This lesson will discuss a disorder known as exocrine pancreatic insufficiency, the major causes of its development, clinical signs to look out for, and treatment options.
Commercials for diet products usually tout one of two main things. They either promise you'll lose lots of fat around a certain area or that you'll lose weight period. Then, of course, they go into the whole 'you'll look beautiful and will be able to fit into your high-school clothing again' spiel only to end up being sued several years later for causing liver failure in people who took their supplement.
If you take an iffy supplement to lose weight or you exercise to do so, that's one thing. That's expected weight loss. The problem lies in conditions where you can eat normal amounts of food but still lose a lot of weight in the process without any exercise or supplements. While there are many disease processes that cause this, we'll focus in on one of them right now.
What Is Exocrine Pancreatic Insufficiency?
This specific process, one whereby a person loses a lot of weight despite eating normal or even increased amounts of food, is called exocrine pancreatic insufficiency. In more specific terms, exocrine pancreatic insufficiency, or EPI for short, is a disease process whereupon a deficiency of exocrine pancreatic enzymes occurs, leading to improper breakdown and absorption of food.
The process of breaking down and later on absorbing nutrients begins in your mouth and continues in your stomach and thereafter in the intestines. This process is aided by bile being secreted out of your gallbladder and enzymes (proteins that help speed up chemical reactions) from the pancreas. Even the physical motions of your stomach and intestines help to break down food. It's quite a complicated process for something as simple and delicious as food!
This process reminds me of an example. If you've ever been to a scrapyard, then you've almost certainly seen how different members of the team perform different tasks along the way to stripping down the car before its final destruction. Valuable things like radios or speakers may be taken out, then specific metals are stripped out and oil removed, all before the car is completely destroyed. Correspondingly, each part of your digestive system has its own role in stripping food of essential particles so that they can be absorbed.
This is where the exocrine pancreas comes into play.
What Does the Exocrine Pancreas Do?
The exocrine pancreas is one of those scrapyard workers that performs its own unique job. It's different from its brother, the endocrine pancreas. The endocrine pancreas secretes hormones you've almost certainly heard about, like insulin. The exocrine pancreas secretes enzymes responsible for the digestion of food, including amylase, protease, and lipase. Both the exocrine and endocrine pancreas make up the one and only pancreas in your body, it's just that we as humans have divided it up in order to classify its different functions.
If you weren't already aware, a protease, not very surprisingly given its name, helps to break down proteins. Lipase is an enzyme that helps to break down lipids, which are fats. Again, look at the first three letters of the word 'lipase' to easily remember that it connects with 'lipids.'
Since we've covered proteins and fats, that only leaves out carbohydrates. Therefore, amylase is the enzyme responsible for breaking down carbohydrates.
The important thing to note here is that the digestion and breakdown of fats, proteins, and carbohydrates occurs thanks to the entire pathway I described before. However, it is pancreatic lipase that is by far and away the most important thing that is responsible for the digestion of fat. And because fat provides much more caloric energy than either carbohydrates or proteins, if something goes wrong with the exocrine pancreas, we are going to lose a lot of weight because we can't consume the one thing that causes us to gain so much weight in the first place: fat!
That's why all of those late-night commercials tout their fat-burning power! Now you know.
Clinical Signs and Symptoms
Since fat cannot be absorbed well and neither can the other nutrients as well as before, people with EPI obviously suffer from weight loss. In logical sequence, because the fat cannot be broken down, it cannot be absorbed. Since the fat isn't absorbed into the body, there's only one place for it to go: out into the toilet bowl. This leads to steatorrhea, which is the excretion of abnormal quantities of fat in the feces, leading to pale and very foul-smelling stool.
Consequently, the feces oftentimes floats at the very top of the toilet bowl. Try to figure out why this may be the case on your own for a second. If you haven't figured it out yet, then go to your kitchen and pour yourself a glass of water. Then find some olive or vegetable oil, which are two types of fat. Go ahead and add a few drops to the glass. Either one will float at the very top of the water. Fat floats in water - that's your answer as to why that will also occur with the feces.
Besides all of that, some serious passage of gas will be common as a result of your gut bacteria interacting with all of that undigested fat, which they will treat as a yummy meal for themselves!
Causes, Diagnostics, and Treatment
The big question by now should be, 'What causes EPI?' Well, EPI is many times not a disease process by itself so much as a consequence or part of another process.
Chronic pancreatitis - that is to say, long-term inflammation of the pancreas - leads to the destruction of pancreatic tissues. That means the enzyme-producing factories in the pancreas that make all of these enzymes are basically burned down to the ground, leading to EPI.
Another condition that may cause EPI is cystic fibrosis, an inherited condition that results in abnormally thick secretions in multiples organs, such as the pancreas and lungs.
This means that the pancreas actually makes pancreatic enzymes, unlike in serious cases of chronic pancreatitis, but these enzymes are secreted in a gooey gel that plugs up the drainage channels that normally funnel these enzymes from the pancreas into the intestines.
Imagine a ton of molasses spilling on a road, as per the Boston Molasses Disaster. All that molasses would block streets and plug up the drainage channels lining the curbs, messing up traffic patterns and proper outflow of rainwater through the drainage channels.
Besides cystic fibrosis, other causes of EPI include celiac disease, Crohn's disease, and a whole lot more.
To diagnose EPI and to differentiate it from other causes of malabsorption, such as diseases that affect the intestinal tract alone, we can use fat-absorption tests and blood and fecal tests that will show decreased levels of pancreatic enzymes or their precursors, such as trypsinogen or trypsin.
Once diagnosed, treatment includes diet modification to include more vitamins, less fat, and pancreatic enzyme replacement therapy, which helps people properly break down the food they eat.
Replacing pancreatic enzymes that aren't being produced or secreted makes sense. Minimizing fat intake also logically makes sense. But I also want you to think about why vitamins, especially A, D, E, and K, would need to be replaced in some cases as well. Think about the pathophysiology of EPI and what you know about vitamins A, D, E, and K. Those vitamins are fat-soluble vitamins. Malabsorption of fat, as per EPI, can thereby lead to a decrease of them in the body, requiring supplementation in people.
If you work with dogs and cats, then they will almost always need supplementation with cobalamin due to an intestinal overgrowth of bacteria associated with EPI. This overgrowth leads the bacteria to munch on vitamin B12, cobalamin, before your furry friend can get enough of it for themselves.
All right, time for a review. We discussed exocrine pancreatic insufficiency. This is a disease process whereupon a deficiency of exocrine pancreatic enzymes occurs, leading to improper breakdown and absorption of food.
The exocrine pancreas secretes enzymes responsible for the digestion of food, including amylase, protease, and lipase.
Lipase is an enzyme that helps to break down lipids, which are fats. And in EPI, it is fat malabsorption that is the most affected, followed by proteins and carbohydrates.
Fat malabsorption leads to steatorrhea, which is the excretion of abnormal quantities of fat in the feces, leading to pale and very foul-smelling stool in people with EPI.
EPI can be caused by many things, including chronic pancreatitis and cystic fibrosis, an inherited condition that results in abnormally thick secretions in multiples organs, such as the pancreas and lungs.
Diagnosis is made with blood tests, stool samples, and other means. Treatment includes vitamin supplementation, pancreatic enzyme therapy, and dietary changes.
Following this lesson, you should be able to:
- Define exocrine pancreatic insufficiency (EPI)
- Describe the role of the exocrine pancreas and lipase in digestion and absorption
- Identify the signs and symptoms of EPI
- Explain what causes EPI and how it is diagnosed and treated