Many studies have implicated an association between oral contraceptive use and an increased risk of myocardial infarction (Boyce, 1963; Mann, Vessey, Thorgood & Doll, 1975). Past studies have often been inconsistent in their findings with specific debate regarding risks associated with second and third generation contraceptive formulations. Tanis et al. (2001) published a research paper in the New England Journal of Medicine in an attempt to clarify this risk connection according to the type and dose of progesterone and estrogen used in oral contraceptions along with the presence of prothrombotic genes. More specifically this study sought to look at oral contraceptives as an increased risk factor for myocardial infarction in a direct comparison of third and second-generation formulations.
Myocardial infarction in women has been associated with numerous risk factors such as hypertension, smoking and diabetes mellitus, as too has the use of oral contraceptives. Tanis and associates explored the research question that differences in the formulation of current contraceptions dispose users to varied risk.
They assessed the effect of the type of progesterone used (levonorgestrel compared to gestodene and desogestrel) and the dose of estrogen in oral contraceptives as an associated risk with myocardial infarction.
In a nationwide case-control study women between 18 to 49 years were invited to participate. To explore the issue in question groups were matched with age and area of residence. Subjects supplied information on contraceptive use, health and a gene analysis was conducted on most of the cohort. Using a matched control group to compare to women that had survived myocardial infarction this research methodology had undeniable human relevance compared with previous conclusions drawn from animal or in vitro studies.
The results suggested that the risk of myocardial infarction indeed varied between known formulations of oral contraception. Odds ratio testing of cohort data indicated...