Rheumatoid arthritis is one of the autoimmune diseases in which the gender difference is clear: the incidence is in fact two to three times greater in the female sex. For this reason, hormones and hormonal variations typical of the female genus may also play a role in the risk of onset of the disease. According to recent research carried out between Sweden and the United States, oral contraceptives are associated with a reduction in risk. We talk about this topic with Professor Carlo Selmi, Head of Rheumatology and Clinical Immunology at Humanitas Hospital and lecturer at the University of Milan.
In addition to contraception, the authors of the research published in the Annals of the Rheumatic Diseases also investigated the relationship between the risk of rheumatoid arthritis and breastfeeding. The research team analyzed the data for more than 2,600 women affected by this disease compared to about 4,100 women in the control group. All women, at least eighteen years old and living in Sweden, had taken part in a previous study. The level of anti-citrulline antibodies (ACPAs), highly specific antibodies to rheumatoid arthritis, had been measured in a blood sample.
It was found that women who had taken oral contraceptives had a lower risk of developing rheumatoid arthritis than those who had never taken oral contraceptives: lower than 15% in women who were following contraceptive therapy and 13% in women who had taken contraceptives before taking part in the study. The association was significant for women who tested positive for anti-citrulline antibodies.
Taking the “pill” for a little over seven years (average duration among participants) was associated with a 19% reduction in risk, whether the ACPA test was positive or negative.
What can this association explain?
The mechanism could be the same that explains the improvement of rheumatoid arthritis during pregnancy. It is women’s hormones, especially estrogens, that have a possible non-negative impact on the patient affected by rheumatoid arthritis,” says the professor. In any case – he emphasizes – it is not possible to sustain in any way that hormonal contraception can be included in the therapy of rheumatoid arthritis”.
Another important fact emerges from the research: “Although seropositivity to anti-citrulline antibodies does not give the certainty of developing rheumatoid arthritis, subjects positive to this test may develop a more severe form of rheumatoid arthritis”.
Lifestyle and Rheumatoid Arthritis Risk
The study, of an observational nature, which therefore does not conclude data in terms of cause and effect, finally found no significant association between breastfeeding and the risk of rheumatoid arthritis.
What advice can you give for the prevention of this inflammatory disease? “The only virtuous behavior that can be adopted for this purpose is to abstain from cigarette smoking,” concludes Professor Selmi.