Serum cotinine and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanonol levels among non-Hispanic Asian American smokers and nonsmokers as compared to other race/ethnicities: Data from NHANES 2011-2012

- Non-Hispanic Asians and Hispanics smokers had the lowest serum cotinine levels.
- Non-Hispanic Asians smokers had the lowest urinary NNAL levels.
- Nonsmokers with SHS exposure had substantially higher cotinine and NNAL levels.
- Serum nicotine/cotinine and NNAL have different elimination kinetics.

The objective of this study was to evaluate serum cotinine and total urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanonol (NNAL) levels from a nationally representative sample of non-Hispanic Asian Americans as compared with other racial/ethnic groups. Data from the latest National Health and Nutrition Examination Survey for the years 2011-2012 were used for this purpose. The total sample size used was 4580. Regression models were fitted to estimate serum cotinine and urinary NNAL levels for smokers and nonsmokers aged 20 years and older adjusted for other factors that affect these levels. For nonsmokers, exposure to second hand smoke at home was associated with about 30 times higher serum cotinine levels when compared to those without such exposure (0.717 ng mL−1 vs. 0.024 ng mL−1, p < 0.01). NNAL levels among nonsmokers with second hand smoke exposure at home were about twenty times what they were in those without such exposure (9 pg mL−1 vs. 109 pg mL−1, p < 0.01). As compared to other racial/ethnic groups, the lowest adjusted serum cotinine levels occurred in non-Hispanic Asian smokers (92.6 ng mL−1) and Hispanics (84.5 ng mL−1) as compared to non-Hispanic whites (143.8 ng mL−1) and non-Hispanic blacks (158.4 ng mL−1). Urinary NNAL levels for smokers were in the order: non-Hispanic Asian (0.121 ng mL−1) < non-Hispanic blacks (0.139 ng mL−1) < Hispanics (0.201 ng mL−1) < non-Hispanic whites (0.234 ng mL−1). Compared to non-Hispanic whites, non-Hispanic blacks had substantially higher levels of serum cotinine but substantially lower levels of urinary NNAL irrespective of smoking status thus pointing towards differences in elimination kinetics of nicotine/cotinine and NNAL.