Acute Health Effects of Low Temperature Exposure

Not Applicable

Not yet recruiting

• Conditions: Respiratory System; Cognitive Function; Cardiovascular System
• Interventions: Other: Low temperature (16#) group; Other: Moderate temperature (22#) group

• Registration Number: NCT06076629
• Lead Sponsor: Fudan University

Brief Summary

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

Detailed Description

The investigators will conduct a randomized controlled human exposure crossover study among about 50 healthy young adults in Shanghai, China. Each subject will be exposed twice: once to the low temperature (16#) and once to the moderate temperature (22#) in a chamber for about 2-2.5 hours. During the exposure session, each subject will be requested to rest. Health examinations will be conducted immediately prior to exposure (within 1 hour before the exposure session), during the period of exposure, and after exposure (within 2 hours after the exposure session). Health examinations include spirometry, Holter monitoring, blood pressure tests, cognitive function tests, symptom questionnaires, and magnetic resonance imaging. Investigators plan to collect blood, urine, exhaled breath condensate, and oropharyngeal swabs samples.

Study Timeline

• Study First Submitted: 2023-09-08
• Status Verified: 2023-10
• Study First Submitted QC: 2023-10-03
• Last Update Submitted: 2023-10-03
• Study Start: 2023-10-10
• Study First Posted: 2023-10-11
• Last Update Posted: 2023-10-11
• Primary Completion: 2023-11-15
• Study Completion: 2024-12-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 50

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 the ability to read and understand Chinese smoothly.

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 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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Low temperature (16#) group	Low temperature (16#) group	Subjects in exposure group will be exposed to low temperature (16#) for about 2 hours in a chamber.
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.

Primary Outcome Measures

Name	Time	Method
Forced expiratory volume in one second	Lung function will be examined before exposure and half an hour after the exposure session	Investigators plan to measure forced expiratory volume in one second (FEV1) by spirometry.
Maximal mid-expiratory flow	Lung function will be examined before exposure and half an hour after the exposure session	Investigators plan to measure maximal mid-expiratory flow (MMEF) by spirometry.
Heart Rate Variability Parameters	Volunteers will be asked to wear electrographic Holter monitors for 24 hours from 1:00 P.M. at the day of intervention to 1:00 P.M. at the next day.	Investigators plan to measure heart rate variability (HRV) parameters (e.g., SDNN, PNN50, LF, HF)
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.
Forced vital capacity	Lung function will be examined before exposure and half an hour after the exposure session	Investigators plan to measure forced vital capacity (FVC) by spirometry
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.

Secondary Outcome Measures

Name	Time	Method
Results of simple reaction time	Simple reaction time will be examined before exposure and immediately after the exposure session	Investigators plan to measure the changes of cognitive function using visual simple reaction time test.
Activated brain regions demonstrating brain activity related to the low temperature exposure	MRI will be examined 1 hour after the exposure session	Investigators plan to conduct magnetic resonance imaging (MRI) after exposure. The MRI data will be processed through Data Processing and Analysis for Brain Imaging (DPABI) sofrware to obtain brain activity parameters, such as fractional amplitude of low-frequency fluctuation (fALFF). Brain regions that change after exposure between the two groups would be further idenfitied.
Results of visual memory	Visual memory will be examined before exposure and immediately after the exposure session	Investigators plan to measure the changes of cognitive function using visual memory test. Every level, a number of tiles will flash white. The participants will be required to memorize them, and pick them again after the tiles are reset. Higher levels refer to better visual memory.
Changes of skin temperature	Skin temperature will be examined from 1:00 P.M. to 4:30 P.M. at the day of intervention	The changes of wrist skin temperature will be measured
Changes in cerebral hemodynamics demonstrating brain activity related to the low temperature exposure	fNIRS will be examined before exposure and immediately after the exposure session	Investigators plan to conduct functional near-infrared spectroscopy (fNIRS) to measure the changes in oxygenated hemoglobin and deoxygenated hemoglobin after exposure. Matlab would be applied to process data and evaluate the changes in cerebral hemodynamics associated with low temperature exposure

Trial Locations

Locations (1)

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