In a study of more than 6,000 people from around the world who had RA, about 79 percent of them women, Finnish researchers found that women had poorer outcomes in key measures such as symptoms and severity, especially in areas based on their responses to questionnaires.

The findings appear in the online journal Arthritis Research and Therapy.

"Obvious differences between genders exist in the prevalence, age at onset and level of production of harmful arthritis autoantibodies," study leader Tuulikki Sokka, a rheumatology consultant at Jyväskylä Central Hospital in Finland, said in a news release issued by the journal. "Furthermore, women report more symptoms and poor scores on most questionnaires, including scores for pain, depression, and other health-related items."

Some gender differences, though, stem from how disease activity is measured rather than from the disease itself, Sokka said.

"Women have less strength than men, which has as much of a major effect in the functional status of patients with RA as it does in the healthy population," Sokka said. "In fact, the gender differences in musculoskeletal performance remain, even among the fittest individuals." That's why, she said, male and female athletes generally don't compete against one another.

"Given that [a] woman is the 'weaker vessel' concerning musculoskeletal size and strength, and her baseline values are lower than men's, the same burden of a musculoskeletal disease may appear to be more harmful to a woman than to a man," Sokka explained.

More information

The National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about rheumatoid arthritis.