We investigated whether the normal anabolic effects of acute hyperaminoacidemia were maintained after 5 days of oxandrolone (Oxandrin, Ox)-induced anabolism. Five healthy men [22 +/- 3 (SD) yr] were studied before and after 5 days of oral Ox (15 mg/day). In each study, a 5-h basal period was followed by a 3-h primed-continuous infusion of a commercial amino acid mixture (10% Travasol). Stable isotopic data from blood and muscle sampling were analyzed using a three-compartment model to calculate muscle protein synthesis and breakdown. Model-derived muscle protein synthesis increased after amino acid infusion in both the control [basal control (BC) vs. control + amino acids (C+AA); P < 0.001] and Ox study [basal Ox (BOx) vs. Ox + amino acids (Ox+AA); P < 0.01], whereas protein breakdown was unchanged. Fractional synthetic rates of muscle protein increased 94% (BC vs. C+AA; P = 0.01) and 53% (BOx vs. Ox+AA; P < 0.01), respectively. We conclude that the normal anabolic effects of acute hyperaminoacidemia are maintained in skeletal muscle undergoing oxandrolone-induced anabolism.

TexasAssociation 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)(7)(8)(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. RESEARCH DESIGN AND METHODSA 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 (HbA 1c 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 but no palpable adnexal masses. Laboratory studies revealed extreme hyperandrogenism (Table 1). A computed tomography scan and pelvic ultrasound did not detect ovarian masses. Nonetheless, she underwent total hysterectomy with bilateral salpingooophorectomy because of the increased risk for endometrial cancer (endometrial thickening, 8.6 mm) and possible virilizing ovarian tumor. Microscopic examination revealed a 0.9-cm Leydig cell tumor, nonhilar type, in the right ovary. Northern blot analysis (17) showed abundant expression of mRNA for P450 SCC and P450 17a in the tumor but no expression in stromal tissue from the contralateral ovary, indicating absence of hyperthecosis or PCOS.Glyburide was held pre-and postoperatively, and fasting glucose remained normal (Table 1). Approximately 6 months postoperatively, fasting glucose increased to 204 mg/dl, and glyburide was reinstituted. There were no changes in blood pressure, antihypertensive medications, or self-reported diet or physical activity. Virilization decreased postoperatively.After ins...