Is Intramuscular Fat a Threat to Cardiovascular Health?

Cardiovascular diseases are the leading cause of death globally, causing around 17.9 millions deaths per year. More than four out of five cardiovascular deaths are due to heart attacks and strokes, while majority of it occurs in individuals under the age of 70 making it the deadliest opponent of humankind. ^[1]

For all these years, many behavioral and environmental risk factors were considered to be the major causes for heart disease. One such factor is the deposition of excess body fat. However, latest studies suggest that how fat is distributed in our body also contribute to increased heart disease, regardless of other risk factors.

The study, from Brigham and Women’s Hospital and Faculty at Harvard Medical School, Boston, has found that the location where fat is stored may also increases heart related risk, even in those of a healthy weight.

Viviany Taqueti, MD, MPH (the lead author of the study) articulated the significance of the study through a press release.

The study, published in the European Heart Journal, found that intramuscular fat(IMF) increases a person’s risk of serious heart disease, regardless of their body mass index (BMI).^[2] Intramuscular fat (aka marbling fat) is the white fat deposited within skeletal muscle tissue and It mainly consists of triglyceride and phospholipids.

The subject of study was 669 participants, with an average age of 63 years, who were undergoing cardiac stress testing with PET/CT at Brigham and Women’s Hospital from 2007 to 2014. The researchers measured the fat and muscle amounts of the patients and location of fat deposition. From these measurements, they calculated the ratio of intramuscular fat to 'total fat + muscle' - to quantify the amount of fat deposition in muscles in each participant. For the whole time period, they were observed and evaluated for heart related complications.

The key insights from the study are:

1. Intramuscular fat infiltration was associated with coronary microvascular dysfunction(CMD) and other adverse heart conditions, independent of the conventional heart risk factors and BMI.

2. For every 1% increase in fatty muscle fraction, CMD risk surged by 2%, and risk of future serious heart disease by 7%.

3. Skeletal muscle quantity and quality affects the coronary function and heart health along with traditional parameters.

What can be done to improve cardiovascular health?

We are yet to learn how to specifically reduce intramuscular fat. However, reducing the overall body fat percentage and following a few healthy habits can keep us away from cardiovascular diseases.

Some healthy practices that can be incorporated into our life includes:

· Follow a healthy diet.

· Get physically active.

· Quit smoking and drinking.

· Maintain a healthy diet.

· Manage stress levels.

· Keep track of cholesterol, blood sugar and pressure levels.

References

1. https://www.who.int/health-topics/cardiovascular-diseases#tab=tab_1 (Accessed on January 25, 2025)

2. European Heart Journal, Skeletal muscle adiposity, coronary microvascular dysfunction, and adverse cardiovascular outcomes https://doi.org/10.1093/eurheartj/ehae827 (Accessed on January 25, 2025)

(Input from various sources)

(Rehash/Jithin Paul/MSM)