Excess 11-Oxygenated Androgens in Women With Severe Insulin Resistance Are Mediated by Adrenal Insulin Receptor Signaling.
Academic Article
Overview
abstract
CONTEXT: Syndromes of severe insulin resistance (SIR) include insulin receptoropathy, in which all signaling downstream of the insulin receptor is lost, and lipodystrophy, in which some signaling pathways are impaired and others preserved. Women with SIR commonly have ovarian hyperandrogenemia; adrenal-derived 11-oxygenated androgens, produced by CYP11B1, have not been studied. OBJECTIVE: We aimed to evaluate classic pathway androgens (androstenedione, testosterone) and 11-oxygenated androgens in women with SIR and hyperandrogenemia, and to elucidate the role of insulin receptor signaling for 11-oxygenated androgen production by comparing lipodystrophy and receptoropathy. METHODS: Steroid hormones were quantified using LC-MS/MS in a cross-sectional study of 18 women with hyperandrogenemia and SIR (11 lipodystrophy, 7 receptoropathy) and 23 controls. To assess ovarian vs adrenal origin, steroids were compared in receptoropathy patients with (Ovary+) vs without (Ovary-) ovarian function. RESULTS: Compared with controls, classic androgens were elevated in both lipodystrophy and receptoropathy, and 11-oxygenated androgens were increased in lipodystrophy (2.9-fold higher 11β-hydroxyandrostenedione (11OHA4), 2.4-fold higher 11-ketoandrostenedione (11KA4), 3.6-fold higher 11-ketotestosterone (11KT); P < 0.01), but not receptoropathy. Product-to-precursor ratios for CYP11B1 conversion of androstenedione to 11OHA4 were similar in lipodystrophy and controls but decreased in receptoropathy (6.5-fold lower than control; P = 0.001). Classic androgens were elevated in Ovary + but not Ovary- patients. CONCLUSIONS: 11-Oxygenated androgens are elevated in lipodystrophy but not receptoropathy. In SIR, insulin receptor signaling is necessary for adrenal hyperandrogenemia but not ovarian hyperandrogenemia; excess classic androgens are derived from the ovaries. Insulin receptor signaling increases adrenal 19-carbon steroid production, which may have implications for more common disorders of mild IR.
