While people may assume only those who are overweight have to worry about the impact of a fatty heart, the reality is that thin people can also have this sometimes life-threatening condition.
“We know that being obese doubles the risk of heart failure,” said study author Dr. Satish Kenchaiah, associate professor of medicine and cardiology at the Icahn School of Medicine at Mount Sinai Hospital in New York. “But we found that having excess pericardial fat further enhances this risk, above and beyond the heart failure risk associated with well-known obesity indicators, such as body mass index and waist circumference.”
“These findings highlight that adipose tissue around the heart may be particularly dangerous to heart health,” said Dr. Gregg C. Fonarow, professor of cardiovascular medicine at UCLA, who was not involved in the study.
Being thin doesn’t equal a healthy heart
Having a healthy body weight doesn’t necessarily guard people against fat accumulation around the heart or the harm associated with it, the study reported.
The study had 6,785 participants, almost evenly split between women and men. Of the study’s lean participants — defined by the study as having a body mass index (BMI) of less than 25 — 10% had a high amount of pericardial fat. That number jumped to 29% for overweight individuals — those with a BMI between 25 and less than 30 — and 55% for the group considered obese, or participants with a BMI equal to or greater than 30.
And regardless of one’s body weight, the higher the amount of pericardial fat present, the greater the risk of heart failure, the study found.
“It’s not just the overall amount of body fat, but the concentrated depot of fat around the heart (that is linked to heart failure),” Kenchaiah said.
“There’s a lot more to assessing health than knowing one’s body weight,” said Kristen Smith, registered dietitian nutritionist and bariatric surgery program coordinator at Piedmont Healthcare in Atlanta. “An individual with a normal BMI may have fat stored in locations in their body that could put them at increased risk for chronic diseases and heart failure.”
“This study is a good example of why health care providers need to focus on talking about healthy behaviors, not just body weight,” said Julie Stefanski, registered dietitian nutritionist and spokesperson for the Academy of Nutrition and Dietetics.
How to reduce your chances of a fatty heart
Experts say eating a healthy diet and exercising regularly is key to managing excess pericardial fat, and those habits can help prevent it from developing in the first place.
“It is important to follow a heart healthy diet that focuses on fruits and vegetables, fiber-rich whole grains, seafood, nuts, legumes and seeds, as well as eating a few meatless meals per week and incorporating omega-3 rich seafood into at least two meals per week,” said Smith, who is also a spokesperson for the Academy of Nutrition and Dietetics.
Exercise lowers the total amount of fat in the body, including the amount of fat around the heart. A sufficient amount of movement can include brisk walking for 30 minutes to 45 minutes per day or counting 10,000 steps per day for as many days in the week as possible, Kenchaiah explained.
Current physical activity guidelines from the American Heart Association recommend getting at least 150 minutes per week of moderate intensity aerobic activities, such as brisk walking or dancing, or 75 minutes of vigorous aerobic activity like running or cycling.
Additionally, research has shown that weight loss can reduce pericardial fat, and these reductions may help to improve overall cardiovascular health.
For those with extreme obesity who are finding it difficult to lose weight with diet changes and exercise, weight loss surgery may help to decrease overall body fat as well as pericardial fat, according to Kenchaiah.
How people get a “fatty heart”
The human heart expands to fill blood into its chambers and contracts to pump blood to the rest of the body.
Pericardial fat can potentially spread into heart muscle cells — the ones that contract and squeeze the blood — or get in between these cells and cause stiffening of the heart and pump dysfunction, Kenchaiah explained.
Pericardial fat is also correlated with plaque (fatty deposits) in coronary arteries, which can lead to heart attacks and subsequently to heart failure, Kenchaiah added.
The study, which included a nationally representative sample of about 7,000 people ages 45 to 84, excluded those with pre-existing cardiovascular disease and controlled for both non-modifiable risk factors such as age and race, as well as modifiable risk factors such as cigarette smoking, excessive alcohol consumption, high blood pressure, high cholesterol and diabetes. It found that pericardial fat independently increased the risk of heart failure in women and men.
“Importantly, the study shows even if accounting for total body fat, diabetes and other heart failure risk factors, there remains increased risk associated with increased pericardial fat,” Fonarow said.
Women are at higher risk
Women tend to have less pericardial fat than men, according to the study. But women are at a higher risk of heart failure from pericardial fat than men: Every 1.4 fluid ounces of fat around the upper to mid portion of the heart increased the risk of heart failure by 44% in women and 13% in men, the researchers found. And women with high amounts of pericardial fat had double the risk of heart failure, while men had 50% increased risk.
Future studies will need to clarify the explanation for the gender differences, according to Kenchaiah.
Based on the study’s enrollment criteria and findings, all people between the ages of 45 and 84 years without pre-existing cardiovascular disease should be screened for excess pericardial fat volume, Kenchaiah said.
How often one should be screened is yet to be determined, according to Kenchaiah. That said, while the cost-effectiveness of screening everyone in this age group is being determined, testing people with known risk factors of heart failure (such as hypertension, diabetes, high cholesterol and triglycerides, and coronary artery disease) for excess pericardial fat is prudent, Kenchaiah added.
The level of pericardial fat you have can be determined with a CT scan, similar to the process used in the study. For those who have a high amount, according to Kenchaiah it’s important to screen people for “the big four”: high blood pressure, high blood sugar, abnormal cholesterol level, and any evidence of heart attacks or coronary heart disease.
“If any of these are present, (your health care provider should) aggressively intervene,” Kenchaiah said.
Managing blood sugar, as well as maintaining normal cholesterol and triglyceride levels is also key. Avoiding tobacco use is also important, according to Stefanski.
“We don’t have the data yet, but we presume that eating right, staying fit, maintaining healthy weight, and modifying risk factors, when present, can prevent excess fat from depositing around the heart” Kenchaiah added.