Thyroid disease is a common endocrine disorder for reproductive-aged women [45], and affects female reproductive health in several ways, including modulating the HPO axis, regulating the effects of prolactin and leptin on gonadotropin-releasing hormone (GnRH), and altering binding proteins that affect the bioavailability of sex steroids [24,46,47,48,49]. Here, LEP is linked to endocrine system disorder.