Why are rheumatoid arthritis patients at risk of heart disease?

Treating rheumatoid arthritis patients with a high-density lipoprotein (HDL) may limit their risk of developing heart disease, according to a study by Melbourne researchers.

Conducted by the Baker Heart and Diabetes Institute, in collaboration with the Walter and Eliza Hall Institute and the University of Alabama at Birmingham, the study highlights the different cellular response in mice with rheumatoid arthritis towards the progression of heart disease, compared with those with traditional risk factors. It has been published in the European Heart Journal.

“While it is well known that rheumatoid arthritis causes external physical problems such as swelling of the joints, at a cellular level it can also cause inflammation and activation of the immune system leading to development of chronic conditions like heart disease,” said Associate Professor Andrew Murphy, lead author on the study.

“The study highlights that rheumatoid arthritis is a chronic inflammatory disorder that significantly increases the risk of cardiovascular disease independent of traditional risk factors, making risk assessment for heart disease challenging.”

The study identified the mechanism behind this specific pathway in mice with rheumatoid arthritis — an increase in the number of circulating myeloid cells associated with advancement of heart disease. The good news is, targeting these cellular cholesterol defects through an injection of reconstituted HDL could limit plaque build-up and, therefore, the possibility of heart disease.

The altered cellular cholesterol findings were also observed in people with rheumatoid arthritis, indicating that people with an autoimmune disease might be on a dangerous pathway that could lead to heart attack and stroke if they are not managed differently to the general population. The research may additionally have implications for people with other autoimmune diseases such as lupus, said Associate Professor Murphy, which also places them at high risk of heart disease.

He said the next step is to identify what causes accumulation of cellular cholesterol, particularly in the stem cells that make circulating white blood cells, and to explore if new anti-inflammatory therapies being trialled to reduce heart disease are more effective in individuals with autoimmune disorders.

Image credit: ©stock.adobe.com/au/verinize