Type 3c diabetes develops when your pancreas experiences damage, such as from chronic pancreatitis or cystic fibrosis. People with Type 3c diabetes often also have a lack of pancreatic enzymes that are important for digestion. Type 3c diabetes is manageable with oral diabetes medications and/or insulin.
Type 3c diabetes develops when your pancreas experiences damage that affects its ability to produce insulin. Conditions like chronic pancreatitis and cystic fibrosis can lead to pancreas damage that causes diabetes. Having your pancreas removed (pancreatectomy) also results in Type 3c diabetes.
Diabetes is a condition that happens when your blood sugar (glucose) is too high. It develops when your pancreas doesn’t make any or enough insulin (a hormone), or your body isn’t responding to the effects of insulin properly.
Your pancreas has two main functions:
Pancreas damage that leads to Type 3c diabetes often also affects your pancreas’s ability to produce the enzymes that help with digestion. This condition is called exocrine pancreatic insufficiency (EPI).
Other names for Type 3c diabetes include:
Researchers estimate that Type 3c diabetes represents 1% to 9% of all diabetes cases. This range is wide because Type 3c isn’t as well-known, and people with the condition are often misdiagnosed with Type 2 diabetes.
The main difference between these types of diabetes is what causes them.
Type 1 diabetes is an autoimmune disease in which your immune system attacks and destroys insulin-producing cells in your pancreas for unknown reasons. People with Type 1 always need insulin to manage the condition.
Type 2 diabetes develops when your body doesn’t make enough insulin and/or your body’s cells don’t respond normally to the insulin (insulin resistance). People with Type 2 diabetes may manage the condition with lifestyle changes, oral medication and/or insulin.
Type 3c diabetes results from damage to your pancreas that isn’t autoimmune. People with Type 3c often also lack the enzymes their pancreas makes for digestion. In this type, the amount of insulin your pancreas makes can vary. Some people take oral diabetes medications and others need insulin to manage the condition.
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The symptoms of Type 3c diabetes are the same as other forms of diabetes. They include:
People with Type 3c diabetes typically also have symptoms of exocrine pancreatic insufficiency, which include:
It’s important to see a healthcare provider if you have these symptoms.
Type 3c diabetes develops when your pancreas experiences enough damage to affect its ability to make insulin. The damage can result from the following underlying conditions or situations:
Chronic pancreatitis is long-term inflammation in your pancreas. Constant inflammation causes scarring of your pancreas tissues (fibrosis), which eventually stops it from making enzymes and hormones. About 25% to 80% of people with chronic pancreatitis develop Type 3c diabetes.
There are two main forms of chronic pancreatitis:
Chronic pancreatitis is the most common cause of Type 3c diabetes — it represents about 79% of cases.
There’s a strong link between diabetes and pancreatic cancer, especially pancreatic ductal adenocarcinoma (the most common kind). About 50% of people diagnosed with pancreatic cancer also have diabetes.
Tumors from pancreatic cancer could potentially damage your pancreas and cause Type 3c diabetes. Researchers estimate that pancreatic cancer is the cause of about 8% of Type 3c diabetes cases.
Hemochromatosis, also called iron overload, is a condition in which your body stores too much iron.
Normally, your intestines absorb just the right amount of iron from the food you eat. But with hemochromatosis, your body absorbs extra iron and stores it in your organs, especially your heart, liver and pancreas.
Iron stores in your pancreas can cause damage, leading to Type 3c diabetes.
Hemochromatosis causes about 7% of all Type 3c diabetes cases.
Cystic fibrosis (CF) is a genetic (inherited) condition that causes sticky, thick mucus to build up in organs, including your lungs and pancreas.
This mucus can scar and damage your pancreas, which can prevent it from producing enough insulin, resulting in Type 3c diabetes.
Sometimes, a person with cystic fibrosis experiences insulin resistance (like in Type 2 diabetes) due to the condition. This is more likely to happen when the person is sick, on steroid medications or is pregnant.
More than 35% of adults living with CF have Type 3c diabetes. This form of diabetes is also called CF-related diabetes (CFRD).
Cystic fibrosis causes about 4% of all Type 3c diabetes cases.
A pancreatectomy is a surgery that removes part or all of your pancreas. You may need a pancreatectomy for many reasons, such as for pancreatic cancer, pancreatic cysts or severe chronic pancreatitis.
A pancreatectomy may or may not result in Type 3c diabetes. A partial pancreatectomy will leave some insulin-secreting cells behind. Sometimes they’re enough to keep your blood sugar in a healthy range.
If you’re having a total pancreatectomy, you’ll have diabetes afterward unless your surgeon can preserve some of your insulin-producing cells. Sometimes, your surgeon can transplant some of these cells into your liver.
Pancreatectomies cause about 2% of all Type 3c diabetes cases.
It can be difficult for healthcare providers to diagnose Type 3c diabetes. This is because it isn’t a very common or well-known type of diabetes. Providers tend to misdiagnose it as Type 2 diabetes, which is a much more common form. If you have a known pancreatic condition, it’s less difficult to diagnose Type 3c.
Providers have to confirm diabetes, confirm damage to your pancreas and rule out other types of diabetes to diagnose Type 3c.
They may order the following tests to do so:
The treatment for Type 3c diabetes varies based on the underlying cause and how much of your pancreas is damaged (or surgically removed).
Your treatment needs may change over time if your pancreas becomes more damaged. For example, an oral medication may work well to manage your blood sugar at first. But you may eventually need insulin to keep your blood sugar levels in range if your pancreas produces less and less insulin.
Other management strategies for Type 3c diabetes include:
Diabetes is a complex condition, so its management involves several strategies. In addition, diabetes affects everyone differently, so management plans are highly individualized. You’ll likely benefit from regular visits with your healthcare team to monitor how well your treatment plan is working.
The only way to prevent Type 3c diabetes is to try to prevent the underlying conditions that cause it, if possible. Inherited conditions like cystic fibrosis and hereditary pancreatitis aren’t preventable. But there are steps you can take to try to prevent acquired pancreatitis, such as moderating your alcohol consumption and maintaining healthy triglyceride levels.
The prognosis (outlook) for Type 3c diabetes varies greatly depending on several factors, including:
Chronic high blood sugar can cause severe complications, which are often irreversible. Several studies have shown that untreated chronic high blood sugar shortens your lifespan and worsens your quality of life.
However, it’s important to know that you can live a healthy life with diabetes. The following are key to a better prognosis:
Blood glucose levels that remain high for too long can damage your body’s tissues and organs. This is mainly due to damage to your blood vessels and nerves, which support your body’s tissues.
Cardiovascular (heart and blood vessel) issues are the most common type of long-term diabetes complication. They include:
Other diabetes complications include:
If you have a condition that affects your pancreas, such as chronic pancreatitis or hemochromatosis, talk to your healthcare provider about your risk of developing Type 3c diabetes. They’ll likely order regular tests to monitor for diabetes.
If you have Type 3c diabetes, you’ll need to see your healthcare team regularly to manage both diabetes and the underlying condition that caused it.
A note from Cleveland Clinic
It can be discouraging to learn that you’ve developed diabetes from a pancreatic condition. Managing Type 3c diabetes involves consistent care and diligence. While it’ll likely be very overwhelming at first, over time you’ll get a better grasp on managing the condition and being in tune with your body.
Be sure to see your healthcare team regularly. Managing Type 3c diabetes — and the condition that caused it — involves a team effort. You’ll want medical professionals, friends and family on your side. Don’t be afraid to reach out to them if you need help.
Last reviewed by a Cleveland Clinic medical professional on 05/08/2023.
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