Racial Differences in Nicotine Reduction: Pooled Results from Two Double-Blind Randomized Controlled Trials.

Introduction: Tobacco regulatory policies are generally intended to apply to all segments of the population and to be equitable. Results from clinical trials on switching from commercial cigarettes to reduced nicotine cigarettes have included black populations but race-specific findings are not widely reported.

Methods: Data were pooled from two parallel randomized controlled trials of gradually reduced nicotine in cigarettes from 11.6 mg per cigarette down to 0.2 mg nicotine (very low nicotine content; VLNC) vs. usual nicotine content (UNC) cigarettes (11.6 mg) over an 18-week period in smokers with low socioeconomic status (SES) and mental health conditions, respectively. We used linear regression to determine the potential effects of cigarettes and biomarker reductions (blood cotinine and exhaled carbon monoxide) when using VLNC study cigarettes. An intention-to-treat (ITT) analysis included all randomized participants regardless of adherence to the protocol. A secondary compliance analysis compared control subjects (11.6 mg cigarettes) only to those switched to low nicotine cigarettes who were biochemically determined to be compliant to exclusively using VLNC cigarettes.

Results: Both Black and White VLNC smokers had significantly lower plasma cotinine and exhaled carbon monoxide compared to those randomized to UNC cigarettes. The treatment × race interaction term was not significant for the outcome measures in both the ITT and secondary compliance analyses, except for cotinine in the ITT analysis (Whites: - 190 ng/mL vs. Blacks: - 118 ng/mL; p = 0.05).

Conclusions: A reduced nicotine regulation for cigarettes would result in substantial reduction in exposure to nicotine and toxicants in Black and White smokers.