Impact of smoking status on incident hypertension in a Japanese occupational population

Hypertension and tobacco smoking pose independent risks for cardiovascular diseases, but their association is unclear especially in Japanese. We investigated the impact of smoking status on the risk of new-onset hypertension in male and female Japanese workers. We evaluated 5439 subjects without hypertension who participated in medical check-ups in 2007-2018. The outcome was the development of hypertension (blood pressure ≥140/90 mmHg or initiation of antihypertensive drugs). Cox's proportional hazards models were used to assess the association between smoking status and the hypertension incidence. During the average 6.0-year follow-up, 1395 individuals (25.6%) developed hypertension. The crude incidence rates of hypertension (per 100 person-years) were: current non-smokers (n = 3033), 3.4; quitters (n = 445), 4.2; and sustained smokers (n = 1961), 5.7. The multivariable-adjusted hazard ratio was 1.34 (1.20-1.50) for sustained smokers and 1.03 (0.86-1.24) for quitters compared to current non-smokers (P for trend <0.01). In stratified analyses, the risk of incident hypertension was significantly higher in the sustained smokers with lower blood pressure or without diabetes at baseline versus the current non-smokers. A significant risk reduction of hypertension development due to smoking cessation was revealed in the subjects with higher blood pressure levels at baseline or without body weight gain after smoking cessation. Smoking was an independent risk factor for incident hypertension. Smoking cessation reduced the risk of hypertension development compared to sustained smoking, especially among the subjects with higher blood pressure levels. Maintaining one's body weight after smoking cessation would also help prevent hypertension development.