Chapter 6 
compared with risk for smokers of higher tar and nicotine cigarettes. There is 
no consistent evidence that risk for this disease is associated with the tar and 
nicotine yield of the cigarettes smoked. 
For CVD, the 1981 conclusion remains appropriate: . . . the 
overall changes in the composition of cigarettes that have 
occurred during the last 10 to 15 years have not produced a clearly 
demonstrated effect on cardiovascular disease, and some studies 
suggest that a decreased risk of CHD may not have occurred 
(U.S. Department of Health and Human Services, 1981, p. 125). 
Our research needs have changed little from the agenda set out 
in that report 15 years ago. The report called for further surveillance 
of the characteristics of smoke in relation to the type of cigarettes, 
further characterization of compensatory changes in smoking, better 
understanding of doses of tobacco smoke components delivered to the 
lung, and additional epidemiologic research. Ongoing characterization of 
the health consequences of the changing cigarette should be implemented 
and maintained through cohort studies such as CPS-I or case-control 
methods. New biomarkers of exposure and dose should be applied to 
better understand the relationships of FTC tar and nicotine yields with 
biologically effective doses of smoke components. 
QUESTION-AND-ANSWER SESSION 
DR. PETITTI: It actually does amaze me that the conclusions of this report 
are the same as they were in 1981. It also amazes me how little information 
has developed in this field over the past 14 years. 
I wanted you to comment on an issue that was, I think, not particularly 
well addressed in the 1981 report and has troubled me about the 
epidemiological data. It has to do with the tendency to examine the 
risk of lung cancer in strata defined by number of cigarettes smoked per 
day. When you define smoking by number of cigarettes smoked per day, 
you do take into account compensation by inhalation and amount smoked, 
but you don't take into account any kind of compensation that might 
occur because of a tendency to smoke an increased number of cigarettes 
per day and smoking a lower yield brand. That would suggest that in order 
to take that into account in the epidemiology, you would have to move 
people to a different category of number of cigarettes smoked per day. 
Do you think that epidemiology can address this issue, and how do you 
think that places limitations on the first conclusion related to lung cancer, 
particularly? 
DR. SAMET: It is a good question and I think much of the discussion 
about smokers' behavior that will follow will get at just how complex the 
physiology is and how difficult it is to make these determinations in the 
laboratory. 
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