health Center-based Prospective Study (JPHC Study) is a prospective cohort study of men and women aged 40-69 years in 1990 who were followed up through 2013 for mortality. In this cohort of 87,385 subjects who did not move residence during follow-up, average PM 2.5 levels from 1998 to 2013 by linkage with 1-km 2 grids of PM 2.5 concentration were assigned to the residential addresses of all participants. To avoid exposure misclassification, we additionally evaluated the association between 5-year (1998-2002) cumulative exposure level and mortality during the follow-up period from 2003 to 2013 in 79,078 subjects. Cox proportional hazards models were used to calculate the association of long-term exposure to PM 2.5 on mortality, with adjustment for several individual confounding factors., Results: Average PM 2.5 was 11.6 µg/m 3 . Average PM 2.5 exposure was not associated with all-cause mortality or cancer and respiratory disease mortality. However, average PM 2.5 was positively associated with mortality from cardiovascular disease (hazard ratio (HR) of 1.23 (95%CI=1.08-1.40) per 1-µg/m 3 increase; in particular, HR in mortality from cerebrovascular disease was 1.34 (95%CI=1.11-1.61) per 1-µg/m 3 increase. Additionally, these results using cumulative 5-year PM 2.5 data were similar to those using average PM 2.5 over 15 years., Conclusions: We found evidence for a positive association between PM 2.5 exposure and mortality from cardiovascular disease in a Japanese population, even in an area with relatively low-level air pollution., (© 2022. The Author(s).)

We examined the association between acute exposure to sulfur dioxide (SO 2 ) and mortality, using historical data from 1972-1991 in Yokkaichi, Japan. We used a time-stratified case-crossover study design. We included all causes of death, excluding external causes, between 1972 and 1991 in Yokkaichi and the neighboring town, Kusu of the Mie Prefecture (N = 29,839). We obtained daily estimations of SO 2 concentrations during the study period. We then conducted conditional logistic regression analysis to examine association between SO 2 exposure and all-cause and cause-specific mortality. Exposure to SO 2 increased the risk of all-cause and cause-specific mortality in a non-linear manner. The relationship between SO 2 exposure and mortality outcomes remained after adjustment for co-pollutants such as particulate matter and nitrogen dioxide. Historical data from Yokkaichi, Japan, showed that SO 2 exposure increased the risk of all-cause and cause-specific mortality.

Background: Factors influencing the susceptibility of the elderly to the adverse health effects of short-term exposure to desert dust have yet to be explored. We aimed to identify the disease histories that increase the susceptibility of the elderly to disease onset induced by dust events., Methods: We used a time-stratified case-crossover design using data on 17,874 elderly residents (≥65 years) of Okayama, Japan, who were transported to hospital emergency rooms because of cardiovascular and respiratory diseases between 2006 and 2010. We used conditional logistic models to calculate the odds ratios (ORs) per interquartile increase of Asian dust. We then conducted stratified analyses based on patients with or without a history of chronic disease., Results: Dust concentration was associated with a higher risk of cardiovascular (3-day lag), cerebrovascular (same day), and respiratory (3-day lag) disease onset. Patients with a history of respiratory disease had a higher risk of cardiovascular (OR: 1.09 [95% confidence interval (CI) = 1.00, 1.19] vs. 0.99 [0.97, 1.01]; P for interaction = 0.03) or cerebrovascular (1.15 [1.01, 1.31] vs. 0.99 [0.97, 1.01]; P = 0.02) disease onset (2-day lag) than those without. Patients with diabetes also had a higher risk of cerebrovascular disease onset (1.09 [1.00, 1.19] vs. 0.99 [0.97, 1.01]; P = 0.05) (2-day lag). In contrast, patients with a history of cerebrovascular disease had a lower risk of respiratory disease., Conclusions: People with a history of respiratory disease or diabetes might have a greater susceptibility to cardiovascular disease from Asian dust and would therefore benefit from proactive interventions during desert dust events.

Objective: To evaluate the direct health effects of Asian dust on ambulance calls and its role as an effect modifier on the effects of anthropogenic air pollution in Japan., Methods: The subjects were 51,945 elderly residents who visited hospital emergency departments from 2006 to 2010. We evaluated the impact of Asian dust by time-series analyses and the excess risk from suspended particulate matter (SPM) stratified by Asian-dust exposure., Results: Asian dust was associated with daily ambulance calls due to all-cause, cardiovascular, and respiratory disease independently of SPM, for example, the relative risk per interquartile increase in Asian dust (3-day lag) was 1.021 (1.002 to 1.039) for cardiovascular disease. Furthermore, Asian dust modified the effects of SPM on cardiovascular and respiratory diseases., Conclusions: Asian dust had adverse effects and modified the effect of SPM.

Background and Purpose: Few studies have examined the effect of hourly changes in air pollution on cardiovascular disease morbidity. We evaluated the associations between hourly changes in air pollution and the risks of several types of cardiovascular disease., Methods: We used a time-stratified case-crossover design. Study participants were 10,949 residents of the city of Okayama, Japan, aged≥65 years who were taken to hospital emergency rooms between January 2006 and December 2010 for onset of cardiovascular disease. We calculated city representative hourly average concentrations of air pollutants from several monitoring stations and examined the associations between air pollution exposure before the case event, focusing mainly on suspended particulate matter, and disease onset., Results: Suspended particulate matter exposure 0 to <6 hours before the case events was associated with risks of onset of cardiovascular and cerebrovascular disease; odds ratios after 1 interquartile range increase in suspended particulate matter exposure were 1.04 (95% confidence interval, 1.01-1.06) for cardiovascular disease and 1.04 (95% confidence interval, 1.00-1.08) for cerebrovascular disease. We observed an elevated risk of hemorrhagic as well as ischemic stroke, but the risk was slightly higher for hemorrhagic stroke, and this elevation was persistent. Women tended to have higher effect estimates., Conclusions: This study provides further evidence that particulate matter exposure increases the risks of onset of cardiovascular and cerebrovascular disease (including hemorrhagic stroke) shortly after exposure.

We compared cardiovascular and metabolic markers between undiagnosed and known diabetes among 3045 subjects who had voluntary health check and no cardiovascular disease. Subjects with undiagnosed diabetes had poorer profiles of these markers than those with known diabetes. Undiagnosed diabetes should be recognized as a condition with these risks., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Objective: Desert dust, which is included in course particles, is considered to have potential toxicity. The effect modification of desert dust on associations between anthropogenic air pollution and mortality has been evaluated. However, the independent effects of Asian dust are less clear. Thus, we evaluated the effects of Asian dust on mortality independent of particulate matter (PM) in western Japan., Methods: We obtained daily mean concentrations of Asian dust using Light Detection and Ranging measurements and suspended particulate matter (SPM) concentrations (approximately PM(8)) during March 2005 to December 2010. We then evaluated city-specific associations of Asian dust and SPM with daily mortality using a time-series analysis targeting 1 379 052 people aged 65 or above living in 47 cities. The city-specific results were then combined with a Bayesian-hierarchical model., Results: Asian dust did not modify the effects of SPM on mortality. Meanwhile, Asian dust was adversely associated with mortality independent of SPM. The excess risk following a 10 μ/m(3) increase in mean of the current to the previous 2 days Asian dust concentration was 0.6% (95% CI 0.1 to 1.1) for heart disease, 0.8% (95% CI 0.1 to 1.6) for ischaemic heart disease, 2.1% (95% CI 0.3 to 3.9) for arrhythmia and 0.5% (95% CI 0.2 to 0.8) for pneumonia mortality. Furthermore, the effects of Asian dust were stronger in northern areas close to the Eurasian continent (source of Asian dust)., Conclusions: Asian dust had adverse effects on circulatory and respiratory mortality independent of PM.

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has created a remarkable and varying impact in every country, inciting calls for broad attention. Recently, the Bacillus Calmette-Guérin (BCG) vaccination has been regarded as a potential candidate to explain this difference. Herein, we hypothesised that the past epidemic of Mycobacterium tuberculosis (M. tuberculosis) may act as a latent explanatory factor for the worldwide differences seen in COVID-19 impact on mortality and incidence. We compared two indicators of past epidemic of M. tuberculosis, specifically, incidence (90 countries in 1990) and mortality (28 countries in 1950), with the mortality and incidence of COVID-19. We determined that an inverse relationship existed between the past epidemic indicators of M. tuberculosis and current COVID-19 impact. The rate ratio of the cumulative COVID-19 mortality per 1 million was 2.70 (95% confidence interval [CI]: 1.09–6.68) per 1 unit decrease in the incidence rate of tuberculosis (per 100,000 people). The rate ratio of the cumulative COVID-19 incidence per 1 million was 2.07 (95% CI: 1.30–3.30). This association existed even after adjusting for potential confounders (rate of people aged 65 over, diabetes prevalence, the mortality rate from cardiovascular disease, and gross domestic product per capita), leading to an adjusted rate ratio of COVID-19 mortality of 2.44, (95% CI: 1.32–4.52) and a COVID-19 incidence of 1.31 (95% CI: 0.97–1.78). After latent infection, Mycobacterium survives in the human body and may continue to stimulate trained immunity. This study suggests a possible mechanism underlying the region-based variation in the COVID-19 impact. [ABSTRACT FROM AUTHOR]

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Abstract: In Japan in 1968, rice-oil contaminated by polychlorinated biphenyls and polychlorinated dibenzofurans caused severe food poisoning, termed “Yusho” (oil disease). Several previous studies attempted to evaluate the effects targeting officially-certified Yusho patients. However, these studies have several limitations such as the left-truncated nature of the registry or residual confounding arising from the referent population selection. We thus conducted an area-based standardized mortality ratios (SMRs) study using vital statistics. A severely affected area (Tamanoura area) was adopted as the exposure group, with a reference population from Nagasaki prefecture in Kyushu, which included the Tamanoura. A large number of residents in Tamanoura were exposed to the rice-oil (28% of all the certified cases as of 2009). We estimated SMRs of non-cancer and cancer diseases for the years 1968–2002. Shortly after the exposure, SMRs of all causes, diabetes mellitus, cardiovascular disease, pneumonia/bronchitis, and bronchus/lung cancer were elevated. In particular, SMRs of heart disease were 1.97 [95% confidence intervals (CI): 1.09–3.56] in 1968, 2.05 (95% CI: 1.16–3.60) in 1969, and 1.89 (95% CI: 1.05–3.41) in 1975. However, we did not observe clear increase in SMRs more than 10years after the exposure. This study provides further evidence in Yusho, especially on acute effects on non-cancer mortality. [Copyright &y& Elsevier]

Abstract: Recent studies suggest potential adverse effects of methylmercury exposure on cardiovascular disease, although the evidence of association with hypertension is still inconsistent. Therefore, we evaluated the effects of methylmercury exposure on hypertension in Minamata. We used data derived from the 1971 population-based survey in Minamata and neighboring communities. We also utilized data on hair mercury content of the participants (derived from a 1960 investigation). We adopted two exposure indices (residential area and hair mercury content) and two hypertension outcomes (past history of hypertension and hypertension defined by measurements in the examination). Then, we estimated the adjusted prevalence odds ratio (POR) and its confidence interval (CI) of both hypertension outcomes in relation to residential area and hair mercury content. In the Minamata area (high exposure area), 87% (833) of the eligible population (aged ≥10 years) participated in the 1971 investigations. In the Goshonoura area (middle exposure area) and the Ariake area (low exposure area), 93% (1450) and 77% (755), respectively, of the eligible population participated. Compared with subjects in the Ariake area, the subjects in the Minamata area manifested hypertension more frequently, and PORs observed for two hypertension outcomes were 1.6 (95% CI: 1.2–2.1) and 1.4 (95% CI: 1.1–1.9), respectively. Furthermore, dose-response trends with hair mercury content were observed for both hypertension outcomes. The present finding supports the causal relationship between methylmercury exposure and hypertension. [Copyright &y& Elsevier]

Background: Physical activity recommendations for older adults with poor health needs to be understood. Purpose: This study aims to examine the association between the frequency of physical activity and mortality among a sample of elderly subjects, most of whom were under treatment for pre-existing disease. Methods: Data on the frequency of leisure-time physical activity, walking for transportation, and non-exercise physical activity were obtained from a population-based cohort study in Shizuoka, Japan. Of the randomly selected 22,200 residents aged 65–84 years, 10,385 subjects were followed from 1999 to 2006 and analyzed. Hazard ratios (HRs) and 95% CIs were obtained for all-cause; cardiovascular disease (CVD); and cancer mortality, after adjusting for covariates such as pre-existing disease(s). A subgroup analysis that was restricted to subjects under treatment for pre-existing disease(s) at baseline was further conducted. Data were collected between 1999 and 2006, and all analyses were conducted in 2008 and 2009. Results: Every physical activity was associated with a reduced risk of all-cause and CVD mortality, among not only the total sample but even those under treatment. The HRs for CVD mortality among participants with 5 or more days of non-exercise physical activity per week for the total sample and those with pre-existing disease(s) were 0.38 (95% CI=0.22, 0.55) and 0.35 (95% CI=0.24, 0.52), respectively, compared with no non-exercise physical activity. The association between physical activity and cancer mortality was not clear. Conclusions: This study suggests a protective effect of physical activity on all-cause and CVD mortality among Japanese elderly people with pre-existing disease. [Copyright &y& Elsevier]