Excess Adiposity in Youth: Subclinical Cardiovascular Disease and Future Implications

Abstract

Excess adiposity remains a serious public health threat; 33% of U.S. adolescents are classified as having overweight or obesity. Adolescent obesity is associated with a 3.5 times higher lifetime risk of cardiovascular disease (CVD) mortality, thus subclinical CVD phenotypes such as carotid intima-media thickness (cIMT) have become widely accepted as relevant to earlier stages of CVD in youth. In the first manuscript, we developed a risk prediction model that predicted cIMT in middle adulthood using relevant CVD risk factors in adolescence. Longitudinal associations were observed between most CVD risk factors in adolescence and increased cIMT in middle adulthood; our risk prediction model poorly predicted cIMT in middle adulthood based on discrimination and calibration metrics. In the second manuscript, we contrasted longitudinal data from two bi-racial cohort studies by examining the association between CVD risk factors and cIMT in two distinct periods of life. Higher body mass index was associated with an increased cIMT in the younger cohort. In the older cohort, no association was present between body mass index and cIMT; higher systolic blood pressure was associated with increased cIMT. The American Heart Association set 2020 Strategic Impact Goals that defined CVD risk factors to include in the concept of ideal cardiovascular health (ICH). In the final manuscript, we examined the prevalence of ICH by adiposity level in youth, including severe obesity. We then generated a continuous ICH sample z-score, and examined the distribution of the ICH sample z-score by adiposity level in youth. Children with overweight/obesity and severe obesity had lower ICH sample z-scores than those with normal weight. Taken together, these three projects provide insight into the relationship between excess adiposity and subclinical CVD and cardiovascular health in youth. In addition, this dissertation considers metrics that have the potential to address excess adiposity prevention efforts in youth.