Preclinical and clinical data suggest modulating effects of appetite-regulating hormones and stress perception on food intake. Nicotine intake also interferes with regulation of body weight. Especially following smoking cessation gaining weight is a common but only partially understood consequence. The aim of this study was to examine the interaction between smoking habits, the appetite regulating hormone leptin, negative affectivity, and stress vulnerability on eating behavior in a clinical case-control study under standardized conditions. In a large population-based study sample, we compared leptin and cortisol plasma concentrations (radioimmunoassay) between current tobacco smokers with high cognitive restraint and disinhibition in eating behavior and smokers scoring low in both categories as assessed with the Three Factor Eating Questionnaire (TFEQ; Stunkard & Messick, 1985). As a measure for smoking effects on the stress axis, the saliva cortisol concentrations were compared before and after nicotine smoking. Additionally, stress perception was assessed with the Perceived Stress Scale (PSS), symptoms of depression and anxiety with the Beck Depression Inventory (BDI) and the State Trait Anxiety Inventory (STAI). In smokers showing high cognitive restraint and disinhibition we found significantly higher leptin concentrations than in the group of smokers scoring low in both categories. Furthermore there was a significant group difference in saliva cortisol concentrations after nicotine intake. Smokers showing high cognitive restraint and disinhibition were also characterized by significantly higher scores in the STAI, the PSS and the BDI. Our results suggest that smokers with a pathological eating behavior show an impaired neuroendocrine regulation of appetite and are prone to experience higher levels of stress and negative affectivity. This interaction of behavioral and neuroendocrinological factors may constitute a high risk condition for gaining weight following smoking cessation.
