The impact of body weight on smoking cessation in German adults.

Objective: To assess the relevance of pre-existing body weight for successful smoking cessation among women and men.

Methods: We carried out a retrospective cohort analysis among 4270 ever smoking participants of a general health screening examination in Germany recruited from July 2000 to June 2002 aged 50 to 74, who provided lifetime histories of both body weight and smoking.

Results: In the extended Cox model, the relative cessation rate (RCR) increased significantly with increasing body mass index (BMI) among both genders (test for trend: P < 0.01 for women and P < 0.0001 for men). In women, this effect was mainly due to a lower cessation rate in low-weight (BMI <20) smokers (adjusted RCR = 0.76, 95% confidence interval (CI) 0.62-0.95), whereas in men, the effect was mainly due to a higher cessation rate among overweight and obese smokers (adjusted RCR = 1.26, 95% CI 1.11-1.35, and 1.38, 95% CI 1.17-1.63, respectively) compared to normal-weight smokers.

Conclusions: While in men, overweight and obesity are associated with increased smoking cessation, possibly related to increased health concerns, in women, low weight is associated with decreased smoking cessation, possibly related to increased fear of weight gain.