Poverty Status and Clustering of Cardiometabolic Risk Factors and Metabolic Syndrome among African Americans: Results from the National Health and Nutritional Examination Survey 2001-2006

Background: African Americans (AA) are disproportionally affected by cardiovascular disease as compared to other racial-ethnic groups. Exposure to adverse socioeconomic conditions may partially explain disparities in risk factors and prevalence and cardiovascular diseases for AA. We aim to study the impact of poverty status on metabolic syndrome (MetS) and its components among African Americans. Methods: We used data from the National Health and Nutritional Examination Survey (NHANES) cycles 2001-2006. We defined MetS using the Joint Scientific Definition as the presence of any 3/5 components: elevated blood pressure (BP), elevated triglycerides (TGL), lower high-density lipoprotein cholesterol (LDL), elevated fasting plasma glucose (FPG), and elevated waist circumference (WC). Poverty to income ratio (PIR) was categorized as below poverty (<1), above poverty (1 - 3) and high income (>3) groups. We used multivariable survey-weighted logistic regression models to study the impact of poverty status of prevalence of MetS and its components among AA men and women. Results: Overall, the average aggregate prevalence of MetS among AA sample was 22% in our study with prevalence being 25% for women and 18% among men (p < 0.001). In regression models, among women, living below poverty (PIR < 1) was associated with a higher prevalence/odds of having metabolic syndrome compared to those living in the high-income group (PIR > 3) (OR = 1.57, 95%CI = 1.00 - 2.46, p = 0.05) with no association observed among men (OR (PIR < 1 vs PIR >= 1) = 0.70, 95%CI = 0.43 - 1.19, p = 0.13). Further, similar associations were observed for individual components among women including: elevated waist circumference (OR = 2.04, 95%CI = 1.37, 3.01, p < 0.001), elevated triglycerides (OR = 1.85, 95%CI = 1.02 - 3.36, p = 0.04), reduced HDL (OR = 2.04, 95%CI = 1.15, 3.60, p = 0.02) and elevated blood pressure (OR = 2.16, 95%CI = 1.34 - 3.49, p = 0.002) as compared to women in high income group (PIR > 3). No association of poverty status with MetS and its components were observed among AA men. Clustering of factors identified key groups that define MetS among women included WC. Conclusion: African American women living below poverty have a higher likelihood of having MetS and 4 of 5 individual components. Clustering of these factors differ across men and women and should be further explored as tools for clinical management. Main Points: 1) Metabolic syndrome remains an important public health burden among African Americans and shows disparities by socioeconomic status; 2) Women living below poverty were more likely to have MetS and associated components as compared to women living above poverty; 3) Clustering of components gave us snapshot of factors that should be considered to develop gender specific targeted health interventions for MetS among African Americans.