Women with celiac disease may be more likely to also be diagnosed with the eating disorder anorexia nervosa, researchers suggest.

In a  large  study, a diagnosis of anorexia nervosa was more likely both before a celiac disease diagnosis, and afterward.

“Before this study, there have been published a few small `case reports’ of patients with celiac disease developing eating disturbances after their celiac disease diagnosis,” said lead study author Dr. Karl Marild, a researcher at the University of Colorado in Aurora.

“This, however, is the first large study to show an association between celiac disease and anorexia nervosa,” Marild said by email.

Anorexia nervosa is an emotional disorder that involves an obsessive desire to lose weight by refusing to eat. Celiac disease is an autoimmune disorder in which consumption of the gluten protein in wheat, barley or rye leads to damage of the small intestine and problems with absorption of nutrients from food.

The two disorders sometimes share similar symptoms, like fatigue, abdominal problems, discomfort after eating, excessive weight loss and an inability to absorb certain nutrients.

For the study, researchers examined data collected from 1987 through 2009 on almost 18,000 Swedish women diagnosed with celiac disease and roughly 89,000 women around the same age who didn’t have the autoimmune disorder.

After a celiac disease diagnosis, women were 46 percent more likely to be diagnosed with anorexia nervosa, researchers report in Pediatrics. After an anorexia diagnosis, women had twice the odds of a later diagnosis of celiac disease.

More specifically, each year during the study period, a new diagnosis of anorexia nervosa was made in about 0.03 percent in women with a diagnosis of celiac disease, compared to about 0.02 percent in women without celiac disease.

Also, the researchers report, nearly 0.2 percent of women with celiac disease had been previously diagnosed with anorexia nervosa, compared to only about 0.1 percent of women in the study who didn’t have celiac disease.

The study wasn’t a controlled experiment designed to prove that celiac disease causes anorexia, or that the reverse is true, the authors note.

It’s possible that at least some patients were initially misdiagnosed with one disease when they had the other disorder, the researchers point out. At least some of the overlap in diagnoses of both conditions might be explained by what’s known as “surveillance bias,” or the fact that women being closely monitored due to one issue with eating might be more likely to be evaluated for another food-related health problem.

In addition, dietary restrictions prescribed for celiac disease might trigger an obsessive eating pattern that leads to anorexia, Marild said.

The potential for misdiagnosis may be particularly important in treating teens, Dr. Neville Golden, an adolescent medicine researcher at Stanford Children’s Health in California writes in an accompanying editorial.

“Both celiac disease and anorexia nervosa may have similar symptoms: abdominal discomfort after eating, a feeling of fullness, changes in bowel habits and weight loss,” Golden said by email. “So the correct diagnosis may not always be clear.”

With either diagnosis, it’s important that patients see a specialist, said Alice Bast, chief executive officer of Beyond Celiac, a patient advocacy organization.

“The higher level of scrutiny by informed healthcare providers may unearth problems that might fly under the radar otherwise,” Bast, who wasn’t involved in the study, said by email.