Serum Testosterone to Androstenedione Ratio Predicts Metabolic Health in Normal-Weight Polycystic Ovary Syndrome Women.

CONTEXT: Increased aldo-keto reductase 1C3 (AKR1C3)-mediated conversion of androstenedione (A4) to testosterone (T) promotes lipid storage in subcutaneous (SC) abdominal adipose in overweight/obese polycystic ovary syndrome (PCOS) women. OBJECTIVE: This work examines whether an elevated serum T/A4 ratio, as a marker of enhanced AKR1C3 activity in SC abdominal adipose, predicts metabolic function in normal-weight PCOS women. METHODS: This prospective cohort study took place in an academic center and comprised 19 normal-weight PCOS women and 21 age- and body mass index-matched controls. Interventions included circulating hormone/metabolic determinations, intravenous glucose tolerance testing, total body dual-energy x-ray absorptiometry, and SC abdominal fat biopsy. Serum T/A4 ratios, hormone/metabolic measures, and AKR1C3 expression of adipocytes matured in vitro were compared between female types; serum T/A4 ratios were correlated with serum lipids, adipose insulin resistance (adipose-IR), homeostatic model assessment of insulin resistance (HOMA-IR) and insulin sensitivity (Si). RESULTS: Increased serum T/A4 ratios (P = .040) and log adipose-IR values (P = .002) in PCOS women vs controls were accompanied by AKR1C3 messenger RNA overexpression of PCOS adipocytes matured in vitro (P = .016). Serum T/A4 ratios in PCOS women, but not controls, negatively correlated with log triglycerides (TGs: R = -0.65, P = .002) and the TG index (R = -0.57, P = .011). Adjusting for serum free T, serum T/A4 ratios in PCOS women remained negatively correlated with log TG (R = -0.57, P = .013) and TG index (R = -0.50, P = .036), respectively, without significant relationships with other metabolic measures. CONCLUSION: An elevated serum T/A4 ratio, as a marker of enhanced AKR1C3 activity in SC abdominal adipose, predicts healthy metabolic function in normal-weight PCOS women.

Accelerated subcutaneous abdominal stem cell adipogenesis predicts insulin sensitivity in normal-weight women with polycystic ovary syndrome.

OBJECTIVE: To examine whether subcutaneous (SC) abdominal adipose stem cell differentiation into adipocytes in vitro predicts insulin sensitivity (Si) in vivo in normal-weight women with polycystic ovary syndrome (PCOS) and controls. DESIGN: Prospective cohort study. SETTING: Academic medical center. PATIENT(S): Eight normal-weight women with PCOS and 8 age- and body mass index-matched controls. INTERVENTION(S): Women underwent circulating hormone/metabolic determinations, intravenous glucose tolerance testing, total-body dual-energy x-ray absorptiometry, and SC abdominal fat biopsy. MAIN OUTCOME MEASURE(S): PPARγ and CEBPa gene expression and lipid content of adipocytes matured in vitro were compared between women with PCOS and control women, and correlated with patient characteristics, systemic Si, and adipose insulin resistance (adipose-IR). RESULT(S): Serum androgen levels, adipose-IR, and percentage of android fat were greater in women with PCOS than control women. Stem cell PPARγ and CEBPa gene expression increased maximally by day 12 without a female-type effect. In control cells, gene expression positively correlated with fasting serum insulin levels (both genes) and adipose-IR (CEBPa) and negatively correlated with Si (CEBPa). Conversely, CEBPa gene expression in PCOS cells negatively correlated with adipose-IR and serum free testosterone, whereas total lipid accumulation in these cells positively corelated with Si. CONCLUSION: In normal-weight women with PCOS, accelerated SC abdominal adipose stem cell differentiation into adipocytes in vitro favors Si in vivo, suggesting a role for hyperandrogenism in the evolution of metabolic thrift to enhance fat storage through increased cellular glucose uptake.