Endocrine_CCT (2) Flashcards
What features would decrease in growth hormone cause?
- central obesity
- atherosclerosis
- dry, wrinkly skin
- low strength and low balance and wellbeing
- decrease in excersie ability
- decreased cardiac output
- osteoporosis
- decreased glucose
What feature would gonadotropism (due to low pituitary secretion) cause?
Decreased gonadotrophins, FSH__,LH__:
- oligomenorrhoea or amenorrhoea
- decreased fertility
- decreased libido
- osteoporosis
- breast atrophy
- dyspareunia
- erectile dysfunction
- decreased muscle bulk
- hypogonadism
What would decrease in the following cause:
- prolactin
- TSH
- ACTH
- Prolactin -absent lactation
- TSH -hypothyroidism
- ACTH -adrenal insufficiency.
What is panhypopituitarism
- Panhypopituitarism is a deficiency of all anterior pituitary hormones
- caused by radiation/surgery or a pituitary tumour
Investigations in hypopituitarism disorders
- LH and FSH -either decreased or normal
- Testosterone or oestradiol are low
- TSH is low or normal
- T4 is low
- Prolactin might be high due to the loss of hypothalmic dopamine that normally inhibits its release
- Insulin-like growth factor-1 is decreased
- Cortisol is low
- U&E -will show low sodium and that is to the dilution.
- Hb is low, normochromic, normocytic
What may happen to prolactin in hypopituitarism?
Prolactin might be high due to the loss of hypothalmic dopamine that normally inhibits its release
Other tests in hypopituitarism
- Short Synacthen Test -and this is to assess the adrenal axis
- Insulin tolerance test
It involves IV insulin to induce hypoglycaemia causing stress to increase the cortisol and GH section. It is done in the morning and water only taken at 10pm.
- Arginine and growth hormone releasing hormone test
- Glucagon stimulation test is alternative when ITT is contraindicated
Management of hypopituitarism
- hormone replacement and treatment of underlying cause
- Hydrocortisone -for 2ndary adrenal failure
- Thyroxine if hypothyroid
- Testosterone enanthate 250mg IM every 3 weeks, daily topical gels or buccal mucoadhesive tablets
- Oestrogen, transdermal oestradiol patches or contraceptive pill, as this will eceed replacement needs
- to prevent osteoporosis (if hypogonadism)
- Gonadotropin therapy is needed to induce fertility in both men and woman.
Symptoms of acromegaly
- Acroparaesthesia (paraesthesia in the extremities)
- Amenorrhoea
- Decreased libido
- Increase sweating
- Snoring
- Arthralgia
- Backache
- ‘my rings won’t fit nor my old shoes’
- Curly hair
- Malocclusion (incorrect relation between two teeth)
Signs of acromegaly
- increase growth of hands, jaw and feet
- Coarsening face
- Wide nose
- Big supraorbital ridges
- Macroglossia
- Widey spaced teeth
- Puffy lips, eyelids and skin is oily.
- Scalp folds
- Skin darkening
- Acanthosis Nigerians
- Laryngeal dyspnoea
- Obstructive sleep apnoea
- Goitre
- Carpel tunnel signs
- Hemianopia
Complications of acromegaly
- Impaired glucose tolerance
- Vascular: increase blood pressure, LV hypertrophy
- Cardiomyopathy
- Arrhythmias
There is an increased risk of ischaemic heart disease and stroke →this is due to BP and insulin resistance and GH-induced increase in fibrogen and decrease in protein S.
- Neoplasia, there is an increased risk of colon cancer
Ix in acromegaly
- ↑glucose
- ↑Calcium and phosphate
- An oral glucose tolerance test is needed
- MRI look for hypopituitarism, visual fields and acuity and ECG, Echo and old photos if possible.
Is GH test reliable in testing for acromegaly?
GH: don’t rely on a random GH as the secretion is pulsatile and during peaks acromegalic and normal levels overlap.
GH also increases in stress, sleep, puberty and pregnancy.
What’s the definitive test for acromegaly?
Definitive test is the oral glucose tolerance (OGTT) with serial GH measurements
Oral glucose tolerance test
- in normal patients GH is suppressed to < 2 mu/L with hyperglycaemia
- in acromegaly there is no suppression of GH
- may also demonstrate impaired glucose tolerance which is associated with acromegaly
Management of acromegaly
Aim: to correct or prevent the tumour compression by excising the lesion and to reduce the GH and IGF-1 levels
Three-part strategy of treatment:
- Transsphenoidal surgery is the first line
- If surgery fails to correct the hypersections then try Somatostatin analogues or radiotherapy
- The GH antagonist pegvisomant
Classification of hypothyroidism (3)
Hypothyroidism may be classified as follows:
- primary hypothyroidism: there is a problem with the thyroid gland itself, for example an autoimmune disorder affecting thyroid tissue
- secondary hypothyroidism: usually due to a disorder with the pituitary gland (e.g.pituitary apoplexy) or a lesion compressing the pituitary gland
- congenital hypothyroidism: due to a problem with thyroid dysgenesis or thyroid dyshormonogenesis
Common cause of hyperthyroidism
- thyrotoxicosis
What’s the most common cause of thyroid problems in the developed world?
autoimmunity
The most common cause of hypothyroidism
Hashimoto’s thyroiditis
- autoimmune disease, associated with type 1 diabetes mellitus, Addison’s or pernicious anaemia
- may cause transient thyrotoxicosis in the acute phase
What drugs can induce hypothyroidism (2)
- Lithium
- Amiodarone
What’s de Quervain’s?
- other name and result
- associated features (2)
Subacute thyroiditis (de Quervain’s) -> hypothyroidism
- associated with: a painful goitre and raised ESR
The most common cause of hypothyroidism in the developing world is…
Iodine deficiency
What’s Ridel’s thyroiditis?
Ridel’s thyroiditis -> hypothyroidism
- fibrous tissue replacing the normal thyroid parenchyma
- causes a painless goitre
What disease commonly causes hyperthyroidism?
Graves’ disease
- most common cause of thyrotoxicosis
- as well as typically features of thyrotoxicosis other features may be seen including thyroid eye disease
Toxic nodular goitre
- what is this
- what does it cause
Toxic nodular goitre -> hyperthyroidism
- autonomously functioning thyroid nodules that secrete excess thyroid hormones
What drug (1) may cause hyperthyroidism?
amiodarone
Presenting features of hypothyroidism
Presenting features of hyperthyroidism
What thyroid antibodies we may test for (3)?
A number of thyroid autoantibodies can be tested for -> the majority of thyroid disorders are autoimmune
The 3 main types are:
- Anti-thyroid peroxidase (anti-TPO) antibodies
- TSH receptor antibodies
- Thyroglobulin antibodies
TSH receptor antibodies -> in around 90-100% of patients with Graves’ disease
anti-TPO antibodies-> in around 90% of patients withHashimoto’s thyroiditis
What imaging test do we do for Ix of multinodular goitre?
nuclear scintigraphy; toxic multinodular goitre reveals patchy uptake
Treatment of hypothyroidism
thyroxine in the form of levothyroxine to replace the underlying deficiency.
Treatment of hyperthyroidism
Patients with thyrotoxicosis may be treated with:
- propranolol: this is often used at the time of diagnosis to control thyrotoxic symptoms such as tremor
- carbimazole: blocks thyroid peroxidase from coupling and iodinating the tyrosine residues on thyroglobulin → reducing thyroid hormone production
*Agranulocytosis is an important adverse effect to be aware of
- radioiodine treatment
What’s the diagnosis in the following
What’s the diagnosis?
Signs of Grave’s disease
- Eye disease (thyroid eye disease) exophthalmos, ophthalmalgia
- Pretibial myxoedema: oedematous swellings above lateral malleoli: the termmyxoedemais confusing here.
- Thyroid acropachy: extreme manifestation, with clubbing, painful finger and toe swelling, and periosteal reaction in limb bones
Management of thyroid eye disease
Management (TED - in Grave’s)
- Stop smoking and treat the cause
- symptomatically (artificial tears, sunglasses, avoid dust, elevate bed when sleeping to ↓periorbital oedema)
- Diplopia may be managed with a Fresnel prism stuck to one lens of a spectacle (aids easy changing as the exophthalmos changes)
- severe disease then try high-dose IV methylprednisolone
- Surgical decompression is used for severe sight-threatening disease or for cosmetic reasons once the activity of the eye disease has reduced.
Pathophysiology of Grave’s
What are the risks of thyroidectomy?
Thyroidectomy: risks
- damage to unilateral recurrent laryngeal nerve -hoarse voice, dyspnoea few days after the surgery and hypoparathyroidism
- If the damage is bilateral then that is a very life-threatening condition and will therefore lead to upper airway obstruction, in this case the patient has to be intubated
- Patients will become hypo so their thyroid need to be replaced
- post-thyroidectomy laryngeal oedema is rare but it is potentially life threatening complication of this procedure
It is usually due to the development of post-operative haematoma that obstructs the venous and lymphatic drainage of the larynx leading to the laryngopharyngeal oedema.. This will present 2-6 hours post-surgery.
What is myxoedema?
hypothyroidism
What’s the mechanism by which amiodarone causes:
- hypothyroidism
- hyperthyroidism
Amiodarone (class III anti-arrhythmic)
- an iodine-rich structutally like T4
- 2% of users will get significant thyroid problems from it.
- Hypo: can be caused by toxicity from iodine excess (T4 release is inhibited
- Thyrotoxicosis may be caused by a destructive thyroditis causing hormone release
How often and what do we monitor in Amiodarone use?
TFTs 6 monthly
What’s subclinical thyroiditis?
Subclinical hyperthyroidism
occurs when ↓TSH with normal T4 and tT3
