The Associations Between Smoking Habits and Serum Triglyceride or Hemoglobin A1c Levels Differ According to Visceral Fat Accumulation

BACKGROUND Whether smokers and former smokers have worse lipid profiles or glucose levels than non-smokers remains unclear. METHODS The subjects were 1152 Japanese males aged 42 to 81 years. The subjects were divided according to their smoking habits (nonsmokers, former smokers, and current smokers) and their visceral fat area (VFA) (<100 cm(2) and ≥100 cm(2)). RESULTS The serum triglyceride (TG) levels of 835 males were assessed. In the VFA ≥100 cm(2) group, a significantly greater proportion of current smokers (47.3%) exhibited TG levels of ≥150 mg/dL compared with former smokers (36.4%) and non-smokers (18.8%). The difference in TG level distribution between former smokers and non-smokers was also significant. However, among the subjects with VFA of <100 cm(2), the TG levels of the three smoking habit groups did not differ. The serum hemoglobin A1c (HbA1c) levels of 877 males were also assessed. In the VFA <100 cm(2) group, significantly higher proportions of current smokers (17.9%) and former smokers (14.9%) demonstrated HbA1c levels of ≥5.6% compared with non-smokers (6.3%). In contrast, in the VFA ≥100 cm(2) group, significantly fewer former smokers displayed HbA1c levels of ≥5.6% compared with non-smokers and current smokers. Furthermore, the interaction between smoking habits and VFA was associated with the subjects' TG and HbA1c concentrations, and the associations of TG and HbA1c concentrations and smoking habits varied according to VFA. CONCLUSIONS Both smoking habits and VFA exhibited associations with TG and HbA1c concentrations. The associations between smoking habits and these parameters differed according to VFA.