Effect of menthol cigarettes on biochemical markers of smoke exposure among black and white smokers.

STUDY OBJECTIVES Black smokers have been reported to have higher serum cotinine levels than do white smokers, and have higher rates of most smoking-related diseases, despite smoking fewer cigarettes per day. Another striking racial difference is the preference for mentholated cigarettes among black smokers. The contribution of menthol to variability in biochemical markers of cigarette smoke exposure (end-expiratory carbon monoxide and serum cotinine) was evaluated in a biracial sample. DESIGN Descriptive cross-sectional. SETTING A university smoking research laboratory. PARTICIPANTS Sixty-five black and 96 white adult established smokers who were paid for their participation. MEASUREMENTS Information was obtained through direct observation, self-report (interview and self-administered questionnaires), measurement of butts collected for a week, and laboratory analyses of the biochemical markers of exposure. RESULTS Compared with the white smokers, the black smokers had significantly higher cotinine and carbon monoxide levels per cigarette smoked and per millimeter of smoked tobacco rod (both p < 0.001). After adjusting for race, cigarettes per day, and mean amount of each cigarette smoked, menthol was associated with higher cotinine levels (p = 0.03) and carbon monoxide concentrations (p = 0.02). CONCLUSIONS The use of menthol may be associated with increased health risks of smoking. Menthol use should be considered when biochemical markers of smoke exposure are used as quantitative measures of smoking intensity or as indicators of compliance with smoking reduction programs. In addition, the effect of menthol on total "dose" should be considered in any efforts to regulate the amount of nicotine in cigarettes.