Sibling study provides clues to the link between cardiovascular disease and RA

It has been known for quite some time that rheumatoid arthritis (RA) gives a slightly increased risk of cardiovascular disease. Researchers, however, do not yet know exactly why this is. A new study, which shows a slightly increased risk of cardiovascular disease in the siblings of people with RA, may, however, provide new clues.

Researchers at Karolinska Institutet and Umeå University used the Swedish rheumatology register SRQ to study 7,492 people with RA and 10,671 of their siblings who share both parents. When they combined the data with other registers, they found that the siblings of people with RA had a slightly increased risk of developing cardiovascular disease when compared with people who were not siblings of a person with RA.

- The siblings end up somewhere between RA patients and the general population when it comes to risk increase. This indicates that it is not simply the increased inflammation in RA causes the increased risk of suffering from cardiovascular disease, said Johan Askling to the Dagens Medicin periodical

The study did not correct the figures for influences such as smoking and socioeconomic factors. But the researchers now plan to go further to distinguish whether the increased risk is due to lifestyle and other environmental factors or whether the reason that siblings of people with RA also have an increased risk of cardiovascular disease is genetic.

The study may lead to increased knowledge about why people with RA have an increased risk of cardiovascular disease. But even now, researchers can say that it is not only the increased inflammation in the bodies of people with RA which gives the increased risk. This could lead to new advice on preventing cardiovascular disease in people with RA.

Article in Dagens Medicin (swe): https://www.dagensmedicin.se/artiklar/2018/06/15/syskon-till-ra-patienter-kan-ha-okad-risk-for-hjart--karlsjukdom/

Science report in Annals of the Rheumatic Diseases: https://ard.bmj.com/content/77/Suppl_2/119.1