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 Overview

• Status: Completed
• Conditions: Cigarette Smoking
• Intervention / Treatment: Drug: Nicotine; Other: cigarette smoking

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 16
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Israel
  • Tel-Hashomer Ramat-Gan, Israel
    • The Institute of Military Physiology Heller Institute of Medical Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• age 18-30
• healthy
• after medical checkup
• after signing concent form
• for the smokers: smoking 0.5-1.5 packs of cigarettes a day at least 2 years.

Exclusion Criteria:

• heart disease
• respiratory disease
• baseline bp above 140/90 mmHg
• diabetes
• anhydrosis
• skin disease
• acute illness
• detoxification from nicotine
• allergy to nicotine
• smoking other then specified in the inclusion criteria

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: smokers; This arm consists of smokers.	Drug: Nicotine; 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	Drug: Nicotine; both groups will be given nicotine lozenges before a VO2 test and a HTT.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heat tolerance	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.	2-3 days
VO2max	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.	2-3 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rectal temperature	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	experimental days 4,5,6
Heart rate	During the HTT and the VO2 test heart rates will be monitored continuously and will be stored by a heart rate wristwatch, (POLAR, Finland).	experimental days 4,5,6

Collaborators and Investigators

• Sponsor: Sheba Medical Center
• Collaborators: International Diabetes Federation
• Investigators: Principal Investigator: Amit Druyan, M.D, Sheba Medical Center

Study record dates

Study Major Dates

• Study Start: June 1, 2012
• Primary Completion (Actual): December 1, 2013
• Study Completion (Actual): May 1, 2014

Study Registration Dates

• First Submitted: May 6, 2012
• First Submitted That Met QC Criteria: May 9, 2012
• First Posted (Estimate): May 11, 2012

Study Record Updates

• Last Update Posted (Estimate): May 9, 2014
• Last Update Submitted That Met QC Criteria: May 8, 2014
• Last Verified: May 1, 2014

More Information

Terms related to this study

• Keywords: exercise; smoking; heat stroke; heat tolerance
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Cholinergic Agents; Ganglionic Stimulants; Nicotinic Agonists; Cholinergic Agonists; Nicotine
• Other Study ID Numbers: SHEBA-11-8767-AD-CTIL