Deaths from cardiovascular disease have stayed the same in the U.S. since 2010. This is not good news. The plateau follows a decades-long decline in cardiovascular deaths. What happened that halted the progress?

One reason may be the rise in cardiovascular risk factors such as diabetes, hypertension and high cholesterol among U.S. adults over the last 15 years.

The jump in these risk factors seems to reflect the increase in proportion of U.S. adults who are unaware of their risk for these conditions and so take no steps to prevent them from developing. A study by researchers from Harvard University and the University of Chicago has found that between 2013 and 2023 adults' awareness of their risk for these conditions dropped. Many did not know the numbers that point to a risk for cardiovascular disease, heart attack or stroke or neglected to be screened for them.

The proportion of adults between the ages of 20 and 44 who were unaware they had hypertension increased by more than 15 percent.

The pandemic may be one reason for this disconnect. During the pandemic, people's access to health care, including seeing their primary care provider and getting preventive screenings, was disrupted, Rishi Wadhera, corresponding author on the study, told TheDoctor. Because of this, “We were worried that unawareness of these risk factors for cardiovascular disease may have increased during the pandemic.”

This proved to be the case. When researchers used data from the National Health and Nutrition Examination Survey and looked at more than 15,200 adults 20 years old or older who had hypertension, diabetes or high cholesterol levels. If a person being surveyed had not been told by a doctor they had one of these risk factors, they were considered unaware of their risk.

The proportion of adults who were didn't know they had hypertension or who received a new prescription for an antihypertensive medication increased by more than three percent during the 10-year study period.

The proportion of women who were unaware they had hypertension also increased significantly — by more than five percent. This increase is concerning because when women come to a hospital with symptoms of a heart attack, they are often not diagnosed at first and are less likely to receive treatment, Wadhera said.

Younger people often think they don't need to see a doctor and get preventive screenings, but treating risk factors earlier in life can help prevent events like a heart attack or stroke later.

Survey respondents were divided by age into two groups: 20 to 44 years old and 45 years old and older. The proportion of adults between the ages of 20 and 44 who were unaware they had hypertension increased by more than 15 percent, a significant jump.

Young adults may think they don't need to see a doctor and get preventive screenings, but early diagnosis provides a big advantage. Treating risk factors earlier in life can help prevent events like a heart attack or stroke later, explained Wadhera, an associate professor of medicine at Harvard Medical School and an associate professor of health policy and management at Harvard T.H. Chan School of Public Health.

Even though adults' awareness of their risk of prediabetes, diabetes and cholesterol levels did not change significantly across age groups or between men and women, Wadhera, who is also associate director of the Richard A. and Susan F. Smith Center for Outcomes Research at Beth Israel Deaconess Medical Center, is interested in finding out why it has not improved.

The study is published in JAMA Cardiology.