Celiac disease is far more common than thought
February 10, 2003
A massive, multi-center study has found that celiac disease is much more common in the United States than previously believed. The study, published in the 10 February 2003 issue of the Archives of Internal Medicine, found that one out of every 133 Americans has celiac disease. Since only about one out of 4,700 Americans has been diagnosed, this means that 97 percent of cases in this country go undetected.
The prevalence is far higher for those considered "at risk." One out of 22 people with a first-degree relative has the disease, one out of 39 with a second-degree relative, and one out of 56 people with symptoms but no diagnosed relative.
"Celiac disease is a much greater problem in the United States than has previously been appreciated," write the researchers, who recommend screening of those at greatest risk, "to alleviate unnecessary suffering, prevent complications and improve the quality of life."
"We hope this study will change the perspective of the health care community and that physicians will be more likely to test their patients for celiac disease," says Alessio Fasano, MD, the study's principal investigator and professor of pediatrics, medicine and physiology at the University of Maryland School of Medicine.
"Undetected, untreated celiac disease is a recipe for trouble," says Stefano Guandalini, MD, professor of pediatrics and director of the University of Chicago Celiac Disease Program.
"When this disease is diagnosed and treated early we can prevent complications," says Guandalini, "but there is so little awareness of celiac disease in this country, even among physicians, that we often see people only after they develop severe problems. For a disease that can usually be treated effectively with a modified diet, that's a horrible waste."
Celiac disease is a digestive disorder triggered by the protein gluten, which is found in wheat, barley and rye. Gluten can trigger an autoimmune reaction in the intestines of genetically susceptible people, which causes a variety of gastrointestinal symptoms and prevents the proper absorption of food and nutrients, leading to serious health consequences. People with celiac disease, however, can lead normal, healthy lives by following a gluten-free diet.
"Gluten is poison to celiac patients," says Fasano. "Avoiding gluten requires major lifestyle changes, and it impacts entire families."
Symptoms of celiac disease vary among individuals. Most common are diarrhea, constipation and abdominal pain, but "it can be a difficult disease to diagnose," adds Fasano, because symptoms can also include weight loss, anemia, osteoporosis, lassitude and depression. Sometimes, there are no symptoms.
This new study demonstrates that celiac disease is just as prevalent in the U.S. as in Europe, where it is considered common, affecting an estimated one out of 130-to-300 people.
"Equal recognition of celiac disease has been frustratingly slow to reach the U.S," says Guandalini, who trained in Italy. "In Europe, it typically takes a few weeks to go from the first symptoms to a diagnosis. In the U.S., the average lag time between onset and diagnosis is 11 years."
"If physicians believe that CD is rare, "note the study authors, "they are less likely to test for it." Third-party payers may compound that delay. In this study, insurance companies denied payment for an intestinal biopsy (to confirm the diagnosis) for 21 percent of the patients who had a positive blood test.
This study, the largest ever on the prevalence of celiac disease in the U.S., took place over five years and included blood samples from 13,145 adults and children from 32 states.
Blood tests were performed for about 9,000 people considered "at-risk" because they had relatives with celiac disease, symptoms such as diarrhea, or other disorders associated with celiac disease, such as diabetes or anemia. Another 4,000 study participants without symptoms or affected relatives were considered "not at-risk."
Celiac disease is an autoimmune disease, like type-1 diabetes or rheumatoid arthritis. Many scientists are beginning to suspect that celiac disease may "set the stage" for other autoimmune disorders, says Guandalini. "People who are diagnosed late or who continue to eat gluten have a higher prevalence of autoimmune diseases," he adds.
For someone to develop an autoimmune disease, explains Fasano, they must have a genetic predisposition and an environmental trigger. "Celiac disease is the only autoimmune disease where that trigger is known."
Today's study supports the case for screening for celiac disease. There is an accurate blood test that costs about $80.
"We are not ready to test the general population," says Guandalini, "but it now makes sense to screen those at risk: anyone with a close relative, children with gastrointestinal problems suggesting celiac disease or related conditions such as type-1 diabetes, short stature or Down syndrome, and adults with symptoms or with disorders that are associated with celiac disease, such as anemia, osteoporosis or infertility.
The centers involved in this study include the University of Maryland, University of Chicago, Columbia, Wake Forest, Marshall University, Children's Hospital of Los Angeles, Mayo Clinic and the Instituto per l'Infanzia Burlo Garofalo, Trieste, Italy. This study was funded by a grant from Istituto Di Ricerca C.C.S. Burlo Garafolo, and by many celiac patients, their families and friends.
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