The Relationships Between Testosterone, Body Composition, and Insulin Resistance A lesson from a case of extreme hyperandrogenism

A ssociation between hyperandro-genism and insulin resistance iswell recognized in women with polycystic ovary syndrome (PCOS) (1). However, earlier evidence (2) suggesting an insulin-antagonizing effect of andro-gens has been overshadowed by more recent studies demonstrating that antian-drogen treatment with flutamide (3) or GnRH agonists (4,5) does not alter insulin resistance in PCOS. Conflicting results have been reported in non-PCOSwomen, with some studies (1,6–9) suggesting that testosterone may be related to insulin re-sistance and others (10,11) showing no correlation. Recent data suggest that some of these discrepancies may be explained by racial disparities, since only obese Af-rican-American women exhibited a posi-t ive relationship between insulin resistance and gonadal androgens (6). In-conclusive data have also been reported in men given testosterone in replacement or supraphysiologic doses, with some stud-ies (12) suggesting a sensitizing effect of testosterone on glucose metabolism and others (13–16) showing no effect. Nonetheless, androgens can influ-ence body composition, which is associ-ated with insulin sensitivity. Thus, it is conceivable that testosterone might indi-rectly influence insulin sensitivity via its effects on body composition. We report the results of hormonal, metabolic, and body composition studies before and 1 month and 9 months after a Leydig cell tumor removal in a postmenopausal woman