One person dies every 34 seconds from cardiovascular disease in the U.S., according to the Centers for Disease Control and Prevention, making it the leading cause of death for men, women, and people of most racial and ethnic groups and steady declines in cardiovascular mortality throughout the second half of the 20th century have stalled over the past decade.
- By JACQUELINE MITCHELL | Beth Israel Deaconess
Public health experts have expressed concern that these trends may reflect worsening cardiovascular health among younger adults in their 20s, 30s, and 40s.
However, no study to date has comprehensively evaluated changes in the prevalence of cardiovascular risk factors among this group, nor have recent trends among younger adults been examined by race and ethnicity.
In a study published March 5 in JAMA and presented at the American College of Cardiology Scientific Session, Harvard Medical School researchers at Beth Israel Deaconess Medical Center analyzed more than a decade's worth of data to examine rates of cardiovascular risk factors - such as high blood pressure, diabetes, obesity, and smoking - among U.S. adults from 2009 to March 2020.
They also looked at treatment rates for these risk factors and whether the treatments successfully controlled high blood pressure and elevated blood sugar. The researchers observed a rise in hypertension and significant increases in diabetes and obesity rates among young adults, with no significant improvement in control of blood pressure or blood sugar. The scientists also observed substantial variation in these trends by race and ethnicity.
"The onset of cardiovascular risk factors early in life is associated with a higher risk of heart disease and acute events, such as heart attack and stroke, resulting in a substantial loss of quality of life and years of life," said corresponding author Rishi Wadhera, HMS assistant professor of medicine and section head of health policy and equity research at the Smith Center for Outcomes Research in Cardiology at Beth Israel Deaconess. "Therefore, the substantial rise in the burden of cardiovascular risk factors among young adults will have major public health implications as the population ages."
This serial cross-sectional study included medical data and self-reported information from 12,924 young adults aged 20 to 44 who participated in the long-running National Health and Nutrition Examination Survey conducted by the CDC. The study population included 51 percent female, 57 percent white, 12 percent Mexican American, 8 percent other Hispanic, 13 percent Black, and 10 percent other race and ethnicities.
Wadhera and colleagues observed that the prevalence of hypertension increased from 9 percent during 2009-2010 to 12 percent a decade later. Similarly, the researchers saw statistically significant increases in rates of diabetes, which climbed from 3 to 4 percent, and obesity, which rose from 33 to 41 percent during the study period. The percentage of young adults with a smoking history was high and did not change.
In contrast, rates of high cholesterol declined from 41 percent in 2009-2010 to 36 percent in 2017-2020, a decrease the scientists suggest reflects government regulation of the use of trans fatty acids and other partially hydrogenated oils in packaged convenience foods and fast-food restaurants.
The researchers found substantial variation in prevalence of risk factors by race and ethnicity. Mexican Americans were the only group to experience a significant increase in diabetes. Obesity significantly increased across all racial and ethnic groups except Black adults. While rates of hypertension increased among Mexican Americans and other Hispanic adults, Black adults experienced the highest rates of hypertension.
"Hypertension prevalence in young Black adults was at least two times more likely than in all other racial and ethnic groups, with no improvement over the study period," said first author Rahul Aggarwal, HMS clinical fellow in medicine at Brigham and Women's Hospital and a research fellow at the Smith Center. "Black adults have high rates of stroke, heart failure, and hypertensive renal disease, as well as the highest premature cardiovascular mortality rates in the country - in part due to a high burden of hypertension. These inequities are rooted in structural racism. Scalable and realistic solutions are needed - both community-based programs and large-scale health system initiatives that screen for and treat uncontrolled blood pressure in young Black adults, in combination with concerted policy efforts to address socioeconomic disparities."
The researchers also examined cardiovascular risk factor treatment and control rates among young adults. Treatment rates for hypertension did not significantly change during the study, with approximately 55 percent of young adults with high blood pressure receiving treatment. However, among those receiving treatment, more than three-quarters achieved target blood pressure in 2017-2020. Rates of diabetes treatment were also low, with one out of two young adults on therapy for diabetes. Nearly half of young adults on treatment for diabetes had poor blood sugar control.
"The suboptimal treatment rates for high blood pressure and diabetes are concerning and may be because many young adults aren't aware of their diagnosis," said Wadhera. "The rise in cardiovascular risk factors that we observed could result in higher lifetime rates of heart attack, stroke, and heart failure, and have major public health implications over the long term. Our findings should be a call to action to intensify public health and clinical interventions focused on the prevention and treatment of cardiovascular risk factors in young adults."
Authorship, funding, disclosures
Co-authors included Robert Yeh of Beth Israel Deaconess and Karen Joynt Maddox of Washington University School of Medicine.
This study was funded by the National Heart, Lung, and Blood Institute (NHBLI) (grant R01HL164561).
Yeh receives research support from the NHBLI and from the Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology and receives personal fees from Biosense Webster, grants and personal fees from Abbott Vascular, AstraZeneca, Boston Scientific, and Medtronic, outside the submitted work. Wadhera receives research support from the NHBLI. He currently serves as a consultant for Abbott and CVS Health, outside the submitted work. For a complete list of disclosures, please see the publication.
