3 Key Takeaways
Plain English Summary- 01Core Finding
We used the Acute Exacerbation of Chronic Obstructive Pulmonary Disease Registry (ACURE) data and assigned residential temperature exposure using ERA5-Land, a reanalysis dataset of European Centre for Medium-Range Weather Forecasts.
- 02Study Evidence
Tested in a observational cohort study (5,634 patients) at the real-world cohort stage.
- 03Practical Meaning
Observational cohort findings reveal real-world links, though lifestyle or unmeasured factors cannot be fully ruled out without an RCT.
What This Means for You
Lower temperature and extreme cold events, particularly CCS, were associated with AECOPD onset. Symptom-onset timing may better capture temperature-related associations than admission timing. These findings highlight the need for targeted cold-weather prevention strategies to reduce AECOPD burden.
The Discovery
Non-optimal temperatures and extreme temperature events may trigger acute exacerbations of COPD (AECOPD), but most evidence is admission based, potentially misclassifying exposure timing and obscuring susceptible groups. We used the Acute Exacerbation of Chronic Obstructive Pulmonary Disease Registry (ACURE) data and assigned residential temperature exposure using ERA5-Land, a reanalysis dataset of European Centre for Medium-Range Weather Forecasts. Cold spells (CS) were defined as consecutive days below location-specific low-temperature thresholds, and compound cold spells (CCS) as concurrent daytime and nighttime cold spells. Associations with reported symptom onset were estimated using a time-stratified case-crossover design, conditional logistic regression with distributed lag nonlinear models. Subgroup and cytokine analyses assessed susceptibility and inflammation. Among 5,634 patients with AECOPD (mean age, 69.4 ± 9.5 years; 78.8% male), lower temperature was associated with higher odds of AECOPD onset, whereas higher temperature was not. The strongest associations occurred for CS lasting ≥3 days and CCS lasting ≥2 days over lag 0-3 days, with ORs of 1.84 (95% CI, 1.22-2.78) and 4.31 (95% CI, 2.07-8.97), respectively. Nearly half had delayed admission within 14 days. Using admission rather than onset dates attenuated estimates by 88.8% for CS and 84.8% for CCS. Associations were stronger among older adults, men, smokers, patients with severe AECOPD in the past year or previously diagnosed COPD, and those using combination inhaler in the preceding year. CS were also associated with higher TNF-α, IL-6, and CXCL-11 concentrations.
How It Works, Simply
This pulmonology research focuses on inflammation. Researchers evaluated it using an observational cohort study (5,634 patients) at the real-world cohort stage of medical research.
3 Key Takeaways
Clinical Takeaways- 01Core Finding
We used the Acute Exacerbation of Chronic Obstructive Pulmonary Disease Registry (ACURE) data and assigned residential temperature exposure using ERA5-Land, a reanalysis dataset of European Centre for Medium-Range Weather Forecasts.
- 02Study Evidence
Tested in a observational cohort study (5,634 patients) at the real-world cohort stage.
- 03Practical Meaning
Observational cohort findings reveal real-world links, though lifestyle or unmeasured factors cannot be fully ruled out without an RCT.
Key Numbers
Biological Mechanism & Study Design
Study Design & Cohort
Observational cohort study
Observational cohort study (5,634 patients) · Real-World Cohort
Biological Pathway & Modality
Inflammation
Intervention: Associations between temperatures, extreme temperature events, and onset of acute
Experimental Findings & Endpoints
Non-optimal temperatures and extreme temperature events may trigger acute exacerbations of COPD (AECOPD), but most evidence is admission based, potentially misclassifying exposure timing and obscuring susceptible groups.
We used the Acute Exacerbation of Chronic Obstructive Pulmonary Disease Registry (ACURE) data and assigned residential temperature exposure using ERA5-Land, a reanalysis dataset of European Centre for Medium-Range Weather Forecasts. Cold spells (CS) were defined as consecutive days below location-specific low-temperature thresholds, and compound cold spells (CCS) as concurrent daytime and nighttime cold spells.
Associations with reported symptom onset were estimated using a time-stratified case-crossover design, conditional logistic regression with distributed lag nonlinear models. Subgroup and cytokine analyses assessed susceptibility and inflammation.
Among 5,634 patients with AECOPD (mean age, 69.4 ± 9.5 years; 78.8% male), lower temperature was associated with higher odds of AECOPD onset, whereas higher temperature was not. The strongest associations occurred for CS lasting ≥3 days and CCS lasting ≥2 days over lag 0-3 days, with ORs of 1.84 (95% CI, 1.22-2.78) and 4.31 (95% CI, 2.07-8.97), respectively.
Nearly half had delayed admission within 14 days. Using admission rather than onset dates attenuated estimates by 88.8% for CS and 84.8% for CCS.
Associations were stronger among older adults, men, smokers, patients with severe AECOPD in the past year or previously diagnosed COPD, and those using combination inhaler in the preceding year. CS were also associated with higher TNF-α, IL-6, and CXCL-11 concentrations.
Clinical Translation & Practice Context
Lower temperature and extreme cold events, particularly CCS, were associated with AECOPD onset.
Symptom-onset timing may better capture temperature-related associations than admission timing. These findings highlight the need for targeted cold-weather prevention strategies to reduce AECOPD burden.
The Bottom Line · Clinical Pearl
“Lower temperature and extreme cold events, particularly CCS, were associated with AECOPD onset.”
Published in Chest · Current Stage: Real-World Cohort