National Institute of Health

Researchers show that excess fat accumulation around the heart might be an independent warning sign irrespective of BMI

Body mass index (BMI) and waist circumference are two standard health metrics used to gauge overall fitness and well-being. While these are usually associated with cardiac fat, it is not clear if cardiac fat has an independent role in heart diseases. Now, researchers from South Korea and USA show that cardiac fat is indeed a strong risk factor for heart diseases, highlighting a useful marker for cardiac health other than BMI.

A new study by researchers from KNIH reveals that “fatty heart,” or excess visceral fat around the heart, can be an independent marker for poor cardiac health and recommends exercise and good diet to stay fit.

Image credit: William Choquette from Pexels.

It is no secret that a good diet and lifestyle is essential for our physical as well as mental well-being. The two standard metrics for good health are the body mass index (BMI) and waist circumference, which is related to belly fat. Excess belly fat has been shown to be an independent risk factor for type 2 diabetes and heart disease. However, general obesity may not be sufficient in determining health because “visceral fat,” or fat accumulation around abdominal organs, can also lead to a poor prognosis.

“Pericardial adipose tissue” (PAT), characterized by the accumulation of fat around and inside the outer covering of the heart, is often associated with general obesity and, by extension, to heart diseases. However, whether PAT has an independent role in influencing cardiac health has remained controversial, until now.

In a new study published in Cardiovascular Diabetology, a research team led by Prof. Seong Hwan Kim from Korea University Ansan Hospital, South Korea, set out to unearth any likely association between PAT and heart diseases. “There is no single perfect indicator for obesity. Although BMI is practical and widely used, the presence of excess cardiac fat could be an early warning sign, regardless of BMI,” explains Prof. Kim. This study was supported by grants (2015-P71001-00 and 2016-E71003-00) from the Korean Centers for Disease Control and Prevention.

The study included 2,471 participants from the Korean Genome Epidemiology Study, with 50.9% of them being women without any prior history of cardiovascular disease. The participants underwent 2D-echocardiography with tissue Doppler imaging (TDI), which examined the functioning of the heart by measuring the velocity of the heart muscle during the heart cycle, and computed tomography (CT), which used X-rays to detect abnormalities.

The team found that men were more likely to show the presence of PAT than women. Moreover, men with extra PAT also showed abnormal blood pressure as well as relatively higher blood glucose and cholesterol levels. Additionally, higher pericardial fat levels were associated with an increased left ventricular (LV) mass index and left atrial (LA) volume index as well as with decreased systolic and early diastolic TDI velocities, all of which indicated deteriorating cardiac health.

Interestingly, the associations between PAT and various indicators of decreased cardiac health remained intact even after accounting for BMI and waist circumference.

“PAT was independently associated with subclinical LV structural and functional deterioration, irrespective of the status of the standard obesity measures,” says Prof. Kim.

What are the implications of these findings? “Considering that it is not feasible to measure all the different kinds of visceral fat accumulations in the body, a lifestyle involving balanced nutrition and regular physical activity is a legitimate approach to better health and well-being,” comments Prof. Kim

The study thus confirms, once again, that, obese or not, a good diet and exercise are the key to staying fit.

Reference

About National Institute of Health in Korea

The Korea National Institute of Health (KNIH), one of the major operating components of the Ministry of Health and Welfare, leads the nation’s medical research. Over the past seven decades, the KNIH has made unwavering efforts to enhance the public’s health and innovate biomedical research. The KNIH seeks to eradicate diseases and make people healthier. The KNIH establishes a scientific basis and evidence underlying health policy as well as provides national research infrastructures. We also promote public health research. To this end, we make efforts to enrich a health research environment by granting funds to research projects and keeping our resources, data, and facilities more open and accessible to researchers.

Website: http://www.nih.go.kr/eng/

About Professor Seong Hwan Kim

Dr. Seong H. Kim is a Professor of Medicine at Korea University, South Korea. He received his Ph.D. degree in Cardiology from Korea University in 2008. An echocardiography expert, Dr. Kim conducts research on insulin resistance, obesity, hypertension, and metabolic syndrome. From 2017 to 2019, he worked with Prof. Sun Kim, an endocrinologist, as a Visiting Professor at the Stanford University Hospital, where he studied the association between type 2 diabetes and heart disease. He is currently the Editor-in-Chief of the Journal of Cardiovascular Imaging, the official journal of the Korean Society of Echocardiography.