Addison's Disease - Overview (clinical features, pathophysiology, investigations, treatment)

hello in this video we're going to talk about Addison's disease when you think of Addison's disease just think of it as being opposite to Cushing's disease however it's more that Addison's disease is characterized by insufficiency of all the hormones produced by the adrenal cortex so before going into Addison's disease it's important to revise the anatomy and the physiology of the endocrine system as well moreso focusing on the adrenal cortex and it's hormones so here we have the brain within the brain is an important endocrine area called the hypothalamus below the hypothalamus are the pituitary glands made up of the anterior and posterior pituitary glands in this part we're only going to focus on the anterior pituitary gland Here I am depicting circulation which is the blood and here is one adrenal gland we have two adrenal glands sitting above two kidneys the adrenal glands has a cortex the outer part of the adrenal gland and it has the medulla which is the inner pod the adrenal gland produces hormones in response to the brain specifically in response to the hypothalamic pituitary axis the hypothalamus produces a hormone called cortical tropic releasing hormone Kuroko tropic releasing hormone stimulates cells within the anterior pituitary gland to secrete adeno Carrico tropic stimulating hormone or ACTH for short ACTH will then enter circulation ACTH will then travel towards the adrenal glands specifically the adrenal cortex where it will stimulate the adrenal cortex to produce and secrete hormones the hormones produced by the adrenal cortex are three and they're categorized as mineral corticoids such as aldosterone glucocorticoids such as cortisol and androgens it's important to note that androgen secretion from the adrenal cortex has minimal role in males rather it has more of an important role in females androgen in men are mainly produced by the testes an increase in cortisol in circulation will have a negative feedback on the hypothalamus it will tell the hypothalamus to stop producing any more critical troop and releasing hormone thus decreasing the stimulation of adrenal cortex hormone production so what do these adrenal cortex hormones actually do what does the mineral corticoids glucocorticoids and androgens do exactly well mineral corticoids mainly aldosterone has a function to increase sodium and water retention in a body and they primarily work on the kidneys and so they retain sodium and water resulting in an increase in blood pressure glucocorticoids such as cortisol does many things the effects are usually long-term and is often referred to as the stress response effects of cortisol include immunosuppression and because it is immunosuppression it is also anti-inflammatory this also means that infection risk increases glucocorticoids has a profound effect on metabolism it causes weight gain and insulin resistance glucocorticoids causes skin thinning and in the bone glucocorticoid stimulates osteoclast ik activity which are the bone eating cells resulting in increase in osteopenia and osteoporosis which is bones with low mineral density increasing the risk of bone fractures finally cortisol itself has an effect on blood pressure which will increase the blood pressure the androgen secreted by the adrenal glands as mentioned earlier has more of an effect on females from what we have learnt we can see that the adrenal glands have a big role in maintaining our body's homeostasis over production of the adrenal cortex hormones can cause big problems but also under production of adrenal cortex hormones can have severe consequences Addison's disease is essentially any cause of primary adrenal cortex insufficiency or in other words a decrease in production of adrenal cortex hormones so let's look at some examples again here we have the brain we have the main structure to focus on the hypothalamus and the anterior pituitary gland here is the circulation the adrenal glands have receptors on them here I'm drawing a receptor on the adrenal cortex the hypothalamus releases corticotropin-releasing hormone which stimulates the anterior pituitary gland to produce a de daño Carrico tropic hormone or ACTH for short ACTH goes into circulation and stimulates the adrenal cortex as mentioned earlier the main cause of primary adrenal insufficiency and therefore the main cause of Addison's disease are antibodies being produced against adrenal cortex cells as well as plus -21 hydroxylase enzyme within the adrenal gland and these antibody production actually accounts for 70% of cases of Addison's disease the autoimmune attack of the adrenal cortex causes damage and therefore reduces the production of the mineral corticoids glucocorticoids and androgens a decreased production of mineral corticoids will cause a reduction of sodium and water retention and so will reduce the blood pressure a decrease in blood pressure will cause tachycardia as a compensatory mechanism a reduction in androgens does not really have an effect on males rather more of an effect on females causing a decrease in libido a reduction of the glucocorticoids by the autoimmune attack causes many things basically the opposite effects of what glucocorticoid steroids would otherwise do this means that people with Addison's disease will have weight loss skin pigmentation and fatigue in general further because there is a decrease in glucocorticoids this means the negative feedback is off remember negative feedback only occurs when there is an increase in hormone levels in the blood with no negative feedback by the glucocorticoids or cortisol the hypothalamus will produce more corticotropin-releasing hormone and therefore stimulate the anterior pituitary to produce more adrenocorticotropic hormone the increase in Carrico tropic releasing hormone will actually stimulate other hormones produced by the pituitary gland in crew including prolactin so now the question is what are the effects of having reduced adrenal cortex hormone levels what are the effects on our body clinical presentation as we've learned Addison's disease is essentially primary adrenal insufficiency and so the clinical presentation include tiredness dizziness and nausea weight loss vomiting diarrhea abdominal pain hyperpigmentation which is generalized decreased libido which is mainly in female arthralgia and myalgia on clinical examination there will be a low-grade fever signs of dehydration and loss of hair you can also note cachexia as well as postural hypotension which is a decrease in blood pressure the difference between lying down and standing up finally tachycardia is also present to compensate for the low blood pressure let's go back to the main diagram again as mentioned OTO antibodies against the adrenal cortex and the enzyme 21 hydroxylase accounts for 70% of Addison's disease cases however there are other causes including infections adrenal cortex malignancy secondary malignancy of the adrenal cortex from metastasis elsewhere such as the lungs adrenal cortex hemorrhage or infarction the per the patient might be on warfarin which predisposes them to this Addison's disease can be caused by infiltration diseases such as hemochromatosis and amyloidosis there are also at Regina causes such as removal of the adrenal glands which will obviously cause a reduction in the adrenal cortex hormones a rare congenital cause is characterized by ambiguous genitalia and this is known as congenital adrenal hyperplasia finally medications that can cause a decrease in cortisol production can cause Addison's this includes etomidate meter tane and amino Bluetooth amide some of these drugs of which are usually used to treat Cushing's syndromes risk factors for Addison's disease include female gender because most autoimmune diseases actually tend to occur in females having an autoimmune disease adrenal cortex ohto antibody production adrenal hemorrhage is another risk factor tuberculosis infection meningococcal infection with adrenal hemorrhage and of course using medications that can induce Addison's disease is a risk factor recapping primary adrenal insufficiency is Addison's disease which has multiple many causes secondary adrenal insufficiency is caused by hypothalamic pituitary dysfunction investigations into Addison's disease so in Addison's disease there is reduced production of mineral corticoids and decreased production of glucocorticoids however because of low amounts of the good corticoids as we learned negative feedback does not occur and so there is an increase in acth production by the anterior pituitary gland and so investigations to be perform include checking serum ACTH which will show an increase in serum ACTH and also checking for the presence of adrenal auto antibodies there will be an increase in serum cortisol other blood tests include full blood count and performing EUC which may show hyponatremia hyperkalemia and increase in urea finally imaging such as CT scan is important which may reveal adrenal tumors or adrenal hemorrhage a thyroid function test is also important as one of the main differentials for Addison's disease is Graves disease management of Addison's disease the most important part is to educate the patient particularly to never miss a dose of medication and we will learn the reason why the medications for Addison's disease include replacing the hormones which are lost this means using glucocorticoid replacements such as hydrocortisone mineral coracoid replacements such as fludrocortisone and this will replace diminished endogenous mineral coracoid production androgen replacement are mainly for females finally for management monitoring is important because of the complications associated with Addison's disease or mainly also because of the medication used as well too much glucocorticoids replacement can cause secondary Cushing's it can also cause osteopenia and osteoporosis increasing the risk of bone fractures mineral corticoids and glucocorticoid replacement can also cause secondary hypertension but most serious complication is adrenal crisis which is where there is a sudden drop in glucocorticoid levels this is often caused when patients on long term glucocorticoids suddenly stopped taking the glucocorticoid replacement or because they are not taking enough glucocorticoids in general what happens the patient on long term glucocorticoids will increase glucose glucose coracoid levels which will have a negative feedback on the hypothalamus and so because of this negative feedback there will be a decrease in ACTH and remember in patients with Addison's disease the adrenal cortex does not work properly they don't produce enough glucocorticoids especially now with the reduced ACTH the little remaining functional part of the adrenal cortex will not produce anything and just atrophy and become non functioning and so if all the sudden glucocorticoid replacement therapy is stopped they will literally be no adrenal cortex hormones and this is essentially adrenal crisis and so patient education is vital it's important to not miss doses encouraged them to wear a mobile bracelet and third point double the dose of glucocorticoids during febrile illness or during periods where it is necessary you

Channel: Armando Hasudungan

Views: 423,268

Keywords: addison's disease, adrenal glands, addisons disease, adrenal gland disease, endocrine disease, low adrenal gland hormones, addison's crisis, medicine, endocrinology, primary adrenal insufficiency, secondary adrenal insufficiency, adrenal deficiency, causes, treatment of addisons, pathophysiology of addison's disease, pathogenesis, autoimmune disease, cushing's disease, mechanism of disease, armando hasudungan, low aldosterone and cortisol, hypocortisolism, endocrine disorder

Id: wqJUifWOGEo

Length: 16min 27sec (987 seconds)

Published: Wed Mar 22 2017