Photo Credit: Kurgenc
Chronic obstructive pulmonary disease (COPD) is a leading global cause of morbidity and mortality, with environmental factors playing a significant role in disease exacerbation. A recent systematic review and meta-analysis, published online in Science of the Total Environment, examined the impact of extreme temperatures—both heat and cold—on COPD-related hospitalizations and deaths, identifying key vulnerable populations.
“Extreme temperatures, both heat and cold, significantly impact global health, particularly affecting those with chronic respiratory diseases such as [COPD],” study authors wrote. “COPD is a leading cause of morbimortality (morbidity and mortality) worldwide, accounting for approximately 3.3 million deaths annually and ranking as the third leading cause of death globally.”
“Numerous studies have explored the associations between temperature extremes and COPD exacerbations, highlighting that both extremely high and low temperatures can lead to increased hospital admissions and mortality.”
The analysis included data from 25 observational studies conducted between 2000 and 2024, evaluating the effects of extreme temperature exposure on COPD outcomes. Findings revealed that extreme heat increased COPD morbidity and mortality risks by 1.16-fold and 1.19-fold, respectively. The effects of extreme cold were even more pronounced, with a 1.32-fold increase in overall risk. Specifically, cold exposure led to a 1.47-fold increase in COPD morbidity and a 1.23-fold increase in mortality. These findings highlight the heightened vulnerability of COPD patients to both hot and cold environmental conditions.
Importantly, certain subpopulations exhibited greater sensitivity to temperature extremes. Women with COPD experienced a higher risk of adverse outcomes from extreme heat compared to men. Similarly, older adults, particularly those aged 70 and above, faced increased risks from both heat and cold exposure. Geographic disparities were also evident, with Asian populations being highly susceptible to both temperature extremes, while European populations were predominantly affected by extreme cold. These variations suggest the influence of genetic, physiological, and environmental factors in COPD exacerbations linked to climate conditions.
The physiological mechanisms underlying these associations are well-documented. Heat exposure can lead to dehydration, increased mucus viscosity, and impaired pulmonary function, exacerbating COPD symptoms. Cold exposure, on the other hand, is associated with bronchoconstriction, increased airway resistance, and heightened susceptibility to respiratory infections, all of which contribute to acute exacerbations and hospitalizations.
“Moreover, extreme heat and cold were associated with morbimortality risk among older adults. Asian populations were sensitive to both temperature extremes, whereas Europeans were predominantly susceptible to extreme cold,” they concluded.
“This variability in response to extreme temperatures affects COPD morbidity and mortality, emphasizing the need for tailored medical and emergency responses to effectively mitigate health risks during extreme weather events.”
