A further study of FTC yield and nicotine absorption in smokers.

The relationship between nicotine yield as determined by the FTC method and nicotine absorption was examined in 72 smokers in a more rigorous repetition of a previous study of 33 smokers. For this study, 113 smokers evenly distributed across four FTC "tar" yield ranges were recruited, only 72 demonstrated reasonable compliance with the study criteria with regard to sample collections and cigarette brand style consistency. Subjects recorded the number of cigarettes smoked daily and collected a 24-h urine sample and a saliva sample on 3 consecutive days. Nicotine absorption was determined by monitoring urinary excretion of nicotine and its metabolites. In addition, saliva samples were monitored for cotinine using radioimmunoassay (RIA). The correlation of the relationship for nicotine absorbed per cigarette was positive and significant (r = 0.31, P = 0.008) but weaker than in the previous study. Only smokers in the highest yield range showed any statistical difference from smokers in the lower ranges. Our results suggest that FTC nicotine yield is weakly related to nicotine absorption and that smoker-controlled factors exert a great influence on the amount of nicotine absorbed by smokers. Compensation is substantial but incomplete for the minority (by market share) of smokers at the low end of the yield scale. It is uncertain how well any alternative set of machine parameters would predict nicotine absorption for the majority of smokers, even if it were more predictive for the small number of smokers at the lower yield part of the range.