Associations of smoking cessation with visceral fat area and prevalence of metabolic syndrome in men: the Hitachi health study

Weight gain after smoking cessation may deteriorate metabolic risk profiles, including that for metabolic syndrome. How risk profiles change according to the duration of smoking cessation and whether the visceral fat area (VFA) or the subcutaneous fat area (SFA) contributes to these changes remains uncertain. The subjects comprised 5,697 Japanese men who underwent an abdominal computed-tomography examination during a health check-up. Using never smokers as a reference group, the odds ratios of having metabolic syndrome and its components, defined using the National Cholesterol Education Program Adult Treatment Panel IIIcriteria, were calculated for each smoking category with adjustments for age, alcohol drinking, and physical activity (model 1) using a logistic regression analysis. Additional adjustments were also made for either VFA (model 2) or SFA (model 3). Current smokers had the lowest VFA (120.4 cm2) whereas ex-smokers (124.0-132.0 cm2) had a higher VFA than nonsmokers (123.1 cm2). Among the ex-smokers, VFA tended to decrease with increasing years of smoking cessation. In model 1, the odds ratios of having metabolic syndrome for current smokers and ex-smokers with smoking cessation for ≤ 4, 5-9, 10-14, and ≥ 15 years were 1.02, 1.33, 1.36, 1.40, and 1.09, respectively. The elevated odds ratios among ex-smokers (≤ 14 years) were reduced by 35-55.6% after further adjustment for VFA but not for SFA. Smoking cessation is associated with a deterioration of the metabolic risk profile, which can be ascribed, at least in part, to an increase in VFA not SFA.