Over the past 20 years, healthcare professionals have worked to reduce the incidence of heart disease across the U.S. But a new study published Tuesday in JAMA Cardiology suggests that low-income individuals haven't benefited as much from these efforts and remain highly vulnerable to develop heart disease.
Researchers found that low-income Americans were more likely to be diagnosed with cardiovascular disease compared with high-income Americans, who have seen heart disease incidences decline over a 15-year period.
"There is an increasing gap among high-income adults and low-income adults," said Ayodele Odutayo, lead author of the study and a graduate student at the University of Oxford.
Odutayo and her colleagues examined data from the National Health and Nutrition Examination Survey for 1999 to 2014, which combines interviews and physical examinations from participants.
From 2011 to 2014, about 16.5% of individuals at or below the federal poverty level had a 20% or higher risk for developing cardiovascular disease versus 9.5% of high-income individuals.
The percentage of risk for cardiovascular disease also decreased over the 15-year time period for high-income individuals compared with low-income individuals. From 1999 to 2014, the risk of cardiovascular disease declined by 2.5% for high-income individuals while the risk for the disease increased by 1.6% for low-income individuals.
The study also compared four risk factors for cardiovascular disease: smoking status, systolic blood pressure, diabetes and cholesterol.
Smoking and high blood pressure were more common among low-income individuals versus high-income individuals. From 2011 to 2014, 36% of low-income individuals smoked compared with 8.8% of high-income individuals. The study also found that over the 15-year period smoking hardly decreased among the low-income group—by just 0.5%—but dropped 5.3% among high-income individuals.
The incidence for diabetes increased across all income levels, but the prevalence of diabetes still remained higher for low-income individuals at just over 20% from 2011 to 2014 compared with about 10% for high-income individuals.
"Although diabetes is getting worse for everyone, it's more urgent among low-income people because they already have a higher prevalence for the disease," Odutayo said.
Insurance status likely contributes to low-income individuals' increased likelihood to develop cardiovascular disease, Odutayo said. Low-income individuals are also more likely to have health plans with high deductibles or premiums and narrower provider networks. This could prevent providers from addressing issues involving social determinants of health when treating low-income patients.
"Just the presence of insurance doesn't prevent against disease," Odutayo said.