This is a randomized controlled human exposure crossover study. Investigators aims to assess the acute effects of high temperature exposure and the underlying mechanisms.
The investigators will conduct a randomized controlled human exposure crossover study among about 30 healthy young adults in Shanghai, China. Each subject will be exposed twice: once to the high temperature (32℃) and once to moderate temperature (22℃) in a chamber for about 2 hours. During the exposure session, each subject will be requested to rest. Health examinations will be conducted immediately prior to exposure, during the period of exposure and after exposure. Health examinations include symptom questionnaire, blood pressure tests, cognitive function tests, magnetic resonance imaging, skin tests, spirometry, and Holter monitoring. Investigators plan to collect blood, urine and oropharyngeal swabs samples.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
SINGLE
Enrollment
30
The exposure group will be exposed to high temperature (32℃) in a chamber for about 2 hours, resting during the whole periods.
The exposure group will be exposed to thermoneutral temperature (22℃) in a chamber for about 2 hours, resting during the whole periods.
Department of Environmental Health, School of Public Health, Fudan University
Shanghai, Shanghai Municipality, China
Changes of pulse wave velocity measured by an arteriography device performing oscillometric measurement
Pulse wave velocity (PWV) is one of the arterial stiffness indicators. The changes of PWV will be measured.
Time frame: Pulse wave velocity will be examined before exposure and immediately after the exposure session
Changes of AIx@75 measured by an arteriography device performing oscillometric measurement
Augmentation index normalized to 75 bpm heart rate (AIx@75) is one of the arterial stiffness indicators. The changes of AIx@75 will be measured.
Time frame: AIx@75 will be examined before exposure and immediately after the exposure session
Changes of reflection magnitude measured by an arteriography device performing oscillometric measurement
Reflection magnitude is one of the arterial stiffness indicators. The changes of reflection magnitude will be measured.
Time frame: Reflection magnitude will be examined before exposure and immediately after the exposure session
Results of Stroop Tests
Investigators plan to measure the changes of cognitive function using Stroop Test. The time taken to complete the test could reflect cognitive function, and a shorter time means better cognitive function.
Time frame: The tests will be conducted before exposure and immediately after the exposure session
Changes of forced expiratory volume in the first second (FEV1)
Investigators plan to measure the changes of the forced expiratory volume in 1 s (FEV1) using a smart spirometer (Model A1, BreathHome, China) supervised by professional medical staff. Before the pulmonary function test, subjects will practice several times by themselves. During the examination, each subject stands and clamps the nose clip, and repeats the test, with the best result as the criterion. FEV1 reflect pulmonary function.
Time frame: The tests will be examined before exposure and half an hour after exposure
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Changes of forced vital capacity (FVC)
Investigators plan to measure the changes of forced vital capacity (FVC) using spirometer (Model A1, BreathHome, China). FVC reflects the expiratory resistance of large airways.
Time frame: FVC will be examined before exposure and half an hour after exposure
Changes of peak expiratory flow rate (PEF)
Investigators plan to measure the changes of peak expiratory flow (PEF) using smart spirometer (Model A1, BreathHome, China). PEF reflects airway patency and respiratory muscle strength.
Time frame: FVC will be examined before exposure and half an hour after exposure
Changes of maximum expiratory flow rate at 25% vital capacity (MEF25)
Investigators plan to measure the changes of maximum expiratory flow rate at 25% vital capacity. MEF25% reflects the early stage of expiratory flow rate.
Time frame: MEF25 will be examined before exposure and half an hour after exposure
Changes of maximum expiratory flow rate at 50% vital capacity (MEF50)
Investigators plan to measure the changes of maximum expiratory flow rate at 50% vital capacity using smart spirometer (Model A1, BreathHome, China). MEF50 reflects the interim stage of expiratory flow rate.
Time frame: MEF50 will be examined before exposure and half an hour after exposure
Changes of maximum expiratory flow rate at 75% vital capacity (MEF75)
Investigators plan to measure the changes of maximum expiratory flow rate at 50% vital capacity (MEF75%) using smart spirometer (Model A1, BreathHome, China). MEF75 reflects the terminal stage of expiratory flow rate.
Time frame: MEF75 will be examined before exposure and half an hour after exposure
Blood Pressure
The changes of systolic blood pressure (SBP) and diastolic blood pressure (DBP) will be measured.
Time frame: Blood pressure will be examined before exposure and immediately after the exposure session
Results of Schulte table Tests
Investigators plan to measure the changes of cognitive function using Schulte table. The time taken to complete the test and the accuracy could reflect cognitive function. Less time and greater accuracy mean better cognitive function.
Time frame: The tests will be conducted before exposure and immediately after the exposure session
Activated brain regions demonstrating neural activity related to the high temperature exposure
Investigators plan to measure brain activity associated with high temperature exposure by magnetic resonance imaging (MRI). Brain imaging data will be extracted from MRI data. The fractional amplitude of low frequency fluctuation (fALFF) would be extracted to reflect neural activity of brain regions.
Time frame: 1 hour after exposure session
Activated brain regions demonstrating neural connectivity related to the high temperature exposure
Investigators plan to measure brain activity associated with high temperature exposure by magnetic resonance imaging (MRI). Brain imaging data will be extracted from MRI data. The degree of centrality (DC) would be extracted to reflect neural connectivity of brain regions.
Time frame: 1 hour after exposure session
Activated brain regions demonstrating neural synchronization related to the high temperature exposure
Investigators plan to measure brain activity associated with high temperature exposure by magnetic resonance imaging (MRI). Brain imaging data will be extracted from MRI data. The regional homogeneity (ReHo) would be extracted to reflect neural synchronization of brain regions.
Time frame: 1 hour after exposure session
Changes of airway inflammation indicator fractional concentration of carbon monoxide (FeCO)
Investigators plan to measure the changes of fractional concentration of carbon monoxide.
Time frame: FeCO will be examined before exposure and half an hour after exposure
Changes of airway inflammation indicator fractional exhaled nitric oxide (FeNO)
Investigators plan to measure the changes of fractional exhaled nitric oxide.
Time frame: FeNO will be examined before exposure and half an hour after exposure