O-46: Relationship of liver fat with cardiovascular risk in youth of South Asian, white, and African American ancestry: the CHAriSmA study
S Chung, N Malandrino, I N Kacker, R Townsend, I R Kamel, G Zandieh, R J McCarter, P B Barker, S C Hui, I Ozdemir, A Kelly, S N MaggeAbstract
Introduction
Individuals of South Asian (SA) ancestry have greater liver fat (LF) and cardiovascular (CV) risk than African Americans (AA) or Whites (W). LF independently predicts CV disease in adults. This association remains controversial in youth.
Objectives
We studied the relationship of LF with CV risk measures, i.e. arterial stiffness and the International Childhood Cardiovascular Cohort (i3C) derived hazard ratio (HR), in SA, AA and W adolescents and young adults (AYA).
Methods
A cross-sectional study of SA, AA and W AYA (12–21y), BMI ≥80%ile (BMI ≥23 kg/m2 if ≥18y). Arterial stiffness [pulse wave velocity (PWV, m/s), augmentation index at heart rate 75 (Aix75, %)] was obtained via tonometry. i3C HR was calculated using smoking, systolic blood pressure, BMI, total cholesterol and triglycerides z-scores. %LF was measured by 1H-MRS in a subset of participants. Generalized robust linear regression models determined the relationship of LF with CV risk.
Results
Of 156 AYA (Age 19.2±2.2y, BMI z-score 1.2±0.6kg/m2, mean±SD), 56% were female, 53 SA, 49 AA, 54 W. SA were 1.3y older. SA and AA had higher Aix75 than W (predicted marginal mean±SE: SA 17±2, AA 17±2, W 7±2; p for multiple comparisons≤0.006), with no difference in PWV (SA 5.4±0.1, AA 5.1±0.1, W 5.4±0.1; p≥0.06) or i3C HR (SA 1.36±0.08, AA 1.29±0.1, W 1.39±0.1; p≥0.50). %LF (N=96) was highest in SA (SA 2.0 [1.0, 5.3], AA 0.9[0.4, 1.9], W 0.9[0.4, 1.7], median[IQR], p≤0.01). 1-unit increase in %LF was associated with an increase of 2.5% in Aix75, 0.1 m/s in PWV, and 0.09-unit in i3C HR, adjusting for age, sex, Tanner stage, ancestry, mean arterial pressure (all p<0.05). The relationship of %LF with Aix75 and i3C HR remained significant after adjusting for atherogenic lipids, lipoproteins and C-reactive protein.
Conclusions
In SA, AA and W AYA, LF was related to CV risk independent of atherogenic lipids and inflammation. SA and AA had higher Aix75 than W. Our study suggests that in SA AYA, increased Aix75 is related to higher LF, independent of slightly higher age.