Urinary anatalline and nicotelline cut-points to distinguish between exclusive and dual use of tobacco products.

Objective: This study measured anatalline and nicotelline, two minor tobacco alkaloids, to discriminate between exclusive smokeless tobacco (SLT) use, exclusive electronic nicotine delivery systems (ENDS) use, exclusive cigarette use, dual SLT and cigarette use, and dual ENDS and cigarette use.
Methods: N  = 664 urine samples from participants in the Population Assessment of Tobacco and Health Study were analyzed for anatalline and nicotelline. Geometric means and 95% confidence intervals were calculated for biomarker levels and their ratios. Non-parametric Receiver Operating Characteristic analyses were used to determine optimal cut-points of natural log-transformed biomarker ratios for distinguishing between tobacco use groups.
Results: The anatalline/nicotelline ratio distinguished exclusive cigarette from exclusive SLT use (threshold = 18.1, sensitivity = 89.3%, specificity = 86.4%, AUC = 0.90), and exclusive SLT from exclusive ENDS use (threshold = 12.8, sensitivity = 96.4%, specificity = 76.3%, AUC = 0.90) very well, but had reduced sensitivity and specificity when distinguishing exclusive cigarette from exclusive ENDS or any dual use with cigarettes.
Conclusions: This research fills a gap in understanding the public health consequences of SLT and ENDS use by providing objective measures that can signal use of these products alone or in combination with cigarettes.