New research shows that rheumatoid arthritis (RA) can triple the risk of dying prematurely from heart disease in people with a particular gene-set.
Inflammation associated with the disease is thought to help the process which blocks arteries, and researchers have now discovered that whether or not this happens appears to depend on an immune system gene called HLA-DRB1.
And the study, published in the journal Arthritis & Rheumatism, found that having certain versions of the gene together with a particular type of antibody and a smoking habit created a potentially deadly combination.
The Arthritis Research Campaign-funded study focused on 1,022 patients, mostly women, who began to show symptoms of (RA) at around the age of 54.
Over the course of a year, 24% of the patients died and in just under a third of these cases cardiovascular disease was given as the cause of death.
For individuals with hazardous versions of the HLA-DRB1 gene, the risk of heart disease death was increased more than three-fold, and the impact was aggravated by the interaction with smoking.
Professor Alan Silman, medical director of the Arthritis Research Campaign and one of the researchers, said: "We have known for some time that smoking is a major risk factor for developing rheumatoid arthritis, but this study confirms that rheumatoid arthritis patients with this particular genetic variant who continue to smoke are putting themselves in considerable danger of life-threatening cardiovascular disease."