Development of biomarkers of effect from chronic tobacco usage. Part 3: Potential metabolomics biomarkers of tobacco effect
Epidemiological data indicate that consumption of moist snuff is associated with reduced harm relative to cigarette smoking. However, a need exists for interim biomarkers of effect (BioEff) that would be useful to assess the health effects of tobacco. To identify potential BioEff in smokers and moist snuff consumers (MSC), we performed global untargeted metabolomic profiling of plasma and urine collected from smokers and MSC, using mass spectrometry. Analyses revealed a general concordance between the data obtained from the two matrices among biological pathways influenced by tobacco exposure (details presented in an accompanying poster). For example, smokers experienced exacerbated oxidative stress and inflammatory pathways relative to MSC. Based on the differential levels of metabolites detected, random forest analyses separated non-tobacco consumers (NTC), smokers, and MSC with a high (96%) accuracy when all metabolites were included. Overall, smokers showed more pronounced biochemical changes compared to MSC, which facilitated the separation of smokers from non-smokers (MSC and NTC). On the other hand, MSC showed more subtle changes in metabolite profiles, and were more difficult to separate from NTC but could still be separated. The smokers and MSC cohorts could also be segregated with a high (95%) accuracy. In addition, panels of a few metabolites that may be useful for segregating the two tobacco consumer cohorts were identified from these metabolomic profiling data. These metabolites could be used as potential BioEff, pending further validation. In summary, global metabolomic profiles and panels of selected metabolites may be used to assess the effect of tobacco consumption on biological pathways in plasma and urine.