More than 60 years later, historic discriminatory housing policies are still associated with health disparities — specifically, ones involving cardiometabolic health disorders, according to a Houston Methodist Hospital researcher.

Using historic maps and contemporary prevalence data, Dr. Sadeer Al-Kindi and a team of researchers found significantly higher rates of coronary artery disease, stroke and chronic kidney disease in areas once bound by the segregation tactic known as redlining. They also found increased rates of obesity, diabetes and smoking.

"We did this study to learn more about the impact of intergenerational racism and segregation, to see if living in these previously redlined communities is an independent risk factor for poor cardiovascular health, separate from contemporary health and socioeconomic status," said Dr. Al-Kindi, associate director of Cardiovascular Prevention and Wellness at Houston Methodist Hospital and the study's principal investigator. "It turns out that yes, the harmful legacy of redlining can still be seen in the health care outcomes of these communities nearly 60 years after the practice was outlawed."

The associations remained even after accounting for age, comorbidities and other demographic and socioeconomic factors, according to the study, published in the Journal of the American College of Cardiology.

From the 1930s to the 1960s, the Home Owners' Loan Corporation (HOLC) created maps of nearly 200 U.S. cities based on racial and ethnic composition, housing conditions and environmental factors. Neighborhoods were ranked from A ("best") to D ("hazardous"), with the latter designated as "redlined" areas.

Redlined communities experienced severe disinvestment and marginalization and were often denied public and private funding, city services and other resources. Meanwhile, residents of redlined communities were largely prevented from accessing loans or buying property, trapping them in the under resourced areas.

"Multiple studies have shown that current residents of historically redlined communities still face higher rates of poverty, less access to health care and green space and even have higher rates of cancer," said Dr. Al Kindi. "Our study was the first to examine cardiometabolic outcomes in these communities, addressing a critical gap in knowledge that we can use to help craft meaningful interventions."

The study revealed that neighborhoods with poorer HOLC grades exhibited worse health outcomes. For instance, cholesterol screening rates were higher in better-graded areas (A: 88.4%, D: 84.0%), as were routine health visits (A: 78.2%, D: 76.0%). Conversely, the prevalence of uninsured adults was almost double in redlined areas (A: 10.5%, D: 21.4%).

Cardiometabolic risk factors also showed stark disparities. The prevalence of diabetes increased from 9.2% in A-graded areas to 13.5% in D-graded areas; obesity rates rose from 28.5% to 35.3%; and smoking rates climbed from 13.1% to 20.6%.

Statistically significant increases were noted in the prevalence of coronary artery disease (A: 5.3%, D: 6.2%), stroke (A: 2.9%, D: 4.2%) and chronic kidney disease (A: 2.7%, D: 3.6%). These associations persisted even after adjusting for factors like age, demographic composition, and environmental exposures, though the strength of the associations was somewhat attenuated.

"Although redlining was outlawed in the 1960s, I think this study shows that its legacy persists in various forms of subtle discrimination that shape socioeconomic and residential structures and perpetuate health inequities," Dr. Al-Kindi noted. "It also highlights the need for targeted public health interventions and policies aimed at mitigating the health disparities faced by residents of historically redlined neighborhoods."

Dr. Al-Kindi and colleagues from Case Western Reserve University, where he previously worked, have published multiple studies examining cardiometabolic health and historic redlining and have presented findings in public health forums across the country.