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Here's another likely health impact from climate change to add to the ever-growing list: more frequent chronic obstructive pulmonary disease (COPD) exacerbations.

Each 1°C increment in outdoor temperature, after adjustment for humidity levels, was associated with a 2% increase in odds that COPD patients would experience exacerbations 2 days later (P=0.002), reported Supaksh Gupta, MD, a pulmonology fellow at the University of Washington in Seattle.

Scheduled for presentation Sunday at the virtual , and highlighted in an distributed beforehand, the research reinforces the mounting evidence that a warming climate will be an unhealthier climate for many.

For example, one study examined , following a heat wave in mid-July 2006 affecting much of Western Europe. While Portugal was not especially hard-hit -- the worst , where temperatures reached 10°C higher than normal, topping 100°F in some parts of Germany -- the Atlantic coastal city saw increases of up to 9% in COPD-related deaths for certain subgroups.

The study by Gupta and colleagues drew on U.S. data collected as part of the NIH-funded . The researchers correlated local weather data for 1,117 members of the cohort, who were current or former smokers with at least one COPD exacerbation since joining the study, with the timing of those exacerbations. Participants' mean age was 63 (SD 9).

Exacerbation rates began to increase the day after temperature rises were recorded, and remained higher through most of the week after these temperature spikes. This increase in exacerbation risk peaked at day 2, and was also significantly higher than baseline at days 3 and 6.

The ERS press release noted that it remains unclear how warm temperatures contribute to COPD exacerbations, but a phenomenon called hyperinflation (also known as hyperventilation) may be involved.

"During dynamic hyperinflation, a person does not exhale completely before starting to inhale again," the organization explained. "This can lead to less efficient and effective breaths. At its extreme, dynamic hyperinflation could lead to increased pressure in the chest cavity and a subsequent decrease in blood flow back to the heart."

The press release also pointed out that the elderly -- the population most affected by COPD -- are often less able to stay adequately hydrated and don't adjust as well to high temperatures as younger people. Hot, damp air may also trigger bronchoconstriction directly.

Commented Gupta, "While not conclusive, the study suggests that those living with COPD may want to avoid exposure to adverse and extreme environmental conditions by limiting outdoor activities during periods of elevated temperatures relative to normal. Moreover, while not within the scope of this paper but based on previously existing literature, those who reside in areas with increased temperature, or increased temperature variability, may benefit from access to indoor air cooling."

An independent scholar quoted by ERS emphasized the importance of this and other studies examining the health effects of rising global temperatures.

"The climate emergency is proving to have far-reaching effects in areas of everyday life where it might not necessarily be expected to have an impact," said Zorana J. Andersen, PhD, MSc, of the University of Copenhagen. "This study offers a fascinating insight into the way it could be affecting the lives of people living with COPD and is yet more proof of the urgent need to tackle climate change."

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