The study used a nested-case control design to measure baseline sex steroid hormone levels (serum total and free estradiol, estrone sulfate, total and free testosterone, dehydroepiandrosterone sulfate) and sex hormone binding globulin to determine whether these predicted subsequent risk of coronary heart disease (CHD). A total of 350 case subjects and 350 control subjects were selected from women who were free from cardiovascular disease and cancer at study entry and were not using hormone replacement therapy at baseline. Cases were those women who subsequently developed a documented myocardial infarction or underwent coronary artery revascularization (N=350), while control subjects were selected from study participants who remained free from CHD during follow-up. Controls were matched 1:1 for age, ethnicity, smoking and follow-up time. The study also examined correlations between sex steroid hormone levels and other previously funded analyses of biomarkers, including thrombotic and inflammatory markers, lipoproteins, fasting glucose and insulin. Detailed baseline data including anthropometrics and behavioral factors allowed control for confounding.