DALLAS, Texas — A little extra “padding” around the belly doesn’t necessarily mean someone is obese. In fact, body mass index (BMI) shows that healthy weight individuals can come in all shapes and sizes. Unfortunately, researchers warn that carrying more weight around the midsection can still increase a person’s risk for heart disease.
“This scientific statement provides the most recent research and information on the relationship between obesity and obesity treatment in coronary heart disease, heart failure and arrhythmias,” says Tiffany M. Powell-Wiley, M.D., M.P.H., FAHA, in a release from the American Heart Association. “The timing of this information is important because the obesity epidemic contributes significantly to the global burden of cardiovascular disease and numerous chronic health conditions that also impact heart disease.”
VAT? What is that?
The team from the National Institutes of Health say there’s more that goes into obesity’s link to cardiovascular health than just overall BMI. The study highlights the impact of abdominal obesity, or visceral adipose tissue (VAT), on heart health. Doctors commonly determine VAT through waist circumference, or waist-to-hip ratio. Previous research has proven that VAT can predict heart failure and death, independently of the patient’s BMI.
Researchers recommend that doctors document both abdominal measurement and BMI during regular health care visits. Abdominal obesity, even in healthy weight people, also has a link to fat buildup around the liver. This can cause non-alcoholic fatty liver disease, another trigger for heart disease.
“Studies that have examined the relationship between abdominal fat and cardiovascular outcomes confirm that visceral fat is a clear health hazard,” Powell-Wiley adds.
The new report finds the health risks surrounding VAT are so strong, they may even outweigh typical obesity risks. Study authors note patients who are overweight or obese but have low levels of fat around the midsection could have lower heart disease risks than others. However, researchers caution that the concept of “metabolically healthy obesity” differs depending on sex and ethnicity.
How can people get rid of their belly fat?
Researchers estimate there are about three billion people who classify as overweight (BMI between 25-29.9) or obese (BMI over 30). Obesity is a complex condition, which can depend on biological, psychological, environmental, and even societal factors. Obesity also contributes to greater risks for coronary artery disease, high cholesterol, diabetes, high blood pressure, and sleep disorders.
For their report, the team evaluated research on managing or treating obesity — and particularly visceral adipose tissue. Their review finds reducing calories and aerobic exercise are the best ways to reduce abdominal fat. Researchers say just meeting the current recommendation of 150 minutes of physical activity per week will accomplish this. They add that even if some individuals don’t experience noticeable weight loss, the combination of dietary changes and physical activity can lead to less belly fat.
Study authors point out these changes also help to improve blood sugar, blood pressure, and cholesterol levels. However, some studies find lifestyle change programs don’t result in fewer coronary events, such as a heart attack.
On the other hand, the report reveals bariatric surgery for weight loss does lead to a lower risk of developing coronary artery disease. The difference may come from the larger amounts of weight being removed during bariatric surgery.
“Additional work is needed to identify effective interventions for patients with obesity that improve cardiovascular disease outcomes and reduce cardiovascular disease mortality, as is seen with bariatric surgery,” notes Powell-Wiley, chief of the Social Determinants of Obesity and Cardiovascular Risk Laboratory in NIH’s Division of Intramural Research at the National Heart, Lung, and Blood Institute.
Solving the ‘obesity paradox’
Although overweight and obese populations possess strong risk factors for developing cardiovascular disease, studies find they’re not always at high risk for suffering negative coronary events. This is what scientists refer to as the “obesity paradox.”
Study authors say one of the reasons for this is likely that overweight people generally get screened earlier for heart disease than people with a healthy weight. This leads to them receiving earlier diagnoses and treatments for any heart issues.
“The underlying mechanisms for the obesity paradox remain unclear,” Powell-Wiley explains. “Despite the existence of the paradox for short-term cardiovascular disease outcomes, the data show that patients with overweight or obesity suffer from cardiovascular disease events at an earlier age, live with cardiovascular disease for more of their lives and have a shorter average lifespan than patients with normal weight.”
Researchers add their review also shows “convincing data” that too much weight can cause atrial fibrillation. Doctors describe this common heart rhythm disorder as a quivering or irregular heartbeat that can lead to poor blood flow. The study estimates that obesity may cause a fifth of all atrial fibrillation cases.
“The research provides strong evidence that weight management be included as an essential aspect of managing atrial fibrillation, in addition to the standard treatments to control heart rate, rhythm and clotting risk,” the NIH researcher says.
“It’s important to understand how nutrition can be personalized based on genetics or other markers for cardiovascular disease risk,” Powell-Wiley concludes. “As overweight and obesity prevalence increases among adolescents worldwide, it is critical to address how best to develop upstream primary prevention interventions and better treatment strategies, particularly for young patients with severe obesity.”
The study appears in the journal Circulation.