Study Suggests Rheumatoid Arthritis Getting Rarer

April 9, 2002

Mon Apr 8, 5:26 PM ET

By Will Boggs, MD

NEW YORK (Reuters Health) - Rheumatoid arthritis (RA) has become less

common over the past 40 years, but the survival rate of patients with RA

has not improved, according to a report.

This decline suggests, say Dr. Sherine E. and colleagues from

Mayo Clinic in Rochester, Minnesota, that environmental factors may play

a role in causing RA.

RA is a chronic disease marked by inflammation in the joints that causes

pain, swelling and loss of mobility. It is an autoimmune disease,

meaning it arises from an abnormal immune system attack on the body's

own tissue.

and her team reviewed medical records of Rochester residents to

investigate trends in RA incidence and mortality between 1955 and 1994.

Their findings are published in the March issue of Arthritis &

Rheumatism.

The average age at diagnosis of RA remained the same over the study

period, at 58 years, the authors report.

Overall and by gender, the incidence rate of RA declined progressively

over time, the researchers note. The overall incidence fell from 61.2

people with RA per 100,000 in 1955-1964 to 32.7/100,000 by 1985-1994.

The incidence fell more markedly in women than in men.

Survival in RA patients was significantly lower than in the general

population, the investigators note, with these patients facing a 27%

increased risk of death. Survival remained " nearly identical " over time.

" The incidence of RA appears to be declining, and the findings suggest

that an environmental factor may play a role in etiology, " or cause,

told Reuters Health. favors an etiology involving " an

environmental/infectious agent with a latent period between exposure and

disease affecting a genetically susceptible host. "

SOURCE: Arthritis & Rheumatism 2002;46:625-631.

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