Changes in weight, cardiovascular risk factors and estimated risk of coronary heart disease following smoking cessation in Japanese male workers: HIPOP-OHP study

Aim: It is well established that people gain weight after smoking cessation; however, changes in cardiovascular risk factors and the estimated risk of coronary heart disease following smoking cessation have yet to be fully clarified. Methods: The participants were 1,995 Japanese male workers at 11 workplaces who participated continuously in the High-risk and Population Strategy for Occupational Health Promotion (HIPOPOHP) study. Participants with a smoking habit had cardiovascular risk factors measured at baseline and over a 4-yr period. Their estimated incidence risk of coronary heart disease was calculated by a formula based on a previous cohort study. Results: Successful abstainers who had stopped smoking for at least 6 months at the end of the follow-up period had weight gains of approximately 2 kg. These subjects had significant worsening of the following factors compared to continuing smokers: systolic and diastolic blood pressure, total cholesterol, triglyceride and fasting blood sugar levels. In contrast, HDL-cholesterol levels improved significantly. When the overall instantaneous incidence risk of coronary heart disease prior to smoking cessation was assumed to be 1.00, the estimated risk was 0.76 (95%CI: 0.68-0.85) in successful abstainers due mainly to smoking cessation, despite weight gain. Conclusion: Although smoking cessation leads to weight gain, the estimated risk of coronary heart disease was decreased markedly by smoking cessation.