The role of omentin-1 in female reproduction: a critical review.

White adipose tissue is now recognized as an active endocrine organ that secretes numerous bioactive molecules known as adipokines. These proteins regulate essential physiological processes, including energy metabolism, inflammation, and reproduction, while disturbances in their secretion are linked to conditions such as infertility, obesity, and diabetes. Omentin-1, also termed intelectin-1, is a secreted trimeric lectin conserved across mammals. In addition to systemic actions that improve insulin sensitivity, enhance glucose uptake, and suppress oxidative stress and inflammation, omentin-1 exerts important functions within the female reproductive system. It is expressed in the hypothalamus, pituitary gland, ovary, oocyte, and placenta, where it influences cell proliferation, apoptosis, and hormone production. Through these actions, omentin-1 contributes to hormonal homeostasis, follicular development, oocyte maturation, luteal function - integrating energy balance with female fertility. Altered circulating or local levels of omentin-1 have been observed in polycystic ovary syndrome, endometriosis, ovarian and endometrial cancers, preeclampsia, and gestational diabetes. This review aims to summarize current knowledge on omentin-1 expression and function in the female reproductive system within hypothalamus - pituitary - ovary axis and its role in reproductive pathologies.