Switching to Progressively Reduced Nicotine Content Cigarettes in Smokers With Low Socioeconomic Status: A Double-Blind Randomized Clinical Trial.

INTRODUCTION: The Food and Drug Administration issued an advanced notice of proposed rulemaking for setting a product standard for nicotine levels in cigarettes, with an emphasis on minimally or non-addicting very low nicotine content (VLNC). METHODS: A 33 week, two-arm, double-blind randomized trial conducted in Hershey, Pennsylvania, USA and Washington, DC, USA included adult daily cigarette smokers (≥5 cigarettes per day) with less than a college degree, and who had no plans to quit within the next six months. Participants were randomized to either reduced nicotine content (RNC) study cigarettes tapered every three weeks to a final VLNC (0.2 mg/cigarette) for six weeks or to usual nicotine content (UNC) study cigarettes (11.6 mg/cigarette). Outcomes included acceptability of study cigarettes measured by attrition (primary outcome), compliance, reduction in cigarette dependence and tobacco biomarkers, and post-intervention cessation. RESULTS: The RNC (n = 122) versus UNC (n = 123) group had higher attrition (adjusted Hazard Ratio 3.4; 95% confidence interval [CI] 1.99 to 5.81). At the end of the intervention, cotinine levels were 50% lower in the RNC group (mean group difference -137 ng/mL; 95% CI -172, -102). The RNC group smoked fewer CPD (-4.1; 95% CI -6.44, -1.75) and had lower carbon monoxide levels (-4.0 ppm; 95% CI -7.7, -0.4). Forty seven percent (29/62) of the RNC group were biochemically-confirmed compliant with smoking VLNC cigarettes (mean cotinine = 8.9 ng/ml). At three month follow-up, only compliant VLNC smokers quit with an assisted quit attempt (N = 6/22, 27%). CONCLUSIONS: This study supports a VLNC standard in cigarettes. IMPLICATIONS: Differential dropout and noncompliance indicate some smokers had difficulty transitioning to cigarettes with reduced nicotine. These smokers will benefit from supplemental nicotine in medicinal or noncombustible tobacco products if a nicotine reduction standard is established. Other smokers successfully transitioned to very low nicotine content cigarettes exclusively and substantially reduced their exposure to nicotine.

Characteristics of Adult Cigarette Smokers Who "Relight" and the Effects of Exposure to Tobacco Smoke Constituents.

INTRODUCTION: About half of smokers relight their cigarette, a habit that is a risk factor for chronic bronchitis and possibly lung cancer. Little is known about the characteristics of smokers who relight and their dependence on nicotine. It is unknown whether relighting affects exposure to tobacco smoke constituents. This study examined the characteristics of relighters of usual brand cigarettes and whether relighting affects exposure to selected tobacco smoke constituents. METHODS: We explored relighting status and frequency, using baseline data from 248 adult smokers participating in studies of reduced nicotine cigarettes in relation to demographic and cigarette characteristics, smoking behaviors, nicotine dependence, biomarkers of exposure (exhaled carbon monoxide, blood cotinine), and biomarkers of oxidative stress (ratio of oxidized/reduced glutathione). RESULTS: 69.4% (n = 172) of subjects reported relighting, and they relit an average of five cigarettes out of 20. Both relighters and non-relighters smoked a mean of 20 cigarettes per day (p = .6). Relighting was significantly associated with higher nicotine dependence, use of longer rod cigarettes, older age, lower income, and unemployment. There were no significant associations between relighting and blood cotinine, exhaled carbon monoxide or measures of oxidized/reduced blood glutathione. CONCLUSIONS: The majority of subjects were relighters, who had higher levels of nicotine dependence than non-relighters. Relighters had similar levels of plasma cotinine and exhaled carbon monoxide to non-relighters. IMPLICATIONS: No study has compared the cigarette characteristics and biomarkers of exposure of adult cigarette smokers who relight with those who do not. Relighting behavior was common in our sample and was associated with low income, not currently working, higher nicotine dependence, cigarette rod length, daily cigarette use years, and a lifetime history of depressed mood.