Androgens in the maternal and fetal circulation: association with insulin resistance.

Objective: To examine maternal insulin resistance in relationship with maternal and fetal androgen levels as well as with term placenta mRNA and protein abundance of steroidogenic enzymes implicated in androgen dynamics. Methods: The study included 20 women with gestational diabetes mellitus and 27 controls tested using a 120 min., 75 g oral glucose tolerance test. Maternal and fetal plasma concentrations of total testosterone, dihydrotestosterone (DHT) and dehydroepiandrosterone (DHEA) were measured by high-performance gas chromatography and chemical ionization mass spectrometry at 26.1 +/- 3.7 weeks of pregnancy. Results: Glycemic response to oral glucose over 120 min. as well as Matsuda insulin sensitivity and HOMA insulin resistance (HOMA-IR) indices were significantly associated with maternal testosterone levels (r = 0.31, r = -0.37 and r = 0.35 respectively, p <= 0.05 for all). Among male offspring, a positive association between maternal and fetal testosterone levels was observed (r = 0.43, p <= 0.05). Testosterone levels were higher in the cord blood of newborns from insulin-resistant mothers compared to newborns from insulin-sensitive mothers (0.48 +/- 0.36 nmol/L vs. 0.29 +/- 0.18 nmol/L p <= 0.05). No difference was observed in mRNA abundance or protein expression of placental steroidogenic enzymes according to the degree of maternal insulin resistance. Conclusion: Our results demonstrate a possible association between fetal and maternal androgen concentrations in relationship with insulin resistance.