Celiac disease (CD) is an inflammatory gastrointestinal disorder that harms the small intestine and is triggered by gluten-containing foods. The disorder affects around 1 in 141 people in the United States, according to the National Institute of Diabetes and Digestive and Kidney Diseases, and it tends to be more prevalent in women.
People with AN may perceive themselves as overweight when, in fact, they may be the opposite. Although the disorder affects both genders, anorexia is 2.5 times more prevalent in women.
Both of these conditions tend to affect adolescents and young adults in particular, so a team of researchers set out to examine the link between the two conditions in young women.
The findings were published in the journal Pediatrics, and the first author of the study is Dr. Karl Marild of the Barbara Davis Center at the University of Colorado.
Studying the link between CD and AN diagnoses
The study examined 17,959 Swedish women who were diagnosed with CD between 1969 and 2008. The median age at which participants received their CD diagnosis was 28 years, and 353 participants were diagnosed with AN at a median age of 17 years.
The patients were clinically followed for 1,174,401 person-years. "Person-time" is a measurement commonly used in health studies to calculate incidence rates of an illness. It combines the number of participants and the time they spent contributing to the study.
The researchers also examined a control group of 89,379 women who did not have CD.
A total of 54 of the almost 18,000 patients with CD received a diagnosis of AN, compared with 180 of their 89,379 age-matched counterparts. This corresponds to an incidence rate of AN after a CD diagnosis of 27/100,000 person-years.
Some of the patients had a record of AN before being diagnosed with CD - more specifically, 33 participants with CD and 76 control participants had a history of AN before their CD diagnosis.
Adults with CD have double the rate of subsequent AN
Overall, the study revealed a "bidirectional" association between CD and AN both before and after receiving the CD diagnosis.
More specifically, adults aged 20 and over who had been previously diagnosed with CD were twice as likely to develop AN later in life than their CD-free counterparts, and young women who were diagnosed with CD before the age of 19 were 4.5 times more likely to have also been previously diagnosed with AN than the controls.
The results remained the same after the researchers adjusted for socioeconomic variables and type 1 diabetes.
Because the study was observational, researchers could not draw any conclusions on causality. However, they speculate that a possible reason for the association could be that people with CD were initially misdiagnosed with AN, or the other way around. This may be due to the fact that the two chronic gastrointestinal disorders have very similar symptoms.
In a commentary accompanying the study, authors Neville H. Golden and K.T. Park suggest that an "excessive focus on diet in patients with CD may lead to development of AN in susceptible individuals." Golden and Park also write:
"An important finding of this study is that misdiagnosis or delayed treatment of CD can occur during adolescence, a particularly vulnerable period of growth and development.
The findings of this study warrant attention both in the initial clinical assessment and ongoing reassessment of both conditions, especially in those patients not responding to traditional therapy. "