Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women and a major cause of anovulatory infertility. A diagnosis of PCOS is established based the presence of two out of three clinical symptoms, which are criteria accepted by the ESHRE/ASRM (European Society of Human Reproduction and Embryology/American Society for Reproductive Medicine). Gonadotropin-releasing hormone (GnRH) is responsible for the release of luteinizing hormone, and follicle stimulating hormone from the pituitary and contributes a leading role in controlling reproductive function in humans. The goal of this review is to present the current knowledge on neuroendocrine determinations of PCOS. The role of such neurohormones as GnRH, and neuropeptides kisspeptin, neurokinin B, phoenixin-14, and galanin is discussed in this aspect. Additionally, different neurotransmitters (gamma-aminobutyric acid (GABA), glutamate, serotonin, dopamine, and acetylcholine) can also be involved in neuroendocrine etiopathogenesis of PCOS. Studies have shown a persistent rapid GnRH pulse frequency in women with PCOS present during the whole ovulatory cycle. Other studies have proved that patients with PCOS are characterized by higher serum kisspeptin levels. The observations of elevated serum kisspeptin levels in PCOS correspond with the hypothesis that overactivity in the kisspeptin system is responsible for hypothalamic-pituitary-gonadal axis overactivity. In turn, this causes menstrual disorders, hyperandrogenemia and hyperandrogenism. Moreover, abnormal regulation of Neurokinin B (NKB) is also suspected of contributing to PCOS development, while NKB antagonists are used in the treatment of PCOS leading to reduction in Luteinizing hormone (LH) concentration and total testosterone concentration. GnRH secretion is regulated not only by kisspeptin and neurokinin B, but also by other neurohormones, such as phoenixin-14, galanin, and Glucagon-like peptide-1 (GLP-1), that have favorable effects in counteracting the progress of PCOS. A similar process is associated with the neurotransmitters such as GABA, glutamate, serotonin, dopamine, and acetylcholine, as well as the opioid system, which may interfere with secretion of GnRH, and therefore, influence the development and severity of symptoms in PCOS patients. Additional studies are required to explain entire, real mechanisms responsible for PCOS neuroendocrine background.

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Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age. A diagnosis of PCOS is established when a patient exhibits two of three Rotterdam criteria: oligoovulation or anovulation, excess androgen activity, and polycystic ovarian morphology. The pathogenesis of PCOS, as it affects adolescents, is often discussed in terms of a “two-hit” theory. This refers to a stepwise process in which the first “hit” is an inborn congenitally programmed predisposition, while the second “hit” arises from a provocative factor such as insulin resistance. The dynamic physiological and anatomical changes which occur in puberty make for a challenging diagnosis in this group of patients. It is important to be mindful of the physiological particularities in adolescence which often mimic the symptoms of PCOS. In their first-year post-menarche, approximately 75% of menstruating adolescents report their cycle to last between 21–45 days. Recent studies have shown that regular menstrual cyclicity is only achieved within 2–3 years post-menarche. Anovulation, as a crucial diagnostic element for PCOS, features in about half of early-post-menarchal adolescents. Hirsutism and acne are the most common clinical manifestations of hyperandrogenism, and mild features are developed by most adolescents as a result of elevated androgen levels. Distinguishing between a pathological sign and normal features of maturation is often difficult. A polycystic ovarian morphology (PCOM) through ultrasound has been found in up to 40%, 35%, and 33.3% of patients when assessed at 2, 3, and 4 years, respectively, after menarche. PCOM in adolescence is not associated with future abnormalities in ovulatory rate or menstrual cycle duration. For this reason, international guidelines recommend against the use of pelvic ultrasound until 8 years post-menarche. The primary aim of management is focused mainly on improving hormonal and metabolic status, the prevention of future comorbid complications, and generally improving the overall quality of life in young women with PCOS. Considerable controversy surrounds the choice of optimal pharmacological treatment to address PCOS in adolescents. Reliable studies, which include this sub-section of the population, are very limited. There is a lack of robust and reliable trials in the literature addressing the use of combined oral contraceptives. Further work needs to be undertaken in order to provide safe and effective care to the adolescent population in this regard.

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The bony skeleton, as a structural foundation for the human body, is essential in providing mechanical function and movement. The human skeleton is a highly specialized and dynamic organ that undergoes continuous remodeling as it adapts to the demands of its environment. Advances in research over the last decade have shone light on the various hormones that influence this process, modulating the metabolism and structural integrity of bone. More recently, novel and non-traditional functions of hypothalamic, pituitary, and adipose hormones and their effects on bone homeostasis have been proposed. This review highlights recent work on physiological bone remodeling and discusses our knowledge, as it currently stands, on the systemic interplay of factors regulating this interaction. In this review, we provide a summary of the literature on the relationship between bone physiology and hormones including kisspeptin, neuropeptide Y, follicle-stimulating hormone (FSH), prolactin (PRL), adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), growth hormone (GH), leptin, and adiponectin. The discovery and understanding of this new functionality unveils an entirely new layer of physiologic circuitry.