Abstract P252: Passive Smoking in Childhood and Mortality From Coronary Heart Disease in Adulthood Among Japanese Men and Women: The Jacc Study

Abstract

Background: Secondhand smoke exposure among adults is an established risk factor for cardiovascular disease, but little is known about the impact of passive smoking in childhood on risk of adverse cardiovascular outcome in adulthood. We examined whether childhood exposure to secondhand smoke is associated with mortality from coronary heart disease(CHD) in adulthood among Japanese men and women. Methods: We analyzed the data for 71,459 participants ( 31,027 men and 40,432 women) aged 40-79 years, with no history of CHD, stroke, or cancer at the baseline (1988-1990) and who completed a lifestyle questionnaire including the number of family members who smoked at home in childhood(0,1,2 and 3+ members) under the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study). Results: The sex-specific proportions of current smokers were 49.0% for 0 member, 54.3% for 1 member, 56.8% for 2 members and 59.3% for 3+members among men, and the respective proportions among women were 3.3%, 5.2%, 7.2%, and 11.2%.During the median follow-up of 18.9 years, a total of 955 (589 men and 366 women) deaths from CHD were reported. There was a dose-response relationship between the number of smoking family members at home and CHD mortality at adulthood among the middle aged (40-59 years); the multivariable HRs, adjusting for age, sex, history of hypertension and diabetes, body mass index, smoking status, alcohol consumption, hours of exercise and walking, perceived mental stress, educational level and employment status, were 1.05 (95% CI: 0.74, 1.48) for 1 family member, 1.27(0.83, 1.94) for 2 family members and 2.34(1.17, 4.68) for 3+ family members compared with no family member(p for trend=0.04). Such an association was not observed for the older persons aged 60-79 years.The excess CHD mortality associated with 3+ family members among the middle-aged was more evident among never or ex-smokers than among current smokers: the respective multivariable HRs were 3.74(1.40, 10.01) and 1.90(0.72, 5.06). Conclusions: Passive smoking exposure in childhood was associated with increased risk of mortality from CHD in adulthood, primarily for the middle aged men and non-current smokers.