Hormones endocrine disorders

An endocrine disorder first described by the British Physician Thomas Addison in the mid 1800 s. The adrenal glands fail to produce sufficient amounts of glucocorticoid hormones (cortisol) and sometime mineralocorticoid (aldosterone). If left untreated it is life-threatening, the patient will show muscle weakness, hyperpigmentation and even depression. Typical treatment is hydrocortisone replacement therapy. 

Endocrine disorders Thyroid hormone therapy in patients with concomitant diabetes mellitus or insipidus or adrenal insufficiency (Addison disease) exacerbates the intensity of their symptoms. 

Given that the seat of hormonal modulation is in the limbic-hypothalamic-pituitary axis, endocrine changes serve as important correlates to major psychiatric disorders. These changes include basal hormone concentrations, as well as responses to pharmacological challenges. Equally important, endocrine disorders may present with psychiatric symptoms (e.g., manic symptoms in hyperthyroidism, severe depression in hypercortisol ism, psychotic symptoms associated with Cushing s syndrome). Commonly used neuroendocrine tests include the following. 

Diagnosis of Endocrine Disorders. Hormones or their antagonists can be administered to determine the presence of excess endocrine function or endocrine hypofunction. For example, hormones or their synthetic analogs can be administered that either increase or decrease pituitary secretion to determine if pituitary function is normal. Likewise, antagonists to specific hormones can be administered to see if symptoms are caused by excessive hormone production. Specific examples of how hormones are used to diagnose endocrine abnormalities are presented in subsequent chapters. 

Although replacement therapy is basically limited to endocrine disorders, it still plays an important therapeutic role in clinical pharmacology. The number of people requiring replacement therapy for diabetes and hypothyroidism alone makes insulin and thyroid hormone among the most commonly prescribed drugs in the United States. For example, the drug Synthroid is taken daily by 8 million people to correct hypothyroidism, and its share of the market is worth 600 million per year. As more information is discovered about the role of other endogenous substances in the body, new examples of replacement therapy will occur. 

Addison s disease an endocrine disorder associated with the adrenal gland, when low levels of steroid hormones are produced. 

Obesity is a condition that is influenced by genetic and environmental factors (such as energy intake and expenditure, fetal nutrition, culture). There are four major physiological causes of obesity endocrine disorders (growth hormone deficiency, Cushing syndrome), genetic syndromes (Prader-Willi syndrome or Alstrom syndrome), disorders of the central nervous system (tumor, trauma) or the most common cause, multifactorial or primary obesity (caused by an interaction of multiple genes). 

Another consequence of the interdependent nature of the endocrine system is that manifestation of an endocrine disorder is virtually always associated with changes in synthesis or concentration of multiple hormones. For example, in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-treated rats, the decrease in thyroid... 

Hormones of both synthetic and biological origin are known endocrine disruptors. The best known of these is diethylstilbesterol (DES), a synthetic estrogen that was prescribed by physicians to prevent spontaneous abortions in women from 1948 to 1971. Daughters of women who took DES have suffered a host of reproductive problems including a reduction in fertility, abnormal pregnancies, immune system disorders, periods of depression, and early onset of vaginal clear-cell adenocarcinomas and reproductive tract cancer. Known hormonal endocrine disruptors are listed in Table 4.5. 

Kapoor D, Jones TH. Smoking and hormones in health and endocrine disorders. Eur J Endocrinol 152(4) 491 9. 

Although several chapters of this textbook detail a variety of endocrine disorders, a brief introduction is appropriate here. In general, endocrine diseases result from either a deficiency or an excess of a single hormone or several hormones, or from resistance to the action of hormones. Hormone deficiency can be congenital or acquired and hormone excess can be from endogenous overproduction (from within the body) or exogenous overmedication. Hormone resistance can occur at several levels, but can most simply be characterized as receptor mediated, postreceptor mediated, or at the level of the target tissue. The clinical manifestations will depend on the hormone system affected and the type of abnormality. 

Annual follow-up should include assessment of hormone therapy compliance and evaluation for signs and symptoms of associated endocrine disorders. ... 

Hyperparathyroidism results from oversecretion of PTH. This condition leads to excessive bone turnover and demineralization and must be treated by removal of the parathyroid gland. The disorder is classified into primary, secondary, and tertiary hyperparathyroidism. Sporadic primary hyperparathyroidism is the third most common endocrine disorder, after diabetes and hyperthyroidism. It is most common in females older than 55 years of age and the leading cause is a single adenoma, which secretes the hormone constitu-tively, without regulation. Symptoms can include osteopenia and bone fractures, renal stones resulting from hypercalciuria, peptic ulcer disease, and pancreatitis. In milder cases, patients are asymptomatic or suffer only muscle weakness, fatigue, and/or depression. 

The overriding intluenee of stress on die endocrine system makes the diagnosis of endocrine disorders in the critically ill patient very difficult. Ill patients may have hyperglycaemia. high scaini cortisol or abnormal thyroid hormone results. These could be misinterpreted as diabetes mellilus, Cushing s syndrome or thyroid disease. 

Endocrine disorders nltimately involve abnormalities of hormone production or action. Etiologies of a relatively large number of these diseases with well-defined genetic bases have been identified. 

Testosterone 17p-hydroxy-androst-4-en-3-one, an important androgen synthesized in the interstitial cells of the testicle. It stimulates growth of the prostate and seminal vesicles, and promotes sperm maturation and development of male secondary sexual characteristics. Apart from mammalian testes, T. also occurs in blood and urine. It was first isolated in 1935 from bovine testes. Esters of X, e.g. T. propionate, are used in the treatment of male sex hormone deficiency, endocrine disorders in gynecology and in geriatrics. For structure and biosynthesis, see Androgens. 

Endocrine or hormonal dysregulation (Addison s disease, Cushing s disease, hyper- or hypothyroidism, menstrual-related or pregnancy-related or perimenopausal mood disorders)... 

---