Reporting Genetic Markers and the Social Determinants of Health in Clinical Cardiovascular Research-It Is Time to Recalibrate the Use of Race

Variations in how medical researchers report patient demographics: a retrospective analysis of published articles

Background

The use of demographic variables in the medical literature has been a topic of much recent debate. Recent studies found that race and socioeconomic status (SES) are inconsistently reported. Best-practice use of sex and gender has been contentious. We aimed to characterise the state of medical demographic reporting in greater detail, especially regarding geography and specific terms used in articles.

Methods

Original articles were included from issues of the New England Journal of Medicine (NEJM), JAMA, The Lancet, and the American Journal of Epidemiology (AJE) published from 1 January to 31 December 2020 (n = 640). Articles without human participants, case reports, or with only aggregate data were excluded, leaving 594 articles. Use of age, sex, gender, race, ethnicity, and SES were coded, as well as corresponding author and participant geography.

Findings

99.0% of articles reported age. While 92.9% reported sex alone, only 4.7% used the term gender and 1.0% transgender. 47.8% of articles reported race and 29.6% reported ethnicity. Studies with U.S. corresponding authors or participants were significantly more likely to report race (72.9% and 73.7% respectively) or ethnicity (47.3% and 45.3% respectively) than those without (25.9% and 25.6% for race, 14.2% and 16.3% for ethnicity), p < 0.01 for all. Of articles reporting race, 40.9% used only a Black-white binary; of those reporting ethnicity, 85.2% included two or fewer terms. Under 5.0% of all articles used Office of Management and Budget (OMB) categories. Across all articles, 33.0% reported SES, from 15.2% in NEJM to 80.2% in AJE.

Interpretation

We found that while some factors (age, sex) are reported consistently, others (gender, race, ethnicity, SES) are not, despite recent attention. Authors often rely on binary or limited categories that inadequately capture human diversity. The presence of U.S. researchers or participants increased the reporting of race and/or ethnicity, highlighting wide variations that persist even as multinational collaborations become widespread. Researchers should reflect on their use of these terms, justify their decisions, and report results with care.

Funding

None.

Social Determinants of Cardiovascular Disease

Social determinants of health (SDoH), which encompass the economic, social, environmental, and psychosocial factors that influence health, play a significant role in the development of cardiovascular disease (CVD) risk factors as well as CVD morbidity and mortality. The COVID-19 pandemic and the current social justice movement sparked by the death of George Floyd have laid bare long-existing health inequities in our society driven by SDoH. Despite a recent focus on these structural drivers of health disparities, the impact of SDoH on cardiovascular health and CVD outcomes remains understudied and incompletely understood. To further investigate the mechanisms connecting SDoH and CVD, and ultimately design targeted and effective interventions, it is important to foster interdisciplinary efforts that incorporate translational, epidemiological, and clinical research in examining SDoH-CVD relationships. This review aims to facilitate research coordination and intervention development by providing an evidence-based framework for SDoH rooted in the lived experiences of marginalized populations. Our framework highlights critical structural/socioeconomic, environmental, and psychosocial factors most strongly associated with CVD and explores several of the underlying biologic mechanisms connecting SDoH to CVD pathogenesis, including excess stress hormones, inflammation, immune cell function, and cellular aging. We present landmark studies and recent findings about SDoH in our framework, with careful consideration of the constructs and measures utilized. Finally, we provide a roadmap for future SDoH research focused on individual, clinical, and policy approaches directed towards developing multilevel community-engaged interventions to promote cardiovascular health.

Neighborhood Environment Associates with Trimethylamine-N-Oxide (TMAO) as a Cardiovascular Risk Marker

BACKGROUND

Neighborhoods and the microbiome are linked to cardiovascular disease (CVD), yet investigations to identify microbiome-related factors at neighborhood levels have not been widely investigated. We sought to explore relationships between neighborhood deprivation index (NDI) and the microbial metabolite, trimethylamine-N-oxide. We hypothesized that inflammatory markers and dietary intake would be mediators of the relationship.

METHODS

African-American adults at risk for CVD living in the Washington, DC area were recruited to participate in a cross-sectional community-based study. US census-based neighborhood deprivation index (NDI) measures (at the census-tract level) were determined. Serum samples were analyzed for CVD risk factors, cytokines, and the microbial metabolite, trimethylamine-N-oxide (TMAO). Self-reported dietary intake based on food groups was collected.

RESULTS

Study participants (n = 60) were predominantly female (93.3%), with a mean (SD) age of 60.83 (+/-10.52) years. Mean (SD) NDI was -1.54 (2.94), and mean (SD) TMAO level was 4.99 (9.65) µmol/L. Adjusting for CVD risk factors and BMI, NDI was positively associated with TMAO (β = 0.31, p = 0.02). Using mediation analysis, the relationship between NDI and TMAO was significantly mediated by TNF-α (60.15%) and interleukin)-1 β (IL; 49.96%). When controlling for clustering within neighborhoods, the NDI-TMAO association was no longer significant (β = 5.11, p = 0.11). However, the association between NDI and IL-1 β (β = 0.04, p = 0.004) and TNF-α (β = 0.17, p = 0.003) remained. Neither NDI nor TMAO was significantly associated with daily dietary intake. Conclusion and Relevance: Among a small sample of African-American adults at risk for CVD, there was a significant positive relationship with NDI and TMAO mediated by inflammation. These hypothesis-generating results are initial and need to be confirmed in larger studies.