RA occurs in an estimated 0.78 to 0.94 per cent of the adult population in Britain, with women two or three times more likely to suffer than men. Peak onset is in the 40-60 age group. Three quarters of cases are first diagnosed in people of working age. The highest prevalence is among the over 70s.1
RA is associated with genetic influences, especially the HLA-DRB1 gene, which may account for one third of genetic susceptibility. Smoking is associated with a doubling of RA risk in men and a 1.3 times increased risk in women. It may also increase the risk of severity and reduce the response to treatment.
As with OA, BMI is a significant factor in RA: being overweight increases RA risk by 15 per cent, while being obese increases risk by 21 to 31per cent.
Around one in six people with RA also have depression. RA is also associated with a doubling of the risk of a heart attack and a 30 per cent increase in stroke risk. One in ten people are also likely to develop interstitial lung disease, increasing the risk of early death.1
Two thirds of people (68 per cent) with RA are physically inactive. In addition to increasing the risk of falls, reduced mobility in RA and treatments such as steroids may potentially double the risk of OA.