Adiponectin and leptin systems in human endometrium during window of implantation.

Objective: To measure the expression of adiponectin, leptin, and their respective receptors in the human endometria of fertile women compared with women with unexplained recurrent implantation failure (IF) during the window of implantation.

Design: Controlled, prospective, clinical study.

Setting: Teaching hospital and university research laboratory.

Patient(s): Thirty-one endometrial biopsies from women with IF and 19 fertile controls.

Intervention(s): Human endometrial biopsies.

Main Outcome Measure(s): Gene and protein expression of endometrial biopsies.

Result(s): Endometrial leptin expression was significantly lower in the IF group compared with fertile women. In contrast, leptin receptor (Ob-R) expression was higher in endometria of women with IF. Concerning the adiponectin system, adiponectin was expressed to the same extent in both groups. Conversely, the expression of its two receptors, AdipoR1 and AdipoR2, was reduced in endometria of women with IF compared with fertile women.

Conclusion(s): Although progesterone resistance seems to be a common state of the endometrium in some human reproductive disorders, such as endometriosis or polycystic ovary syndrome, modification in leptin endometrial expression seems to be specific to IF. These results strongly suggest that changes in Ob-R and AdipoR expression profiles [1] should be implicated in the development of uterine receptivity, and [2] may therefore be potential new targets for prediction of IF.