Acute Health Effects of High Temperature Exposure

Not Applicable

Active, not recruiting

• Conditions: Cognitive Function; Respiratory System; Cardiovascular System
• Interventions: Other: moderate temperature (22℃) group; Other: high temperature (32℃) group

• Registration Number: NCT05575752
• Lead Sponsor: Fudan University

Brief Summary

This is a randomized controlled human exposure crossover study. Investigators aims to assess the acute effects of high temperature exposure and the underlying mechanisms.

Detailed Description

The investigators will conduct a randomized controlled human exposure crossover study among about 40 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 Timeline

• Study First Submitted: 2022-09-28
• Study First Submitted QC: 2022-10-08
• Study First Posted: 2022-10-12
• Study Start: 2022-10-23
• Primary Completion: 2022-11-19
• Status Verified: 2024-09
• Last Update Submitted: 2024-09-27
• Last Update Posted: 2024-10-01
• Study Completion: 2024-12-31

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

• Living in Shanghai during the study period;
• Body mass index > 18.5 and ≤ 28;
• right-handed;
• receiving or having received higher education;
• with ability to read and understand Chinese smoothly.

Read More

Exclusion Criteria

• Smoking and alcohol abuse;
• Current drug and dietary supplements intake;
• Subjects with allergic diseases, such as allergic rhinitis, allergic asthma, and atopy;
• Subjects with cardiovascular diseases, such as congenital heart disease, pulmonary heart disease, and hypertension;
• Subjects with respiratory diseases, such as asthma, chronic bronchitis, and chronic obstructive pulmonary disease;
• Subjects with chronic diseases, such as diabetes, chronic hepatitis, and kidney disease;
• Subjects who have a history of major surgery due to the cardiovascular, cerebrovascular, respiratory, or neurological diseases;
• Subjects with neurologic disorders, such as stroke, traumatic brain injury, epilepsy, and schizophrenia;
• Abnormal spirometry (FEV1 and FVC ≤ 75% of predicted and FEV1/FVC ≤ 0.65);
• Subjects with color vision disabilities.

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
moderate temperature (22℃) group	moderate temperature (22℃) group	Subjects in exposure group will be exposed to moderate temperature (22℃) for about 2 hours in a chamber.
high temperature (32℃) group	high temperature (32℃) group	Subjects in exposure group will be exposed to high temperature (32℃) for about 2 hours in a chamber.

Primary Outcome Measures

Name	Time	Method
Changes of pulse wave velocity measured by an arteriography device performing oscillometric measurement	Pulse wave velocity will be examined before exposure and immediately after the exposure session	Pulse wave velocity (PWV) is one of the arterial stiffness indicators. The changes of PWV will be measured.
Changes of AIx@75 measured by an arteriography device performing oscillometric measurement	AIx@75 will be examined before exposure and immediately after the exposure session	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.
Changes of reflection magnitude measured by an arteriography device performing oscillometric measurement	Reflection magnitude will be examined before exposure and immediately after the exposure session	Reflection magnitude is one of the arterial stiffness indicators. The changes of reflection magnitude will be measured.
Results of Stroop Tests	The tests will be conducted before exposure and immediately after the exposure session	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.
Changes of forced expiratory volume in the first second (FEV1)	The tests will be examined before exposure and half an hour after exposure	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.
Changes of forced vital capacity (FVC)	FVC will be examined before exposure and half an hour after exposure	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.
Changes of peak expiratory flow rate (PEF)	FVC will be examined before exposure and half an hour after exposure	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.
Changes of maximum expiratory flow rate at 25% vital capacity (MEF25)	MEF25 will be examined before exposure and half an hour after exposure	Investigators plan to measure the changes of maximum expiratory flow rate at 25% vital capacity. MEF25% reflects the early stage of expiratory flow rate.
Changes of maximum expiratory flow rate at 50% vital capacity (MEF50)	MEF50 will be examined before exposure and half an hour after exposure	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.
Changes of maximum expiratory flow rate at 75% vital capacity (MEF75)	MEF75 will be examined before exposure and half an hour after exposure	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.

Secondary Outcome Measures

Name	Time	Method
Blood Pressure	Blood pressure will be examined before exposure and immediately after the exposure session	The changes of systolic blood pressure (SBP) and diastolic blood pressure (DBP) will be measured.
Results of Schulte table Tests	The tests will be conducted before exposure and immediately after the exposure session	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.
Activated brain regions demonstrating neural activity related to the high temperature exposure	1 hour after exposure session	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.
Activated brain regions demonstrating neural connectivity related to the high temperature exposure	1 hour after exposure session	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.
Activated brain regions demonstrating neural synchronization related to the high temperature exposure	1 hour after exposure session	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.
Changes of airway inflammation indicator fractional concentration of carbon monoxide (FeCO)	FeCO will be examined before exposure and half an hour after exposure	Investigators plan to measure the changes of fractional concentration of carbon monoxide.
Changes of airway inflammation indicator fractional exhaled nitric oxide (FeNO)	FeNO will be examined before exposure and half an hour after exposure	Investigators plan to measure the changes of fractional exhaled nitric oxide.

Trial Locations

Locations (1)

Department of Environmental Health, School of Public Health, Fudan University; 🇨🇳 Shanghai, Shanghai, China