Family history increases risk of rheumatoid arthritis

The role of genes and environment in the development of rheumatoid arthritis have come under scrutiny again in a large study from the US. And the picture is becoming a little clearer.
The study looked if having family members with rheumatoid arthritis or lupus increased the risk of developing rheumatoid arthritis, and what role environmental factors played.
A total 65,457 women involved in the Nurses’ Health Study provided information on whether family members had rheumatoid arthritis/lupus. Of these, 493 cases of rheumatoid arthritis/lupus were validated.
After taking other factors into account (such as smoking, alcohol, body mass index, breastfeeding, menopause, hormone use and menstrual regularity) the experts found that family history of rheumatoid arthritis or lupus was associated with a higher chance of developing rheumatoid arthritis.
But the data showed that smoking, being overweight and premenopausal status made a difference too.
“Women with familial rheumatoid arthritis/lupus had a four-fold increased risk for rheumatoid arthritis that remained significant after adjusting for environmental factors,” the researchers conclude. “A large proportion of rheumatoid arthritis risk was attributable to environmental factors, even among those with familial rheumatoid arthritis/lupus.”
A spokeswoman for Arthritis Research UK comments:
“The genes you inherit from your parents may increase your chances of developing rheumatoid arthritis, but genetic factors alone do not cause it. Even if you have an identical twin, who shares all the same genetic material as you, and they have rheumatoid arthritis, you only have a one in five chance of developing it too. Lifestyle factors such as smoking and eating lots of red meat also play a part.
“Lupus isn’t passed directly from a parent to their children, but if you have a close relative with lupus you are at increased risk of developing it yourself. If you have lupus there’s about a one in 100 chance of your child developing it later in life.”

To read the original research click here.

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