title: Differential effects of oral glucose-mediated versus intravenous hyperinsulinemia on circulating androgen levels in women.
abstract: OBJECTIVE
  To determine whether transient endogenous or continuous exogenous hyperinsulinemia produced different changes in circulating gonadal steroid levels because insulin is a putative regulator of gonadal steroid secretion in polycystic ovarian syndrome (PCOS).
  
  
  METHODS
  An oral glucose tolerance test (OGTT) and a 2-hour euglycemic clamp (+100 microU/mL [718 pmol/L] steady-state insulin levels) were performed in obese patients with PCOS (n = 7) in nonobese patients with PCOS (n = 5), and in age- and weight-matched ovulating normal women (obese normal n = 7, nonobese normal n = 6).
  
  
  RESULTS
  Despite increased insulin levels, the levels of T and androstenedione (A) decreased in three of the four groups during the OGTT (nonobese normal women showed a slight increase in T during the OGTT). In contrast, the continuous 2-hour insulin infusion resulted in increased androgen levels. When all four groups were pooled, the difference in the changes in A levels between the two tests was significant, and the difference in T levels between the two tests approached significance.
  
  
  CONCLUSIONS
  Transient physiological hyperinsulinemia produced by an oral glucose load was associated with a decrease rather than an increase in circulating androgen levels. The effects on circulating androgen levels of oral glucose-mediated increases in insulin levels were significantly different from those of a continuous intravenous insulin infusion. Sustained hyperinsulinemia produced by exogenous insulin infusion appeared to be required to increase androgen levels in women; transient physiological increases in insulin levels after an oral glucose load were insufficient to produce hyperandrogenism. Postmeal hyperinsulinemia does not contribute to hyperandrogenism in women.
authors.affiliation: Mount Sinai School of Medicine, City University of New York, New York.
authors.forename: J H
authors.initials: JH
authors.lastname: Fox
authors.forename: T
authors.initials: T
authors.lastname: Licholai
authors.forename: G
authors.initials: G
authors.lastname: Green
authors.forename: A
authors.initials: A
authors.lastname: Dunaif
mesh_terms: D000328:Adult; D000735:Androstenedione / Q000097:blood*; D015992:Body Mass Index; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood*; D009765:Obesity / Q000097:blood / Q000150:complications; D011085:Polycystic Ovary Syndrome / Q000097:blood* / Q000150:complications; D013739:Testosterone / Q000097:blood*
chemical_list: D007328:Insulin; D013739:Testosterone; D000735:Androstenedione