Oral contraceptives (OCs) are the most widely used method of reversible birth control.
However, the long-term cardiovascular safety of the widely used low-dose OCs
(ethinyl-estradiol < 50 mcg) is still debated. Although cardiovascular events are rare in
young women whether they use OCs or not, the risks of myocardial infarction and ischemic
stroke are increased among users of OCs who have conventional cardiovascular risk factors
such as use of tobacco, diabetes or hypercholesterolemia. However, the risk of cardiovascular
events in OC users with emerging cardiovascular risk factors (such as obesity and the
metabolic syndrome) have not been investigated. Recently, the metabolic syndrome has been
linked with the risk of cardiovascular disease. The syndrome is a clustering of risk factors
in a single individual, and its underlying cause may be insulin resistance. Whether the
metabolic syndrome predicts a higher cardiovascular risk in OC users has not been studied.
This is a critical problem because the metabolic syndrome is prevalent in 24% of adults.
Until the cardiovascular risks in users of OC are clearly defined, the appropriate use of OC
with the least harm would not be possible.
The investigator's long-term goal is to understand the best way to prevent and treat
cardiovascular disease in women. The objective of this particular project is to obtain pilot
data on the extent to which the metabolic syndrome and obesity affects glucose metabolism and
cardiovascular risks in women taking OCs. The researchers hypothesize that women with
metabolic syndrome and obese women will have worsened glucose metabolism and elevated
cardiovascular risks associated with OC use, when compared to normal weight women without the
metabolic syndrome. Results of this study will clarify the risk factors for cardiovascular
events in women taking OCs, and will serve as pilot data for a National Institutes of Health
(NIH) proposal. Once the cardiovascular risk factors of OC users are understood, clinicians
can make better informed decisions about contraceptive choices for their patients.