Exposure to Parental Smoking in Childhood Is Associated With Increased Risk of Carotid Atherosclerotic Plaque in Adulthood Epidemiology

and mediating variables, the relative risk of developing carotid plaque in adulthood increased among those children with 1 or both parents who smoked (relative risk, 1.7; 95% confidence interval, 1.0–2.8; P =0.04). Although children whose parents exercised good “smoking hygiene” (smoking parents whose children had nondetectable cotinine levels) had increased risk of carotid plaque compared with children with nonsmoking parents (relative risk, 1.6; 95% confidence interval, 0.6–4.0; P =0.34), children of smoking parents with poor smoking hygiene (smoking parents whose children had detectable serum cotinine levels) had substantially increased risk of plaque as adults (relative risk, 4.0; 95% confidence interval, 1.7–9.8; P =0.002). Conclusions —Children of parents who smoke have increased risk of developing carotid atherosclerotic plaque in adulthood. However, parents who exercise good smoking hygiene can lessen their child’s risk of developing plaque. ( Circulation . 2015;131:1239-1246. DOI: 10.1161/CIRCULATIONAHA.114.013485.)