Abstract P183: Contribution Of Childhood Risk Factors To Sex Differences In Adult Carotid Imt And Plaques: The Childhood Determinants Of Adult Health Study

Background: Understanding the origins of sex differences in cardiovascular diseases (CVD) may help with prevention. We examined sex differences in carotid artery IMT and plaques in adulthood including the contribution of childhood risk factors. Methods: Boys and girls aged 7-15 years old from the Australian Schools Health and Fitness Survey in 1985 were followed up in the Childhood Determinants of Adult Health study at ages 36-49 years between 2014-19. Sex differences in adult carotid IMT and plaques, identified with 2D ultrasound of left and right carotid arteries, were examined with linear and log binomial regression, respectively. Childhood sociodemographic, psychosocial, health-related behavioural and biomedical risk factors that might contribute to sex differences in carotid IMT/plaques were identified with purposeful model building. Results: Among 1,286 men and women with vascular measurements of carotid IMT (53% women, mean carotid IMT 0.63 mm ± 0.09 standard deviation) women had thinner carotid IMT measurements than men (β coefficients -0.053 95% CI -0.063, -0.043). Adjusting for age standardised waist circumference (WC), waist/hip ratio (WHR), waist/height ratio (WHtR) and systolic blood pressure (SBP) in childhood reduced the sex difference of carotid IMT in adulthood (see Figure), but a significant sex-difference in carotid IMT remained. Women had a 42% lower risk of plaques than men (Relative Risk 0.58 95% CI 0.42, 0.79). School achievement levels, endurance/power fitness and SBP in childhood partially explained the sex difference in the prevalence of plaques at adulthood (see Figure) as the sex difference decreased and became statistically insignificant. Conclusion: Various factors in childhood had contributed to thicker carotid IMT and higher prevalence of carotid plaques in men compared to women. These findings suggest that the origins of adult sex differences in CVD may begin in childhood. There may be benefits of sex-specific primary prevention programs starting in childhood.