Results of a new Mayo Clinic study suggest that the incidence of rheumatoid arthritis (RA) among American women is on the rise, and that environmental factors—such as vitamin D deficiency, smoking and oral contraceptive use—may be to blame.
The findings are especially worrisome due to the fact that the number of reported cases of RA had declined for four consecutive decades before the latest study period.
Lead study author Sherine Gabriel and her colleagues found that the incidence of RA in women increased by 2.5 percent per year from 1997 to 2005. In contrast, the occurrence of the condition among men fell by 0.5 percent each year during the same period.
While the reasons for the increase in reported cases of RA is not known, the research team suggests that individuals may be able to lower their risk of developing the condition by changing their behaviors and utilizing vitamin D supplements.
"Public health measures are already under way to address many of the environmental risk factors that have been implicated in RA risk, including interventions that encourage smoking cessation and efforts focused at optimizing levels of physical activity, vitamin D intake, and oral hygiene," said Ted Mikuls, of the University of Nebraska Medical Center, in an accompanying editorial.