(HealthDay News) — Extreme hot and cold temperatures are associated with an increased risk for mortality from common cardiovascular conditions, according to a study published online in Circulation.
Barrak Alahmad, MD, MPH, PhD, from the Harvard T. H. Chan School of Public Health in Boston, and colleagues assembled a database of daily counts of specific cardiovascular causes of death from 567 cities in 27 countries across 5 continents in overlapping periods ranging from 1979 to 2019 to examine the association between temperatures and cardiovascular deaths. Deaths from any cardiovascular cause (32,154,935), ischemic heart disease (11,745,880), stroke (9,351,312), heart failure (3,673,723), and arrhythmia (670,859) were included in the analyses.
The researchers found that compared with the minimum mortality temperature (the temperature associated with the least mortality), at extreme temperature percentiles, heat (99th percentile) and cold (1st percentile) were associated with an increased risk for dying from any cardiovascular cause, ischemic heart disease, stroke, and heart failure. Hot and cold days (above the 97.5th percentile and below the 2.5th percentile) accounted for 2.2 and 9.1 excess deaths for every 1000 cardiovascular deaths, respectively. The proportion of excess deaths from extreme hot and cold days was highest for heart failure, with 2.6 and 12.8 excess deaths per every 1000 heart failure deaths, respectively.
“One in every 100 cardiovascular deaths may be attributed to extreme temperature days, and temperature effects were more pronounced when looking at heart failure deaths,” a coauthor said in a statement.