Subjects will then be randomized to one of three 12-week treatment arms, 1) Group 1 (Placebo); 2) Group 2 (Depot GnRH agonist (Zoladex) + T + placebo); or 3) Group 3 (Zoladex + T + aromatase inhibitor (anastrozole)). The rationale for this study design is as follows. Under normal physiological conditions, administration of T leads to a concomitant increase in E2 levels due to endogenous conversion by the aromatase enzyme system. Therefore, in order to dissect the relative roles of T and E2 on insulin sensitivity, one group of subjects will receive T in conjunction with the aromatase inhibitor, anastrozole.