MONTREAL, April 8 (UPI) -- Canadian researchers have linked initial use of oral contraceptives to an increased risk of lupus.
The study, published in Arthritis Care & Research, finds a significant increased risk of newly diagnosed systemic lupus erythematosus associated with the first three months of use of first- and second-generation contraceptives containing higher doses of estrogen.
Hormones are believed to play a role in systemic lupus erythematosus because the ratio of women to men with systemic lupus erythematosus -- an autoimmune disease -- is 9 to 1 and the incidence increases after puberty.
Study leader Dr. Samy Suissa of the Center for Clinical Epidemiology at Jewish General Hospital of McGill University in Montreal used data for 1.7 million women ages 18-45 taken from the United Kingdom General Practice Research Database of more than 6 million people.
The women, all of whom had been prescribed combined oral contraceptives containing estrogen and progestogen were followed for eight years. A first time systemic lupus erythematosus diagnosis was found in 786 women, usually in the first three months of combined oral contraceptives use.
