The influence of atmospheric temperature on long-term CPAP-usage in patients with obstructive sleep apnea

Although seasonal variations in CPAP-usage are often attributed to changes in temperature, no real-world study has evaluated the influence of temperature on long-term CPAP-usage.

The TempCPAP study is a retrospective real-life cohort study. Adult patients newly treated and undergoing at least 1 month of CPAP were included. Daily 12-PM temperature data from the nearest weather station was assigned to each patient and CPAP-usage was collected using telemonitoring data. The primary objective of the study was to investigate the relationship between temperature and CPAP-usage.

8151 patients (37.2 % women) with a median age of 61 (IQ_25-75: 51-71) years, initial AHI of 36 (29-49.6) events/h, treated for a median duration of 1.6 years (0.7-3.0), and with a CPAP-usage of 5.4 (3.0-6.9) h/day were included. The relationship between CPAP-usage and temperature was non-linear. The best model found two breakpoints at 18 °C and 29 °C. CPAP-usage dropped drastically when the temperature exceeded 29 °C, as each 1 °C increase was associated with a 3.6-min reduction in CPAP-usage. Compared to temperatures of less than 5 °C, temperatures above 30 °C resulted in a mean reduction in CPAP-usage of 30.3 (confidence interval (CI95 %): 29.3-31.4) minutes/day, achieving the minimal clinically important difference of 30 min in 46.6 % of patients.

In patients undergoing long-term CPAP therapy, temperatures over 29 °C at 12-PM were associated with reduced CPAP-usage.

TempCPAP is registered with health data hub (n°20475117).