The role of the thyroid in polycystic ovary syndrome

Abstract

Polycystic ovary syndrome (PCOS) is the most common endocrine and metabolic disease in women of childbearing age and can cause metabolic disorder, infertility, and increased anxiety and depression; as a result, it can seriously affect the physical and mental health of fertile women. PCOS is a highly clinically heterogeneous disease with unclear etiology and pathogenesis, which increases the difficulty of treatment. The thyroid gland has complex regulatory effects on metabolism, reproduction, and emotion, and produces hormones that act on almost all cells of the human body. The clinical manifestations of PCOS are similar to some thyroid diseases. Furthermore, some thyroid diseases, such as subclinical hypothyroidism (SCH), not only increase the incidence rate of PCOS, but also exacerbate its associated metabolic abnormalities and reproductive disorders. Interestingly, PCOS also increases the incidence of some thyroid diseases. However, the role of the thyroid in PCOS remains unclear. This review is intended to thoroughly explore the critical role of the thyroid in PCOS by summarizing the comorbidity of PCOS and thyroid diseases and their combined role in metabolic disorders, related metabolic diseases, and reproductive disorders; and by analyzing the potential mechanism through which the thyroid influences the development and progression of PCOS and its symptoms. We hope this review will provide a valuable reference for the role of the thyroid in PCOS.

Keywords: metabolic abnormalities; pcos; potential mechanism; reproductive disorders; thyroid.

Figure 1

Schematic summary of the role of the thyroid in polycystic ovary syndrome (PCOS). Hyperinsulinism and obesity are necessary for full-blown pathogenesis of PCOS. Thyroid hormones participate in the regulation of blood glucose at the central and peripheral levels. Hypothyroidism has been shown to cause insulin resistance. THs regulate lipid metabolism. Decreased thyroid function readily leads to lipid metabolism disorders, including obesity. The immune state of the body also plays a key role in PCOS. HT and GD are common AITDs that have been repeatedly shown to increase PCOS risk in women. Sex hormones are regulated by Thyroid signal pathway. THs, Thyroid hormones; HT, Hashimoto’s thyroiditis; GD, Graves’ disease; AITD, autoimmune thyroid disease; SCH, subclinical hypothyroidism.