Measuring nicotine intake among highly-dependent adolescent smokers: comparability of saliva and plasma cotinine concentrations

Environmental tobacco smoke exposure is associated with increased levels of metals in children's saliva

BACKGROUND

Exposure to environmental tobacco smoke (ETS) has been associated with detectable levels of cotinine (a nicotine metabolite) in children's saliva. However, tobacco smoke also contains toxic and essential trace metals, including chromium (Cr), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni) and zinc (Zn).

OBJECTIVE

The current study examines whether there is a relationship between ETS exposure, as gauged by salivary cotinine, and salivary levels of these metals in a subset (n = 238) of children from the Family Life Project.

METHODS

Using inductively-coupled-plasma optical emission spectrophotometry, we measured levels of metals in saliva from children at ~90 months of age. Salivary cotinine was measured using a commercial immunoassay.

RESULTS

We found that Cr, Cu, Mn, and Zn were detected in most samples (85-99%) with lower levels of detection for Pb and Ni (9.3% and 13.9% respectively). There were no significant differences in any of the metal concentrations between males and females, nor were levels associated with body mass index, although significant differences in salivary Cr and Mn by race, state and income-to-needs ratio were observed. Children with cotinine levels >1 ng/ml had higher levels of Zn (b = 0.401, 95% CI: 0.183 to 0.619; p = 0.0003) and Cu (b = 0.655, 95% CI: 0.206 to 1.104; p = 0.004) compared to children with levels <1 ng/ml, after controlling for multiple confounders, including sex, race, BMI and income-to-needs ratio. Further, we show that children whose cotinine levels were >1 μg/L were more likely to have detectable levels of Pb in their saliva (b = 1.40, 95% CI: 0.424 to 2.459; p = 0.006) compared to children with cotinine levels <1 ng/ml, also considering confounders.

IMPACT STATEMENT

This is the first study to demonstrate significant associations between salivary cotinine and salivary levels of Cu, Zn and Pb, suggesting that environmental tobacco smoke exposure my be one source of increased children's exposure to heavy metals. This study also demonstrates that saliva samples can be used to measure heavy metal exposure, and thus serve as a non-invasive tool for assessing a broader range of risk indicators.

Molecularly imprinted polymers as a selective sorbent for forensic applications in biological samples-a review

Molecularly imprinted polymers (MIP) consist of a molecular recognition technology with applicability in different areas, including forensic chemistry. Among the forensic applications, the use of MIP in biological fluid analysis has gained prominence. Biological fluids are complex samples that generally require a pre-treatment to eliminate interfering agents to improve the results of the analyses. In this review, we address the development of this molecular imprinting technology over the years, highlighting the forensic applications of molecularly imprinted polymers in biological sample preparation for analysis of stimulant drugs such as cocaine, amphetamines, and nicotine.

Busgang S, Matt GE. Comparison of Liquid Chromatography Mass Spectrometry and Enzyme-Linked Immunosorbent Assay Methods to Measure Salivary Cotinine Levels in Ill Children

Objective: Cotinine is the preferred biomarker to validate levels of tobacco smoke exposure (TSE) in children. Compared to enzyme-linked immunosorbent assay methods (ELISA) for quantifying cotinine in saliva, the use of liquid chromatography tandem mass spectrometry (LC-MS/MS) has higher sensitivity and specificity to measure very low levels of TSE. We sought to compare LC-MS/MS and ELISA measures of cotinine in saliva samples from children overall and the associations of these measures with demographics and TSE patterns. Method: Participants were nonsmoking children (N = 218; age mean (SD) = 6.1 (5.1) years) presenting to a pediatric emergency department. Saliva samples were analyzed for cotinine using both LC-MS/MS and ELISA. Limit of quantitation (LOQ) for LC-MS/MS and ELISA was 0.1 ng/ml and 0.15 ng/ml, respectively. Results: Intraclass correlations (ICC) across methods = 0.884 and was consistent in sex and age subgroups. The geometric mean (GeoM) of LC-MS/MS = 4.1 (range: < LOQ - 382 ng/mL; 3% < LOQ) which was lower (p < 0.0001) than the ELISA GeoM = 5.7 (range: < LOQ - 364 ng/mL; 5% < LOQ). Similar associations of cotinine concentrations with age ( < -0.10, p < 0.0001), demographic characteristics (e.g., income), and number of cigarettes smoked by caregiver ( > 0.07, p < 0.0001) were found regardless of cotinine detection method; however, cotinine associations with sex and race/ethnicity were only found to be significant in models using LC-MS/MS-derived cotinine. Conclusions: Utilizing LC-MS/MS-based cotinine, associations of cotinine with sex and race/ethnicity of child were revealed that were not detectable using ELISA-based cotinine, demonstrating the benefits of utilizing the more sensitive LC-MS/MS assay for cotinine measurement when detecting low levels of TSE in children.

Discrepancies in the Validity of Self-Reported Cigarette Smoking in Adults With and Without ADHD

Objective: Attention-deficit/hyperactivity disorder (ADHD) is associated with an increased smoking prevalence and impairments in executive function, which may negatively affect the validity of self-reported smoking rates. This study compares the utility of self-reported smoking with salivary cotinine in adult smokers and nonsmokers with and without ADHD. Methods: Participants (N = 82) were adult smokers and nonsmokers with and without ADHD (n = 35 ADHD and n = 47 controls) from an observational study. Odds ratios (ORs) for accuracy of self-reported smoking compared to salivary cotinine were calculated using diagnosis (ADHD vs. control), gender, age, education, employment, and number of cigarettes per day as predictors. Post-hoc analysis stratified sensitivity, specificity, and accuracy of self-reported smoking in individuals with ADHD and without ADHD. Results: The initial analysis identified education as a significant independent predictor of odds of accuracy, OR = 6.22, p = .013, after adjusting for diagnosis, gender, age, employment, and cigarettes per day. Post-hoc analysis revealed that sensitivity, specificity, and accuracy of self-reported smoking was 100% for individuals with ADHD who had more than high school education compared to those with high school or less, which was 83.3%, 45.5%, and 65.2%, respectively. Self-reported smoking of control participants with greater than a high school education had a sensitivity of 85.7%, a specificity of 91.7%, and an accuracy of 88.5%. Control participants with a high school or lower education had a sensitivity of 54.6%, a specificity of 90%, and an accuracy of 71.4% for their self-reported smoking. Conclusions: Individuals with ADHD and high school or lower education showed the lowest specificity and accuracy in their self-reported smoking, which may affect documented smoking prevalence rates. This is a secondary analysis of data collected as part of a clinical trial registered as NCT00915798 at www.clinicaltrials.gov .

Nurse-initiated intervention programs: future directions for cessation and prevention of adolescent smoking

Tobacco use in adolescence remains at unacceptable levels. Increasing teen knowledge about the dangers of smoking appears to be insufficient in changing adolescent attitudes regarding the use of tobacco. To incite change and increase their effectiveness, adult smoking cessation programs need to be tailored to adolescents. Ultimately, intrapersonal, interpersonal, and environmental factors that underlie tobacco use and smoking behaviors in adolescents must be identified. The nurse's role is both in identification of the adolescent smoker and assessment of the smoking behavior. Future directions in nursing practice, nursing education, and research surrounding tobacco use in youth are discussed.