Neighborhood redlining leaves lasting imprint on heart health

Decades after racially discriminatory housing and lending practices were banned, new research suggests that historic neighborhood redlining continues to affect cardiometabolic health and associated risk factors.

“Policies that were initiated in the 1930s continue to have a truly significant impact on shaping the cardiovascular health of an entire nation,” said lead author Sadeer Al-Kindi, MD, Case Western Reserve University School. of Medicine, Cleveland, Ohio.

“We’re hoping to shed some more light on this, so that we can hopefully move the needle towards improving health outcomes and reducing disparities,” he said. lecoeur.org | Medscape Cardiology.

The term redlining comes from the Home Owners’ Loan Corporation (HOLC) color-coded 1930s federal maps that ranked the creditworthiness of neighborhoods in nearly 200 cities across the United States. Areas were categorized as A (“best” or green), B (“still desirable” or blue), C (“definitely in decline” or yellow), and D (“dangerous” or red).

While redlining was banned in the 1960s, it has reinforced segregation in American cities for generations and has been linked to contemporary health inequalities, including asthmacertain types of cancer, premature birthmental health and other chronic illnesses.

A MESA 2021 analysis of about 4,800 adults in six U.S. cities found that black adults living in historically demarcated areas had lower heart health scores than blacks in green A-rated areas.

This study extends this work by examining health indicators in CDC PLACES Database for 38.5 million U.S. residents in 11,178 HOLC-classified census tracts in the Midwest, Northeast, South, and West. The researchers also linked census tract-level exposure to particles larger than 2.5 µm and diesel particulates as potential environmental confounders.

In each region, the percentage of black and Hispanic residents was lowest in green HOLC areas (13.2% and 8.5%, respectively) and highest in red HOLC areas (32.2% and 28, 8%, respectively).

As posted on July 4 in the Journal of the American College of Cardiologysignificant increases were seen in HOLC grades from green to red in the prevalence of: diabetes (9.2% to 13.5%), smoking (13.1% to 20.6%), obesity (28.5% to 36.3%), hypertension (30.0% to 33.6%), coronary artery disease [CAD] (5.3% to 6.2%), stroke (2.9% to 4.2%) and chronic kidney disease [CKD] (2.7% to 3.6%; P <.001 for all only hypercholesterolemia went in the opposite direction going from green zones to red>P

Associations between neighborhood areas and coronary artery disease, stroke, and CKD were weak but remained statistically significant in the fully adjusted model, which included comorbidities, risk factors, demographic composition, as well as environmental exposures .

The associations were largely uniform from region to region; however, the southern and northeastern states had the largest gap between HOLC red and green zones for CAD (1.8% vs. 41.5%), stroke (23.3% vs. 86, 2%) and CRI (18.5% versus 59.3%).

“That’s what I expected, but I didn’t expect the magnitude of the association to be so strong,” Al-Kindi said. “But this is consistent with previous studies that have shown a relationship between various health outcomes, lung disease, other illnesses, within each neighborhood risk category.”

The observational study cannot explain the reasons for the disparities, but they may be related to lack of access to care, unhealthy behaviors, psychological stress due to racial discrimination and financial constraints, and disproportionately higher exposures. raised to nearby sources of environmental pollution, he noted.

“We adjusted for air pollution and diesel exhaust and found that there is an attenuation of the relationship, suggesting at least preliminary that some of these relationships can also be explained. by relationships or disparities in environmental exposures,” he said. . “We call it ‘environmental racism’.”

One of the areas researchers are currently working on is identifying in redlined vs. non-redlined neighborhoods how various factors interact with each other, including air pollution, environmental urban design, toxicity of soil/environment and, above all, gun violence, Al-Kindi said.

“I think there’s a neighborhood effect to some degree,” he said. “This neighborhood effect could be a combination of all of the above and requires further study as a marker of cardiovascular disease, both for prediction but also to identify gaps so we can address it.”

Although the 2021 MESA analysis suggested that living in historically demarcated neighborhoods was only associated with cardiovascular health among black people, data was not available to model differences between racial and ethnic minorities, said Al-Kindi.

Other limitations include self-reported health outcomes in the PLACES database; unmeasured confounders such as behavioral and genetic factors; and the fact that the definition of redlining census tract boundaries has not been standardized across studies.

Commenting for lecoeur.org | Medscape Cardiology, Keith B. Churchill, MD, president of Yale New Haven Hospital, New Haven, Connecticut, said he would like to dig deeper into the differential data between southern and northeastern states and why cholesterol was moving in the direction opposed to other cardiometabolic risk factors. But the aggregate data, he said, is not surprising.

“It’s probably more of a confirmation than a surprise,” he said. “But I agree with their conclusion that there is a real need for microanalysis in these particular areas and populations regarding access to care, healthy food issues, overall household value, economics that constantly motivates him and the general environment in the field, and then brainstorm solutions to those particular problems.”

Given the scale of the problem, Churchill said it would not only take a lot of time and intellectual expertise to really untangle the problems and think of solutions, but that the financial impact of putting solutions in place on the table would be important.

“I think, most importantly, it really means being very aggressive in our recognition of issues around the social determinants of health and gender and how they impact our overall health and our cardiometabolic health,” Churchill said. “And, doing what we can on an individual basis to not only identify but also work on the steps from a clinical perspective, from a medical perspective and from an environmental perspective. [These are areas] over which we have some control [in our ongoing efforts] to improve the overall health and well-being of the patients and populations we serve. »

The authors and Churchill do not report any relevant financial relationship.

J Am Coll Cardiol. Published online July 4, 2022. Summary

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