This study was supported financially by the Swedish Research Council (A.L.H., 20324), Karolinska Institutet and the Stockholm County Council. None of the authors has any conflict of interest to declare.

Lifestyle intervention alters, but does not fully restore, ER and AR expression in proliferative and secretory endometrium of obese women with PCOS.

All receptors involved in thyroid hormone function are expressed in monkey uterus, and they are all regulated by long-term steroid hormone treatment. These findings suggest that there is a possibility of direct actions of thyroid hormones, thyroid-stimulating hormone and thyrotropin-releasing hormone on uterine function.

TIB treatment influences the protein expression of sex hormone receptors in monkey endometrium differently from that observed after conventional hormone therapy. We suggest that the observed differences in AR expression by TIB as compared with combined treatment may be of importance for endometrial atrophy as well as for the beneficial bleeding profile associated with this treatment.