Short-Term Effects of Personal Exposure to Temperature Variability on Cardiorespiratory Health Based on Subclinical Non-Invasive Biomarkers

Abstract

Mounting literatures have explored the cardiorespiratory health effects of the daily temperature, but such effects of temperature variability was rarely explored. We investigated the acute associations of personal levels of temperature variability with cardiorespiratory biomarkers. Forty eligible participants underwent repeated health measurements for four times in Hefei, Anhui Province, China. We collected personal-level temperature data using temperature/humidity loggers. Temperature variability parameters included diurnal temperature range (DTR), the standard-deviation of temperature (SDT) and temperature variability (TV). Cardiorespiratory health indicators included three BP parameters [systolic BP (SBP), diastolic BP (DBP) and mean article pressure (MAP)], fractional exhaled nitric oxide (FeNO), and four saliva biomarkers [C-reactive protein (CRP), cortisol alpha-amylase and lysozyme]. Linear mixed-effect regression models were used to estimate temperature effects with adjustment of several confounders. There were association between temperature variability and cardiorespiratory biomarkers. The magnitude and statistical significance of these associations differed by temperature variability parameters, by biomarkers and by lags of exposure. Specifically, temperature variability parameters were inversely associated with BP and saliva lysozyme; positively associated with airway inflammation biomarkers [FeNO and saliva CRP] and oxidative stress biomarkers in saliva samples [cortisol and alpha-amylase]. The results were robust to further control for air pollutants, and the changes were more prominent in females than in males. Short-term personal temperature exposure was significantly associated with altered cardiorespiratory biomarkers among healthy young adults. The current findings might have some implications for clinical management and public health intervention.

Keywords: Temperature, Cardiorespiratory health, Blood pressure, Inflammation, Oxidative stress, Immune function