More and More Women Diagnosed with Rheumatoid Arthritis

During the period of 1995 to 2007, the incidence of rheumatoid arthritis has risen in women, according to a published study in the journal of Arthritis & Rheumatism.

The study was performed by researchers from the Mayo Clinic. The researchers suggested that environmental factors, such as cigarette smoking, vitamin D deficienct, and lower dose synthetic estrogens in oral contraceptives, may be responsible for the increase. The rise in RA follows a four-decade period of decline.

The study, led by Sherine Gabriel, MD, MSc, included more than 50 years of RA epidemiology data. The team expanded on prior research and screened the medical records of 1,761 Olmsted County, Minesota residents age 18 and older who received one or more diagnoses of arthritis, with the exception of degenerative arthritis or osteoarthritis. A diagnosis of RA was made in 466 patients. The mean age at RA incidence was 55.6 years, with 321 females (69%) in the study cohort.

“We observed a modest increase of RA incidence in women during the study period, which followed a sharp decline in incidence during the previous 4 decades," said Gabriel, in a news release.

From 1995 to 2007, RA incidence in women increased by 2.5% per year. A decrease of 0.5% was reported for men within that time frame.

"As expected we found an increase in RA prevalence during the same time period," said Gabriel, in a news release.

The age- and sex-related prevalence of RA increased from 0.62% in 1995 to 0.72% in 2005.

"Reasons for the increase in incidence we found are unknown, but environmental factors likely play a role and should be further explored," Gabriel said, in a news release.