US Poverty Drives CVD in Low-Income Adults Beyond Traditional Risk Factors

Rates of MI and deaths from CVD among US adults under age 65 who live below the poverty line are twice those of people with higher socioeconomic status, largely for reasons unrelated to traditional risk factors, new data suggest.

Among the 31.2 million adults aged 35 to 64 years with a household income below 150% of the federal poverty level or an educational level less than a high school diploma, factors such as smoking, hypertension, hypercholesterolemia, diabetes, and obesity account for only about 40% of the excess cardiovascular risk, said lead investigator Rita Hamad, MD, PhD (University of California, San Francisco).

“The remaining 60% is associated with poverty and all the things that go along with poverty: low education, potentially the stress of being in poverty, poor neighborhoods, etc. We didn't tease out what exactly all of those different factors were, but we found that it's not just that these low socioeconomic status people are more likely to engage in things that give them a higher burden of traditional risk factors,” Hamad told TCTMD.

While she wasn’t shocked by the numbers, some physicians might be.

“I think it might come as a surprise to realize that a lot of what we treat in the clinical setting is actually determined by all of these things outside of healthcare, these social and economic risk factors,” she observed. “We need to do a better job of integrating social services into healthcare settings, either by having a social worker who can refer people to the services they need or by doing increased screenings to better understand the risk factors that are driving this increased burden of disease.” Hamad added that the findings highlight the need for cross-sectoral interventions and policies that can address specific disparities that the healthcare system is not necessarily designed to do on its own.

In an editorial accompanying the study, George A. Mensah, MD (National Institutes of Health, Bethesda, MD), concurs that addressing traditional CVD risk factors is not enough to prevent premature CVD death.

“The time has now come to also tackle the social, environmental, and socioeconomic determinants of health and associated cardiovascular health disparities,” Mensah writes.

Social Conditions and Disease

For the study, published online May 27, 2020, in JAMA Cardiology, Hamad and colleagues used  computer simulations to project the excess burden of early CVD attributable to traditional risk factors versus factors associated with low socioeconomic status.

Compared with adults who had higher socioeconomic status, men living below the federal poverty level were more likely to smoke while women had worse metabolic indicators and diabetes. When the investigators simulated the impact of individual risk factors, “the potential improvement associated with addressing the independent risk of low socioeconomic status was greater than that for addressing any traditional risk factor alone,” Hamad et al write. Among the traditional risk factors, smoking cessation and diabetes prevention were associated with the highest chance at reducing excess risk in women.

Additional calculations among the youngest age group living in poverty (1.3 million adults aged 35 years in 2015) estimated that 250,000—or approximately 20%—would be expected to develop CVD by the time they reached age 65. Among those younger individuals, nearly half of their risk-factor burden exceeds what’s expected in people of similar age with higher socioeconomic status.

In his editorial, Mensah notes that tackling disparities is not as simple as providing equal access and equal care to all. “The persisting challenges in eliminating CVD disparities may be attributed, in part, to the paucity of interventions that address social determinants of health,” he writes.

According to Hamad and colleagues, interventions that solely target traditional risk factors, for example, could actually increase disparities and result in those in the higher socioeconomic status groups being more likely to benefit.

“Current prevention guidelines from the American College of Cardiology and American Heart Association highlight the importance of screening people for socioeconomic disadvantages that may hamper their ability to afford nutritious food or to engage in physical activity, although no recommendations are given for how to help those with a concerning screen,” Hamad and colleagues note. They say high-quality studies are needed to test downstream clinical interventions aimed at minimizing traditional risk among people living in poverty.

Although the research was conducted well before the advent of COVID-19, Hamad told TCTMD that greater understanding of the links between socioeconomic status and disease and how to optimize interventions have never been more relevant. Recent data suggest that minorities in the United States are being disproportionately affected by infections and deaths.

“We know that cardiovascular disease has come up again and again as a risk factor for severe COVID-19 illness,” Hamad said. “These low-income groups that are already being hard hit by cardiovascular disease now have another disease process that they're also even more at risk for because of all of the ways that COVID-19 and the shelter-in-place mitigating strategies affect lower socioeconomic status groups.”