Comparison of Liquid Chromatography Mass Spectrometry and Enzyme-Linked Immunosorbent Assay Methods to Measure Salivary Cotinine Levels in Ill Children

The Associations of Trans-3'-Hydroxy Cotinine, Cotinine, and the Nicotine Metabolite Ratio in Pediatric Patients with Tobacco Smoke Exposure

(1) Background: Trans-3'-hydroxy cotinine (3HC) and cotinine (COT) are tobacco smoke exposure (TSE) biomarkers and the 3HC/COT ratio is a marker of CYP2A6 activity, an enzyme which metabolizes nicotine. The primary objective was to assess the associations of these TSE biomarkers with sociodemographics and TSE patterns in children who lived with ≥1 smoker. (2) Methods: A convenience sample of 288 children (mean age (SD) = 6.42 (4.8) years) was recruited. Multiple linear regression models were built to assess associations of sociodemographics and TSE patterns with urinary biomarker response variables: (1) 3HC, (2) COT, (3) 3HC+COT sum, and (4) 3HC/COT ratio. (3) Results: All children had detectable 3HC (Geometric Mean [GeoM] = 32.03 ng/mL, 95%CI = 26.97, 38.04) and COT (GeoM = 10.24 ng/mL, 95%CI = 8.82, 11.89). Children with higher cumulative TSE had higher 3HC and COT (β^ = 0.03, 95%CI = 0.01, 0.06, p = 0.015 and β^ = 0.03, 95%CI = 0.01, 0.05, p = 0.013, respectively). Highest 3HC+COT sum levels were in children who were Black (β^ = 0.60, 95%CI = 0.04, 1.17, p = 0.039) and who had higher cumulative TSE (β^ = 0.03, 95%CI = 0.01, 0.06, p = 0.015). Lowest 3HC/COT ratios were in children who were Black (β^ = -0.42, 95%CI = -0.78, -0.07, p = 0.021) and female (β^ = -0.32, 95%CI = -0.62, -0.01, p = 0.044). (4) Conclusion: Results indicate that there are racial and age-related differences in TSE, most likely due to slower nicotine metabolism in non-Hispanic Black children and in younger children.

Hand nicotine as an independent marker of thirdhand smoke pollution in children's environments

BACKGROUND

Hand nicotine (HN) levels measure children's exposure to tobacco smoke pollutants from thirdhand and secondhand smoke. HN is associated with urinary and salivary cotinine, but the associations of HN with other tobacco smoke exposure (TSE) markers remain unknown.

OBJECTIVES

We compared levels of HN and four urinary TSE biomarkers: cotinine, trans-3'-hydroxycotinine (3HC), nicotelline N-oxides, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and children's sociodemographic and TSE patterns. We also examined if HN is a plausible pathway for children's exposure to active smoking.

METHODS

Data were collected from 175 non-smoking patients (Mean (SD) age = 5.4 (3.4) years) who lived with ≥1 cigarette smoker(s). HN and TSE biomarker levels were determined using LC-MS/MS. Multivariate and multivariable regression analyses were conducted to examine associations between TSE markers and parent-reported measures, controlling for sociodemographics.

RESULTS

Of the five markers of TSE, cotinine (R² = 0.221; p = 0.003) and HN (R² = 0.247; p = 0.001) showed the strongest overall associations. Of the five markers, only cotinine showed significantly higher levels among Black children (β^=0.307,p<0.05) independent of age, reported exposure, and home smoking bans. Cotinine (β^=0.010,p<0.05), NNAL (β^=0.012,p<0.05), and HN (β^=0.011,p<0.05) showed significant positive associations with reported exposure independent of race, age, and home smoking bans. NNAL (β^=-0.285,p<0.05) and HN (β^=-0.336,p<0.05), but not cotinine, 3HC, and N-oxides, showed significantly lower levels among children who lived in homes with smoking bans. Child age, hand surface area, home smoking ban, and reported exposure independently accounted for 21 % of the variance in HN levels (p = 0.002). HN accounted for 30 % of the variance in cotinine independent of child race and child age.

DISCUSSION

HN levels were associated with modifiable tobacco-related behaviors and shows promise as a marker of sources of THS pollution in a child's environment not captured by measurement of urinary cotinine alone. HN levels provide additional information about TSE, complementing other biomarkers when assessing children's overall TSE.

Tobacco smoke exposure and fractional exhaled nitric oxide levels among U.S. adolescents

BACKGROUND

Fractional exhaled nitric oxide (FeNO) can objectively guide clinical practice in the assessment, diagnosis, and treatment of eosinophilic airway inflammation. FeNO values may be affected by current smoking, but the role of tobacco smoke exposure (TSE) is understudied.

OBJECTIVE

This study investigated the associations between biochemically validated and self-reported TSE and FeNO levels among U.S. nonsmoking adolescents without asthma.

METHODS

National Health and Nutrition Examination Survey 2007-2012 data were used. TSE was assessed via serum cotinine and self-reported measures. We assessed FeNO continuously and using cutpoints of >35 ppb and >50 ppb to indicate likely eosinophilic inflammation in children and adults, respectively. We conducted linear and logistic regression adjusting for potential covariates.

RESULTS

Overall, 34.0% of adolescents had low cotinine (0.05-2.99 ng/ml), 6.2% had high cotinine (≥3.00 ng/ml), and 11.9% had home TSE. Compared to adolescents with no/minimal cotinine, adolescents with high cotinine were at reduced odds to have FeNO >35 ppb (adjusted odds ratio [aOR] = 0.54, 95%CI = 0.43,0.69). Adolescents with low cotinine had lower FeNO values (β = -2.05, 95%CI = -3.61,-0.49), and were also at decreased odds to have FeNO >35 ppb (aOR = 0.74, 95%CI = 0.66,0.83) and FeNO >50 ppb (aOR = 0.62, 95%CI = 0.53,0.72). Adolescents with home TSE were at reduced odds to have FeNO >50 ppb (aOR = 0.72, 95%CI = 0.57,0.91) than adolescents without home TSE. Adolescents with a higher number of cigarettes/day smoked inside their home were at reduced odds to have FeNO >35 ppb (OR = 0.98, 95%CI = 0.97,0.99) and FeNO >50 ppb (OR = 0.98, 95%CI = 0.96,0.99).

CONCLUSIONS

TSE was associated with decreased FeNO levels. The addition of TSE may be clinically important when interpreting thresholds for FeNO.

Hand Nicotine and Cotinine In Children Exposed to Cigars: A Pilot Study

Objectives

Past research has not examined secondhand and thirdhand smoke (THS) exposure in children of cigar smokers. We examined hand nicotine and cotinine levels in children of cigar smokers to explore the contribution of cigar smoke to tobacco smoke exposure (TSE).

Methods

Participants were children (N = 24; mean (SD) age = 6.5 (3.6) years) whose parents smoked cigars only or poly-used cigars and/or cigarettes. Primary outcomes were hand nicotine and urinary cotinine levels.

Results

All children had detectable hand nicotine (range: 7.6-312.5ng/wipe) and cotinine (range: 0.3-100.3ng/ml). Positive correlations were found between hand nicotine and cotinine (r = 0.693, p = .001), hand nicotine and parents who also smoked cigarettes (r = 0.407, p = .048), and hand nicotine and number of smokers around the child (r = 0.436, p = .03). Hand nicotine (r = -0.464, p = .02), but not cotinine (r = -0.266, p = .26), was negatively correlated with child age. Multiple regression results indicated a positive association between hand nicotine and cotinine (p = .002; semi-partial r² = 0.415), irrespective of child age.

Conclusions

The significant association of hand nicotine with urinary cotinine suggests that THS pollution should be assessed in evaluating children's overall TSE to cigars and other tobacco products, and hand nicotine may be a proxy for overall TSE. Younger children may have increased THS pollutant uptake.

High Cotinine and Healthcare Utilization Disparities Among Low-Income Children

INTRODUCTION

This study assesses the associations of child salivary cotinine, parent-reported smoking, and child tobacco smoke exposure with the number of child healthcare visits and hospital admissions over a 6-month period. This study also assesses the relationships between participant characteristics and child cotinine.

METHODS

Longitudinal data were evaluated from a sample of 313 clinically ill children aged 0-9 years who lived with a smoker and presented to a pediatric emergency department or urgent care in 2016-2018. In 2020, cotinine measurements were log transformed, and Poisson and linear regression were performed.

RESULTS

The majority of the children came from low-income homes (66.1%) and had public insurance/self-pay (95.5%). Child cotinine concentrations ranged from 0.1 to 332.0 ng/mL (geometric mean=4.8 ng/mL, 95% CI=4.1, 5.5). Poisson regression results indicated that each 1-unit increase of log-cotinine concentration was associated with an increase in pediatric emergency department visits over a 6-month period after the baseline visit, with an adjusted RR of 1.16 (95% CI=1.01, 1.34). Each 1-unit increase of log-cotinine concentration was associated with an increase in the frequency of hospital admissions over the 6-month period, with an adjusted RR of 1.50 (95% CI=1.08, 2.09). No differences were found between parent-reported smoking or child tobacco smoke exposure and healthcare utilization. Linear regression results indicated that children who were younger (β= -0.227, p=0.049), were White (geometric mean=5.5 ng/mL), had a medical history of prematurity (geometric mean=8.1 ng/mL), and had a winter baseline visit (geometric mean=6.5 ng/mL) had higher cotinine concentrations. Children living in apartments (geometric mean=5.5 ng/mL) and multiunit homes (geometric mean=5.5 ng/mL) had higher cotinine concentrations than those in single-family homes (geometric mean=3.6 ng/mL).

CONCLUSIONS

Routine biochemical screening could identify children who are in need of intensive tobacco smoke exposure reduction interventions.

A Parental Smoking Cessation Intervention in the Pediatric Emergency Setting: A Randomized Trial

We examined the efficacy of a pediatric emergency visit-based screening, brief intervention, and referral to treatment (SBIRT) condition compared to a control condition (Healthy Habits Control, HHC) to help parental smokers quit smoking. We enrolled 750 parental smokers who presented to the pediatric emergency setting with their child into a two-group randomized controlled clinical trial. SBIRT participants received brief cessation coaching, quitting resources, and up to 12-weeks of nicotine replacement therapy (NRT). HHC participants received healthy lifestyle coaching and resources. The primary outcome was point-prevalence tobacco abstinence at six weeks (T1) and six months (T2). The mean (SD) age of parents was 31.8 (7.7) years, and 86.8% were female, 52.7% were Black, and 64.6% had an income of ≤$15,000. Overall abstinence rates were not statistically significant with 4.2% in both groups at T1 and 12.9% and 8.3% in the SBIRT and HHC groups, respectively, at T2. There were statistically significant differences in SBIRT versus HHC participants on the median (IQR) reduction of daily cigarettes smoked at T1 from baseline (−2 [−5, 0] versus 0 [−4, 0], p = 0.0008),at T2 from baseline (−4 [−9, −1] vs. −2 [−5, 0], p = 0.0006), and on the mean (SD) number of quit attempts at T2 from baseline (1.25 (6.5) vs. 0.02 (4.71), p = 0.02). Self-reported quitting rates were higher in SBIRT parents who received NRT (83.3% vs. 50.9%, p = 0.04). The novel use of the pediatric emergency visit to conduct cessation interventions helped parents quit smoking. The near equivalent abstinence rates in both the SBIRT and HHC groups may be due to underlying parental concern about their child’s health. Cessation interventions in this setting may result in adult and pediatric public health benefits.