Concentrations of urine cotinine and hydroxycotinine among US children, adolescents, and adults: data from NHANES 2013–2014

Purpose: The objective of this study was to evaluate variabilities in the levels of urine cotinine and hydroxycotinine by age, gender, race/ethnicity and smoking status among US residents.Materials and methods: Data from NHANES (N = 3135) were analysed by fitting regression models with log10-transformed values of urine cotinine and hydroxycotinine as dependent variables. Separate models were fitted for children aged 6-11 years, adolescents aged 12-19 years, and adults aged ≥20 years. Models were stratified by smoking status. Those self-reporting using combustible and/or smokeless tobacco products during the last 5 days were classified as being smokers.Results: No gender differences were observed. Among non-smokers, non-Hispanic blacks had the highest levels of cotinine and hydroxycotinine and Hispanics had the lowest levels of cotinine and hydroxycotinine. Among smokers, non-Hispanic whites had the highest levels of cotinine and hydroxycotinine. Exposure to environmental tobacco smoke at home and other indoor environments was associated with as much as 500% higher levels of cotinine and hydroxycotinine.Conclusions: In addition to currently available data on cotinine in serum and NNAL in urine, availability of data on cotinine and hydroxycotinine in urine provides another tool to monitor the smoking health of the US population.