Association of outdoor temperature with lung function in a temperate climate

Area of Science:

• Environmental Health
• Pulmonary Medicine
• Epidemiology

Background:

• Acute exposure to cold, dry air can trigger bronchoconstriction.
• The influence of daily outdoor temperature on lung function is not well understood.

Purpose of the Study:

• To investigate the association between daily outdoor temperature and lung function.
• To examine if temperature modifies the relationship between air pollution and lung function.

Main Methods:

• Utilized satellite remote sensing data to model temperature.
• Analyzed repeated lung function measures from 5896 participants in the Framingham Heart Study cohorts.
• Employed linear mixed-effects models and penalized splines to assess associations and non-linear effects.

Main Results:

• Higher average temperatures over 1, 2, and 7 days were associated with lower lung function (e.g., each 5°C increase in previous-week temperature linked to a 20 mL decrease in forced expiratory volume in 1 second).
• Negative associations between temperature and lung function were observed primarily in winter and spring.
• Associations between fine particulate matter and lung function were evident on warmer days but not cooler days.

Conclusions:

• Daily outdoor temperature, particularly during colder seasons, is associated with reduced lung function.
• Temperature may influence lung function through behavioral changes that increase exposure to environmental factors.
• The impact of air pollution on lung function may be exacerbated by unseasonably warm temperatures.