(Reuters Health) – Adults with undiagnosed celiac disease often have nutritional deficiencies as the only sign of the disease, say researchers.
Doctors often look for typical signs like unexplained weight loss or extreme thinness, but the hallmark of celiac disease may be low levels of vitamins and other micronutrients, according to a report by Mayo Clinic Proceedings.
"People have preconceived ideas about what celiac disease is," said study co-author Dr. Joseph Murray, a professor of medicine at the Mayo Clinic in Rochester, Minn. "They expect to see patients who, because of malabsorption of nutrients and diarrhea, end up getting thin with many disabilities. But now we have many patients who have not lost weight – and many who are overweight – but still have micronutrient deficiencies. While they are not losing calories, they are not absorbing some vital nutrients. "
Practically speaking, this means that doctors need to be alert to low levels of certain micronutrients, particularly iron, vitamin D and zinc, Murray said. As many patients are not doing regular blood tests, they may need to be in tune with the telltale symptom of iron deficiency: fatigue, he added.
"It's a very common symptom," Murray said. "People come in and say they do not have the energy they used to use, whether during exercise or daily activities. This illustrates that they may be iron deficient because of the hidden celiac disease. They do not have diarrhea or abdominal pain but do not have iron because of damaged bowels. And although a patient who consumes large amounts of iron can absorb enough to correct the anemia, it will not correct the inflammation in the intestines and will not prevent other complications that may occur later in life. "
The initial screen for coeliacs is a blood test, Murray said. "If this comes back positive, the patient will need to be referred to a gastrointestinal specialist, since you want to make sure you are really celiac before you come to a life-long diagnosis that will require lifelong treatment."
Murray suspects that up to 50 percent of adults with celiac disease are not diagnosed because they do not have weight loss and other signs and symptoms considered typical of the disease or because they have placed themselves on a gluten-free diet that can distort the test results blood.
Murray and his colleagues closely examined the 309 newly diagnosed adults with celiac disease between 2000 and 2014. Patients were matched by age with participants from the National Health and Nutrition Examination Survey (NHANES), a nationally representative database.
When researchers compared newly diagnosed celiac patients to NHANES participants, they found some major differences in nutrient levels. Zinc was deficient in 59.4% of those with celiac disease versus 33.2% of controls; copper was low in 6.4% of celiac patients versus 2.1% of controls, folate was low in 3.6% of celiac patients versus 0.3% of controls and vitamin B12 was low in 5.3% of celiac patients versus 1.8% of controls.
Among the celiac patients, iron was low in 30.8%, but there were no controls with iron measurements to compare. And unlike traditional assumptions about celiac and thinness, weight loss was observed in only 25.2% of patients diagnosed with the disease.
Murray hopes the new study will alert early primary care physicians who may notice nutritional deficiencies in their patients. He warns them to remember "just because someone is overweight does not mean they do not have celiac disease."
Unfortunately, doctors tend to be caught treating symptoms instead of looking for an underlying cause, said Dr. David Whitcomb, a professor in the division of gastroenterology, hepatology and nutrition at the University of Pittsburgh. Although nutritional deficiencies are common in the general public, they are more common among people with celiac disease, Whitcomb said.
"The message is that if you see nutritional deficiencies, you should start thinking about celiac disease," Whitcomb said. "That way you can save these patients from damage to the intestines."
SOURCE: bit.ly/2XCi8Wq Mayo Clinic Proceedings, online June 24, 2019.