The Relationships Between Testosterone, Body Composition, and Insulin Resistance

Association between hyperandrogenism and insulin resistance is well recognized in women with polycystic ovary syndrome (PCOS) (1). However, earlier evidence (2) suggesting an insulin-antagonizing effect of androgens has been overshadowed by more recent studies demonstrating that antiandrogen treatment with flutamide (3) or GnRH agonists (4,5) does not alter insulin resistance in PCOS. Conflicting results have been reported in non-PCOS women, with some studies (1,6–9) suggesting that testosterone may be related to insulin resistance and others (10,11) showing no correlation. Recent data suggest that some of these discrepancies may be explained by racial disparities, since only obese African-American women exhibited a positive relationship between insulin resistance and gonadal androgens (6). Inconclusive data have also been reported in men given testosterone in replacement or supraphysiologic doses, with some studies (12) suggesting a sensitizing effect of testosterone on glucose metabolism and others (13–16) showing no effect.Nonetheless, androgens can influence body composition, which is associated with insulin sensitivity. Thus, it is conceivable that testosterone might indirectly 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.A 64-year-old gravida 7, para 7, Hispanic woman was referred for evaluation of virilization starting ∼10 years earlier and progressing over the past 3 years. Menses were regular before menopause (age 50). Diabetes was diagnosed 2 months before presentation and was well controlled by 1.5 mg glyburide daily (HbA1c 4.8%). She had a 22-year history of hypertension, treated with benazepril and amlodipine. A physical examination revealed male pattern alopecia, masculine habitus, abdominal obesity, clitoromegaly, and breast atrophy …