Use of oral contraceptives for 7 or more consecutive years associated with lower risk of rheumatoid arthritis.
The use of oral contraceptives is linked to a lower risk of rheumatoid arthritis (RA), new findings show.
RA is 2 to 3 times more common in women than men. Although research suggests RA may be caused by reproductive and hormonal elements, data have failed to produce conclusive results.
In a study published in the Annals of Rheumatic Diseases, investigators sought to examine the potential link between the development of RA and oral contraceptives and/or breastfeeding among adult women with at least 1 child.
Data were used from the Swedish Epidemiological Investigation of Rheumatoid Arthritis, which was comprised of women 18 years and older residing in a defined area of Sweden between 1996 and 2014.
Overall, 2578 women with arthritis and 4129 matched controls were included in the final analysis. Blood samples were obtained from all participants to screen for antibodies to RA. Furthermore, the participants were questioned in-depth about contraceptive and reproductive histories, lifestyle, whether they breastfed their kids, and level of education.
Of the participants, 884 women with RA and 1949 controls had breastfed at least 1 child between the 2006 and 2014.
The results of the study showed women who used oral contraceptives at any point had a lower risk of developing RA than women who never had.
The risk was 15% lower in women currently on the pill and 13% lower among past users. Furthermore, the association was more significant among women who tested positive for anti-citrullinated protein antibodies (ACPA) compared with women who had never used the pill. This finding held true even after the investigators accounted for tobacco use and alcohol consumption.
Use of the pill for more than 7 years was associated with a 19% lower risk of RA, with no differences found if women tested positive or negative for ACPA.
An estimated 9 of 10 individuals who test positive for ACPA antibodies will have RA, which could even indicate more serious disease.
A lower risk of RA was identified among women who had breastfed at least 1 child, but this was found to not be significant after adjusting for potential factors.
RA affects more than 1.3 million individuals in the United states, and as many as 1% of the population worldwide. It is one of the most common autoimmune disorders.