"Our findings," explains lead study author Dr. Muhammad S. Panhwar, a resident in internal medicine at Case Western Reserve University in Cleveland, OH, "suggest that IBD should be considered an independent risk factor for heart disease."
The study is to feature at the 2018 annual scientific session of the American College of Cardiology, which will be held in Orlando, FL.
IBD is a long-term disease that inflames the gut, or gastrointestinal (GI) tract. The gut becomes inflamed because the immune system attacks healthy and beneficial cells — such as of the gut tissue and friendly bacteria — as if they presented a threat.
Two types of IBD
Because the symptoms of IBD are usually more aggressive — with more frequent flare-ups — in women and younger people, these groups are thought to have higher levels of inflammation.
Estimates based on survey data collected in 2015 suggest that around 3 million adults in the United States "have ever received a diagnosis of IBD." This figure is one third higher than the 2 million estimated in 1999.
Celiac disease should also not be confused with IBD, although it has some of the same symptoms and also inflames the gut. Celiac disease is caused by a specific immune response to gluten, a group of proteins that are present in some grains such as wheat.
IBD patients have independent heart risk
For their analysis, Dr. Panhwar and colleagues used anonymized data from the electronically stored medical records of more than 17.5 million people, aged 18–65, who belonged to 26 healthcare systems across the U.S.
From the data, they were able to identify which people had been diagnosed with IBD in 2014–2017, and which people — with and without IBD — had experienced heart attacks.
The results showed that 211,870 of the people had been diagnosed with IBD, which is 1.2 percent of the total and in keeping with official U.S. population estimates.
The team found that traditional risk factors for heart disease — such as smoking, diabetes, high blood pressure, and high cholesterol — were more common in people with IBD.
They also found that people with IBD were twice as likely to have experienced a heart attack as people without IBD.
However, even after the results were adjusted to remove the influence of the traditional risk factors and demographic characteristics such as age, gender, and race, they showed that people with IBD still had a higher risk for heart attack.
This independent risk was 23 percent higher than the risk of heart attack in people without IBD.
IBD patients must be 'aggressively screened'
A comparison of subgroups also revealed that women with IBD under 40 years of age were at higher risk for heart attack than men with IBD of the same age.
Above the age of 40, the risk of heart attack was similar in both males and females with IBD.
Dr. Panhwar suggests that physicians should be aggressive in screening IBD patients for heart disease and adopting strategies to reduce the risk.
"Our study adds considerably to a growing set of literature highlighting the importance of chronic inflammation in IBD as having a role in the development of heart disease."
Dr. Muhammad S. Panhwar