Greater reductions in nicotine exposure while smoking very low nicotine content cigarettes predict smoking cessation

• Objective Reducing the nicotine content of cigarettes is a potential regulatory strategy that may enable cessation. The present study investigated the effect of nicotine exposure while smoking very low nicotine content (VLNC) cigarettes on cessation outcomes. The roles of possible sources of nicotine were also explored, including the VLNC cigarette and co-use of cigarettes with normal nicotine content.

• Methods A secondary data analysis of two analogous randomised trials of treatment seeking, adult daily smokers (n=112) who were instructed to smoke VLNC cigarettes for 6 weeks and then make a quit attempt. Controlling for baseline demographic and smoking features, the association between reductions in nicotine exposure during the 6-week trial, assessed by urinary total cotinine and biomarker-confirmed smoking abstinence 1 month later, was tested. Subsequent analyses controlled for the effects of the frequency of VLNC and normal nicotine content cigarette use and the nicotine yield of the VLNC cigarette (0.05 vs 0.09 mg).

• Results Greater reductions in nicotine exposure while smoking VLNC cigarettes predicted abstinence independent of individual differences in baseline smoking, cotinine, dependence, gender and study. Nicotine reduction was largest among individuals who were assigned to smoke a VLNC cigarette with lower nicotine yield and who smoked fewer normal nicotine content and VLNC cigarettes.

• Conclusions In the context of nicotine regulations and corresponding research, factors that undermine nicotine reduction must be addressed, including the availability and use of cigarettes with normal nicotine content and not sufficiently reducing the nicotine yield of cigarettes. Maximising nicotine reduction may facilitate smoking cessation.

Trial registration numbers NCT 101050569 and NCT 00777569.