Celiac disease more prevalent than thought

One out of every 133 Americans may have celiac disease, according to results from one of the largest studies ever on the disease, now found to be much more common in the US than previously thought.

Although serious conditions ranging from diabetes, anemia, short stature, infertility, Down syndrome and diarrhea can all be associated with celiac disease, few people in the US have heard of it, say researchers at the University of Maryland Center for Celiac Research in Baltimore. The researchers screened more than 13,000 people in 32 states for the study.

"We now believe that more than 1.5 million Americans suffer from celiac disease, making it twice as common as Crohn's disease, ulcerative colitis and cystic fibrosis combined,"​ said Dr Alessio Fasano, the study's principal investigator and professor of pediatrics, medicine and physiology at the University of Maryland School of Medicine.

Celiac disease is a digestive disorder that is triggered by the protein gluten, found in wheat, barley and other grains. In people with the disease, gluten in foods can set off an autoimmune reaction in the intestines that causes a variety of gastrointestinal symptoms and prevents the proper absorption of food and nutrients, leading to serious health consequences.

"Symptoms of celiac disease vary among individuals,"​ said Dr Fasano. "It can be a difficult disease to diagnose because symptoms can include anemia, osteoporosis, diarrhea, and constipation. Alternatively, there may not even be any symptoms."​

Preliminary studies found celiac disease in about one out of every 150 people, said Fasano. "This new study demonstrates that celiac disease is just as common in the US as in Europe, which makes sense since there is a genetic link to the disease and many Americans are descended from Europeans,"​ said Dr Fasano, who also heads the division of pediatric gastroenterology at the University of Maryland Hospital for Children.

The researchers are hoping that physicians will be more likely to test their patients for celiac disease, following the study results.

The study took place over five years and included blood samples from 13,145 people, including adults and children. The purpose of the study was to look at the disease's prevalence in both 'at-risk' and 'not at-risk' populations. Nearly 9,000 people were considered 'at-risk' because they either had relatives with celiac disease, symptoms such as diarrhea or abdominal pain, or other disorders associated with celiac disease, including diabetes, Down syndrome or anemia. More than 4,000 study participants were considered 'not at-risk.'

The study found that among 'at-risk' participants, celiac disease was present in one out of 22 people who had first-degree relatives with the disorder. It was also present in one out of every 68 adults with CD-associated symptoms and one out of every 25 children with symptoms. Among those study participants who were considered 'not at-risk,' celiac disease was found in one out of every 133 people.

There is no cure for celiac disease and there are no medications to treat it. People with celiac disease can lead normal, healthy lives by following a gluten-free diet. This means avoiding all products derived from wheat, rye, barley and a few other lesser-known grains. There is varying opinion on whether celiacs can eat oat-based foods.

Celiac disease is an autoimmune disease, just like diabetes and rheumatoid arthritis. "There are two elements that play together for someone to develop an autoimmune disease. You must have a genetic predisposition and there must be some environmental factor to trigger the disease,"​ explained Dr Fasano. "Celiac disease is the only autoimmune disease where that trigger is known - gluten."​

Fasano added: "This study is also very important to the scientific community because researchers will now be able to use this data on celiac disease to help uncover what causes other autoimmune diseases."​