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NCT Number: NCT06652932

Acute Effects of Low Temperature Exposure on Respiratory System

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.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Lung Function

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Environmental Health, School of Public Health, Fudan University

Shanghai, Shanghai Municipality, 200032, China

About this study

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 low temperature (15℃) and once to the 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 lung function tests and exhaled breath test. Investigators plan to collect blood, pharyngeal secretion, exhaled breath condensate and urine samples.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Low temperature (15°C) group

Other

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

Other

The exposure group will be exposed to thermoneutral temperature (22°C) in a chamber for about 2 hours, resting during the whole periods.

Primary outcomes

  1. Changes of forced expiratory volume in the first second (FEV1)

    Time frame: 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.

  2. Changes of forced vital capacity (FVC)

    Time frame: 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.

  3. Changes of peak expiratory flow rate (PEF)

    Time frame: 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.

  4. Changes of maximum expiratory flow rate at 25% vital capacity (MEF25)

    Time frame: 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.

  5. Changes of maximum expiratory flow rate at 50% vital capacity (MEF50)

    Time frame: 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.

  6. Changes of maximum expiratory flow rate at 75% vital capacity (MEF75)

    Time frame: 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.

Secondary outcomes

  1. Changes of fractional exhaled nitric oxide (FeNO)

    Time frame: FeNO will be examined half an hour before exposure and half an hour after exposure

    Investigators plan to measure the changes of fractional exhaled nitric oxide using FeNO monitor (NIOX; Aerocrine AB, Solna, Sweden). FeNO reflects airway inflammation level

  2. Changes of fractional concentration of carbon monoxide (FeCO)

    Time frame: FeCO 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 fractional concentration of carbon monoxide using Pico Smokerlyzer. FeCO reflects level of carboxyhemoglobin in blood.

  3. Changes of skin temperature

    Time frame: Wrist skin temperature will be measured at 1:00 P.M. to 3:00 P.M. on the day of the exposure session

    The changes of wrist skin temperature will be measured

Other outcomes

  1. Differences in protein levels detected in blood Clara cell protein (CC16) between the two exposures

    Time frame: CC16 will be examined at 1:00 P.M. and 4:00 P.M. (one hour after the exposure) on the day of the exposure session

    Investigators plan to measure the changes of Clara cell protein using enzyme linked immunosorbent assay (ELISA). Clara cell protein (CC16) indicate lung epithelial injury.

  2. Differences in protein levels detected in blood chitinase-3-like protein 1 (YKL-40) between the two exposures

    Time frame: YKL-40 will be examined at 1:00 P.M. and 4:00 P.M. (one hour after exposure) on the day of the exposure session

    Investigators plan to measure the changes of chitinase-3-like protein 1 protein using enzyme linked immunosorbent assay (ELISA). YKL-40 represents airway inflammation and remodeling.

  3. Differences in protein levels detected in blood Surfactant Protein-D (SP-D) between the two exposures

    Time frame: SP-D will be examined at 1:00 P.M. and 4:00 P.M. (one hour after exposure) on the day of the exposure session

    Investigators plan to measure the changes of Surfactant Protein-D protein using enzyme linked immunosorbent assay (ELISA). SP-D represents pulmonary injury.

  4. Differences in respiratory microbiota detected in pharyngeal secretion between the two exposures

    Time frame: Respiratory microbiota will be detected at 3:30 A.M. (half an hour after exposure) on the day of the exposure session

    differential respiratory microbiota in pharyngeal secretion related to low temperature exposure will be detected by integrating microbial 16S rRNA sequencing and non-targeted metabolomics.

  5. Differences in metabolic profiling detected in exhaled breath condensate between the two exposures

    Time frame: Metabolic profiling in exhaled breath condensate will be detected at 4:00 P.M. (1 hour after the exposure session)

    The differential metabolic profiling in exhaled breath condensate related to low temperature exposure will be detected by mass spectrometry-based non-targeted metabolomics.

Sponsors and collaborators

Lead sponsor

Fudan University

Other

Registry information

Official study title

Acute Effects of Low Temperature Exposure on Respiratory Health in Healthy Young Adults: A Randomized Controlled Study

Important dates

Study start
2024
Primary completion
2024
Study completion
2026
First posted
Oct 22, 2024
Registry last updated
Feb 27, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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