Rheumatoid arthritis and oral contraceptives in the Greek female population: a case-control study
Linos, A.; Kaklamanis, E.; Kontomerkos, A.; Vagiopoulos, G.; Tjonou, A.; Kaklamanis, P.
British Journal of Rheumatology 28(Suppl 1) 37; Discussion: 42-45
1989
ISSN/ISBN: 0263-7103 PMID: 2819350 DOI: 10.1093/rheumatology/xxviii.suppl_1.37Document Number: 375390
A case control study of rheumatoid arthritis and oral contraceptives (OC) or postmenopausal hormones was begun in women aged 20 in 2 hospitals in Athens, with same hospital, age-matched controls. Cases have diagnosed definite or classical rheumatoid arthritis and are being treated in rheumatology clinics. To date 135 cases and 104 controls have been interviewed. 5 cases (3.7%) and 5 controls (4.8% used OCs, with a mean duration of 2 years for both, giving a relative risk of 0.76. 8 more cases and 6 controls were found who used OC for regulation of their menstrual cycle. 1.5% of cases and 3.8% of controls had used post-menopausal hormones. Univariate analysis showed that the cases had later menarche and fewer pregnancies and live births. Multiple regression analysis did not find OC or postmenopausal hormones significantly linked with rheumatoid arthritis. Number of pregnancies and children, however, were significantly higher in controls. Because of the small numbers and low power of the study, more subjects are being collected.