An association between smoking habits and blood pressure in normotensive Japanese men: a 5-year follow-up study.
BACKGROUND
There are few studies on the effects of smoking on blood pressure (BP) that consider confounding factors such as age, obesity, lifestyle and blood chemistry. As such, we conducted a 5-year follow-up study to clarify the effects of smoking habits on blood pressure in normotensive Japanese men.


METHODS
The subjects were 2107 normotensive male steelworkers aged 40-54 years. They were classified using three indices: smoking habits in 1990, changes in smoking habits, and changes in amount of smoking. The associations between these indices and changes in blood pressure were evaluated using analysis of covariance (ANCOVA). As analyses, BMI, salt intake, physical activity, drinking habit, and results of blood chemistry in 1990 and their changes, age and blood pressure in 1990 were used as covariates.


RESULTS
The cumulative incidence of hypertension in smokers was lower than in non- and ex-smokers. The adjusted mean of change in blood pressure of smokers was significantly lower than in non- and ex-smokers. No significant difference between non-smokers and ex-smokers, or among groups of smokers who varied their amount of smoking was observed.


CONCLUSIONS
Chronic smoking reduces changes in blood pressure and 5-year cumulative incidence of hypertension. However, no significant dose-dependent effect of smoking on changes in blood pressure was observed.
Okubo
Yasushi
Y
Department of Occupational and Environmental Medicine (A2), Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. ookubo@med.m.chiba-u.ac.jp
Suwazono
Yasushi
Y
Kobayashi
Etsuko
E
Nogawa
Koji
K
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005500:Follow-Up Studies; D006184:Habits; D006801:Humans; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology*; D012907:Smoking / Q000208:ethnology*
D009538:Nicotine