[Association between ambient personal temperature exposure and oxygen saturation during sleep in patients with...

To assess the association between personal temperature exposure and oxygen saturation (SpO₂) during sleep in chronic obstructive pulmonary disease (COPD) patients, to analyze potential susceptibility factors and to provide a scientific basis for the adoption of effective measures to safeguard the health of susceptible populations.

In this prospective panel study, 96 stable COPD patients were recruited. From March 2021 to September 2023 in Beijing, all participants completed 202 nights (from 20:00 to 08:00) of dynamic real-time SpO₂ monitoring during sleep, simultaneously monitoring personal exposure level to temperature, alongside environmental humidity and other key air pollutant data. Based on previous clinical studies, SpO₂ < 90% was defined as desaturation to assess the risk of hypoxic events occurring during sleep. Linear mixed-effects models and generalized linear mixed-effects models were used to analyze the association between personal temperature exposure and SpO₂ during sleep, as well as the risk of oxygen desaturation. Interaction models were constructed to evaluate susceptibility factors.

During the study, the average personal temperature exposure was (27.5± 2.6) ℃, with a temperature range from 16.5 ℃ to 40.0 ℃. Short-term exposure to personal temperature was associated with a decline in SpO₂ and an increased risk of oxygen desaturation during sleep in the COPD patients. The effect of temperature exposure was strongest at lag 0-30 min, with a 0.24% (95%CI: -0.28%, -0.20%) decrease in SpO₂, and with an odds ratio (OR) of oxygen desaturation was 1.26 (95% CI: 1.12, 1.42) for each interquartile range (IQR, 6.0 ℃) increase in temperature. Besides, the patients exposed to medium and high humidity levels were more likely to be affected by temperature exposure compared with the patients exposed to low humidity levels. Personal temperature exposure had a stronger effect on SpO₂ during sleep in the patients with global initiative for chronic obstructive lung disease (GOLD) Ⅲ-Ⅳ compared with the patients with GOLD Ⅰ-Ⅱ (P_interaction < 0.05).

From 16.5 ℃ to 40.0 ℃, personal temperature exposure is associated with SpO₂ decline during sleep in COPD patients. There was a significant synergistic amplification between temperature and humidity, patients were more susceptible to damage under high temperature and high humidity conditions. Moreover, patients with poorer lung function are more significantly affected by temperature.