Endocrine System Disorders

What is the cause of most endocrine disorders?

result of too little or too much of a hormone

Describe Graves disease

Prototypical autoimmune cause of hyperthyroidism.

• mass production of T3 and T4

• causes thyroid hyperplasia

• can lead to thyrotoxic crisis/thyroid storm and can be fatal'

• weight loss, increase appetite

• exophthalmos

Would you expect TSH to be high or low in Grave’s disease?

TSH level is very low because the pituitary gland will try to be compensate for the excess T3 and T4 hormones in blood. Pituitary will stop production of TSH

Pathophysiology of exopthalamos

Protrusion of one or both eyes anteriorly out of the orbit due to an increase in orbital contents within the rigid bony orbit. ‘bulging eyes’

Common causes of hypothyroidism

Congenital = lack of thyroid development during fetal life, can lead to cretinism unless treat

Acquired = Deficient hormone synthesis, destruction of thyroid gland, impaired TSH or TRH secretion. Caused by autoimmunity, genetic defects, hashimoto thyroiditis etc

Cause of Hashimoto thyroititis

Autoimmune disorder where your immune system attacks your thyroid

Myxedema

A non-pitting edema caused by hypothyroidism where fibroblasts overproduce proteoglycans that accumulate in tissue and trap water in tissue gel

• most severe form of hypothyroidism

Hypothyroidism treatment

Replace deficient hormone, lifelong replacement therapy initiated and increased gradually.

• most common drug used is Levothyroxine

Cushing Syndrome

Excess of glucocorticoids-hypercortisolism

• women are more likely to develop it

• specifically related to pituitary tumors

• elevated levels of cortisol —> neg. feedback —> pituitary decrease ACTH

Functions of cortisol

Stimulates glucose production, decreases tissue glucose utilzation, increase breakdown and circulation of plasma proteins, increase mobilization of fats, and prevents the release of chemical mediators that trigger the inflammatory response

Why are glucocorticoids prescribed to treat inflammation?

They are used to inhibit the expression of multiple inflammatory genes and are used to supress inflammation and chronic inflammatory diseases.

long term use leads to:

• increased blood glucose

• immune supression

• osteoporosis

Causes of Cushing’s syndrome

• long term high dose use of cortisol like glucocorticoids

• development of too much cortisol

Body appearance alteration in Cushing disease:

Thin arms and legs, a fatty hump between the shoulders, round face, wide purple stretch marks on abdomen, increase fat around the neck

• buffalo hump

• striae

Addison’s disease

A disorder that occurs when the adrenal glands don’t make enough of cortisol and other hormones. Autoimmune destruction of adrenal cortex. It can also be caused by the lack of ACTH

• increased pigmentation

• causes hyponatremia, hypotension, hyperkalemia

3 main types of diabetes mellitus

Type I, Type II, Gestational

Underlying cause type I diabetes

Insulin deficit, 10% of diabetics

Treatment for type I diabetes

Insulin replacement and balanced with exercise

Underlying problem in type II diabetes

Insulin resistance or impaired ability of tissues to use insulin; insufficient insulin in relation to need

What are the 3 Ps?

Polydipsia = excessive thirst

Polyuria = frequent urination

Polyphagia = increased appetite

Diagnostic criteria in type II diabetes

Most individuals are asymptomatic, random or fasting blood glucose measurements. If two fasting blood glucose measurments are over 126 m g/dL, type II diabetes suggested.

Treatment of type II diabetes

Weight control, individualized nutritional consultation, exercise, oralhypoglycemic agents/insulin, goal is to maintain optimal blood glucose levels

Gestational diabetes

Glucose intolerance during pregnancy. Placenta produces HPL which induces sligh insulin resistance in mother.

Outcomes in fetus and newborn if not treated.

Hyperglycemia can lead to large fetus (macrosomia), difficult birth and hypoglycemic crisis after birth. Fetal panceras can over secrete insulin after birth (hypoglycemia from hyperplasia of pancreas), 5-10% have congenital developmental anomalies such as spina bifida or heart defeat

Describe hypo and hyperparathyroidism

Hypoparathyroidism = commonly caused by damage to the glands during thyroid surgery or hypomagnesemia. Low PTH caused neurons to depolarize without usual stimulus, causing spasms and twitches

• test with trousseau sign

Hyperparathyroidism = the gland makes too much PTH. Causes hypercalcemia, highblood pressure

Consequences of hypo and hyperthyroidism

Myxedema

• protein carbohydrate complexes accumulate in the extracellular matrix drawing water into tissues

• non pitting edema tissues