Changes in Biomarkers of Exposure and Subjective Effects When Smokers Switch to Dual Use of Cigarettes and Either Snus or a Dissolvable Tobacco Product: A Summary of Three Clinical Studies

Abstract

SUMMARYA series of ambulatory clinical studies were conducted to evaluate changes in biomarkers of tobacco exposure and subjective product ratings when adult smokers switched to dual use of cigarettes with Camel Strips (Strips), Camel Sticks (Sticks), or Camel (SNUS). In all studies, subjects smoked ad libitum for one week (baseline). In incremental stages over three subsequent weeks, subjects were instructed to reduce cigarettes per day (CPD) by at least 75% and include use of one type of smokeless tobacco product (STP). Product use data was recorded by subjects daily, questionnaires were administered and smoked cigarette filters and used snus pouches were collected weekly, and 24-hour urine samples were collected at baseline and the end of dual use for measurement of biomarkers of tobacco exposure. In total, 100 subjects were enrolled, and 88 completed the studies. At the end of dual use, mean CPD reductions of approximately 60% were reported in all studies. Median levels of biomarkers of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and acrolein either did not statistically significantly change or showed statistically significant decreases in all studies. Serum and urinary nicotine biomarkers did not significantly change. Twentyfive additional biomarkers were measured only in the SNUS study. Of those, 18 biomarkers statistically significantly decreased 12.4-35.7%. No statistically significant increases in biomarker levels were observed in any of the studies. Decreases in some biomarkers confirmed that smoking reductions occurred but were less than the reported CPD reductions. Mouth-level exposure estimates suggest subjects did not significantly alter their puffing behavior to compensate for decreased CPD. Acceptability ratings of cigarettes decreased significantly during dual use, while ratings of Strips and SNUS increased, suggesting that the change in use behavior affected subjects' perceptions of the products. Results from these studies suggest that smokers who switch to dual use with either dissolvable tobacco or snus will likely not increase tobacco constituent exposure and may reduce exposure to some tobacco toxicants, especially those associated with combustion. [Beitr. Tabakforsch. Int. 26 (2015)

Assessment of the Exposure to Aromatic Amines in Users of Various Tobacco/Nicotine Products

“…Excretion of o -Tol in smokers (CC) on Day 3 was in the range of 91.0–260.7 (mean: 150.2) ng/24 h (Table ). This is overall in good agreement with a series of other studies. ,− NU of any tobacco/nicotine products in our study showed o -Tol excretion rates in the range of 30.4–77.2 (mean: 60.2) ng/24 h (Table ). Agreement with reported o -Tol excretions in nonsmokers is acceptable. ,− Urinary o -Tol levels in NU confirm the relatively high and diffuse background exposure of the general population to this aromatic amine. , In some earlier studies, significantly higher o -Tol concentrations in urine (μg/L range) were reported in nonoccupationally exposed smokers and nonsmokers, with no significant differences observed between the two groups. − Possibly, there were issues with the specificity of the analytical methods applied in these studies.…”

Reductions in biomarkers of exposure (BoE) to harmful or potentially harmful constituents (HPHCs) following partial or complete substitution of cigarettes with electronic cigarettes in adult smokers

“…Whether the reductions in exposure to toxicants such as those observed in this study may have the potential to reduce risks for chronic, smoking-caused diseases for long-term e-cigarette users who have partially or completely discontinued cigarette smoking warrants further investigation. It has been previously shown that for those Swedish smokers who completely switch from cigarettes to a noncombustible form of tobacco (snus, which delivers nicotine without smoke) there appears to be an association with lower relative risks for major smoking-related disease, including cancer (Round et al., 2015 ).…”

Biomarkers of Tobacco Exposure Decrease After Smokers Switch to an E-Cigarette or Nicotine Gum

“…Urinary biomarker analysis was performed by ABF GmbH (Munich, Germany), and plasma nicotine and cotinine analysis was performed by Celerion, Inc. (Lincoln, NE). Methods are generally as described in Theophilus et al 34 and Round et al, 35 with one exception. The calculation of total nicotine equivalents includes unconjugated nicotine, unconjugated cotinine, unconjugated trans-3′-hydroxycotinine, nicotine-N-glucuronide, cotinine-N-glucuronide, trans -3′-hydroxycotinine-O-glucuronide, cotinine-N-oxide, nicotine-N-oxide, norcotinine, nornicotine, and 4-hydroxy-4-(3-pyridyl)-butanoic acid 36 …”