An analysis of nearly 2.3 million Europeans found harmful associations between cold weather and death from heart disease, particularly in poor neighborhoods. Late-breaking research is presented at ESC Congress 2022.1 Hot weather was linked to excess deaths from heart disease and stroke in patients with heart disease.
Study author Professor Stefan Agewall of the University of Oslo, Norway, said: “Climate change is causing an increase in average global temperature, but also extreme cold in some regions. intense heat waves.2 Cold weather is also responsible for excess mortality and hospital admissions.3.4 Previously, studies of the cardiovascular effects of heat and cold mostly used aggregate data, such as daily deaths in a city. The EXHAUSTION project used individual data, which allowed us to identify vulnerable subgroups for protective interventions, increasing resilience to future weather events.”
The analysis included 2.28 million adults from five cohort studies conducted in Italy, Germany, the UK, Norway and Sweden between 1994 and 2010. The average age ranged from 49.7 years to 71.7 years and the proportion of women ranged from 36.0% to 54.5%. . Participants with and without cardiovascular disease at baseline were included. Data on mortality and new diseases were collected through death and disease registers and follow-up surveys. Mean daily air temperatures at participants’ home addresses were collected from local weather stations or estimated using weather station temperature data modeling
Relationships between temperature and cardiovascular conditions and death were analyzed for all participants and in subgroups with particular characteristics. A time-stratified case crossover study was used where, for each participant, researchers compared the temperature on the day of the week an adverse event occurred (e.g., Monday) with the temperature on the same day of the week without an adverse event (eg all remaining Mondays) in the same month. The use of within-participant comparisons between days of the same month eliminated potential confounding effects of participant characteristics and time trends.
The analysis revealed increased risks of death from cardiovascular disease in general and ischemic heart disease in particular, as well as an increased risk of new-onset ischemic heart disease associated with cold weather. With a temperature drop of about 10°C, from 5°C to -5°C, the risk of death from cardiovascular disease was 19% higher (relative risk [RR] 1.19; 95% confidence interval [CI] 1.04-1.36) and a high probability of 22% of death from ischemic heart disease (RR 1.22; 95% CI 1.07-1.38). There was a 4% increased risk of new-onset ischemic heart disease associated with a temperature drop of about 11°C from 2°C to -9°C (RR 1.04; 95% CI: 1.01-1.08).
Prof Agewall said: “Relationships between cold temperatures and death were more pronounced in men and people living in neighborhoods of low socio-economic status. The links between cold and new-onset ischemic heart disease were strongest in women and people over 65.”
Heat was not linked to adverse effects in the overall study population. However, increases in temperature from 15°C to 24°C were associated with 25% (RR 1.25; 95% CI 1.12-1.39) and 30% (RR 1.30; 95% CI % 1.10-1.53) increased risks of death from cardiovascular disease and stroke, respectively, in people with heart disease at baseline.
Professor Agewall said: “Clinicians can use this information to provide personalized advice to those most at risk of adverse health effects during hot and cold days. Patients with heart disease should stay hydrated in hot weather. and follow the advice of their cardiologist on the use of medication. We can all consult information on extreme heat and cold alerts and follow the safety advice of local authorities.”
References and notes
1EXHAUSTION will be presented by Dr. Siqi Zhang from Helmholtz Munich during the Latest Science in Primary and Secondary Prevention and Environmental Health session on Friday, August 26 from 2:00 p.m. to 3:15 p.m. CEST in the Dali Hall.
2Robine JM, Cheung SLK, Le Roy S, et al. The death toll exceeded 70,000 in Europe in the summer of 2003. CR Biol. 2008;331:171-178.
3Gasparrini A, Guo Y, Hashizume M, et al. Mortality risk attributable to high and low ambient temperature: a multicountry observational study. Lancet. 2015;386:369-375.
4Sun Z, Chen C, Xu D, Li T. Effects of ambient temperature on myocardial infarction: systematic review and meta-analysis. Environment Pollution. 2018;241:1106-1114.