Heart failure risk doubles with severe obesity

Even after accounting for hypertension, dyslipidemia, and diabetes, obesity appears to be a standalone risk factor for heart failure—although not for other major types of cardiovascular disease (CVD)—according to a prospective community-based study of more than 13,700 people.

This study, published in the Journal of the American Heart Association, showed that people with severe obesity have nearly twice the risk of heart failure than people with a healthy body-mass index (BMI), yet obese individuals have no greater risk for coronary heart disease or stroke.

“Obesity in our study has emerged as one of the least explained and likely most challenging risk factors for heart failure because there is no magic pill to treat it, no drugs that can easily address the problem like there are for high cholesterol and high blood pressure,” said study author Chiadi Ndumele, MD, MHS, Assistant Professor of Medicine and member of the Ciccarone Center for the Prevention of Heart Disease at the Johns Hopkins University School of Medicine in Baltimore, MD.

Weight control helps to prevent CVD. But even with diet and exercise, “people struggle to lose weight and keep it off, and for the morbidly obese, the struggle is often insurmountable,” Dr. Ndumele said.

Consequently, greater emphasis has been placed on controlling the traditional risk factors for reducing cardiovascular risk in people with obesity. However, there are conflicting data whether the relationships of obesity with coronary heart disease and stroke are independent of established risk factors for CVD.

To gain a better understanding of these relationships, Dr. Ndumele and colleagues reviewed data on 13,730 participants in the Atherosclerosis Risk in Communities (ARIC) study. Participants’ average age was 54 and their BMIs ranged from 18 to 50. Nearly two-thirds of participants were women and about 17% were African-American. None had CVD at baseline.

At the end of about 23 years of follow-up, the researchers had recorded 2,235 cases of heart failure, 1,653 cases of coronary heart disease, and 986 strokes.

After the researchers adjusted for age, gender, race, education level, career, smoking, physical activity, and alcohol intake, they found that severe obesity was linked to a nearly four-fold higher risk of heart failure and about a two-fold higher risk for coronary heart disease and stroke when compared with rates for people with a healthy BMI.

After further adjustment for traditional heart disease risk factors of diabetes, hypertension, and dyslipidemia, severe obesity was no longer associated with risks for coronary heart disease and stroke. However, the link between obesity and heart failure risk remained. In fact, every 5-unit increase in BMI was associated with a 29% higher risk of heart failure, the researchers found. 

“Even if my patients have normal blood sugar, cholesterol, and blood pressure levels, I believe I still have to worry that they may develop heart failure if they are severely obese,” Dr. Ndumele said. “If our data are confirmed, we need to improve our strategies for heart failure prevention in this population.”