Cystic fibrosis-related diabetes (CFRD) is a common complication of cystic fibrosis. It shares some features with type 1 and type 2 diabetes but is a separate condition. It may shorten life expectancy but can be treated with insulin.

Cystic fibrosis (CF) is an inherited disorder that causes issues with various organs in the body, including the pancreas. As a result, it can cause a complication known as cystic fibrosis-related diabetes (CFRD), which is considered a separate condition and affects 40% to 50% of adults with CF.

CFRD has become more common over the years as the life expectancy of people with CF has increased. People with CFRD may experience some of the same effects as people with type 1 or type 2 diabetes, including an increase in blood sugar levels (glucose levels) and a possible need to use supplemental insulin to regulate blood sugar.

This article will explain more about CFRD and how it relates to diabetes in general, as well as aspects of managing the condition that you may want to discuss with your healthcare team.

CFRD has features of both type 1 and type 2 diabetes. However, it is a separate condition that starts in a different way and may have different symptoms.

Type 1 diabetes is caused by the body attacking insulin-producing cells in the pancreas and may be triggered by viruses or environmental factors.

Type 2 diabetes is caused by lifestyle and genetic factors that lead to insulin resistance.

Most people with CFRD do not have symptoms when they receive a diagnosis.

For example, although excessive urination (polyuria) and excessive thirst (polydipsia) are symptoms of diabetes mellitus, people with CFRD do not typically have either of these symptoms.

Possible symptoms of CFRD include:

While just 2% of children and 20% of adolescents with CF develop CFRD, growth symptoms typically start a few years before diagnosis and may occur even if a child gets appropriate nutrition.

It’s important to monitor growth in a child with CF to observe these changes.

Most cases of CFRD begin in adulthood. Your doctor may suggest having an oral glucose tolerance test each year to monitor for this condition.

The exact physiological processes that cause CFRD are not entirely understood.

However, researchers believe that impaired pancreas function may originate from problems with the CFTR gene. Issues with this gene may play a role in the body’s ability to release insulin in appropriate amounts to regulate blood sugar.

“Diabetes” is an umbrella term used to describe metabolic diseases caused by changes in blood glucose levels. In CFRD, these changes are caused by inflammation of the pancreas. The affected CFTR gene causes secretions in the pancreas to be thick and sticky, leading to fatty infiltration and scarring (fibrosis) of the pancreas.

When the function of the pancreas is impaired, it cannot secrete insulin effectively to lower blood sugar. High levels of glucose in the body over time can lead to insulin resistance and, in turn, diabetes.

Steroid drugs used to treat CF may also lead to insulin resistance and diabetes.

You can develop diabetes complications over time, especially if you have elevated glucose levels over time. Like diabetes, CFRD can present complications.

The main complications associated with CFRD are decreased lung function and shortened life expectancy.

However, other CFRD complications are similar to those that people with type 1 or type 2 diabetes can develop:

The goal of treatment for CFRD is to regulate blood sugar, improve weight gain, and protect lung function.

Doctors treat CFRD by monitoring glucose levels and prescribing insulin, which is the same hormone that is made by your pancreas. The insulin is injected or delivered through an insulin pump device into the fat under your skin. Depending on the type of insulin you take, it will regulate your blood sugar over a period of time.

The amount of insulin you take before a meal will depend on the carbohydrate ratio of the meal. If you experience fasting hyperglycemia or receive continuous feeding through a gastrostomy tube (G-tube), you may have other insulin needs as directed by your doctor.

Your doctor may encourage you to maintain a certain diet (steady level of calories) before starting insulin to get the most benefit from insulin therapy.

CFRD is a chronic condition that requires continual medical care.

People with CFRD may have a shortened life expectancy, and the most common cause of death among them is pulmonary failure.

Fewer than 25% of people with CFRD live past age 30, while 60% of people with CF and typical blood glucose levels live beyond age 30.

The impact on life expectancy tends to more commonly affect females.

CFRD is a common complication of CF. You may or may not experience classic diabetes symptoms, so it’s important to have routine medical appointments to assess your blood glucose levels. Early diagnosis and appropriate management with insulin may improve the outlook, but CFRD may shorten life expectancy or lead to other health complications.