Biomarkers of tobacco smoke exposure in racial/ethnic groups at high risk for lung cancer.

OBJECTIVES: We examined biomarkers of tobacco smoke exposure among Native Hawaiians, Filipinos, and Whites, groups that have different lung cancer risk. METHODS: We collected survey data and height, weight, saliva, and carbon monoxide (CO) levels from a sample of daily smokers aged 18-35 (n = 179). Mean measures of nicotine, cotinine, cotinine/cigarettes per day ratio, trans 3' hydroxycotinine, the nicotine metabolite ratio (NMR), and expired CO were compared among racial/ethnic groups. RESULTS: The geometric means for cotinine, the cotinine/cigarettes per day ratio, and CO did not significantly differ among racial/ethnic groups in the adjusted models. After adjusting for gender, body mass index, menthol smoking, Hispanic ethnicity, and number of cigarettes smoked per day, the NMR was significantly higher among Whites than among Native Hawaiians and Filipinos (NMR = 0.33, 0.20, 0.19, P ≤ .001). The NMR increased with increasing White parental ancestry. The NMR was not significantly correlated with social-environmental stressors. CONCLUSIONS: Racial/ethnic groups with higher rates of lung cancer had slower nicotine metabolism than Whites. The complex relationship between lung cancer risk and nicotine metabolism among racial/ethnic groups needs further clarification.