Parental smoking and vascular damage in young adult offspring: is early life exposure critical? The atherosclerosis risk in young adults study.

Objective: Our purpose was to study the association between familial and particularly fetal tobacco smoke exposure and vascular damage in young adulthood.

Methods And Results: From a cohort of 732 young adults, birth data were collected and in young adulthood ultrasound measurement of common carotid artery intima-media thickness (CIMT) was performed. Data on parental smoking were obtained by standardized questionnaires. Twenty-nine percent of the mothers smoked during pregnancy. Offspring of mothers who smoked had 13.4 microm thicker CIMT (95% CI: 5.5, 21.3; P=0.001) than offspring of mothers who did not smoke in pregnancy. Adjustment for known CIMT risk factors (participant's age, gender, BMI, pulse pressure, and LDL-cholesterol) yielded no change (9.4 microm, 95% CI: 1.9, 16.3, P=0.01) nor did adjustment for current smoking of parents (10.6 microm, 95% CI: 0.4 to 20.8, P=0.04), for participants' current smoking and pack-years (11.5 microm, 95% CI: 3.5 to 19.4, P=0.004) or for parental socioeconomic status (SES; 13.0 microm, 95% CI: 5.0, 21.1, P=0.002). Thicker CIMT was associated with exclusive paternal smoking in pregnancy, somewhat stronger with exclusive maternal smoking and strongest with both parents smoking (P (linear trend)=0.001). Offspring of particularly mothers who smoked an above median number of cigarettes in pregnancy had thicker CIMT than those smoking less than median or no cigarettes (P (linear trend) <0.0001).

Conclusions: Permanent vascular damage is partly attributable to familial tobacco smoke exposure, an association that might be initiated in gestation.