Reducing nicotine exposure results in weight gain in smokers randomised to very low nicotine content cigarettes

Abstract

Background: The Food and Drug Administration can reduce the nicotine content in cigarettes to very low levels. This potential regulatory action is hypothesised to improve public health by reducing smoking, but may have unintended consequences related to weight gain.

Methods: Weight gain was evaluated from a double-blind, parallel, randomised clinical trial of 839 participants assigned to smoke 1 of 6 investigational cigarettes with nicotine content ranging from 0.4 to 15.8 mg/g or their own usual brand for 6 weeks. Additional analyses evaluated weight gain in the lowest nicotine content cigarette groups (0.4 and 0.4 mg/g, high tar) to examine the effect of study product in compliant participants as assessed by urinary biomarkers. Differences in outcomes due to gender were also explored.

Findings: There were no significant differences in weight gain when comparing the reduced nicotine conditions with the 15.8 mg/g control group across all treatment groups and weeks. However, weight gain at week 6 was negatively correlated with nicotine exposure in the 2 lowest nicotine content cigarette conditions. Within the 2 lowest nicotine content cigarette conditions, male and female smokers biochemically verified to be compliant on study product gained significantly more weight than non-compliant smokers and control groups.

Conclusions: The effect of random assignment to investigational cigarettes with reduced nicotine on weight gain was likely obscured by non-compliance with study product. Men and women who were compliant in the lowest nicotine content cigarette conditions gained 1.2 kg over 6 weeks, indicating weight gain is a likely consequence of reduced exposure to nicotine.

Trial registration number: NCT01681875, Post-results.

Keywords: Harm Reduction; Nicotine; Public policy.

Figure 1. Relationship between weight gain and nicotine exposure

Within 0.4 mg/g and 0.4 mg/g HT groups, weight gain was negatively correlated with the natural log of TNE.

Figure 2. Weight gain over time in compliant and non-compliant individuals randomized to 0.4 mg/g and 0.4 mg/g HT cigarettes

Mean cumulative weight gain in individuals compliant (urinary TNE less than 6.41 nmol/ml at Week 2 and Week 6) or non-compliant (urinary TNE greater than 6.4 at Week 2 or Week 6) on 0.4 mg/g and 0.4 mg/g HT cigarettes, and 15.8 mg/g control group. * indicates P<0.01 comparing compliant and non-compliant groups. # indicates P<0.01 comparing compliant and 15.8 mg/g groups. + indicates P<0.1 comparing compliant and usual brand groups.

Figure 3. Weight gain over time in compliant and non-compliant men and women randomized to 0.4 mg/g and 0.4 mg/g HT cigarettes

Mean cumulative weight gain in women (a) and men (b) compliant (urinary TNE less than 6.41 nmol/ml at Week 2 and Week 6) or non-compliant (urinary TNE greater than 6.4 at Week 2 or Week 6) on 0.4 mg/g and 0.4 mg/g HT cigarettes, and 15.8 mg/g control group. * indicates P<0.01 comparing compliant and non-compliant groups.