Abstract P121: Varying Determinants of Endothelial Dysfunction by Age Group Among Mexican Americans

Endothelial dysfunction assessed by impaired brachial flow-mediated dilation (FMD) is a predictive factor of incident CVD. Most studies included small proportions of Hispanics or Latinos. We aimed to assess determinants of impaired FMD in a large population-based sample of asymptomatic Mexican-Americans. Methods: Cardiometabolic biomarkers, visceral adipose tissue (VAT), and FMD were obtained from 960 participants (57.9% females, mean age 52.1±0.9 years, age 18-85 years) from the Cameron County Hispanic Cohort. Sex-specific median values of %FMD were used to divide participants into two groups: those with FMD below (low %FMD) and above the median (high %FMD). The sample was further stratified into younger (age<55 years) and older (age ≥ 55 years) age groups. Survey-weighted logistic regression analyses were conducted to evaluate the effects of factors on the %FMD groups. Results: There was a high prevalence of obesity (49.1%), hypertension (47.8%), diabetes (26.1%), hypercholesterolemia (46.7%), and metabolic syndrome (38.2%). The median FMD response was 4.2%±0.3% [3.8% (SE 0.4) in males and 4.5% (SE 0.4) in females]. Low %FMD group was significantly older, had higher VAT, SBP, or plasma glucose levels, and had metabolic syndrome compared to those in the high %FMD group. Multivariable-adjusted age-stratified logistic regression analyses showed that among older participants, male gender [OR =2.4 (1.4-4.2)] and having hypertension [OR=2.3 (1.3-4.3)] or pre-diabetes [OR=3.4 (1.5-7.5)] remained significantly associated with odds of low %FMD. Among younger participants, only high LDL [OR=2.8 (1.6-4.9)] or having metabolic syndrome [OR=1.9 (1.1-3.6)] were significantly associated with odds of low %FMD. Conclusion: We found age-dependent associations between cardiometabolic biomarkers and an FMD response below the gender-specific median in a population composed of Mexican-Americans without prior CVD. Targeting specific risk factors by age may mitigate progression to incident CVD in this high-risk group.