Even on a gluten-free diet, symptoms that led to diagnosis continue, study finds
By Amy Ratner, director of scientific affairs
Even when on a gluten-free diet more than half of those with celiac disease remained symptomatic during the five years after diagnosis, a study presented recently at Digestive Disease Week (DDW) found.
Many of these patients had the same symptoms that prompted them to be diagnosed in the first place, according to the researchers affiliated with Harvard University, the Mayo Clinic and the University of Washington.
The study was based on a review of the medical charts of 212 biopsy-confirmed celiac disease patients following a gluten-free diet who were seen at Mayo Clinic between 2012 and 2018 and agreed to join a celiac disease registry. They also had at least two follow-up visits in the first five years after diagnosis and a follow-up biopsy.
In each year from the first to the fifth about 60 percent of patients reported being symptomatic. Thirty-four percent, or 72 patients, were symptomatic at all visits over five years, of which 16 had the same symptoms that prompted diagnosis.
In those who had symptoms, the symptoms that led to diagnosis lingered for the first year in more than 75 percent, for the second year in about 60 percent and in about 50 percent for the third through fifth years. “Those complaining of the same symptoms they had at diagnosis were more prevalent at earlier follow-up than later,” the study says.
Men and those who were diagnosed at an older age “were significantly associated with a lower risk of being symptomatic,” the study found. It included almost 70 percent women. The average age of participants was 43 years old.
At diagnosis, about half of the celiac disease patients had gastrointestinal symptoms only, nearly 15 percent had non-gastrointestinal symptoms only, about 30 percent had a combination of gastrointestinal and non-gastrointestinal symptoms and about 6 percent had no symptoms.
The most common gastrointestinal symptoms at diagnosis were diarrhea, abdominal pain, weight loss, bloating and constipation. Anemia, fatigue, joint stiffness, headache and peripheral neuropathy were the most common non-gastrointestinal symptoms.
Results of the anti-tissue transglutaminase immunoglobulin A (TTG) blood test for celiac disease and biopsies were not significantly associated with being symptomatic or not, said Isabel Hujoel, MD, lead study author and a gastroenterologist at the University of Washington Medical Center.
However, when researchers looked at causes for ongoing symptoms in those who showed healing of the lining of the intestine through a follow-up biopsy, they found that physicians most frequently cited microscopic colitis or irritable bowel syndrome (IBS). More than two thirds of patients who had biopsies had intestinal healing.
Microscopic colitis is an inflammation of the large intestine that causes persistent watery diarrhea. Colon tissue is examined under a microscope to diagnose the condition, which is associated with celiac disease and other autoimmune conditions. IBS also affects the large intestine, causing cramps, abdominal pain, bloating, gas, diarrhea or constipation or both. There is no test for IBS, and it is usually diagnosed when other conditions have been ruled out, called a diagnosis of exclusion.
Researchers’ review of the nearly one third of patients whose biopsy showed ongoing damage of the intestine, found that gluten exposure was the most frequent cause cited by physicians. Nine patients did not have a follow-up biopsy over the five years after diagnosis.
Patients had an average of three follow-up doctor visits over the five years.
Close follow-up is needed during the initial years after a celiac disease diagnosis, the study concludes. Additionally, other causes for celiac disease symptoms post diagnosis should be evaluated, the authors wrote in their poster presentation at DDW, an annual conference for physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery.
Previous studies have also shown that people with celiac disease on the gluten-free diet continue to have symptoms, elevated antibodies to gluten detected in blood tests and damage to the nutrient lining of the intestine.
Studies have shown that even after two years on the gluten-free diet, 30 to 60 percent of adults with celiac disease have persistent gut damage. Data also suggests that this is true in more than 33 percent of adults regardless of having symptoms or positive blood tests.
Non-responsive celiac disease, which is defined as persistent symptoms, signs or abnormalities typical of the condition despite 6 to 12 months of strict adherence to a gluten-free diet, affects up to 30 percent of patients, according to a 2020 study.
Researchers at the University of Chicago Celiac Center found in a 2017 study that even after more than two years on the gluten-free diet about 60 percent of children and adults have ongoing non-gastrointestinal symptoms. Short stature, fatigue and headache were most common in children, while iron deficiency anemia, fatigue, headaches and psychiatric symptoms were most common in adults.
A 2016 study of children with celiac disease found one in five may not heal despite following the gluten-free diet for at least a year. The children, who were seen between 2008 and 2015, also had a follow-up biopsy at least 12 months after starting a gluten-free diet. The study found that 19 percent had persistent intestinal damage when the second biopsy was done.
A study by researchers in Rome found that about one-third of people with celiac disease on the gluten-free diet had persistent symptoms or signs of malabsorption at the point when a follow-up biopsy was done. People with celiac disease who seem to be doing well on a gluten-free diet may have ongoing, low-level intestinal inflammation, according to another new study that looked at complete protein profiles in biopsy samples. Study authors said their findings raise the question of whether the standard gluten-free diet is sufficient to stop the immune reaction that occurs in celiac disease.