CLimate Impacts on Myocardial infarction deaths in the Athens TErritory: the CLIMATE study

Proposal of a workplace classification model for heart attack accidents from the field of occupational safety and health engineering

Research on occupational accidents is a key factor in improving working conditions and sustainability. Fatal accidents incur significant human and economic costs. Therefore, it is essential to examine fatal accidents to identify the factors that contribute to their occurrence. This study presents an overview of fatal heart attack accidents at work in Spain over the period 2009-2021. Descriptive analysis was conducted considering 13 variables classified into five groups. These variables were selected as predictors to determine the occurrence of this type of accident using a machine learning technique. Thirteen Naïve Bayes prediction models were developed using an unbalanced dataset of 15,616 valid samples from the Spanish Delta@database, employing a two-stage algorithm. The final model was retained using a General Performance Score index. The model selected for this study used a 70:30 distribution for the training and test datasets. A sample was classified as a fatal heart attack if its posterior probability exceeded 0.25. This model is assumed to be a compromise between the confusion matrix values of each model. Sectors with the highest number of heart attacks are 'Health and social work', 'Transport and storage', 'Manufacturing', and 'Construction'. The incidence of heart attacks and fatal heart attack accidents is higher in men than in women and higher in private sector employees. The findings and model development may assist in the formulation of surveillance strategies and preventive measures to reduce the incidence of heart attacks in the workplace.

Impact of Climate on the Incidence of Acute Coronary Syndrome - Differences Between Japan and Thailand

Background: Although there are many reports of temperature being associated with the onset of acute coronary syndrome (ACS), few studies have examined differences in ACS due to climatic differences between Japan and Thailand. The aim of this joint Japan-Thailand study was to compare patients with myocardial infarction in Japanese and Thai hospitals in different climates. Methods and Results: We estimated the climate data in 2021 for the Wakayama Prefecture and Chonburi Province, two medium-sized cities in Japan and Thailand, respectively, and ACS patients who were treated at the Wakayama Medical University (WMU) and Burapha University Hospital (BUH), the two main hospitals in these provinces (ACS patient numbers: WMU, n=177; BUH, n=93), respectively. In the Chonburi Province, although the average temperature was above 25℃, the number of ACS cases in BUH varied up to threefold between months (minimum: July, 4 cases; maximum: October, 14 cases). In Japan and Thailand, there was a mild to moderate negative correlation between temperature-atmospheric pressure at the onset of ACS, but different patterns for temperature-humidity (temperature-atmospheric pressure, temperature-humidity, and atmospheric pressure-humidity: correlation index; r=-0.561, 0.196, and -0.296 in WMU vs. r=-0.356, -0.606, and -0.502 in BUH). Conclusions: The present study suggests that other climatic conditions and factors, not just temperature, might be involved in the mechanism of ACS.

Impact of atmospheric variables on incidence of acute coronary syndrome amongst Gujarati Asian Indians - IOAPIC study

OBJECTIVES

The study evaluated the effects of climatic conditions and its variables on incidence of ACS in Gujarati Asian Indians.

METHODS

In this multicentric, retrospective, observational case control study of a total of 3256 patients, the Electronic Medical Records (EMS) of all 740 patients who were hospitalised for ACS at the 2 tertiary care centres of Ahmedabad over 3 years between January 2017 to December 2019 were compared with demographically matched 2516 non- ACS, CAD controls were compared for the impact of climatic parameters viz. temperature, barometric pressure, humidity as reported by monthly averages by the state meteorological department for monthly incidence of ACS.

RESULTS

The highest number of ACS cases were observed during the month of September (N=127; 27%) followed by August (N=123; 26%). Higher humidity and decreasing atmospheric pressure were associated with highest occurrence of ACS in the state of Gujarat. ST elevation Myocardial Infarction (STEMI) was the most common type of ACS (N=598; 80.8%). In ACS, the Coefficient of correlation for humidity was 0.712 (P= 0.009), while that for temperature was 0.506 (P=0.093). Effect of atmospheric pressure was found to be significant with a negative Coefficient of correlation of -0.571 (P=0.052). However amongst the controls, the coefficient of correlation for humidity was 0.062 (P=0.722) and atmospheric pressure Correlation coefficient was 0.107 (P=0.539) non-significant.

CONCLUSIONS

The higher humidity/temperature and lower atmospheric pressure had a positive correlation with the incidence of ACS with highest incidence noted in August and September in the state of Gujarat.

The Impact of Meteorological Factors and Air Pollutants on Acute Coronary Syndrome

Purpose of Review

Several studies have found that air pollution and climate change can have an impact on acute coronary syndromes (ACS), the leading cause of death worldwide. We synthesized the latest information about the impact of air pollution and climate change on ACS, the latest data about the pathophysiological mechanisms of meteorological factors and atmospheric pollutants on atherosclerotic disease, and an overall image of air pollution and coronary heart disease in the context of the COVID-19 pandemic.

Recent Findings

The variation of meteorological factors in different seasons increased the risk of ACS. Both the increase and the decrease in apparent temperature were found to be risk factors for ACS admissions. It was also demonstrated that exposure to high concentrations of air pollutants, especially particulate matter, increased cardiovascular morbidity and mortality.

Summary

Climate change as well as increased emissions of air pollutants have a major impact on ACS. The industrialization era and the growing population cause a constant increase in air pollution worldwide. Thus, the number of ACS favored by air pollution and the variations in meteorological factors is expected to increase dramatically in the next few years.

Climatic influences on cardiovascular diseases

Classical risk factors only partially account for variations in cardiovascular disease incidence; therefore, also other so far unknown features, among which meteorological factors, may influence heart diseases (mainly coronary heart diseases, but also heart failure, arrhythmias, aortic dissection and stroke) rates. The most studied phenomenon is ambient temperature. The relation between mortality, as well as cardiovascular diseases incidence, and temperature appears graphically as a ‘‘U’’ shape. Exposure to cold, heat and heat waves is associated with an increased risk of acute coronary syndromes. Other climatic variables, such as humidity, atmospheric pressure, sunlight hours, wind strength and direction and rain/snow precipitations have been hypothesized as related to fatal and non-fatal cardiovascular diseases incidence. Main limitation of these studies is the unavailability of data on individual exposure to weather parameters. Effects of weather may vary depending on other factors, such as population disease profile and age structure. Climatic stress may increase direct and indirect risks to human health via different, complex pathophysiological pathways and exogenous and endogenous mechanisms. These data have attracted growing interest because of the recent earth’s climate change, with consequent increasing ambient temperatures and climatic fluctuations. This review evaluates the evidence base for cardiac health consequences of climate conditions, and it also explores potential further implications.

Ambient temperature and infarct size, microvascular obstruction, left ventricular function and clinical outcomes after ST-segment elevation myocardial infarction

OBJECTIVES

Incidence and prognosis of ST-segment elevation myocardial infarction (STEMI) vary according to ambient temperature and season. We sought to assess whether season and temperature on the day of STEMI are associated with infarct size, microvascular obstruction (MVO), left ventricular ejection fraction (LVEF) and clinical outcomes after primary percutaneous coronary intervention (PCI).

METHODS

Individual patient data from 1598 patients undergoing primary PCI in six randomized clinical trials were pooled. Infarct size was evaluated by cardiac magnetic resonance within 30 days in all trials. Patients were categorized either by whether they presented on a day of temperature extremes (minimum temperature <0 °C or maximum temperature >25 °C) or according to season.

RESULTS

A total of 558/1598 (34.9%) patients presented with STEMI on a day of temperature extremes, and 395 (24.7%), 374 (23.4%), 481 (30.1%) and 348 (21.8%) presented in the spring, summer, fall and winter. After multivariable adjustment, temperature extremes were independently associated with larger infarct size (adjusted difference 2.8%; 95% CI, 1.3-4.3; P < 0.001) and smaller LVEF (adjusted difference -2.3%; 95% CI, -3.5 to -1.1; P = 0.0002) but not with MVO (adjusted P = 0.12). In contrast, infarct size, MVO and LVEF were unrelated to season (adjusted P = 0.67; P = 0.36 and P = 0.95, respectively). Neither temperature extremes nor season were independently associated with 1-year risk of death or heart failure hospitalization (adjusted P = 0.79 and P = 0.90, respectively).

CONCLUSION

STEMI presentation during temperature extremes was independently associated with larger infarct size and lower LVEF but not with MVO after primary PCI, whereas season was unrelated to infarct severity.

Weather Impact on Acute Myocardial Infarction Hospital Admissions With a New Model for Prediction: A Nationwide Study

Introduction: Cardiovascular disease is one of the leading causes of mortality worldwide. Acute myocardial infarction (AMI) is associated with weather change. The study aimed to investigate if weather change was among the risk factors of coronary artery disease to influence AMI occurrence in Taiwan and to generate a model to predict the probabilities of AMI in specific weather and clinical conditions.

Method: This observational study utilized the National Health Insurance Research Database and daily weather reports from Taiwan Central Weather Bureau to evaluate the discharge records of patients diagnosed with AMI from various hospitals in Taiwan between January 1, 2008 and December 31, 2011. Generalized additive models (GAMs) were used to estimate the effective parameters on the trend of the AMI incidence rate with respect to the weather and health factors in the time-series data and to build a model for predicting AMI probabilities.

Results: A total of 40,328 discharges were listed. The minimum temperature, maximum wind speed, and antiplatelet therapy were negatively related to the daily AMI incidence; however, a drop of 1° when the air temperature was below 15°C was associated with an increase of 1.6% of AMI incidence. By using the meaningful parameters including medical and weather factors, an estimated GAM was built. The model showed an adequate correlation in both internal and external validation.

Conclusion: An increase in AMI occurrence in colder weather has been evidenced in the study, but the influence of wind speed remains uncertain. Our analysis demonstrated that the novel GAM model can predict daily onset rates of AMI in specific weather conditions.

A time-series prediction model of acute myocardial infarction in northern of Iran: the risk of climate change and religious mourning

BACKGROUND

Although various studies have been conducted on the effects of seasonal climate changes or emotional variables on the risk of AMI, many of them have limitations to determine the predictable model. The currents study is conducted to assess the effects of meteorological and emotional variables on the incidence and epidemiological occurrence of acute myocardial infarction (AMI) in Sari (capital of Mazandaran, Iran) during 2011-2018.

METHODS

In this study, a time series analysis was used to determine the variation of variables over time. All series were seasonally adjusted and Poisson regression analysis was performed. In the analysis of meteorological data and emotional distress due to religious mourning events, the best results were obtained by autoregressive moving average (ARMA) (5,5) model.

RESULTS

It was determined that average temperature, sunshine, and rain variables had a significant effect on death. A total of 2375 AMI's were enrolled. Average temperate (°C) and sunshine hours a day (h/day) had a statistically significant relationship with the number of AMI's (β = 0.011, P = 0.014). For every extra degree of temperature increase, the risk of AMI rose [OR = 1.011 (95%CI 1.00, 1.02)]. For every extra hour of sunshine, a day a statistically significant increase [OR = 1.02 (95% CI 1.01, 1.04)] in AMI risk occurred (β = 0.025, P = 0.001). Religious mourning events increase the risk of AMI 1.05 times more. The other independent variables have no significant effects on AMI's (P > 0.05).

CONCLUSION

Results demonstrate that sunshine hours and the average temperature had a significant effect on the risk of AMI. Moreover, emotional distress due to religious morning events increases AMI. More specific research on this topic is recommended.

Associations of Relative Humidity and Lifestyles with Metabolic Syndrome among the Ecuadorian Adult Population: Ecuador National Health and Nutrition Survey (ENSANUT-ECU) 2012

The effects of the physical environment on metabolic syndrome (MetS) are still largely unexplained. This study aimed to analyze the associations of relative humidity of residence, lifestyles, and MetS among Ecuadorian adults. Data from 6024 people aged 20 to 60 years were obtained from an Ecuador national population-based health and nutrition survey (i.e., ENSANUT-ECU, 2012) and the mean annual relative humidity (%) from the Ecuador National Institute for Meteorology and Hydrology (2012). Odds ratio (OR) with 95% confidence intervals (CI) for MetS according to groups of relative humidity were calculated using multiple logistic regression. Living in high relative humidity (>80%) increased ORs of reduced high-density lipoprotein (HDL) cholesterol (1.25; 95 % CI, 1.06–1.56) and MetS (OR = 1.20; 95 % CI,1.01–1.42) in women. Furthermore, physically active men living in high relative humidity showed lower OR of elevated triglycerides (0.56; 95 % CI,0.37–0.85) while menopausal women living in high relative humidity showed increased ORs of MetS (5.42; 95 % CI, 1.92–15.27), elevated blood pressure (3.10; 95 % CI, 1.15–8.35), and increased waist circumference (OR = 1.34; 95 % CI, 1.09–1.63). Our results show that residence in high relative humidity and menopausal status increase ORs of MetS and its components in Ecuadorian women; however, physical activity significantly reduces the OR of elevated triglycerides in men. The obtained findings may help make public health policies regarding environmental humidity management, nutritional education, menopausal care, and physical activity promotion to prevent the onset of MetS among Ecuadorian adults.

Increased plaque rupture forms peak incidence of acute myocardial infarction in winter

BACKGROUND

It has been widely documented that circannual variation has an impact on the incidence and prognosis of cardiovascular diseases. It is unclear why cold ambient temperature increase the incidence of acute myocardial infarction (AMI). We investigated the relationship between the ambient temperature at the onset of AMI, the morphology of the culprit lesion in patients with AMI.

METHODS

We investigated 202 consecutive patients with AMI who underwent optical coherence tomography (OCT). The participants were divided into lower (n = 100) and higher (n = 102) temperature groups based on the ambient temperature. The culprit lesion morphology was compared between the two groups.

RESULTS

The median temperature at the onset of AMI was 16.6 °C. The prevalence of plaque ruptures was higher at lower temperatures (lower 66% vs. higher 45%, p = .003), whereas OCT-erosion was more frequent in the higher temperature group (lower 13% vs. higher 26%, p = .021). The lower temperature group showed more cholesterol crystals (lower 71% vs. higher 54%, p = .014).

CONCLUSION

The peak incidence of AMI in the winter is formed by increased plaque rupture, suggesting environmental temperature has an influence on the pathogenesis of AMI.

Indoor Thermal Environment Long-Term Data Analytics Using IoT Devices in Korean Apartments: A Case Study

IoT-based monitoring devices can transmit real-time and long-term thermal environment data, enabling innovative conversion for the evaluation and management of the indoor thermal environment. However, long-term indoor thermal measurements using IoT-based devices to investigate health effects have rarely been conducted. Using apartments in Seoul as a case study, we conducted long-term monitoring of thermal environmental using IoT-based real-time wireless sensors. We measured the temperature, relative humidity (RH), and CO₂ in the kitchen, living room, and bedrooms of each household over one year. In addition, in one of the houses, velocity and globe temperatures were measured for multiple summer and autumn seasons. Results of our present study indicated that outdoor temperature is an important influencing factor of indoor thermal environment and indoor RH is a good indicator of residents’ lifestyle. Our findings highlighted the need for temperature management in summer, RH management in winter, and kitchen thermal environment management during summer and tropical nights. This study suggested that IoT devices are a potential approach for evaluating personal exposure to indoor thermal environmental risks. In addition, long-term monitoring and analysis is an efficient approach for analyzing complex indoor thermal environments and is a viable method for application in healthcare.

Impact of Qingdao's smoke-free legislation on hospitalizations and mortality from acute myocardial infarction and stroke: an interrupted time-series analysis

BACKGROUND AND AIMS

More than 20 cities in China have enacted local smoke-free laws that prohibit smoking in public places. Only two of these cities have examined the health impact of the law. Enacted in 2013, Qingdao's smoke free-law was stricter than most other municipal smoke-free laws because it did not allow designated smoking rooms. This study aimed to estimate the impact of Qingdao's smoke-free legislation on acute myocardial infarction (AMI) and stroke.

DESIGN, SETTING AND PARTICIPANTS

We used an interrupted time-series design adjusting for underlying secular trends, seasonal patterns and meteorological factors to estimate the impact of the smoke-free law on AMI and stroke events among permanent residents aged 35 years or older in Qingdao, China. The study period was from 1 January 2010 to 31 December 2015, with a post-ban follow-up of approximately 2.5 years.

MEASUREMENT

Outcome measures were weekly numbers of hospitalizations and deaths due to AMI/stroke.

FINDINGS

A total of 10 371 and 56 101 patients were hospitalized, with a principal discharge diagnosis of AMI and stroke, respectively; 32 196 AMI and 49 711 stroke deaths occurred during the study period. Following the smoke-free legislation, an incremental 20% [95% confidence interval (CI) = 14-26%] and 8% (95% CI = 3-13%) decrease per year was observed in AMI and stroke hospitalization rates, respectively. Neither the immediate nor gradual change in AMI nor stroke mortality rates associated with the law was statistically significant (P > 0.05). Post-hoc subgroup analyses indicated that statistically significant reductions in AMI hospitalizations were evident among both the 35-64 (18% per year, 95% CI = 12-27%) and 65-84 (20% per year, 95% CI = 12-27%) age groups. Statistically significant reductions in stroke hospitalization were only in the older subgroup (13% per year, 95% CI = 8-18%).

CONCLUSIONS

The 2013 smoke-free legislation in Qingdao, China was associated with reduction in hospitalization from acute myocardial infarction and stroke among permanent residents aged 35 years or older. There was no statistically significant reduction in mortality from acute myocardial infarctions or stroke.

Impact of Age on Gender Differences in the Acute Myocardial Infarction Onset–Weather Association ― Oita AMI Registry ―

Background: The onset of acute myocardial infarction (AMI) is related to weather conditions, but the impact of age on gender differences in the AMI onset–weather association has not been elucidated.

Methods and Results: We analyzed the Oita AMI Registry and obtained data for 403 enrolled patients. To examine the impact of age, we categorized the patients into 4 groups: young (age ≤65 years) women (n=20); young men (n=123); elderly (age >65 years) women (n=84); and elderly men (n=176). The analyzed meteorological factors were maximum and minimum temperature, intraday temperature difference, average humidity, and average atmospheric pressure. The young women group had a higher minimum temperature (17.7±5.7℃ vs. 13.8±8.2℃, P=0.04), lower intraday temperature difference (7.0±2.6℃ vs. 8.4±2.9℃, P=0.03), higher average humidity (74.5±12.1% vs. 68.1±12.0%, P=0.03), and lower average atmospheric pressure (1,009.5±5.0 hPa vs. 1,012.9±5.8 hPa, P=0.01) than the young men group on the onset day. In the elderly groups, there was no significant difference in meteorological variables except for the intraday temperature difference 2 days before AMI onset.

Conclusions: AMI onset appears to be more sensitive to weather conditions (i.e., minimum temperature, average atmospheric pressure, and average humidity) in young patients than in elderly patients. In particular, young women had AMI on days with low intraday temperature difference and high humidity relative to men.

Atmospheric fronts as minor cardiovascular risk factors, a new approach to preventive cardiology

BACKGROUND

Cardiovascular diseases are the number one cause of death globally and represent 31% of all global deaths. The aim of our study was to determine the influence of front effects on acute cardiovascular diseases (ACVDs).

METHODS

We obtained all ACVD admissions in a Central-European region, Hungary, Budapest. A time-series analysis was applied to 6499 morbidity cases during a five-year period (2009-2013). Poisson-regression model was used and adjusted for air temperature, pressure, humidity, wind velocity, their interactions and seasonality to assess the association of fronts and ACVDs.

RESULTS

There is a positive significant association between ACVDs and a cold front effect lagged by one day (p=0.018) with a relative risk (RR) of 1.095 [95% CI (1.021,1.181)]. Our findings show that among patient subgroups with major cardiovascular risk factors (hypertension, diabetes, hyperlipidemia, history of CVDs) the patterns are similar, but occluded fronts also have a significant effect.

CONCLUSION

Atmospheric fronts could play an important role in the pathogenesis of ACVDs. Our findings might help to provide a better understanding about fronts as minor cardiovascular risk factors and to organize medical prevention more effectively. Our research project may become a basis of a new field of preventive cardiovascular medicine in the future.

Association of onset-season with characteristics and long-term outcomes in acute myocardial infarction patients: results from the Japanese registry of acute myocardial infarction diagnosed by universal definition (J-MINUET) substudy

It is known that incidence and short-term mortality rate of acute myocardial infarction (AMI) tend to be higher in the cold season. The aim of our study was to investigate the association of onset-season with patient characteristics and long-term prognosis of AMI. This was a prospective, multicenter, Japanese investigation of 3,283 patients with AMI who were hospitalized within 48 h of symptom onset between July 2012 and March 2014. Patients were divided into 3 seasonal groups according to admission date: cold season group (December-March), hot season group (June-September), and moderate season group (April, May, October, and November). We identified 1356 patients (41.3%) admitted during the cold season, 901 (27.4%) during the hot season, and 1026 (31.3%) during the moderate season. We investigated the seasonal effect on patient characteristics and clinical outcomes. Baseline characteristics of each seasonal group were comparable, with the exception of age, Killip class, and conduction disturbances. The rates of higher Killip class and complete atrioventricular block were significantly higher in the cold season group. The 3-year cumulative survival free from major adverse cardiac events (MACE) rate was the lowest in the cold season (67.1%), showing a significant difference, followed by the moderate (70.0%) and hot seasons (72.9%) (p < 0.01). Initial severity and long-term prognoses were worse in patients admitted during the cold season. Our findings highlight the importance of optimal prevention and follow-up of AMI patients with cold season onset.

Sex-specific differences regarding seasonal variations of incidence and mortality in patients with myocardial infarction in Germany

BACKGROUND

Seasonal variation regarding the incidence and the short-term mortality of acute myocardial infarction (MI) was frequently reported, but data about sex-specific differences are sparse.

METHODS

We analysed the impact of seasons and temperature on incidence and in-hospital mortality of patients with acute MI in Germany between 2005 and 2015.

RESULTS

The nationwide sample comprised 3,008,188 hospitalizations of MI patients (2005-2015). The incidence was 334.7/100,000 citizens/year. Incidence inclined from 316.3 to 341.6/100,000 citizens/year (β 0.17 [0.10 to 0.24], P < 0.001), while in-hospital mortality rate decreased from 14.1% to 11.3% (β -0.29 [-0.30 to -0.28], P < 0.001). Overall, 377,028 (12.5%) patients died in-hospital. Seasonal variation of both incidence and in-hospital mortality was of substantial magnitude. Seasonal incidence (86.1 vs. 79.0/100,000 citizens/year, P < 0.001) and in-hospital mortality (13.2% vs. 12.1%, P < 0.001) were higher in winter than in summer. Risk to die in winter was elevated (OR 1.080 (95% CI 1.069-1.091), P < 0.001) compared to summer season independently of sex, age and comorbidities. Reperfusion treatment with drug eluting stents and coronary artery bypass graft were more often used in summer. We observed sex-specific differences regarding the seasonal variation of in-hospital mortality: males showed lowest mortality in summer, while females during fall. Low temperature dependency of mortality seems more pronounced in males.

CONCLUSION

Incidence of acute MI increased 2005-2015, while in-hospital mortality rate decreased. Seasonal variation of incidence and in-hospital mortality were of substantial magnitude with lowest incidence and lowest mortality in the summer season. Additionally, we observed sex-specific differences regarding the seasonal variation of the in-hospital mortality.

Effect of statins on the association between high temperature and all-cause mortality in a socioeconomically disadvantaged population: a cohort study

High temperature increases all-cause mortality. Thermoregulatory ability is impaired in persons with elevated serum cholesterol, but can be improved by the administration of statins, even in the short-term. We investigated whether the impact of high temperature (≥24 °C) on all-cause mortality among socioeconomically disadvantaged adults with a current or past indication for a statin is attenuated by current use of a statin with temperature dependence, by using claims data from five US Medicaid programs supplemented with Medicare claims for dual-enrollees and meteorological data from 1999-2010. We identified 3,508,948 persons (3,181,752 person-years) in a 1:1 propensity score-matched cohort. The incidence rate of all-cause mortality (deaths per 1,000 person-years) was 21.9 (95% confidence interval [CI]: 21.6 to 22.3) in current statin users and 30.1 (95% CI: 30.2 to 30.6) in former users. The adjusted odds ratios of mortality for current vs. former statin use were statistically significantly lower than 1.0, suggesting a protective effect of current statin use, on days with high temperature, with either daily average temperature or daily maximum temperature, and declined as daily average temperature increased from 29 °C and daily maximum temperature increased from 34 °C. These results were robust to the adjustment for daily relative humidity.

Outdoor temperature and survival benefit of empiric potassium in users of furosemide in US Medicaid enrollees: a cohort study

OBJECTIVE

Heat is associated with elevated all-cause mortality, and furosemide-induced potassium depletion might be worsened by heat-induced sweating. Because empiric potassium is associated with a marked survival benefit in users of furosemide at a dose of ≥40 mg/day, we hypothesised that this empiric potassium's survival benefit would increase with higher temperature (≥24°C).

DESIGN

Cohort study.

SETTING

Outpatient setting, captured by Medicaid claims, supplemented with Medicare claims for dual enrollees, from 5 US states from 1999 to 2010, linked to meteorological data.

POPULATION/PARTICIPANTS

Furosemide (≥40 mg/day) initiators among adults continuously enrolled in Medicaid for at least 1 year prior to cohort entry (defined as the day following the dispensing day of each individual's first observed furosemide prescription).

EXPOSURE

Interaction between: (1) empiric potassium, dispensed the day of or the day following the dispensing of the initial furosemide prescription, and (2) daily average temperature and daily maximum temperature, examined separately.

OUTCOME

All-cause mortality.

RESULTS

In 1:1 propensity score matched cohorts (total n=211 878) that included 89 335 person-years and 9007 deaths, all-cause mortality rates per 1000 person-years were 96.0 (95% CI 93.2 to 98.9) and 105.8 (95% CI 102.8 to 108.9) for potassium users and non-users, respectively. The adjusted OR of all-cause mortality for potassium use declined (ie, its apparent protective effect increased) as temperature increased, from a daily average temperature of about 28°C and a daily maximum temperature of about 31°C. This relationship was not statistically significant with daily average temperature, but was statistically significant with daily maximum temperature (p values for the interaction of potassium with daily maximum temperature and daily maximum temperature squared were 0.031 and 0.028, respectively).

CONCLUSIONS

The results suggest that empiric potassium's survival benefit among furosemide (≥40 mg/day) initiators may increase as daily maximum temperature increases. If this relationship is real, use of empiric potassium in Medicaid enrollees initiating furosemide might be particularly important on hot days.

Association between extreme temperature and acute myocardial infarction hospital admissions in Beijing, China: 2013-2016

Over the past few decades, a growing body of epidemiological studies found the effects of temperature on cardiovascular disease, including the risk for acute myocardial infarction (AMI). Our study aimed to investigate whether there is an association between extremely temperature and acute myocardial infarction hospital admission in Beijng, China. We obtained 81029 AMI cases and daily temperature data from January 1, 2013 to December 31, 2016. We employed a time series design and modeled distributed lag nonlinear model (DLNM) to analyze effects of temperature on daily AMI cases. Compared with the 10th percentile temperature measured by daily mean temperature (Tmean), daily minimum temperature (Tmin) and daily minimum apparent temperature (ATmin), the cumulative relative risks (CRR) at 1st percentile of Tmean, Tmin and ATmin for AMI hospitalization were 1.15(95% CI: 1.02, 1.30), 1.24(95% CI: 1.11, 1.38) and 1.41(95% CI: 1.18, 1.68), respectively. Moderate low temperature (10th vs 25th) also had adverse impact on AMI events. The susceptive groups were males and people 65 years and older. No associations were found between high temperature and AMI risk. The main limitation of the study is temperature exposure was not individualized. These findings on cold-associated AMI hospitalization helps characterize the public health burden of cold and target interventions to reduce temperature induced AMI occurrence.

Association between sudden unexpected deaths in bathtubs and ambient temperature among elderly Japanese adults: A time-series regression study

BACKGROUND

Sudden unexpected deaths in bathtubs among elderly Japanese adults occur predominantly during the cold season. This study investigated the relationship between these deaths and bathing day temperature among elderly adults in Tokyo.

METHODS

Data for 1408 cases of bath-related deaths from January 1 to December 31, 2015 were obtained from the Tokyo Medical Examiner's Office. We excluded 409 cases for the following reasons: criminal death, injury-related death, suicide, intoxication, non-sudden death, not bathtub-related death, out-of-bathroom death, subject aged under 65 years, undetermined bathing date, institutional housing, and bathing not at subject's home. Ultimately, 999 cases were analyzed. Daily mean temperature data were collected. A time-series regression study was performed to estimate the influence of sex, age, and bathing day temperature. Monthly changes in the population bathing in a bathtub were considered in the model.

RESULTS

The relative risk (RR) of sudden unexpected death in a bathtub was 1.381 for males (95% confidence interval [CI]: 1.218-1.564) compared to females. The RRs were 4.182 (95% CI: 3.523-4.986) and 9.382 (95% CI: 7.836-11.273) among those aged 75-84 years and ≥85 years, respectively, compared to among those aged 65-74 years. The RR increased to 1.092 (95% CI: 1.082-1.102) as the daily mean temperature decreased by 1 °C.

CONCLUSION

Sudden unexpected death in a bathtub correlated with bathing day temperature among elderly Japanese adults, and extremely low temperature, male sex, and older age increased the risk of such death. Our findings provide insight into preventing sudden unexpected deaths in bathtubs.

Diurnal temperature range in relation to death from stroke in China

BACKGROUND

Stroke is the second leading cause of death in the world. It has multiple risk factors of which some, such as ambient temperature, are less well documented.

OBJECTIVE

We aimed to examine the association between diurnal temperature range (DTR) and stroke mortality, and to test the possible effect modification of this association according to gender, age and educational level.

METHODS

Daily data on weather and stroke mortality from 16 provincial capital cities in China for the years 2007-2013 were obtained, with a total of 788,783 deaths from stroke. A quasi-Poisson generalized linear regression combined with a distributed lag non-linear model was used to examine the city-specific DTR effect on stroke mortality. The pooled effects of DTR on stroke mortality were then obtained using a meta-analysis, which was based on restricted maximum likelihood estimation.

RESULTS

The DTR impacts were generally limited to a period of eight days, while significant effects during lag 0-8 days were only found in the cities of Beijing, Zhengzhou, Nanjing, Hefei, Chongqing and Changsha. The DTR effects were significantly and negatively associated with latitudes at lag 0-10 days (r_s = - 0.640, P = 0.008). An increase of 1 °C in DTR was associated with pooled estimate of 0.66% (95%CI: 0.28-1.05%), 0.12% (- 0.26% to 0.51%) and 0.67% (0.26-1.07%) increases in stroke mortality at lag 0-10 days during the total, hot and cold days, respectively. The impact of DTR was much higher in southern China than in northern China [1.02% (0.62% to 1.43%) versus 0.10% (-0.27% to 0.47%) ]. For the individual characteristics, only females, the elderly aged ≥ 65 years, and those with lower educational attainment were vulnerable to DTR.

CONCLUSIONS

DTR has considerable effects on risk of mortality from stroke in various cities in China, especially among the elderly, females, those with low educational level, and people living in southern China. The results can inform decisions on developing programs to protect vulnerable subpopulations from adverse impacts of DTR.

Seasonal Incidence of Acute Coronary Syndrome and Its Features

Introduction

Acute coronary syndrome (ACS) is one of the most common health problems in the world and the leading cause of death.

Goal

The goals of this study are to determine: ACS type, risk factors, incidence and the seasonal distribution of occurrence Spring/Summer, Autumn/Winter, ACS incidence by age and gender, and complications (post-infarction angina and heart failure) and fatal outcomes of ACS per season.

Material and methodology

This study is designed as retrospective-prospective and analytical, which included 250 patients hospitalized in the Intensive Cardiac care unit of the Clinic for heart disease, blood vessels and rheumatism in the period from June 2013 to July 2014. It was assumed that there is the influence of the seasons on the incidence and characteristics of ACS. Material used were the medical records and data from the history of illness.

Results

The most common type of ACS was ST elevation myocardial infarction (STEMI), without statistical significant difference between seasons. Presence of risk factors is not significantly different between seasons, with the hypertension as the most common risk factor for ACS during both seasons. The highest incidence of ACS was recorded in December during the winter season, while the lowest incidence was recorded in March. The occurrence of ACS during the Spring/Summer, Autumn/Winter was different according to age, with more frequent occurrence of ACS in older patients during the winter months. ACS complications (postinfaction angina and cardiac insufficiency) were also statistically different between seasons (p=0.048). Fatal ACS is more often recorded during the season Autumn/Winter compared to Spring/Summer season (p=0.001).

Conclusion

The results suggest seasonal meteorological impact on the incidence, complications and outcomes of ACS, so there is a necessity that patients adapt their lifestyle and health professionals to improve the ACS treatment.

Short-term effects of ozone air pollution on hospital admissions for myocardial infarction: A time-stratified case-crossover study in Taipei

This study was undertaken to determine whether there was a correlation between ambient ozone (O₃) levels and number of hospital admissions for myocardial infarction (MI) in Taipei, Taiwan. Hospital admissions for MI and ambient air pollution data for Taipei were obtained for the period from 2006 to 2010. The relative risk (RR) of hospital admissions for MI was estimated using a time-stratified case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. For the single-pollutant model (without adjustment for other pollutants), increased RR for a number of MI admissions was significantly associated with higher O₃ levels both on warm days (>23°C) and on cool days (<23°C). This observation was accompanied by an interquartile range elevation correlated with a 7% (95% CI = 2%-12%) and 17% (95% CI = 11%-25%) rise in number of MI admissions, respectively. In the two-pollutant models, no significant associations between ambient O₃ concentrations and number of MI admissions were observed on warm days. However, on cool days, correlation between ambient O₃ after inclusion of each of the other five pollutants, particulate matter (PM₁₀ or PM_2.5), sulfur dioxide (SO₂), nitrogen dioxide (NO₂) or carbon monoxide (CO), and number of MI admissions remained significant. This study provides evidence that higher levels of ambient O₃ increase the RR of number of hospital admissions for MI.

Impact of Ambient Temperature on Incidence of Acute Lower Limb Ischemia

BACKGROUND

This was a retrospective study to explore the possible association between atmospheric temperatures with the occurrence of acute leg ischemia (ALI).

METHODS

A linear regression analysis was performed for a period of 10 years on the impact of ambient temperature on the incidence of ALI. Mean ambient temperature on a daily basis was retrieved electronically from our observatory, and the daily incidence of ALI was retrieved from the Clinical Data Analysis and Reporting (CDAR) system. CDAR system could retrieve clinical data from all 42 public hospitals in our region, which provided almost 90% inpatient care of the population. Daily incidence was defined as total number of emergency admissions from all 42 pubic hospitals due to ALI from 00:00 till 23:59 hr of that day.

RESULTS

For the 10-year period, spanning from January 2005 to December 2014, there were a total of 634 recorded ALI with revascularization, 608 (95.9%) of which underwent emergency femoral embolectomy, 15 (2.4%) underwent thrombolysis, and 11 (1.7%) underwent thrombolysis and embolectomy. ALIs with primary amputation or conservative management were excluded from the study. The average daily incidence of ALI was 0.170. A linear regression model was built using mean ambient temperature as independent variable and incidence of ALI as dependent variables. The line of best fit was drawn through the data points. The daily incidence of ALI could be predicted by ambient temperature (in °C) with the equation: incidence = 0.274-0.004 × temperature (linear regression; r = -0.053, r² = 0.003, F = 10.42, and P = 0.001). In other words, daily incidence was 0.274 at 0°C; and for every 10°C increase, the incidence would drop by 0.040. At 30°C, daily incidence of ALI was 0.154.

CONCLUSIONS

This study showed an association of cold temperature and ALI in our population. Measures to protect the susceptible population from cold temperatures should be considered.

Summertime extreme heat events and increased risk of acute myocardial infarction hospitalizations

Few studies have examined the association between exposure to extreme heat events and risk of acute myocardial infarction (AMI) or demonstrated which populations are most vulnerable to the effects of extreme heat. We defined extreme heat events as days when the daily maximum temperature (TMAX) exceeded the location- and calendar day-specific 95th percentile of the distribution of daily TMAX during the 30-year baseline period (1960-1989). We used a time-stratified case-crossover design to analyze the association between exposure to extreme heat events and risk of hospitalization for AMI in the summer months (June-August) with 0, 1, or 2 lag days. There were a total of 32,670 AMI hospitalizations during the summer months in Maryland between 2000 and 2012. Overall, extreme heat events on the day of hospitalization were associated with an increased risk of AMI (lag 0 OR=1.11; 95% CI: 1.05-1.17). Results considering lag periods immediately before hospitalization were comparable, but effect estimates varied among several population subgroups. As extreme weather events are expected to become more frequent and intense in response to our changing climate, community-specific adaptation strategies are needed to account for the differential susceptibility across ethnic subgroups and geographic areas.

Impact of heat waves on nonaccidental deaths in Jinan, China, and associated risk factors

An ecological study and a case-crossover analysis were conducted to evaluate the impact of heat waves on nonaccidental deaths, and to identify contributing factors of population vulnerability to heat-related deaths in Jinan, China. Daily death data and meteorological data were collected for summer months (June to August) of 2012-2013. Excess mortality was calculated and multivariate linear regression models were used to assess the increased risk of heat waves on deaths. Univariate and multivariate logistic regression models were performed to estimate the odd ratios (ORs) of risk factors and their 95 % confidence intervals (CIs). Overall, heat waves were related to 24.88 % excess deaths of total nonaccidental deaths and 31.33 % excess deaths of circulatory diseases, with an OR of 16.07 (95 % CI 8.80-23.33) for total nonaccidental deaths and 12.46 (95 % CI 7.39-17.53) for deaths of circulatory diseases. The case-crossover analysis indicated that older people were more likely to die during heat waves (OR = 1.233, 95 % CI 1.076-1.413) and more deaths occurred outside a hospital during heat waves (OR = 1.142, 95 % CI 1.006-1.296). In conclusion, heat waves have caused excess deaths and significantly increased the risk of circulatory deaths. The risk factors identified in our study have implications for public health interventions to reduce heat-related mortality during extreme heat events.

Influence of meteorological factors on acute aortic events in a subtropical territory

BACKGROUND/OBJECTIVE

This study aims to examine the relationship between weather changes and acute aortic events in a subtropical territory.

METHODS

A linear regression analysis was performed in a pan-territory epidemiological survey for a period of 10 years on the impacts of meteorological factors (ambient temperature, atmospheric pressure, relative humidity, amount of cloud, rainfall, number of lightning strikes, presence of typhoon, and thunderstorm warning) on the daily incidences of acute aortic dissections and ruptured aortic aneurysms. Meteorological variables were retrieved on a daily basis from a well-established observatory, and the daily incidences of aortic dissections and rupture of aortic aneurysms were retrieved from the Clinical Data Analysis and Reporting System.

RESULTS

During the study period (January 2005 to December 2014), 3878 patients were identified as having acute aortic dissections, and 1174 patients had ruptured aortic aneurysms. Corresponding averaged daily incidences were 1.06 and 0.32, respectively. The incidences of aortic dissection and ruptured aortic aneurysm in a day could be predicted by ambient temperature in degrees Celsius using the following linear regression models: (1) incidence of aortic dissection = 1.548 - 0.021 × temperature; (2) incidence of ruptured aortic aneurysm = 0.564 - 0.010 × temperature. In addition, both high atmospheric pressure and absence of thunderstorm warning are positively associated with more aortic dissections. For rupture of aortic aneurysms, high atmospheric pressure and low relative humidity were positive predictors. In multiple regression analysis, however, ambient temperature was the only significant predictor for both acute aortic dissections and ruptured aortic aneurysms.

CONCLUSION

This is the first pan-territory study to show an attributable effect of ambient temperature on acute aortic events. This paper confirms that even in a subtropical country, meteorological variables were important factors influencing acute aortic events.

Drier air, lower temperatures, and triggering of paroxysmal atrial fibrillation

BACKGROUND

The few previous studies on the onset of paroxysmal atrial fibrillation and meteorologic conditions have focused on outdoor temperature and hospital admissions, but hospital admissions are a crude indicator of atrial fibrillation incidence, and studies have found other weather measures in addition to temperature to be associated with cardiovascular outcomes.

METHODS

Two hundred patients with dual chamber implantable cardioverter-defibrillators were enrolled and followed prospectively from 2006 to 2010 for new onset episodes of atrial fibrillation. The date and time of arrhythmia episodes documented by the implanted cardioverter-defibrillators were linked to meteorologic data and examined using a case-crossover analysis. We evaluated associations with outdoor temperature, apparent temperature, air pressure, and three measures of humidity (relative humidity, dew point, and absolute humidity).

RESULTS

Of the 200 enrolled patients, 49 patients experienced 328 atrial fibrillation episodes lasting ≥30 seconds. Lower temperatures in the prior 48 hours were positively associated with atrial fibrillation. Lower absolute humidity (ie, drier air) had the strongest and most consistent association: each 0.5 g/m decrease in the prior 24 hours increased the odds of atrial fibrillation by 4% (95% confidence interval [CI]: 0%, 7%) and by 5% (95% CI: 2%, 8%) for exposure in the prior 2 hours. Results were similar for dew point but slightly weaker.

CONCLUSIONS

Recent exposure to drier air and lower temperatures were associated with the onset of atrial fibrillation among patients with known cardiac disease, supporting the hypothesis that meteorologic conditions trigger acute cardiovascular episodes.

Vulnerabilities to Temperature Effects on Acute Myocardial Infarction Hospital Admissions in South Korea

Most previous studies have focused on the association between acute myocardial function (AMI) and temperature by gender and age. Recently, however, concern has also arisen about those most susceptible to the effects of temperature according to socioeconomic status (SES). The objective of this study was to determine the effect of heat and cold on hospital admissions for AMI by subpopulations (gender, age, living area, and individual SES) in South Korea. The Korea National Health Insurance (KNHI) database was used to examine the effect of heat and cold on hospital admissions for AMI during 2004-2012. We analyzed the increase in AMI hospital admissions both above and below a threshold temperature using Poisson generalized additive models (GAMs) for hot, cold, and warm weather. The Medicaid group, the lowest SES group, had a significantly higher RR of 1.37 (95% CI: 1.07-1.76) for heat and 1.11 (95% CI: 1.04-1.20) for cold among subgroups, while also showing distinctly higher risk curves than NHI for both hot and cold weather. In additions, females, older age group, and those living in urban areas had higher risks from hot and cold temperatures than males, younger age group, and those living in rural areas.

Weather and triggering of ventricular arrhythmias in patients with implantable cardioverter-defibrillators

Outdoor ambient weather has been hypothesized to be responsible for the seasonal distribution of cardiac arrhythmias. Because people spend most of their time indoors, we hypothesized that weather-related arrhythmia risk would be better estimated using an indoor measure or an outdoor measure that correlates well with indoor conditions, such as absolute humidity. The clinical records of 203 patients in eastern Massachusetts, USA, with an implantable cardioverter-defibrillator were abstracted for arrhythmias between 1995 and 2002. We used case-crossover methods to examine the association between weather and ventricular arrhythmia (VA). Among 84 patients who experienced 787 VAs, lower estimated indoor temperature (odds ratio (OR)=1.16, 95% confidence interval (CI) 1.05-1.27 for a 1 °C decrease in the 24-h average) and lower absolute humidity (OR=1.06, 95% CI 1.03-1.08 for a 0.5 g/m(3) decrease in the 96-h average) were associated with increased risk. Lower outdoor temperature increased risk only in warmer months, likely attributable to the poor correlation between outdoor and indoor temperature during cooler months. These results suggest that lower temperature and drier air are associated with increased risk of VA onset among implantable cardioverter-defibrillator patients.

Adiposity and influenza-associated respiratory mortality: a cohort study

BACKGROUND

Obesity was first noted as a risk factor for severe illness associated with pandemic H1N1 infection in 2009, but the relationship between obesity and seasonal influenza remains unclear.

METHODS

We used data from a population-based cohort comprising 66 820 older (≥65 years) participants with a follow-up period from 1998 to 2012. The impact of influenza activity on respiratory mortality rates was estimated using a Cox proportional hazards model adjusted for comorbidities, meteorological factors, and other co-circulating respiratory viruses. We also tested whether the association of influenza with respiratory mortality varied with obesity and/or health status. As a control outcome, we similarly assessed the association of influenza with deaths from external causes, because these deaths should be unrelated to influenza.

RESULTS

Seasonal influenza activity was associated with higher respiratory mortality (hazard ratio [HR], 1.13 for influenza activity in the influenza season vs noninfluenza season; 95% confidence interval [CI], 1.05-1.22). The effect of seasonal influenza was 19% greater in obese individuals than normal-weight individuals (HR, 1.19; 95% CI, 1.01-1.42). The marginally significant and greater effect modification of obesity status on the association between seasonal influenza and respiratory mortality was also observed among older people in good health (HR, 1.35; 95% CI, .97-1.87). No such relations were observed for death from external causes.

CONCLUSIONS

Obesity aggravates the effect of seasonal influenza on respiratory mortality. Priority for influenza vaccine should be considered for obese older people to decrease the burden of influenza.

Short-term exposure to environmental parameters and onset of ST elevation myocardial infarction. The CARDIO-ARSIF registry

BACKGROUND

Environmental parameters have been reported to be triggers of acute myocardial infarction (MI). However, the individual role of each parameter is unknown. We quantified the respective association of climate parameters, influenza epidemics and air pollutants with the onset of ST elevation MI (STEMI) in Paris and the surrounding small ring.

METHODS

Data from the CARDIO-ARSIF registry (Paris and small ring STEMI population), Météo France (Climate), GROG (Influenza epidemic) and AIRPARIF (Air Pollution) were analyzed. The association between short-term exposure (1 day lag time) to environmental parameters and STEMI occurrence was quantified by time series modeling of daily STEMI count data, using Poisson regression with generalized additive models.

RESULTS

Between 2003 and 2008, 11,987 <24H STEMI confirmed by angiography were adjudicated. There was a 5.0% excess relative risk (ERR) of STEMI per 10°C decrease in maximal temperature (95% CI 2.1% to 7.8%: p=0.001) and an 8.9% ERR (95% CI 3.2% to 14.9%: p=0.002) during an influenza epidemic after adjustment on week-days and holidays. Associations were consistent when short-term exposure varied from 2 to 7 days. Associations between lower temperatures and STEMI were stronger in magnitude when influenza epidemic was present. Short-term exposure to climatic parameters or pollutants was not associated with STEMI.

CONCLUSIONS

The present population based registry of STEMI suggests that short-term exposure to lower temperature and influenza epidemic is associated with a significant excess relative risk of STEMI. Subjects at risk for MI may benefit from specific protections against cold temperature and influenza infection.

Impact on human health of climate changes

There is increasing evidence that climate is rapidly changing. These changes, which are mainly driven by the dramatic increase of greenhouse gas emissions from anthropogenic activities, have the potential to affect human health in several ways. These include a global rise in average temperature, an increased frequency of heat waves, of weather events such as hurricanes, cyclones and drought periods, plus an altered distribution of allergens and vector-borne infectious diseases. The cardiopulmonary system and the gastrointestinal tract are particularly vulnerable to the adverse effects of global warming. Moreover, some infectious diseases and their animal vectors are influenced by climate changes, resulting in higher risk of typhus, cholera, malaria, dengue and West Nile virus infection. On the other hand, at mid latitudes warming may reduce the rate of diseases related to cold temperatures (such as pneumonia, bronchitis and arthritis), but these benefits are unlikely to rebalance the risks associated to warming.

Influence of daily individual meteorological parameters on the incidence of acute coronary syndrome

BACKGROUND

A nationwide study was conducted to explore the short term association between daily individual meteorological parameters and the incidence of acute coronary syndrome (ACS) treated with coronary emergency catheter interventions in the Republic of Slovenia, a south-central European country.

METHOD

We linked meteorological data with daily ACS incidence for the entire population of Slovenia, for the population over 65 years of age and for the population under 65 years of age. Data were collected daily for a period of 4 years from 1 January 2008 to 31 December 2011. In line with existing studies, we used a main effect generalized linear model with a log-link-function and a Poisson distribution of ACS.

RESULTS AND CONCLUSIONS

Three of the studied meteorological factors (daily average temperature, atmospheric pressure and relative humidity) all have relevant and significant influences on ACS incidences for the entire population. However, the ACS incidence for the population over 65 is only affected by daily average temperature, while the ACS incidence for the population under 65 is affected by daily average pressure and humidity. In terms of ambient temperature, the overall findings of our study are in line with the findings of the majority of contemporary European studies, which also note a negative correlation. The results regarding atmospheric pressure and humidity are less in line, due to considerable variations in results. Additionally, the number of available European studies on atmospheric pressure and humidity is relatively low. The fourth studied variable-season-does not influence ACS incidence in a statistically significant way.

Neighborhood geographic disparities in heart attack and stroke mortality: comparison of global and local modeling approaches

This study investigated neighborhood geographic disparities in myocardial infarction (MI) and stroke mortality risks in middle Tennessee and identified determinants of observed disparities. Descriptive and spatial analyses were performed on MI and stroke mortality data covering the time period 1999-2007. Besag, York and Molliè (BYM) model was used to investigate spatial patterns. Global (BYM) and local models [Poisson Geographically Weighted Generalized Linear Models (GWGLM)] were used to investigate determinants of the identified spatial patterns. Significant (p<0.05) differences in mortality risks by sex, race, age and education were observed. Rural census tracts (CT) and those with higher proportions of the older populations were associated with high MI and stroke mortality risks. Additionally, CTs with high proportions of widows had significantly higher mortality risks for stroke. There was evidence of geographical variability of all regression coefficients implying that local models complement the findings of the global models and provide useful information to guide local and regional disease control decisions and resource allocation. Identification of high risk CTs is essential for targeting resources and will aid the development of more needs-based prevention programs.

Derivation and validation of BOREAS, a risk score identifying candidates to develop cold-induced hypertension

INTRODUCTION

Blood pressure increases in cold periods, but its implications on prevalence of hypertension and on individual progression to hypertension remain unclear. Our aim was to develop a pre-screening test for identifying candidates to suffer hypertension only in cold months among non-hypertensive subjects.

METHODS

We included 95,277 subjects registered on a primary care database from Girona (Catalonia, Spain), with ≥ 3 blood pressure measures recorded between 2003 and 2009 and distributed in both cold (October-March) and warm (April-September) periods. We defined four blood pressure patterns depending on the presence of hypertension through these periods. A Cox model determined the risk to develop vascular events associated with blood pressure patterns. A logistic regression distinguished those nonhypertensive individuals who are more prone to suffer cold-induced hypertension. Validity was assessed on the basis of calibration (using Brier score) and discrimination (using the area under the receiver operating characteristics).

RESULTS

In cold months, the mean systolic blood pressure increased by 3.3 ± 0.1 mmHg and prevalence of hypertension increased by 8.2%. Cold-induced hypertension patients were at higher vascular events risk (Hazard ratio=1.44 [95% Confidence interval 1.15-1.81]), than nonhypertensive individuals. We identified age, diabetes, body mass index and prehypertension as the major contributing factors to cold-induced hypertension onset.

DISCUSSION

Hypertension follows a seasonal pattern in some individuals. We recommend screening for hypertension during the cold months, at least in those nonhypertensive individuals identified as cold-induced hypertensive by this assessment tool.

Short-term effect of temperature on daily emergency visits for acute myocardial infarction with threshold temperatures

BACKGROUND

The relationship between temperature and myocardial infarction has not been fully explained. In this study, we identified the threshold temperature and examined the relationship between temperature and emergency admissions due to MI in Korea.

METHODS

Poisson generalized additive model analyses were used to assess the short-term effects of temperature (mean, maximum, minimum, diurnal) on MI emergency visits, after controlling for meteorological variable and air pollution (PM10, NO2). We defined the threshold temperature when the inflection point showed a statistically significant difference in the regression coefficients of the generalized additive models (GAMs) analysis. The analysis was performed on the following subgroups: geographical region, gender, age (<75 years or ≥ 75 years), and MI status (STEMI or non-STEMI).

RESULTS

The threshold temperatures during heat exposure were for the maximum temperature as 25.5-31.5°C and for the mean temperature as 27.5-28.5°C. The threshold temperatures during cold exposure were for the minimum temperature as -2.5-1.5°C. Relative risks (RRs) of emergency visits above hot temperature thresholds ranged from 1.02 to 1.30 and those below cold temperature thresholds ranged from 1.01 to 1.05. We also observed increased RRs ranged from 1.02 to 1.65 of emergency visits when temperatures changes on a single day or on successive days.

CONCLUSIONS

We found a relationship between temperature and MI occurrence during both heat and cold exposure at the threshold temperature. Diurnal temperature or temperature change on successive days also increased MI risk.

High relative environmental humidity is associated with diabetes among elders living in Mediterranean islands

BACKGROUND

Climate variation has long been studied in relation to human health. The aim of the present work was to evaluate the relationship between environmental humidity, and air temperature with the prevalence of diabetes, among elderly islanders.

METHODS

During 2005-2011, 1959 elderly (aged 65 to 100 years) individuals from 13 Mediterranean islands were enrolled. Socio-demographic, clinical and lifestyle factors were assessed using standard procedures. Diabetes was defined as fasting blood glucose levels > 125 mg/dl. Relative environmental humidity was measured as a percentage of air moisture and mean daily temperature in degrees Celsius.

RESULTS

For the present analysis 713 men (74 ± 7 years) and 596 women (73 ± 7 years) with complete data were studied; 27% of both men and women had diabetes. The prevalence of diabetes was 42% in the elders living in high relative humidity areas (i.e., >70%) as compared with 24% among those living at low relative humidity residential areas (p < 0.001). After adjusting for age, sex and mean temperature, an increase in the area's relative humidity by 1 degree, increased the likelihood of having diabetes by 12% (OR = 1.12, 95% CI 1.05 to 1.20). No significant association was observed between mean temperature and diabetes (OR = 0.97, 95% CI 0.74, 1.26).

CONCLUSIONS

A considerable proportion of elderly, especially those living in high relative humidity areas, had diabetes. Further research is needed to confirm this observation and to understand the underlying mechanisms.