Parental Smoking in Childhood and Brachial Artery Flow-Mediated Dilatation in Young Adults: The Cardiovascular Risk in Young Finns Study and the Childhood Determinants of Adult Health Study

OBJECTIVE—Passive smoking has been associated with increased cardiovascular morbidity. The present study aimed to examine the long-term effects of childhood exposure to tobacco smoke on endothelium-dependent vasodilation in adults. METHODS AND RESULTS—The analyses were based on 2171 participants in the population-based Cardiovascular Risk in Young Finns (N=2067) and Childhood Determinants of Adult Health (N=104) studies who had measures of conventional risk factors (lipids, blood pressure, adiposity, socioeconomic status) and self-reported parental smoking status when aged 3 to 18 years at baseline. They were re-examined 19 to 27 years later when aged 28 to 45 years. Brachial artery flow-mediated dilatation was measured at follow-up with ultrasound. In analyses adjusting for age, sex, and childhood risk factors, flow-mediated dilatation was reduced among participants who had parents that smoked in youth compared to those whose parents did not smoke (Young Finns9.2±0.1% (mean±SEM) versus 8.6±0.1%, P=0.001; Childhood Determinants of Adult Health7.4±0.6% versus 4.9±0.9%, P=0.04). These effects remained after adjustment for adult risk factors including own smoking status (Young Finns, P=0.003; Childhood Determinants of Adult Health, P=0.03). CONCLUSION—Parental smoking in youth is associated with reduced flow-mediated dilatation in young adulthood measured over 20 years later. These findings suggest that passive exposure to cigarette smoke among children might cause irreversible impairment in endothelium-dependent vasodilation.