Low temperature (15°C) groupModerate temperature (22°C) group
Low temperature (15°C) group: The exposure group will be exposed to low temperature (15°C) in a chamber for about 2 hours, resting during the whole periods.
Moderate temperature (22°C) group: The exposure group will be exposed to thermoneutral temperature (22°C) in a chamber for about 2 hours, resting during the whole periods.
Study summary
This is a randomized controlled human exposure crossover study. Investigators aims to assess the acute effects of low-temperature exposure on respiratory health and the underlying mechanisms.
Eligibility
Sex
ALL
Min age
18 Years
Max age
30 Years
Healthy volunteers
Accepted
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 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.
Primary outcome measure(s)
Changes of forced expiratory volume in the first second (FEV1) — The tests will be conducted at 12:30 A.M. (half an hour before exposure) and 3:30 P.M. (half an hour after the 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 at 12:30 A.M. (half an hour before exposure) and 3:30 P.M. (half an hour after the exposure) Investigators plan to measure the changes of forced vital capacity (FVC) using a portable spirometer (Jaeger Master screen V5.01; CareFusion). FVC reflects the expiratory resistance of large airways.
Changes of peak expiratory flow rate (PEF) — FVC will be examined at 12:30 A.M. (half an hour before exposure) and 3:30 P.M. (half an hour after the exposure) Investigators plan to measure the changes of peak expiratory flow (PEF) using a portable spirometer (Jaeger Master screen V5.01; CareFusion). PEF reflects airway patency and respiratory muscle strength.
Changes of maximum expiratory flow rate at 25% vital capacity (MEF25) — MEF25 will be examined at 12:30 A.M. (half an hour before exposure) and 3:30 P.M. (half an hour after the 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 at 12:30 A.M. (half an hour before exposure) and 3:30 P.M. (half an hour after the exposure) Investigators plan to measure the changes of maximum expiratory flow rate at 50% vital capacity using a portable spirometer (Jaeger Master screen V5.01; CareFusion). MEF50 reflects the interim stage of expiratory flow rate.
Changes of maximum expiratory flow rate at 75% vital capacity (MEF75) — MEF75 will be examined at 12:30 A.M. (half an hour before exposure) and 3:30 P.M. (half an hour after exposure) Investigators plan to measure the changes of maximum expiratory flow rate at 50% vital capacity (MEF75%) using a portable spirometer (Jaeger Master screen V5.01; CareFusion). MEF75 reflects the terminal stage of expiratory flow rate.
Trial sites (1)
Facility
City
Region
Status
Department of Environmental Health, School of Public Health, Fudan University
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
We use cookies to analyse site traffic and improve your experience. With your consent, we may also use cookies for advertising. You can change your choice at any time.