Disease Linked to Untreated Risk Factors in Second and Third Decades of Life
As many as 1 in 100 black men and women develop heart failure before the age of 50, 20 times the rate in whites in this age group, according to new findings from the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. In the study, heart failure developed in black participants at an average age of 39, often preceded by risk factors such as high blood pressure, obesity, and chronic kidney disease 10 to 20 years earlier.
Findings from the 20-year observational study Coronary Artery Risk Development in Young Adults study (CARDIA) are published in the March 19 issue of the New England Journal of Medicine.
By the tenth year of the study, when participants were between ages 28 and 40, 87 percent of black participants who later developed heart failure had untreated or poorly controlled high blood pressure. Black participants who developed heart failure were also more likely in their young adulthood to be obese and have diabetes and chronic kidney disease. Furthermore, 10 years before developing heart failure, they were more likely already to have some level of systolic dysfunction, or impairment in the ability of the heart muscle to contract, visible on echocardiograms.
"The disproportionate rate at which heart failure impacts relatively young African-Americans in this country underscores the importance of recognizing and treating risk factors for heart disease," said Elizabeth G. Nabel, M.D., director, NHLBI.
With heart failure, the heart loses its ability to pump enough blood through the body. The life-threatening condition usually develops over several years. The leading causes of heart failure are coronary artery disease, high blood pressure, and diabetes. About 5 million people in the United States have heart failure, and it results in about 300,000 deaths each year.
CARDIA includes 5,115 black and white men and women (52 percent black, 55 percent women) who were age 18-30 at the start of the study in 1985 and 1986, recruited from Birmingham, Ala., Chicago, Minneapolis, and Oakland, Calif. Participants were followed for 20 years, with physical exams conducted every few years and telephone interviews every six months. Twenty-seven men and women developed heart failure; all but one were black.
Higher blood pressure, greater body mass index, lower HDL (or "good" cholesterol), and chronic kidney disease were all independent predictors at ages 18 to 30 of heart failure developing 15 years later.
"Through this long-term study, we saw the clear links between the development of risk factors and the onset of disease one to two decades later. Targeting these risk factors for screening and treatment during young adulthood could be important for heart failure prevention," said Kirsten Bibbins-Domingo, PhD, MD, study author, University of California, San Francisco.
The study found that each 10 mmHg increase in diastolic blood pressure among blacks in their 20s doubles the likelihood of developing heart failure 10 to 20 years later.
"This study shows how devastating high blood pressure in young adulthood, especially if uncontrolled, can be for developing heart failure later on. Unfortunately, we know from national data that younger adults with high blood pressure are often unaware that they have the condition, and even when they are aware, their blood pressure is often not controlled," said Gina Wei, MD, medical officer, CARDIA study, NHLBI.
The CARDIA study recruited men and women who reported their races as either non-Hispanic black or non-Hispanic white. The term African American was not used.
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