Leptin, hunger, and body weight: Influence of gender, tobacco smoking, and smoking abstinence.

Leptin is a hormone involved in body weight and hunger regulation, and may contribute to the inverse relationship between cigarette smoking and body weight. Leptin levels, body mass indices (BMIs), and hunger ratings were determined in 22 nonsmokers (12 male, 10 female) and 19 cigarette smokers (11 male, 8 female). Smokers were tested after ad lib smoking and following a 24-h smoking abstinence period; nonsmokers came to the laboratory once. Leptin levels were not different among the groups. Hunger ratings, however, were higher after smoking abstinence compared to after ad lib smoking and nonsmokers (Ps<.05); levels of hunger did not differ between ad lib smokers and nonsmokers. Men reported higher hunger levels than did women, but women had higher serum leptin levels than did men, regardless of smoking condition (P<.05). Leptin levels were correlated with BMI (P<.05) among smokers only. This first study on leptin responses in female smokers suggests that leptin levels do not change following a 24-h smoking abstinence period and that leptin may not contribute to increased hunger following smoking abstinence.