Changes in circulating leptin levels during the initial stage of cessation are associated with smoking relapse

Abstract

Rationale: Leptin has been linked to tobacco craving and withdrawal-related symptoms. Very few studies have examined leptin prospectively in both male and female nonsmokers and smokers.

Objectives: We examine leptin concentrations prospectively in both male and female nonsmokers and smokers to assess the associations of leptin with psychological symptoms and smoking relapse during ad libitum smoking, the first 48 h post quit, and 4 weeks post-cessation.

Methods: Self-report psychological, anthropomorphic, and biological measures (cotinine, carbon monoxide, and plasma leptin) were collected before and after 48 h of smoking abstinence. Smokers were stratified at 28 days post quit as abstinent or relapsed if they had smoked daily for seven consecutive days at any point in the 28 days.

Results: Leptin concentration (square root transformed ng/ml) increased over the 48-h abstinence, but only in female abstainers. In contrast, leptin was very stable across time for nonsmokers, relapsers, and males. Cox regression supported that increased leptin was associated with decreased risk of relapse. Leptin was correlated negatively with withdrawal symptoms for abstainers only. Females produce more leptin than males and this level increases from ad libitum smoking to 48-h post quit.

Conclusions: The current analysis indicates that a leptin increase early in cessation predicts abstinence. The increase in women, but not men, in response to abstinence provides further evidence of important gender differences. The negative correlation between leptin and withdrawal symptoms indicates a possible protective effect of leptin. Further research is ongoing to elucidate the psychological and biological determinants of this effect.

Fig. 1

The results indicate a significant relapse group by gender by time interaction for transformed leptin levels across ad libitum smoking and 48-hour abstinence (p < .05; _pη² = .06). Follow up analysis revealed that the female abstainers were the only group to show significant differences across time, here characterized as an increase in leptin during the 48-hr abstinence that was not evident in either the males relapsers. Females also produce more leptin than males (p < .001)..

Fig. 2

The change in leptin from ad libitum smoking to 48-hour abstinence predicted relapse (B = −.86, HR = 0.48, p < .05) but neither gender nor the gender by leptin change interaction did (ps > .10).