Smoking status and body fatness indicators: A cross-sectional survey among 1948 Chinese male adults

Aim: The relationship between cigarette smoking and obesity has been extensively studied, but the existing evidence is inconclusive. Moreover, few previous studies had examined the relationships of cigarette smoking with body mass index (BMI), waist circumference (WC), hip circumference (HC) and waist-to-hip ratio (WHR) simultaneously, which could not fully assess the effects of smoking on fat distribution. This study aimed to investigate the associations of cigarette smoking with BMI, WC, HC and WHR in Chinese male adults. Subjects and methods: A total of 1,948 Chinese male adults (including 982 non-smokers, 846 current smokers and 210 former smokers) were selected from a community-based chronic disease screening project in Guangzhou and Zhuhai, China. The selected subjects were surveyed about their smoking status and history, and their body fatness indicators (BMI, WC, HC and WHR) were measured. A series of analyses of covariance (ANCOVA) were performed to assess associations between smoking behaviors and the body fatness indicators with adjustment for potential confounders. Results: Current smokers had lower BMI (23.3 vs. 23.5 kg/m²) and HC (93.5 vs. 94.1 cm) but higher WHR (0.867 vs. 0.859) than non-smokers. Within current smokers, heavy smokers (>15 cigarettes/day) had higher BMI (23.4 vs. 23.0 kg/m²) than light smokers (1-15 cigarettes/day) without controlling for WC, but this association was reversed after adjusting for WC (23.1 vs. 23.3 cm). Heavy smokers had higher WC and WHR but lower HC than non-smokers. Former smokers who had quit for shorter than 1 year had larger BMI than non-smokers and former smokers who quitted for 1 year or longer. Conclusions: Cigarette smoking is associated with both of the reduced total body mass and the increased waist fat deposit, and the weight gain seems to occur and complete itself in a short time after smoking cessation. These findings may improve the understanding on how cigarette smoking is linked to fat distribution and provide scientific evidence regarding intervention in smoking and obesity.