01). Cross-Correlations Among CPD and Biomarkers of selleck chemicals Cisplatin Exposure by Race Figure 3 presents the correlation coefficients between CPD, urine nicotine equivalents, plasma cotinine, urine NNAL, and urine total PAHs for Black and for White smokers. Compared to White smokers, the correlations were weaker for Blacks for CPD versus nicotine equivalents (r = .031 vs. .258 in Black vs. White, respectively), plasma cotinine (r = .103 vs. .376), urine NNAL (r = .099 vs. .273), and urine PAHs (r = .153 vs. .216). In contrast, the correlations between nicotine equivalents or plasma cotinine and other biomarkers of exposure were generally strong and were similar in magnitude for both races. For urine nicotine equivalents, the correlations in Blacks versus Whites were as follows: urine NNAL, r = .570 versus .

580; and urine PAHs, r = .719 versus 0.783. For plasma cotinine, the correlations were as follows: urine NNAL, r = .452 versus .629; and urine PAHs, r = .556 versus .496. Figure 3. Pearson correlation coefficients between cigarettes per day (CPD), urine nicotine equivalents, urine total 4-(methylnitrosamino)-1-(3)pyridyl-1-butanol (NNAL), and urine total polycyclic aromatic hydrocarbon (PAH) metabolites in African American (a) and … Discussion Main Observations We make several observations in this study that may help to explain differences in smoking behavior in relation to lung cancer risk in Blacks compared to Whites. First, we find that the relationship between the number of cigarettes smoked per day versus daily intake of nicotine (as measured by nicotine equivalents in urine) and tobacco smoke carcinogens is relatively flat for Blacks, whereas there is a weak positive relationship for Whites.

Second, we find a strong correlation in both Blacks and Whites between urine nicotine equivalents or plasma cotinine (reflecting systemic exposure to nicotine) and tobacco smoke carcinogens. Third, we find that the intake of nicotine and carcinogens per cigarette is inversely related to the number of cigarettes smoked per day, and this inverse relationship appears to be stronger for Black than for White smokers. Finally, our data support the use of a spot urine measurement of nicotine equivalents normalized for creatinine as a valid surrogate for exposure to tobacco smoke toxicants in smoking and health epidemiology studies.

Nicotine Equivalents as a Measure of Nicotine Intake We have used the molar sum Cilengitide of nicotine and its five major metabolites normalized by creatinine as an indicator of daily intake of nicotine, termed ��nicotine equivalents.�� We have previously shown that the molar sum of these metabolites accounts for 85%�C90% of the systemic dose of nicotine absorbed from transdermal nicotine, assessed by measuring nicotine clearance and nicotine plasma levels during patch use (Benowitz et al., 1994). Feng et al.