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Cherrell Ball, certified medical assistant, takes Belzoni resident Sarah Ann Hood's blood pressure.
Cherrell Ball, certified medical assistant, takes Belzoni resident Sarah Ann Hood's blood pressure.
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JHS findings link one-third of heart disease, stroke cases to HTN

Published on Monday, October 28, 2019

By: Karen Bascom, kbascom@umc.edu

About one-third of heart disease and stroke cases in African-Americans are related to high blood pressure, according to research by physicians at the University of Mississippi Medical Center.

The study, which uses data from the Jackson Heart Study, was published in JAMA Cardiology October 23.

Several factors contribute to the risk of heart disease and stroke, such as type 2 diabetes, smoking and high cholesterol. But hypertension, or high blood pressure, is the top risk factor for these events, said Dr. Donald “Trey” Clark, assistant professor of medicine at UMMC and lead author of the study.

Portrait of Dr. Donald Clark
Clark

“It is well-established that hypertension is a leading contributor to cardiovascular disease, and we felt that is was important to gauge the impact of hypertension in this population,” Clark said.

To do this, the researchers calculated population attributable risk, or PAR, which estimates how many cases of a disease are related to a particular risk factor.

“PAR is valuable not only because it assesses the relationship between a risk factor and a disease, but also accounts for that risk factor’s prevalence in a population,” Clark said. This makes it useful for determining public health priorities. Slightly more than half of African American adults have hypertension in the United States.

Researchers studied the health records of more than 12,000 African-American adults from the Jackson Heart Study and the Reasons for Geographic and Racial Differences in Stroke study. During follow-up, about one in ten participants had a cardiovascular event during the study. Based on PAR, they found that 32.5 percent of these cardiovascular disease cases were related to high blood pressure.

“This means that, hypothetically, if we eliminated hypertension from this entire population, we expect to reduce cardiovascular disease by about a third,” Clark said.

In black adults under the age of 60, more than half of overall CVD events were linked with hypertension and 69% with stroke, specifically.

“This tells us that the burden of stroke in this younger population is largely attributed to hypertension,” Clark said.

The study is among the first to assess hypertension using the 2017 American College of Cardiology/American Heart Association guidelines for high blood measure, which established 130/80 mmHg as the threshold to diagnose hypertension .

Portrait of Dr. Adolfo Correa
Correa

“Using the new ACC/AHA blood pressure guidelines in this study allowed us to come up with a more accurate estimates of the prevalence of hypertension and of the proportion of CVD that can be attributed to hypertension among African-Americans,” said Dr. Adolfo Correa, director of the Jackson Heart Study and one of the co-authors of the paper.

The Jackson Heart Study is a collaboration between UMMC, Jackson State University, Tougaloo College, the Mississippi State Department of Health, the National Institutes of Health and Jackson-area participants. Its goal is to better understand the reasons for the high burden of heart disease in African Americans and develop strategies to promote heart health.

Regardless of race, there are several actions people can take to reduce their risk of developing high blood pressure.

“Lifestyle changes, such as getting regular physical activity, eating a DASH or Mediterranean-style diet, and/or decreasing alcohol intake can prevent or reduce hypertension,” Clark said.

Portrait of Dr. Paul Muntner
Muntner

“This study shows that we can have a dramatic effect, possibly preventing one-third of heart attacks, strokes and cases of heart failure, if people can do these things to prevent hypertension,”  said Dr. Paul Muntner, senior study author and professor of epidemiology at the University of Alabama-Birmingham.

The research was funded by the National Heart, Lung, and Blood Institute, the National Institute on Minority Health and Health Disparities, the National Institute of General Medical Sciences and the American Heart Association.