Increasing Numbers of US Adults Don’t Know They Have Diabetes, High Blood Pressure or High Cholesterol, Study Shows

BOSTON – In a new report published in JAMA Cardiology, health policy experts at Richard A. and Susan F. Smith Center for Outcomes Research at Beth Israel Deaconess Medical Center (BIDMC) showed that many US adults are unaware they have high blood pressure, diabetes and high cholesterol—three major risk factors for cardiovascular disease and death. Moreover, the investigators showed the proportions of Americans who do not know they have hypertension have increased over the past decade, especially among younger adults and women.

“Young adults were the most likely to not realize that they had high blood pressure, diabetes, or high cholesterol,” said Rishi Wadhera, MD, MPP, MPhil, associate director of the Smith Center, and an associate professor at Harvard Medical School. “It’s especially concerning that one in three young adults were unaware of their high blood pressure, two in five didn’t know they had diabetes, and one in four were unaware of having high cholesterol. That’s a major public health issue.”

Cardiovascular disease is the leading cause of death in the United States, now responsible for roughly one in every three deaths, according to the Centers for Disease Control and Prevention (CDC). In the 1960s, cardiac mortality rates peaked at nearly 50 percent, but decades of medical and surgical innovations as well as public health campaigns regarding smoking, nutrition and exercise guidelines, drove a steep and steady decline. But today, cardiovascular mortality is on the rise again, with particularly sharp increases among younger adults and women under 55.

Wadhera and colleagues used data from a long-running, nationally representative survey to assess the proportion of adults unaware of their hypertension (high blood pressure), diabetes, or high cholesterol, and then compared how that proportion may have changed from 2013-24 to 2021-23. Known as NHANES, the CDC-run National Health and Nutrition Examination Survey combines interviews and physical examinations to assess the health and nutritional status of adults and children in the United States to provide the critical data necessary to guide public health policy, track disease trends, and shape national health guidelines.

The team’s analysis included more than 15,000 adults, mostly middle-aged, who had at least one of the risk factors during physical examination and/or laboratory testing. Overall, the proportion of adults who were found to have hypertension—a chronic condition which is often symptomless — but were unaware of their condition increased significantly during the ten-year study period. The proportion of adults unaware they had diabetes and high cholesterol did not change.

However, when Wadhera and colleagues zoomed in on participants’ age groups, they saw that the increase in unawareness about hypertension was only among younger adults, ages 20 to 44. There was no change in awareness among adults older than 45. Similarly, when they broke out the data by sex, they saw that the proportion of women who were unaware they had hypertension rose over the ten-year study period—a change not observed among men.

“Awareness may have worsened in these populations due to barriers to accessing primary care and preventive services,” said Daniel Johnson, lead author of the study and research fellow at the Smith Center. “Young adults, in particular, may underestimate the future risk of cardiovascular disease and, in turn, underestimate the benefits of routine health screenings.”

“Given declining heart health in young adults, it’s critical that we intensify public health messaging to this group on the importance of screening for high blood pressure, diabetes, and high cholesterol,” said Wadhera. “We need to address gaps in awareness early in life to prevent the onset of cardiovascular disease, or worse, later in life.”

Lucas X Marinacci was co-author. This research was supported by the Sarnoff Cardiovascular Research Foundation; the American Heart Association Established Investigator Award (24EIA1258487) and the National Heart, Lung, and Blood Institute (RO1HL164561).

Dr. Marinacci reported receiving a grant from the National Institutes of Health during the conduct of this study. Dr. Wadhera reported receiving grants from the National Heart, Lung, and Blood Institute during the conduct of the study and personal fees from Chamber Cardio and Abbott Vascular outside the submitted work. No other disclosures were reported.