Association of environmental tobacco smoke exposure with elevated home blood pressure in Japanese women: the Ohasama study

OBJECTIVE: Only a few of numerous epidemiological studies have demonstrated a positive association between environmental tobacco smoke (ETS) exposure and blood pressure (BP), despite experimental studies showing such a positive association. The association between home blood pressure (HBP) and ETS exposure was investigated in the general population. METHODS: Five hundred and seventy-nine nonsmoking Japanese women were enrolled. The participants were classified into four categories according to their responses to a self-administered questionnaire: unexposed women (non-ETS), women exposed at home ETS(home), at the workplace/other places ETS(work/other) and at home and at the workplace/other places ETS(both). Variables were compared using analysis of covariance adjusted for age, marital status, body mass index, diabetes mellitus, stroke, heart disease, hyperlipidemia, alcohol intake, salt intake and activity levels. RESULTS: In participants without antihypertensive medication, systolic morning HBP in ETS(both) was 4 mmHg higher than that in non-ETS (116.8 +/- 1.01 vs. 113.1 +/- 1.08 mmHg, P = 0.02) and systolic morning HBP in ETS(home) and systolic evening HBP in ETS(both) were 3 mmHg higher than those in non-ETS (116.2 +/- 1.07 vs. 113.1 +/- 1.08 mmHg, P = 0.04; and 115.3 +/- 1.02 vs. 111.9 +/- 1.09 mmHg, P = 0.03, respectively). In participants with antihypertensive medication, ETS exposure status was not significantly associated with increased HBP levels. CONCLUSIONS: A positive association between HBP levels and ETS exposure was confirmed. HBP measurement is recommended in population-based studies investigating the effects of ETS exposure. ETS exposure may increase BP, thereby synergistically contributing to unfavorable cardiovascular outcomes along with other deleterious effects of ETS.