Contraceptive pill could raise lupus risk

Wed April 8th, 2009

Women who take the contraceptive pill may be at an increased risk of lupus, according to new research.

It is thought that this autoimmune disease is linked to hormones, as it occurs nine times more often in women than in men, particularly between the ages of 15 and 50.

A new study carried out by Dr Samy Suissa of McGill University in Montreal, Canada, suggests that oral contraceptives are linked to an increased risk of lupus. It was based on more than 1.7 million women in the UK, aged between 18 and 45 years, all taking the combined pill which contains oestrogen and progestogen.

The women were followed for an average of eight years, during which time 786 of the women were diagnosed with lupus.

In the April issue of Arthritis Care & Research, the team report that taking the pill "was associated with a significant increased risk of newly diagnosed lupus". They found that this link was mainly seen in the first three months of use with first- and second-generation contraceptives, which contain higher doses of estrogen.

This suggests "an acute effect in susceptible women and possibly a dose-response effect of oestrogen on lupus onset", possibly due to effects on the immune system.

The authors write: "Our findings that longer-term use of contraceptives is associated with an increased risk of incident lupus (albeit of lower magnitude) and that current use of contraceptives with higher doses of ethinyl oestradiol is associated with an increased risk of incident lupus suggest a possible dose-response effect of oestrogen on lupus onset, which could be an alternative or additional mechanism to favour occurrence of the disease."

Bernier, M. O. et al. Combined Oral Contraceptive Use and the Risk of Systemic Lupus Erythematosus. Arthritis Care & Research, Vol. 61, April 2009, pp. 476-81.

Tags: North America | Rheumatology | Women’s Health & Gynaecology

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