Cystic fibrosis and diabetes link explained

June 2, 2014
"Clubbing" of the fingers is a classic features of Cystic Fibrosis, although not present in many patients. Credit: Jerry Nick, M.D./ Wikipedia

Many people with cystic fibrosis develop diabetes. The reasons for this have been largely unknown, but now researchers at Lund University in Sweden and Karolinska institutet have identified a molecular mechanism that contributes to the raised diabetes risk.

"The increased risk of diabetes has previously been explained by the fact that causes damage to the pancreas, where the blood-sugar regulating
 is produced. We are the first research group to show that the mutated gene that causes cystic fibrosis also plays an important role in the release of insulin. The risk of diabetes is not only explained by the destruction of the pancreas", said Anna Edlund, a doctoral student at Lund University Diabetes Centre.

Cystic fibrosis is the result of a genetic mutation in an ion channel that normally regulates salt transport in cells, primarily in the lungs and pancreas. The mutation leads to a wide variety of symptoms. Individuals with cystic fibrosis produce a lot of thick, viscous mucus. This makes their airways sensitive to infection, and repeated or chronic lung infections are common. The secretion of pancreatic juice from the pancreas to the intestine is hindered, which causes diarrhoea and poor weight gain.

Left untreated, cystic fibrosis is fatal, but with improved treatment of symptoms, survival has improved. Many people with cystic fibrosis now live beyond the age of 40.

"Cystic Fibrosis is a severe health condition and diabetes exacerbates an already problematic situation", said Malin Flodström-Tullberg, a researcher at the Centre for Infectious Medicine, Karolinska institutet.

Many people with cystic fibrosis have poor sugar metabolism. At the age of 30, around one in four people with cystic fibrosis
also has diabetes that requires treatment with insulin. What the researchers have now shown is that the mutation in the cystic fibrosis gene inhibits the secretion of insulin into the blood, which means that the level is insufficient
when the demands on the insulin increase, such as after a meal.

"Normally, insulin is released in two stages. The early stage is a rapid response to raised blood sugar and the later stage aims to restore blood sugar levels. In cystic fibrosis, the early stage of in particular is insufficient", said Anna Edlund, adding:

"Our results also correspond to clinical observations. Many patients with cystic fibrosis who do not have diabetes have normal blood sugar in a fasting state, but raised after a meal."

The researchers have worked on insulin producing cells from mice and deceased donors. They have shown that the cystic fibrosis gene plays an important role
in the complex chain of events that precedes the release of insulin.

When the cells were exposed to high glucose levels, they responded as expected by increasing , but when a preparation that specifically
obstructs the expressed by the cystic fibrosis gene was added, the cells' ability to release insulin fell significantly.

"Despite being common among , surprisingly little is known about the mechanisms behind in this group of individuals. We
need to know what causes the problem in order to develop preventive treatments that improve the cells' ability to secrete insulin. Our study provide a first
piece of increased understanding how CFTR contribute to secretion", said Lena Eliasson, Professor at Lund University Diabetes Centre.

Explore further: New proteins to clear the airways in cystic fibrosis and COPD

More information: Anna Edlund, Jonathan LS Esguerra, Anna Wendt, Malin Flodström-Tullberg and Lena Eliasson. "CFTR and Anoctamin 1 (ANO1) contribute to cAMP amplified exocytosis and insulin secretion in human and murine pancreatic beta-cells." BMC Medicine. DOI: 10.1186/1741-7015-12-87

Related Stories

New proteins to clear the airways in cystic fibrosis and COPD

July 13, 2012

University of North Carolina scientists have uncovered a new strategy that may one day help people with cystic fibrosis and chronic obstructive pulmonary disorder better clear the thick and sticky mucus that clogs their lungs ...

Inhaler approved for cystic fibrosis patients

March 25, 2013

(HealthDay)—The TOBI Podhaler (tobramycin inhalation powder) has been approved by the U.S. Food and Drug Administration to treat cystic fibrosis patients infected with Pseudomonas aeruginosa, a bacterium that can damage ...

Bacterial food web may be key to cystic fibrosis

January 13, 2014

(Medical Xpress)—Cystic fibrosis patients suffer from chronic bacterial infections and thick mucous in their lungs, due largely to a combination of microbial infections and resulting inflammation. A common pathogen, Pseudomonas ...

Recommended for you

Researchers grow retinal nerve cells in the lab

November 30, 2015

Johns Hopkins researchers have developed a method to efficiently turn human stem cells into retinal ganglion cells, the type of nerve cells located within the retina that transmit visual signals from the eye to the brain. ...

Shining light on microbial growth and death inside our guts

November 30, 2015

For the first time, scientists can accurately measure population growth rates of the microbes that live inside mammalian gastrointestinal tracts, according to a new method reported in Nature Communications by a team at the ...

Functional human liver cells grown in the lab

November 26, 2015

In new research appearing in the prestigious journal Nature Biotechnology, an international research team led by The Hebrew University of Jerusalem describes a new technique for growing human hepatocytes in the laboratory. ...

Gut microbes signal to the brain when they are full

November 24, 2015

Don't have room for dessert? The bacteria in your gut may be telling you something. Twenty minutes after a meal, gut microbes produce proteins that can suppress food intake in animals, reports a study published November 24 ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.