Cardiovascular risk reduction in African Americans: Current concepts and controversies

Ancestry specific associations of a genetic risk score, dietary patterns and metabolic syndrome: a longitudinal ARIC study

BACKGROUND

Associations have been observed among genetic variants, dietary patterns, and metabolic syndrome (MetS). A gap in knowledge is whether a genetic risk score (GRS) and dietary patterns interact to increase MetS risk among African Americans. We investigated whether MetS risk was influenced by interaction between a GRS and dietary patterns among Whites and African Americans. A secondary aim examined if molecular genetic clusterings differed by racial ancestry.

METHODS

We used longitudinal data over 4-visits (1987-1998) that included 10,681 participants aged 45-64y at baseline from the Atherosclerosis Risk in Communities study (8451 Whites and 2230 African Americans). We constructed a simple-count GRS as the linear weighted sum of high-risk alleles (0, 1, 2) from cardiovascular disease polymorphisms from the genome-wide association studies catalog associated with MetS risk. Three dietary patterns were determined by factor analysis of food frequency questionnaire data: Western, healthy, and high-fat dairy. MetS was defined according to the 2016 National Cholesterol Education Program Adult Treatment Panel III criteria but used 2017 American Heart Association/American College of Cardiology criteria for elevated blood pressure. Analyses included generalized linear model risk ratios (RR), 95% confidence intervals (CI), and Bonferroni correction for multiple testing.

RESULTS

The Western dietary pattern was associated with higher risk for MetS across increasing GRS tertiles among Whites (p < 0.017). The high-fat dairy pattern was protective against MetS, but its impact was most effective in the lowest GRS tertile in Whites (RR = 0.62; CI: 0.52-0.74) and African Americans (RR = 0.67; CI: 0.49-0.91). Among each racial group within GRS tertiles, the Western dietary pattern was associated with development and cycling of MetS status between visits, and the high-fat dairy pattern with being free from MetS (p < 0.017). The healthy dietary pattern was associated with higher risk of MetS among African Americans which may be explained by higher sucrose intake (p < 0.0001). Fewer genes, but more metabolic pathways for obesity, body fat distribution, and lipid and carbohydrate metabolism were identified in African Americans than Whites. Some polymorphisms were linked to the Western and high-fat dairy patterns.

CONCLUSION

The influence of dietary patterns on MetS risk appears to differ by genetic predisposition and racial ancestry.

Effective recruitment strategies for African-American men and women: the Nutritious Eating with Soul study

Previous studies have found it challenging to recruit African-American (AA) participants into health education research studies. The goal of this article is to describe the recruitment methods used for the Nutritious Eating with Soul (NEW Soul) study, a 2-year randomized behavioral health education intervention, conducted in two cohorts, with emphasis on methods used for reaching men. Participants indicated how they learned about the study on an online screening questionnaire from a list of the recruitment strategies we employed. Due to limited recruitment of men in Cohort 1, recruitment strategies for Cohort 2 focused on reaching men. Across the two cohorts, a total of 568 (23% men) participants completed the online screener and 159 (21% men) completed all baseline assessments and enrolled in the study. The most effective methods for completing screening questionnaires were radio ads, referrals from friends and family, TV interviews, social media posts and community events. Men were primarily recruited via radio ads, whereas women were more often recruited through TV and social media. Radio was an effective way to recruit AA adults into nutrition interventions, particularly men. In addition, low-cost methods, such as personal referrals, social media posts and community events were also effective strategies.

Racial and insurance disparities among patients presenting with chest pain in the US: 2009-2015

BACKGROUND

Nationally representative studies have shown significant racial and socioeconomic disparities in the triage and diagnostic evaluation of patients presenting to the emergency department (ED) with chest pain. However, these studies were conducted over a decade ago and have not been updated amidst growing awareness of healthcare disparities.

OBJECTIVE

We aimed to reevaluate the effect of race and insurance type on triage acuity and diagnostic testing to assess if these disparities persist.

METHODS

We identified ED visits for adults presenting with chest pain in the 2009-2015 National Hospital Ambulatory Health Care Surveys. Using weighted logistic regression, we examined associations between race and payment type with triage acuity and likelihood of ordering electrocardiography (ECG) or cardiac enzymes.

RESULTS

A total of 10,441 patients met inclusion criteria, corresponding to an estimated 51.4 million patients nationwide. When compared with white patients, black patients presenting with chest pain were less likely to have an ECG ordered (adjusted odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.69-0.99). Patients with Medicare, Medicaid, and no insurance were also less likely to have an ECG ordered compared to patients with private insurance (Medicare: OR = 0.79, CI = 0.63-0.99; Medicaid: OR = 0.67, CI = 0.53-0.84; no insurance: OR = 0.68, CI = 0.55-0.84). Those with Medicare and Medicaid were less likely to be triaged emergently (Medicare: OR = 0.84, CI = 0.71-0.99; Medicaid: OR = 0.76, CI = 0.64-0.91) and those with Medicare were less likely to have cardiac enzymes ordered (OR = 0.84, CI = 0.72-0.98).

CONCLUSIONS

Persistent racial and insurance disparities exist in the evaluation of chest pain in the ED. Compared to earlier studies, disparities in triage acuity and cardiac enzymes appear to have diminished, but disparities in ECG ordering have not. Given current Class I recommendations for ECGs on all patients presenting with chest pain emergently, our findings highlight the need for improvement in this area.

Racial disparities in cardiovascular disease risk: mechanisms of vascular dysfunction

Cardiovascular disease (CVD) accounts for a third of all deaths in the United States making it the leading cause of morbidity and mortality. Although CVD affects individuals of all races/ethnicities, the prevalence of CVD is highest in non-Hispanic black (BL) individuals relative to other populations. The mechanism(s) responsible for elevated CVD risk in the BL population remains incompletely understood. However, impaired vascular vasodilator capacity and exaggerated vascular vasoconstrictor responsiveness are likely contributing factors, both of which are present even in young, otherwise healthy BL individuals. Within this review, we highlight some historical and recent data, collected from our laboratories, of impaired vascular function, in terms of reduced vasodilator capacity and heightened vasoconstrictor responsiveness, in the peripheral and cerebral circulations in BL individuals. We provide data that such impairments may be related to elevated oxidative stress and subsequent reduction in nitric oxide bioavailability. In addition, divergent mechanisms of impaired vasodilatory capacity between BL men and women are discussed. Finally, we propose several directions where future research is needed to fill in knowledge gaps, which will allow for better understanding of the mechanisms contributing to impaired vascular function in this population. Ultimately, this information will allow for better lifestyle and therapeutic approaches to be implemented in an effort to minimize the increased CVD burden in the BL population.