Effects of oral contraception with ethinylestradiol and drospirenone on oxidative stress in women 18–35 years old

BackgroundOral contraceptives (OCs) with estrogens and progestins may affect oxidative stress (OS) status.Study designA group of 32 women using oral contraceptives (OCU) containing 0.03 mg ethinylestradiol and 3 mg drospirenone have been compared to a matched control group of 30 noncontraception users (NCU). Blood levels of antioxidants, trace elements and markers of lipid peroxidation were assessed by biochemical methods. A microarray analysis of whole blood mRNA levels of 200 genes involved in OS-dependant pathway was also performed.ResultsLevels of zinc, vitamin E and antibodies to oxidized low-density lipoproteins (LDLs) were not significantly different between the two groups. On the other hand, significant increases in the mean levels of lipid peroxides (+176%, p<.001), oxidized LDLs (+145%, p<.002), copper (+103%, p<.001), Cu/Zn ratio (+100%, p<.001) and a significant decrease in the mean level of β-carotene (−41%, p<.01) were observed in the OCU compared to NCU. There was a highly significant positive correlation between the lipid peroxide levels and the copper-to-zinc ratio. From the 200 genes tested by microarray, one coding for HSP70 was significantly up-regulated (log2 fold change=+ 0.45, p<.02) and one coding for inducible nitric oxide synthase significantly down-regulated (log2 fold change=−0.24, p<.05) in the OCU compared to the NCU.ConclusionsThe recently introduced combination of ethinylestradiol and drospirenone induced the heightening of lipid peroxidation correlated with high levels of copper, a situation that could be associated with increased cardiovascular risk.