Research has linked heart disease to specific autoimmune diseases such as rheumatoid arthritis and lupus. Now, a huge study shows that autoimmune diseases as a group increase your chances of developing heart ills.
Autoimmune diseases such as psoriasis, multiple sclerosis, lupus erythematosus and type 1 diabetes occur when the body engages in friendly fire against its own organs, tissues, joints or bones.
These diseases may more than triple the odds for heart woes, and the excess risk is especially high among younger patients, the study found.
The new study wasn't designed to say how autoimmune diseases are linked to the risk of heart disease, but researchers have their theories.
"Chronic and systemic inflammation is a common denominator across most autoimmune conditions and has been shown to cause a whole range of heart and blood clotting problems," said study co-author Nathalie Conrad, an epidemiologist in cardiovascular science at the University of Leuven in Belgium.
There's likely more to this story, she said. Autoimmune diseases affect connective tissues, small blood vessels and heart cells, and this can result in an increased risk for heart disease.
Shared risk factors likely play a role, too. "We do know that smoking, for example, is a risk factor for certain autoimmune conditions [multiple sclerosis or rheumatoid arthritis], and the same applies to obesity," Conrad said.
There could also be genetic factors involved, she said.
For the study, researchers tapped into electronic health records from the UK's Clinical Practice Research Datalink for information on more than 446,000 people who were newly diagnosed with 19 of the most common autoimmune disorders between 2000 and 2017. All were free of heart disease for at least a year after their diagnosis. Researchers then compared the rate of several types of heart disease among people with and without an autoimmune disease.
The main finding? People with autoimmune disease may be 40% to more than three times more likely to develop heart disease than people without an autoimmune disorder, depending on the specific autoimmune condition. This increase is comparable to what is seen with type 2 diabetes, a well-known risk factor for heart disease.
The autoimmune disorders linked to the highest excess risk were systemic sclerosis, Addison's disease, lupus and type I diabetes, the study showed.
The increased risk for heart disease was particularly high for folks with autoimmune conditions who were younger than 55, the study showed.
The findings held even after researchers controlled for known heart disease risks such as age, blood pressure, body mass index (BMI), smoking, cholesterol and type 2 diabetes.
Follow healthy guidelines
People with an autoimmune disease should follow the general screening and prevention measures for heart disease, including eating a healthy diet, not smoking, and making sure blood pressure and cholesterol levels are where they should be, Conrad noted.
"We know that [cholesterol-lowering] statins are effective in reducing cardiovascular disease in patients with high inflammation, even in those with no other risk factors and normal cholesterol levels," she said. Anti-inflammatory therapy also improves heart outcomes in people with high levels of inflammation.
"Future clinical trials that test the effectiveness of these drug therapies [and possibly new ones] in patients with autoimmune disease will help to derive autoimmune disease-specific prevention measures and implement these in routine clinical practice," Conrad said.
The new findings were presented at the annual meeting of the European Society of Cardiology, in Barcelona, and published Aug. 27 in The Lancet.
Outside experts point out that knowledge is power when it comes to improving heart health in people with autoimmune diseases.
"It has been known for a long time that there is substantially increased risk for cardiovascular disease in many inflammatory and autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus [SLE], inflammatory bowel disease and psoriasis," said Dr. S. Louis Bridges Jr., physician-in-chief and chief of rheumatology at Hospital for Special Surgery in New York City.
There are several possible explanations for this link, he said. Risk factors for heart disease, such as high blood pressure, high cholesterol, smoking and obesity, are more common in some of these diseases than in the general population, he explained.
Medication may play a role
"Drugs commonly used to treat autoimmune diseases, such as corticosteroids, are also likely important factors in the increased risk of [heart disease] in patients with autoimmune diseases," Bridges said.
He echoed that there are ways to keep your heart healthy, including eating a healthy diet, staying physically fit, maintaining a healthy weight, exercising and being active, not smoking, and drinking alcohol in moderation.
"Other tips that apply include managing stress, keeping good oral hygiene, and getting enough sleep," Bridges added.
Autoimmune diseases often start at a younger age than heart disease. "It is very important that young persons with autoimmune disease think about the many years that they will live with their condition," Bridges noted. Be aware of your cholesterol and blood pressure and other risk factors and let your primary care provider know you are concerned about autoimmune disease as a risk factor for heart disease, he suggested.
Dr. Aeshita Dwivedi, a cardiologist at Lenox Hill Hospital in New York City, agreed.
"This study adds to the growing body of evidence that patients with underlying autoimmune conditions are at a higher risk for cardiac conditions," said Dwivedi, who has no ties to the research.
"This study also may assist physicians in being more vigilant about cardiac risk evaluation in patients with autoimmune disease," she said. "When caring for these patients, aggressively treating risk factors like high blood pressure and high cholesterol is key to preventing adverse cardiac events."
Proactively referring people with autoimmune diseases for cardiac evaluation is also important, Dwivedi said.
The American Heart Association has more on the link between inflammation and heart disease.
SOURCES: Nathalie Conrad, PhD, epidemiologist, cardiovascular science, University of Leuven, Leuven, Belgium; S. Louis Bridges Jr., MD, PhD, physician-in-chief, chief, Division of Rheumatology, Hospital for Special Surgery, New York City; Aeshita Dwivedi, MD, cardiologist, Lenox Hill Hospital, New York City; European Society of Cardiology meeting, Barcelona, Spain; The Lancet, Aug. 27, 2022