Progressive commercial cigarette yield reduction: biochemical exposure and behavioral assessment

Abstract

Background: Mandated reduction of exposure to nicotine and other cigarette toxins has been proposed as a possible national regulatory strategy. However, tapering using lower yield commercial cigarettes may not be effective in reducing nicotine or tar exposure due to compensatory smoking behavior. We examined the effects of gradual reduction of nicotine yield in commercial cigarettes on smoking behavior, with an assessment of nicotine intake and exposure to tobacco smoke toxins.

Methods: This 10-week longitudinal study of 20 smokers involved smoking the usual brand followed by different brands with progressively lower machine-determined yields, ranging from 0.9 to 0.1 mg nicotine, each smoked for 1 week. Subjects were followed for 4 weeks after returning to smoking the usual brand (or quitting). Smoking behaviors, biomarkers of tobacco smoke exposure, and cardiovascular effects were measured.

Findings: Cotinine and other biomarkers of smoke exposure remained unchanged comparing the usual brand with the 0.4 mg nicotine brands. A 30% to 40% decrease in nicotine, carbon monoxide, and carcinogen exposure comparing 0.1 mg nicotine cigarettes with baseline was observed. Self-efficacy was significantly increased and dependence decreased after tapering.

Implications: We confirm prior cross-sectional population and experimental studies showing complete compensation for cigarettes down to the 0.4 mg nicotine range. Nicotine and tobacco toxin exposure were substantially reduced while smoking 0.1 mg nicotine cigarettes. Our data suggest that the degree of nicotine dependence of smokers may be lowered with progressive yield tapering. Gradual tapering of smokers from regular to ultralow nicotine yield commercial cigarettes might facilitate smoking cessation and warrants future research.

Figure 1

Cigarette consumption over weeks of the study during progressive yield reduction of cigarettes (weeks 1–6) and after return to usual cigarettes or quitting (weeks 7–10). Yields in the boxes refer to FTC machine-determined nicotine yield. Solid line includes all subjects; dashed line excluded two quitters at week 10. Points, mean for 20 subjects; bars, SE.

Figure 2

Plasma cotinine concentration over weeks of the study during progressive yield reduction of cigarettes (weeks 1–6) and after return to usual cigarettes or quitting (weeks 7–10). Yields in the boxes refer to FTC machine-determined nicotine yield. Solid line includes all subjects; dashed line excluded two quitters at week 10. Points, mean for 20 subjects; bars, SE. *P < 0.05 compared to viral brand.

Figure 3

Plasma nicotine concentration over weeks of the study during progressive yield reduction of cigarettes (weeks 1–6) and after return to usual cigarettes or quitting (weeks 7–10). Yields in the boxes refer to FTC machine-determined nicotine yield. Solid line includes all subjects; dashed line excluded two quitters at week 10. Points, mean for 20 subjects; bars, SE.

Figure 4

Blood carboxyhemoglobin concentration over weeks of the study during progressive yield reduction of cigarettes (weeks 1–6) and after return to usual cigarettes or quitting (weeks 7–10). Yields in the boxes refer to FTC machine-determined nicotine yield. Solid line includes all subjects; dashed line excluded two quitters at week 10. Points, mean for 20 subjects; bars, SE. * P < 0.05 compared to viral brand.

Figure 5

Urine NNAL concentration during progressive yield reduction of cigarettes (weeks 1–6) and after return to usual cigarettes or quitting (weeks 7–10). Yields in the boxes refer to FTC machine-determined nicotine yield. Solid line includes all subjects; dashed line excluded two quitters at week 10. Points, mean for 20 subjects; bars, SE. * P < 0.05 compared to viral brand.

Figure 6

Urine 2-naphthol concentration during progressive yield reduction of cigarettes (weeks 1–6) and after return to usual cigarettes or quitting (weeks 7–10). Yields in the boxes refer to FTC machine-determined nicotine yield. Solid line includes all subjects; dashed line excluded two quitters at week 10. Points, mean for 20 subjects; bars, SE. * P < 0.05 compared to viral brand.