One of the world’s most common genetic diseases — celiac disease — may double the risk of coronary heart disease while raising stroke risk slightly.

Researchers at the Cleveland Clinic said this weekend their new study adds to an “evolving” understanding of how systemic inflammation and autoimmune processes might affect the development of heart disease.

Approximately one percent of the world population suffers celiac disease, a chronic inflammatory condition of the digestive system that damages the small intestine. In advanced stages, people with the disease lose the ability to digest gluten, a protein found in wheat, rye, and barley. Scientists believe the protein is important as a trigger of immune and inflammatory response in the digestive system.

"People with celiac disease have some persistent low-grade inflammation in the gut that can spill immune mediators into the bloodstream, which can then accelerate the process of atherosclerosis and, in turn, coronary artery disease," researcher R.D. Gajulapalli said in a statement. "Our findings reinforce the idea that chronic inflammation, whether it's from an infection or a disease, can have an adverse role in coronary artery disease and heart health in general."

In the study, Gajulapalli and his colleagues analyzed the electronic health records of some 22.4 million patients in 13 health care systems between 1999 and 2013, including some 24,530 with celiac disease. In comparing those patients with others, researchers found no difference diabetes and smoking. They had higher levels of cholesterol but were less likely to have higher blood pressure. Yet the doubling of risk for coronary heart disease, along with the slightly elevated risk for stroke, held after considering such other risk factors as sex, race, diabetes, high blood pressure, and smoking.

Patients older than 65 years of age with celiac disease were significantly more likely to develop coronary heart disease at 9.5 percent of patients, compared to only 5.6 percent of others. But those adult patients 18 to 65 were also more likely to develop the same, at 4.5 percent compared to 2.4 percent.

"This is an important study because it highlights a specific patient population who might be at higher risk for coronary artery disease, even in the absence of traditional cardiovascular risk factors," Gajulapalli said. "We were surprised by the strength of the association, especially in younger people. Patients and doctors should be aware of this association."

Presenting the evidence at the American College of Cardiology’s annual meeting, the researchers called for improved diagnosis of celiac disease, particularly given the association with heart disease and stroke. Though common in the United States with a prevalence of one in 133 Americans, celiac disease is misdiagnosed as much as 80 percent of the time, confused with conditions such as irritable bowel syndrome or lactose intolerance. And the disease is on the rise, the researchers said, noting a quadrupling of prevalence during the past 50 years.

"Whether patients with celiac disease will need more intense risk factor modification like in diabetic patients with coronary artery disease will need to be studied," Gajulapalli said. “For now, he says people with this and other inflammatory diseases should maintain a healthy lifestyle and be aware of traditional cardiovascular risk factors including diabetes, high blood pressure and high cholesterol.”

The researchers added that additional study should examine any possible connection between non-celiac gluten allergies and increased risk for coronary heart disease and stroke.