Hypothyroidism: diagnosis and screening, genetic influences, and treatment options

Abstract

The thyroid hormone 3, 5, 3'-triiodothyronine (T 3 ) is a key regulator of the development, differentiation, and physiology of all cells in an organism. One of the most studied effects of the thyroid hormone is its control of the basal metabolic rate. Thus, modifications in thyroid hormone levels can produce several alterations, including modifications to the REDOX environment, alterations to signal transduction on several levels, and finally cell death. The aim of this review is to describe primary, secondary, and tertiary hypothyroidism from embryonic and fetal development through to the adult organism. In addition, we explore thyroid hormone resistance causes hypothyroidism. Furthermore, we describe how genetic studies illustrate that mutations can cause hypothyroidism. We will present results from clinical and laboratory tests, in diagnosing hypothyroidism that have been used by different organizations to study thyroid diseases. In addition, we propose some methods for diagnosing hypothyroidism in communities that lack the medical infrastructure to use modern methods of diagnosis. We will present a series of cases that demonstrate the importance of diagnosing hypothyroidism during pregnancy, and in the first years of life for the healthy development of the nervous and cardiovascular systems, and the kidney, among others. We describe current treatments for hypothyroidism, but we will put special emphasis on evidence-based personalized treatment for individual patients. Finally, we will include a section that discusses the benefits and complications of hypothyroidism as it relates to cytoprotection, cell damage, and immunomodulation.