A repeatable method for determination of carboxyhemoglobin levels in smokers

Area of Science:

• Toxicology
• Respiratory Medicine
• Public Health

Background:

• Daily variations in expired breath carbon monoxide (CO) and blood carboxyhemoglobin (%COHb) levels can impact smoking research.
• Understanding these variations is crucial for accurately assessing exposure to tobacco smoke constituents.

Purpose of the Study:

• To determine daily variations in CO and %COHb levels in male smokers.
• To evaluate the impact of switching from a 'usual brand' cigarette to a research prototype heated tobacco product (TOB-HT) on these measures.

Main Methods:

• Fourteen male smokers underwent ten afternoon test sessions.
• Measurements included expired breath CO, blood %COHb, hemoglobin, and hematocrit.
• Subjects smoked their usual brand for one week, then a TOB-HT prototype for at least 3 weeks prior to and during the second measurement week.

Main Results:

• Daily measurements of %COHb and expired breath CO were reproducible using the study protocol.
• Switching to the TOB-HT cigarette resulted in a 24.4% increase in %COHb and a 30.6% increase in expired breath CO.
• These increases occurred without a change in the average number of cigarettes consumed.

Conclusions:

• The TOB-HT heated tobacco product leads to significantly higher exposure to carbon monoxide compared to traditional cigarettes.
• The study protocol provides reliable daily measurements of CO and %COHb.
• Further research is needed to understand the long-term health effects of elevated CO exposure from heated tobacco products.