Every part of our body can face a problem once it is displaced from its own position. Fat is not the exception. When some fat is accumulated in an abnormal place in our body, it is called ‘Ectopic Fat’, which has been noticed lately. Then, what is the problem ‘ectopic fat’ can cause? Professor Jihee Ham at Chaum Slimming Clinic will explain this.
What is ectopic fat, which is different from subcutaneous one?
Recently, ectopic fat has attracted more attention among different kinds of fats. The dictionary definition for ‘ectopic’ is ‘to be in an abnormal place or position other than a normal place’. Ectopic fat generally refers to the fat accumulated in a wrong place, at which the fat is not supposed to be.
On the contrary, subcutaneous fat is found underneath the skin between dermis and muscle fascia. Subcutaneous fat helps store energy and maintain the body temperature. It is distributed throughout the body, such as the abdomen, arms, and legs. It is also called 'non-ectopic fat' because it is normally stored in its right place.
The pathogenesis for ectopic fat has not been fully explained yet but it is assumed that overeating and lack of exercise can cause energy-imbalance of which the extra energy is stored in a wrong place as ‘ectopic fat’. This happens when the extra energy increases beyond the capacity of energy acceptance after it is accumulated as subcutaneous fat.
But it is said that whether ectopic or non-ectopic fat is stored can depend on age, gender, race, smoking, genetic element, and other environmental factors as well as a life style. So, it is not easy to know clearly what the pathogenesis is for ectopic fat because several factors can work very complicatedly one another.
Ectopic fat, why is it dangerous?
It is reported that, compared to non-ectopic fat, ectopic fat can bring about more inflammation in the body and increase the risk of cardiovascular diseases. That is, on the aspect of metabolism, ectopic fat gives a bad impact on the body more than subcutaneous fat. A typical ectopic fat is abdominal visceral fat.
Other than that, there is intermuscular adipose tissue (IMAT), liver fat, renal fat, pancreatic fat, perivascular fat, and pericardial fat.
The correlation between ectopic fat and metabolic diseases.
Then, how is ectopic fat related to metabolic diseases? In order to answer this question, a research called Jackson Heart Study was implemented in the US, 2010
With 2,477 adult subjects, the research was conducted by comparing non-ectopic fat of abdominal subcutaneous fat and ectopic fat of abdominal visceral fat. According to the result, as the amount of subcutaneous fat and visceral fat increases, the effects on high-blood pressure, diabetes, and metabolic syndrome can increase as well. Especially the research revealed that visceral fat affects more than subcutaneous fat.
In the same year, in Taiwan, 328 subjects took part in the research and got CT scan, being categorized by abdominal subcutaneous fat (non-ectopic fat) and abdominal visceral fat (ectopic fat) so that the relation can be traced after between the amount of fat and inflammation levels or metabolic indicators.
This study also revealed that visceral fat is more related than subcutaneous fat to increased insulin resistance and inflammation indicators. This means that even if the subjects have the same weight, the same waist size, and the same abdominal fat amount, the one who has more visceral fat (ectopic fat) can have a higher risk of developing chronic diseases and inflammation.
Unforeseen Ambush, the ectopic fat hidden between thigh muscles
Another ectopic fat which has been gathering lots of attention recently is the fat tissue between the muscles in the thigh. This fat tissue between the muscles has been recognized to have the same influence as the abdominal visceral fat does even if the amount of the fat is very small.
According to several recent studies, the fat tissue between thigh muscles is shown to be linked to muscle strength, walking speed, and other physical abilities as well as insulin resistance and inflammation in the body.
In 2013, in the United States, 2,945 adult subjects participated in the Framingham Heart Study, in which the relation was monitored between the amount of fat in the thigh muscles and metabolic indicators.
As a result, the female subjects who had more fat in the thigh had metabolic syndrome while the male had dyslipidemia. In the case of obese patients, it is possible to misunderstand the amount of the abdominal visceral fat, which is related to the metabolic indicator, as the effect of the thigh fat mass just because the subjects who have more fat in the thigh have similar amount of the abdominal visceral fat.
To rule out the error in this study, the amount of abdominal visceral fat was corrected and analyzed, which revealed the relation between the fat mass in the thigh and metabolic diseases. Through this procedure, the link between the thigh fat and metabolism could be explained.
Professor Jihee Ham is practicing at Detox Clinic in Chaum Slimming Clinic after a clinical research assistant professor and a full-time doctor at the Department of Family Medicine in Cha University Bundang Medical Center.
We are specialized in controlling obesity and managing a body shape. By dedicating ourselves constantly to research and development as an active member of ‘Korean Academy of Family Medicine’ and of ‘Korean Society for Bone and Mineral Research’, we are striving to provide better care to our patients.