Evaluating cotinine cutoffs and sociodemographic factors associated with exclusive heavy e-cigarette vaping behavior

IntroductionElectronic cigarette (e-cig) use in previously tobacco-naive individuals may increase the risk of nicotine addiction and adverse health outcomes, including lung injury and cardiovascular disease. This study identifies a subgroup of heavy exclusive e-cig vapers, characterizes their demographics, and establishes an optimal serum cotinine threshold to differentiate them from tobacco-naive individuals. MethodsWe analyzed data from the National Health and Nutrition Examination Survey (2013- 2020) to characterize serum cotinine levels by e-cig use frequency. The optimal cotinine cutoff for identifying heavy exclusive vapers was 2.2 ng/mL (sensitivity 98%, specificity 96%). We used receiver operating characteristic curve analysis to identify the cotinine threshold for discriminating heavy exclusive e-cig vapers from tobacco-naive individuals and logistic regression to explore sociodemographic factors. ResultsExclusive heavy e-cig vapers--defined as those who vaped on four or more of the past five days--had mean cotinine levels (220 {+/-} 38 ng/mL) comparable to cigarette smokers (212 {+/-} 6 ng/mL). These vapers were more likely to be 12-18 (AOR 7.96; 95% CI: [3.38 - 18.7]) or 19-25 [AOR 7.36 [2.84 - 19]) years old and less likely to be female (AOR 0.3 [0.16-0.57]). ConclusionHeavy exclusive e-cig vapers had serum cotinine levels similar to cigarette smokers and were predominantly young males. Public health interventions should target this high-risk subgroup to reduce potential long-term health consequences.