Sex differences in response to reduced nicotine content cigarettes

Background: When switching from usual brand cigarettes, very low nicotine content (VLNC) cigarettes lead to a reduction in the number of cigarettes smoked, toxicant exposure, withdrawal symptoms and dependence. One area that has been relatively unexplored is what factors might moderate the effects of VLNC cigarettes. This exploratory analysis focuses on sex differences in responses to VLNC cigarettes and nicotine replacement therapy. Methods: An exploratory secondary analysis of a randomized trial of 235 participants (58% female, mean age 47. years) comparing a) 0.05-0.09. mg nicotine yield cigarettes; b) 21. mg nicotine patch and 3) 0.05-0.09 nicotine yield cigarettes with 21. mg nicotine patch was conducted. We focused on sex differences in product use, and impact of products on withdrawal response from usual brand cigarettes and abstinence by randomized group. Results: The combination of VLNC cigarettes and nicotine patch was more effective in reducing use of VLNC cigarettes and withdrawal symptoms among males than females, whereas females were equally responsive to VLNC cigarettes with and without the nicotine patch. Females were more likely to quit smoking than males when assigned to either of the conditions that incorporated the VLNC cigarettes; however, males were more likely to quit smoking in the nicotine patch alone condition than females. Conclusion: Sex of the smoker may be an important determinant for effects of VLNC cigarettes and nicotine patch. Future large randomized trials to confirm these results are needed.