Heart Health Outcomes Linked to Low Socioeconomic Status

Author(s):

Despite a decline in deaths from coronary heart disease (CHD) in the United States over the past 40 years, CHD is still the top cause of mortality in the United States—especially in low-income counties. Among individuals who live in these low-socioeconomic-status (SES) areas, which is close to 25% of the US population, myocardial infarctions (MIs) and CHD occurred twice as often compared with people who lived in higher SES areas.

After accounting for such traditional risk factors as smoking status; high body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), and blood pressure; and type 2 diabetes, the authors of a recent JAMA Cardiology study were able to show individuals classified as being of low SES still had an elevated risk of early CHD.

Their computer simulation study used data gleaned from the following sources to estimate the excess burden brought of early CHD-related outcomes among individuals with low SES, compared with high SES, who ranged in age from 35 to 64 years:

Cardiovascular Disease Policy Model (CDPM) was used to gather information on the incidence, prevalence, and mortality from CHD among US adults.
2015 American Community Survey was used to quantify low and high SES areas
2016 National Health and Nutrition Examination Survey was used to help define and stratify traditional risk factors for CHD by age and sex

For this study low SES was defined as “household income below 150% of the federal poverty level or educational level less than a high school diploma.” For 2020, this is $12,760 for an individual; $26,200 for a family/household of 4; or $44,120 for a family/household of 8.

The authors also used a relative risk of 1.58 (95% CI, 1.31-1.90), based on published data from the Atherosclerotic Risk in Communities study, to estimate the connection between low SES and incident CHD.

Overall, the patient population studied was made up of almost 31.2 million US adults with low SES status, and 51.3% were women. Having a low SES equated to higher rates of CHD death per 10,000 person-years among both men and women compared with their higher-SES counterparts: 16.6 (95% CI, 16.5-16.8) and 7.5 (95% CI, 7.4-7.6), respectively, versus 8.9 (95% CI, 8.9-9.0) and 3.4 (95% CI, 3.4-3.4). The low-SES group also had higher rates of smoking, and the women, in particular, had worse metabolic outcome predictors, such as higher BMI, increased LDL-C, and diabetes.

According to the simulation of years 2015 to 2024, which used data from the CDPM to estimate future risk outside of traditional risk factors, the rates per 10,000 person-years for MIs and death from CHD among low SES adults, women and men, were more than twice that of adults living in higher SES areas:

MI: Women: 15.1 (95% uncertainty interval [UI], 13.4-16.9) versus 6.8 (95% UI, 6.3-7.4) Men: 34.8 (95% UI, 31.0-38.8) versus 17.6 (95% UI, 16.0-18.6)
CHD deaths: Women: 5.6 (95% UI, 5.0-6.2) versus 2.5 (95% UI, 2.3-2.6) Men: 14.3 (95% UI, 13.0-15.7) vs 7.6 (95% UI, 7.3-7.9)

In addition, just 40% of the MI and CHD events in the low SES group can be attributed to the traditional risk factors mentioned above, which leaves 60% “attributable to other factors associated with low SES.” Also, according to the simulation, of the 1.3 million low-SES adults at least 35 years old in 2015, 19% have a greater likelihood of developing CHD before age 65. Almost half of those cases being above and beyond what is expected for comparable higher-SES adults.

The authors proffered 3 major reasons for their results:

Greater psychosocial stressors among low-SES adults that are related to chronic poverty
Economic and educational disparities that can restrict access to adequate health care, nutritious food, and safer neighborhoods
Social norms, in that healthier lifestyle choices are more frequently related to having a higher SES.

“This quantification provides insight into the magnitude of disparity between adults with low and those with higher SES that would remain even if traditional CHD risk factors were adequately addressed,” the authors determined. “These findings suggest that, although addressing traditional risk factors may decrease coronary heart disease, the disparities in disease burden will likely remain unless upstream factors associated with low socioeconomic status are addressed.”

They suggest high-quality studies that further investigate where the disparities lie. This way, interventions to can be better tailored to both minimize risk and improve SES as it relates to social determinants of health.

Reference

Hamad R, Penko J, Kazi DS, et al. Association of low socioeconomic status with premature coronary heart disease in US adults. JAMA Cardiol. Published online May 27, 2020. doi:10.1001/jamacardio.2020.1458