Endocrine Diseases Flashcards
What is diabetes?
What does it result in?
- SIMPLY, IN THE BODIES INABILITY TO REGULATE BLOOD GLUCOSE LEVELS
- THIS RESULTS IN HYPERGLYCEMIA FROM DEFECT IN INSULIN SECRETION, ACTION OR BOTH
- LONG TERM, LEADS TO ORGAN DYSFUNCTION, DAMAGE OR FAILURE EG KIDNEYS
What are the main types of diabetes?
- TYPE 1- LACK OF INSULIN SECRETION
- TYPE 2- INSULIN INSENSITIVITY - GESTATIONAL- FIRST DIAGNOSED IN PREGNANCY - MODY- AN AD MUTATION RESULTING IN INEFFECTIVE INSULIN PRODUCTION AND SECRETION
- DIABETES INSIPIDUS
Patho of type 1 diabetes?
Causes?
- TYPE I DIABETES IS A DISORDER THAT RESULTS FROM THE DESTRUCTION OF THE BETA CELLS OF THE PANCREAS, WHICH PRODUCE INSULIN
- OCCURS IN GENETICALLY SUSCEPTIBLE INDIVIDUALS WITH ENVIRONMENTAL TRIGGER FACTORS, ALTHOUGH THE EXACT AETIOLOGY IS NOT WELL UNDERSTOOD
- HLA DR3, HLA DR4, HLA DQB1
- CAN BE TRIGGERED BY A VIRUS
- AUTOIMMUNE ANTIBODY DESTRUCTION OF BETA CELLS
Ix of Diabetes
Management?
- INVESTIGATIONS: • NO C PEPTIDE • PRESENCE OF ANTIBODIES (ANTI ISLET CELL, ANTI INSULIN, ANTI GAD ETC )
- PATIENTS REQUIRE LIFE-LONG INSULIN THERAPY AND CARBOHYDRATE COUNTING (FOR DOSE ADJUSTMENTS)
What is DKA?
Diabetic ketoacidosis
DKA is a serious acute complications of Diabetes Mellitus - It carries significant risk of death and/or morbidity especially with delayed treatment
Patho of DKA
- Insulin deficiency causes an increase in blood glucose (hyperglycaemia & glycosuria)
- Glycosuria causes an osmotic diuresis leading to water and sodium loss.
- The body fails to use glucose as a fuel (insulin is not transporting it into cells)
- The body uses fats as a fuel instead, but this leads to ketosis.
- An excess of ketone bodies will cause a metabolic acidosis.
- Due to the acidosis, K+ ions enter the circulation leading to hyperkalemia
- Depending on the duration of DKA, serum K+ may be high, normal or low but the intracellular K+ stores will be depleted.
- Phosphate depletion will also occur due to the metabolic acidosis
- Na+ loss occurs secondary to the hyperosmotic state
- Dehydration can lead to decreased kidney perfusion and acute renal failure
- Accumulation of ketone bodies contributes to abdominal pain and vomiting
- An increasing acidosis leads to acidotic breathing (Kussmaul) and acetone breath smell (pear drop)
- Usually, untreated DKA will lead to impaired consciousness and coma.
Affects of glucagon to DKA
Glucagon has no affect. It is catabolic and so it breaks down fats (lipolysis) and protein (loss of muscle mass). High levels of insulin mean fat transported into cells and stored. When there is low levels of insulin fat goes back into the blood from the adipocytes. SO the lack of insulin and normal levels of glucagon causes lots of free FA.
This means there will be lot of free fatty acids in the blood. In the liver the free fatty acids gets converted into ketones. Ketones can be used as energy for cells so they are secreted into blood to go to cells (ketonemia). Can test the ketones In the blood. The ketones also give the sweet smell in breath. Ketones are acids so this causes acidosis (acetoacetic acid and beta hydroxybutyric acid). Remember ketones can only be used slowly and so you can get a build-up of ketones in the blood. The acidosis leads to a diabetic ketoacidosis.
Affects of respiratory centre on DKA
The respiratory centre in the medulla oblongata senses the acidosis and causes hyperventilation (rapid deep breathing). Acidosis also causes vasodilation which leads to hypothermia and low blood pressure (hypotension). The hypotension is also from the hyperglycaemia which causes osmotic diuresis which causes hypovolaemia (decreased volume in blood) which causes the low blood pressure. If the hypotension gets worse, it can then lead to shock.
Osmotic diuresis means the patient is losing a lot of fluid which loses a lot of potassium as well (hypokalaemia) which can then cause problems in the heart.
What is DM type 2
CAUSED BY A PROGRESSIVE DEFECT IN THE SECRETION OF INSULIN AND ACTION (INSULIN RESISTANCE)
patho of DM type 2
- It usually begins as insulin resistance, a disorder in which the cells do not use insulin properly.
- As the need for insulin rises, the pancreas gradually loses its ability to produce insulin
- It is a problem with insulin transport receptors. A reduced amount of these receptors causes blood sugar levels to rise in the blood.
- to compensate this the pancreas tries to release more insulin so initially there will be a lot of insulin in type 2 but overtime this decreases because the beta cells get tired and so reduction in mass= insulin decrease. (so this is why some people might need insulin if they have type 2)
What are the clinical features of type 1 and type 2
Age
duration of symtoms
body weight
ketonuria
Rapid death
autoantibodies
complication at diagnosis
FHx
other autoimmune diseases
Normal glucose physiology?
3.5-8mmol per litre
Renal threshold in DM
Renal threshold is 11mmol
Three common symptoms of DM
Glucosuria, Polyuria, Thirst
- In the renal tubules, if there is more glucose (more than 11 mmol) then you will have glucose in urine (glycosuria)
- Glucose attract water so that causes more water to be retained in the urine so that causes more volume of urine (diuresis-abnormally large amount of water being passed).
Weight loss (type1)
What is HbA1c
Some glucose while in the blood diffuse into rbc and that attaches to the Hb and this is glycalated glucose. The amount of glucose in the blood is proportional to the amount of glycalated hb. HbA1c is the test to see the amount. The test gives you an average of glucose in the blood over a period of time (8-12 weeks)
Complications of type 1 DM
DKA
If glucose levels in brain will be low- if too low then you can go into acute hypoglycaemic coma. This happens if we give too much insulin without any food intake because glucose levels would already be low so you would be lowering it further.
THE FOUR MAIN DETERMINING FACTORs of DM type 2
AGE, OBESITY, FAMILY HISTORY AND ETHNICITY
there is no association between HLA and type 2 DM
true or false
True
WHat is HHS?
Diabetic hyperglycemic hyperosmolar syndrome (HHS) is a complication of type 2 diabetes. It involves extremely high blood sugar (glucose) level without the presence of ketones.
HYPERGLYCAEMIA WITHOUT KETONES OR ACIDOSIS.
- VERY SIMILAR PATHOPHYSIOLOGY TO DKA, BUT THE INSULIN DEFICIENCY IS NOT ENOUGH TO CAUSE KETOGENESIS AND LIPOLYSIS.
- SAME MANAGEMENT AS DKA
WHat to look out for if the patient has HHS?
PATIENT WITH UNDIAGNOSED DIABETES, NEWLY DIAGNOSED PATIENT, PATIENT WHO DOES NOT TAKE INTEREST IN THEIR HEALTH, ANYTHING LEADING YOU TO THINK THEY DO NOT TAKE THEIR MEDICATION
Hypothyroidism
common in men or women?
older women
What is the difference between primary and secondary cause of hypthyroidism?
- Primary- cause within the thyroid gland - Failure to produce enough T4/T3
- Secondary- cause within the pituitary/ hypothalamus (central) - Failure to produce enough TSH
Causes for Hypothyroidism?
- AI thyroiditis: Hashimoto’s- Anti-TPO antibodies , Atrophic
- Drugs eg lithium, amiodarone
- Secondary to treatment of hyperthyroidism
- Congenital (1 in 3500 births)
- Iodine deficiency
- Pituitary adenoma
- Surgery/ radiotherapy
- Head trauma
- Vascular- Sheehan’s syndrome
Treatment for hypothyroidism
• Levothyroxine • Synthetic T4 • Titrated until TSH levels are normal
What is myxoedema Coma?
- Severe and life-threatening medical emergency
- Occurs in people with poorly controlled hypothyroidism who are undergoing a stressful event (surgery or infection)
- Features- altered consciousness, confusion, hypothermia, bradycardia, hypotension and accumulation of drugs
What is hyperthyroidism?
Primary?
Secondary?
- Excessive production of thyroid hormone
- Primary- problem with thyroid gland
- Secondary- problem with pituitary/ hypothalamus
Causes of hyperthyroidism?
- Graves disease
- Toxic multinodular goitre
- Hashimoto’s thyroiditis
- Toxic adenoma
- Drugs- amiodarone, iodine
WHat is thyrotoxicosis?
thyrotoxicosis is the clinical manifestation of excess thyroid hormone action at the tissue level due to inappropriately high circulating thyroid hormone concentrations.
Hyperthyroidism, a subset of thyrotoxicosis, refers specifically to excess thyroid hormone synthesis and secretion by the thyroid gland
Causes of thyrotoxicosis
- Exogenous thyroid hormones
- Subacute thyroiditis
- Ectopic thyroid tissue
Hyperthyroidism
symptoms?
What is Graves Disease
Graves’ disease (aka toxic diffuse goitre) is an autoimmune disease that affects the thyroid. - It frequently results in and is the most common cause of hyperthyroidism. - It also often results in an enlarged thyroid.
Patho of graves
- TRAb Antibodies bind to and stimulate the TSH receptors producing excessive thyroid hormone and thyroid enlargement
- More common in women
- Associated with T1DM and Addison’s
What are the three unique features of graves?
- Graves Opthalmopathy (Exophthalmos, periorbital oedema, scleral infections, optic neuropathy, lid lag)
- Graves dermopathy (pretibial myxoedma)
- Thyroid acropachy - digital clubbing, soft tissue swelling of the hands and feet, and periosteal new bone formation.
What is the first line of management for graves/hyperthyroidism?
second line
Carbimazole (reduces thyroid hormone synthesis)
• Propylthiouracil is the second line anti-thyroid drug. It is used in a similar way to carbimazole. There is a small risk of severe hepatic reactions, including death, which is why carbimazole is preferred.
Management of symtoms for hyperthyroidism?
Beta blockers eg propanolol
What is thyroid storm?
- Medical emergency due to exacerbation of severe thyrotoxicosis
- Causes by stressful events eg infection and surgery
Thyroid storm is a very rare, but life-threatening condition of the thyroid gland that develops in cases of untreated thyrotoxicosis (hyperthyroidism, or overactive thyroid). The thyroid gland is located in the neck, just above where your collarbones meet in the middle.
clinical features and management for thyroid storm?
- Clinical features: severe hyperthyroidism, hyperpyrexia, altered mental state, tachycardia, cardiac failure, jaundice/abdo pain
- Managed via anti-thyroid drugs, potassium iodide, beta-blockers, steroids
Most common type of thyroid cancer?
Papillary (80%)
Follicular (10%)
Medullary (5%)
ANaplastic (rare)