Sex hormone-binding globulin expression in the endometria of women with polycystic ovary syndrome

Objective

To evaluate the protein and messenger RNA expression of sex hormone-binding globulin (SHBG) in endometria from women with polycystic ovary syndrome (PCOS).

Design

Case-control study.

Setting

Hospital research unit.

Patient(s)

Thirty-three women with PCOS, and 17 fertile, healthy women of similar age to those with PCOS.

Intervention(s)

Endometrial and blood samples were obtained from women with PCOS (PCOSEs) and from control women (CEs) during the proliferative phase of the menstrual cycle.

Main Outcome Measure(s)

Expression studies for SHBG (immunohistochemistry and reverse transcription-polymerase chain reaction). Hormonal studies for determining sex steroids (T, P, and E₂) and SHBG concentration. Insulin sensitivity was assessed by composite insulin sensitivity index (ISI_composite).

Result(s)

In stroma, the protein expression of SHBG was lower in PCOSEs than in CEs. Epithelial cells had a similar expression of SHBG protein in both groups. Messenger RNA of variant 548 base pairs (wild-type) tended to be lower in PCOSEs compared to CEs. When PCOSEs were classified by insulin resistance, the PCOSEs with normal insulin sensitivity showed an expression of stromal SHBG similar to that observed in CEs.

Conclusion(s)

The low SHBG expression in the stromal compartment of endometria from women with PCOS with insulin resistance may contribute to generate an abnormal steroid milieu in the endometria of these women.

Key Words: Sex hormone-binding globulin, endometrium, polycystic ovary syndrome