Testosterone levels in pregnant women correlate with the insulin response during the glucose tolerance test.

OBJECTIVE

To evaluate the association between insulin/insulin-like growth factor I (IGF-I) systems and androgen levels in pregnancy.

DESIGN

Prospective cohort study.

SETTING

Yale University School of Medicine.

PATIENT(S): Pregnant women undergoing a 100-gram 3-hour glucose tolerance test (GTT).

INTERVENTION(S): Serum samples collected during GTT were analyzed for insulin, androgens, free IGF-I, insulin-like growth factor-binding protein (IGFBP) 1, and estriol.

MAIN OUTCOME MEASURE(S): Observing the relationship between insulin/IGFs and androgen levels.

RESULT(S): The insulin area under the curve (I(AUC)) during GTT correlated positively with total T and free T, but not with dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), or estriol. The peak insulin values (I(max)) during GTT also correlated positively with total T and free T, but not with DHEA, DHEAS, or estriol. There was no statistically significant correlation of T levels with free IGF-I, IGFBP-1, glucose, DHEAS, or estriol. Multiple linear regression analysis modeling showed that I(AUC) and I(max) did have a statistically significant correlation with free T levels.

CONCLUSION(S): This study demonstrates for the first time that I(AUC) and I(max) measured in hyperinsulinemic states such as pregnancy correlate with T levels. In view of the lack of correlation between insulin and DHEAS or estriol, insulin-related T production during pregnancy is likely of ovarian origin.