Abstract
BACKGROUND: Oral contraceptive therapy (OCT) is associated with an increased risk of deep vein thrombosis, venous thromboembolism and stroke. However, the underlying mechanisms have not yet been elucidated. The objective of this study was to investigate the influence of OCT on blood levels of an oxidative stress maker in pre-menopausal women. METHODS: Oxidative stress was determined in 87 pre-menopausal healthy women (24 with and 63 without OCT) using a blood assay for reactive oxygen metabolites (by the d-ROMs test). The subjects with OCT received a triphasic preparation consisting of ethinyl estradiol and norethisterone. RESULTS: Subjects with OCT showed significantly higher d-ROMs levels (median: 380; interquartile range: 328-502 Carr U) than those without OCT (325 [271-369]; P < 0.05). The results remained the same after adjusting for potential confounders. CONCLUSIONS: The use of OCT may increase oxidative stress levels, independent of traditional cardiovascular risk factors, in pre-menopausal women, providing new insights to the primary prevention of vascular complications in these subjects.