The Effect of Smoking on Thermoregulation
To the best of our knowledge, a possible relation between smoking and heat injuries or heat intolerance was never scientifically examined, although such a relation is logical according to the observations that smoking has a thermogenic effect, decreases physical fitness and affects the body's heat dissipation.16 healthy young male volunteers will participate in the study, 8 smokers and 8 non-smokers. They will arrive to our lab four or six times. They will perform VO2 test and heat tolerance test (HTT) in different conditions.
|Study Design:||Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Basic Science
|Official Title:||The Effect of Smoking on Thermoregulation|
- Heat tolerance [ Time Frame: 2-3 days ] [ Designated as safety issue: No ]The test is performed in a climatic chamber at a temperature of 40oC and 40% relative humidity. During the test, the subject walks on a treadmill at a speed of 5 km/hr at a 2% grade for 2h. Body core temperature and heart rate are continuously monitored, and sweat rate is computed from body weight prior to and after the test, corrected for fluid intake. Heat intolerance is determined when body core temperature elevates above 38.5oC, when heart rate elevates above 150 bpm, or when either does not tend to reach a plateau.
- VO2max [ Time Frame: 2-3 days ] [ Designated as safety issue: No ]volunteer's oxygen consumption (VO2) will be monitored continuously with a metabolic chart (ZAN), while running for 10 min on a treadmill under comfortable environmental conditions.
- Rectal temperature [ Time Frame: experimental days 4,5,6 ] [ Designated as safety issue: Yes ]The volunteers will undergo heat tolerance test. Their rectal temperature will be measured by rectal thermistor and will be monitored continuously and viewed by the attending medical staff. Automatically all data will be recorded by the monitoring Biopac system
- Heart rate [ Time Frame: experimental days 4,5,6 ] [ Designated as safety issue: Yes ]During the HTT and the VO2 test heart rates will be monitored continuously and will be stored by a heart rate wristwatch, (POLAR, Finland).
|Study Start Date:||June 2012|
|Estimated Study Completion Date:||May 2013|
|Estimated Primary Completion Date:||April 2013 (Final data collection date for primary outcome measure)|
This arm consists of smokers.
both groups will be given nicotine lozenges before a VO2 test and a HTT.Other: cigarette smoking
the smokers will smoke 2 cigarettes before a VO2 exam and a HTT.
Active Comparator: non-smokers
non-smoking participants in the study
both groups will be given nicotine lozenges before a VO2 test and a HTT.
16 healthy young male volunteers will participate in the study, 8 smokers and 8 non-smokers. They will arrive to our lab four or five times. During their first visit they will go through a VO2 max test in order to evaluate their aerobic fitness, and their physiological efficiency. During their second visit all subjects will go through the same test after exposure to nicotine. During the smokers' third visit they will go through the same test, after exposure to cigarette smoking. During the non-smokers third visit and the smokers fourth visit - they will go through an exercise heat tolerance test without prior smoking. During the fifth visit the smokers will go through an exercise heat tolerance test after exposure to cigarette smoking. During the smokers' sixth visit and the non-smokers fourth visit they will go through an HTT after exposure to nicotine.
|The Institute of Military Physiology Heller Institute of Medical Research|
|Tel-Hashomer Ramat-Gan, Israel|
|Principal Investigator:||Amit Druyan, M.D||Sheba Medical Center|