Impact of temperature and humidity on airway obstruction in a cohort of elderly women

Abstract Background Temperature and relative humidity (RH) impact human health. However, little is known about the combined association between temperature and RH on respiratory health in the elderly. In this study, we evaluated the interactive associations of temperature and RH on airway obstruction in elderly German women. Methods Using data from the second follow-up (2007-2010) of the German SALIA cohort study, we assessed the short-term (Lag0-8) combined association between maximum and minimum temperature (Tmax, Tmin) and RH on airway obstruction. Airway obstruction was defined as the ratio of first second of forced expiration (FEV1) / forced vital capacity (FVC) < 0.70. Multivariable logistic regression with a distributed lag non-linear model (DLNM) was constructed for the interaction between temperature and RH and adjusted for a single pollutant, location, socioeconomic status and smoking status. Results 735 elderly women with an average (±SD) age of 73.46 (±3.09) years were included. Around 16.73% of them had airway obstruction. For non-linear antagonistic Tmax and RH interaction models, we found a U-shaped relationship from Lag 0-8, with an immediate adverse association from Lag0-1 and a significant delayed adverse association from Lag7-8. For non-linear antagonistic Tmin and RH interaction models, the relationship was U-shaped and showed an immediate adverse association from Lag0-1, while there was also a significant delayed association from Lag6-8. Conclusions Climate change increases the likelihood of exposure to adverse temperatures and weather conditions. Vulnerable populations like the elderly are more susceptible to the adverse associations of climate change. In this epidemiological study, we found that exposure to Tmax/Tmin and RH had immediate and delayed adverse associations by increasing respiratory obstruction in elderly women. Increasing public awareness of the danger of interactions between non-optimum temperature and RH on respiratory health is crucial. Key messages • Elderly women’s respiratory health is impacted by temperature and humidity interactions, requiring awareness and proactive measures. • Climate change heightens risk for vulnerable groups, emphasising the need to address environmental impacts on health.