What Is Creeping Fat?

A Type Of Fat Found In People With IBD May Be Related To Inflammation

Crohn's Disease
Crohn's disease has several signs that distinguish it from ulcerative colitis (such as cobblestone sign, shown), but creeping fat seems to be a part of both diseases. Image © JUAN GARTNER / Science Photo Library / Getty Images

Creeping fat is a phenomenon found in patients with Crohn's disease and ulcerative colitis (two types of inflammatory bowel disease, or IBD) that is still not well understood by the medical community. In fact, it has not yet been studied extensively, even though its existence in patients with Crohn's disease has been known for several decades. Crohn's disease is named for Burrill Crohn, because he was the one who first described the disease that was formerly known as regional ileitis.

Dr Crohn described the changes in the adipose tissue (connective tissue, or fat) in patients that had Crohn's disease.

What Is Creeping Fat?

Everyone has fat in their body, and at least a certain amount of fat in their abdomen. Between 15 and 30% body fat is considered normal, even healthy. Rather than just being a part of the body that is passive, adipose tissue is now recognized as an actual organ. It even has a function, and secretes different chemicals. One type is cytokines, which have been associated with IBD because they're found in greater numbers in people who have these diseases as opposed to healthy people. There have been cases where it was found that as much as 50% of the intestine was encased in creeping fat. Not surprisingly, having more of this type of fat is associated with having a more severe case of Crohn's disease.

Previously, creeping fat was thought to be diagnostic of Crohn's disease — that is to say when it was found, the patient was presumed to have Crohn's.

Creeping fat can be seen on a computed tomography scan. However, recently it has been described that patients with ulcerative colitis may also have a form of creeping fat. Most of the knowledge on creeping fat until now focused on Crohn's disease, so relatively little is known about it in ulcerative colitis or indeterminate colitis.

What Is The "Fat" Part Of Creeping Fat?

Creeping fat is not the same as the type of fat we would associate with overweight or obesity. Having this type of fat doesn't mean a person is overweight, nor does it contribute to being overweight or obese. Most patients with Crohn's disease are either at what is considered a low body-mass index, or a healthy body-mass index. It's not unheard of for a patient with IBD to be overweight or obese, but it's not common either. However, as many as half of all patients with Crohn's disease have been shown to have creeping fat around their intestines.

What Can We Do About Creeping Fat?

One question people with IBD may ask is how to prevent creeping fat or what can be done about it if it is present. Even though we've known about it since the 1930s, there is a paucity of research on creeping fat. The exact mechanism of how it affects the course of IBD is not understood, though there are several theories. Some theories are focused especially on the chemicals secreted by the fat and how they affect inflammation and the inflammatory process.

One study showed that the fat has a role in promoting inflammation, and that targeting creeping fat may be a future focus of treatment.

It's also not known exactly why it occurs. Does it occur before the IBD, and have a role in its cause, or is it a result of the IBD? These are questions that research must answer, as scientists begin to uncover this aspect of IBD that so far has been largely ignored.


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Kredel L, Batra A, Siegmund B. "Role of fat and adipokines in intestinal inflammation." Curr Opin Gastroenterol. 2014 Nov;30(6):559-65. doi: 10.1097/MOG.0000000000000116. 6 Aug 2015.

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