9. Endocrine System Pathologies Flashcards
Acromegaly and Gigantism
- Gigantism: Excess growth hormone while the bones are still developing –results in the person growing tomassive heights.
- Acromegaly: Excess growth hormone post-puberty (after growth plates closed). Patient grows ‘outwards’as opposed to ‘upwards’.
Acromegaly and Gigantism: Cause
A pituitary tumour hyper-secreting growth hormone.
Acromegaly and Gigantism: Signs and Symptoms
- Large, prominent facial features, increased size hands & feet.
- Tiredness, deep voice, impotence, joint pain, bone deformities, soft-tissue swellings
Acromegaly and Gigantism: Treatment
• Surgery to remove tumour. Lifelong medications may be needed.
Acromegaly and Gigantism: Complications
- Hypertension, cardiomegaly.
- Type 2 diabetes (growth hormone increased blood glucose levels -> insulin resistance).
- Osteoarthritis, vertebral collapse (back pain).
- Bowel polyps.
Hyperprolactinaemia
Excessive prolactin production
Hyperprolactinaemia: Causes
• Pituitary tumour, acromegaly, pharmacologic (antipsychotics).
Hyperprolactinaemia: Signs and Symptoms
- Galactorrhoea.
- Amenorrhoea (absence of menses –because prolactin inhibits GnRH).
- Decreased libido/sexual dysfunction.
- Subfertility.
Diabetes Insipidus
Deficiency of ADH production or recognition causing the kidneys to over excrete water.
Diabetes Insipidus: Causes
- Cranial: Brain trauma, tumour, encephalitis.
- Renal (Kidney): Chronic kidney disease, hypercalcaemia & hypokalaemia (too much calcium, too little potassium) damages kidney.
Diabetes Insispidus: Signs and Symptoms
- Polydipsia (extreme thirst) -large consumption.
- Polyuria: excess urine production (dilute).
- Weight loss.
- decresed BP, syncope (“fainting” due to hypovolaemia).
Diabetes Insipidus: Diagnosis
- 24 hrurine collection (quantity of urine measured over 24 hours).
- Urine specific gravity –low (i.e. urine is more diluted than normal).
- Blood biochemistry (increased Na).
Diabetes Insipidus: Treatment
- Treat cause.
- ADH replacement
- Rehydration: water & electrolytes
Hypothyroidism
A condition of thyroid hormone deficiency (an “underactive thyroid”).
Hypothyroidism: Signs and Symptoms
SYMPTOMS:
• Tiredness, malaise, weight gain, cold intolerance, constipation, depression.
• Slow cognitively, poor memory, low libido, deep voice, menstrual changes, muscle aches, arthralgia (joint pain)
SIGNS:
• Goitre, dry, brittle skin & thin hair, loss of eyebrows.
• ‘Myxoedema’ (swelling) often around the eyes (deposition of polysaccharides which attract water).
• Physical exam: Slow tendon reflexes, bradycardia.
• Bloods tests: High TSH, low thyroid hormones.
Hypothyroidism: Causes
- Hashimoto’s thyroiditis(autoimmune).
* Iodine deficiency, thyroid destruction (radioactive iodine, surgery, medications, tumour).
Hypothyroidism: Treatment
• Levothyroxine–thyroid hormone replacement
Hyperthyroidism (‘Grave’s disease’)
- Hyperthyroidism is characterised by hyper-metabolism and elevated serum levels of free thyroid hormones (also known as thyrotoxicosis).
- More common in women (10:1).
Hyperthyroidism: Causes
- Graves disease (85%): Autoimmune. Increased IgG antibodies bind to TSH receptor and stimulate production of thyroid hormones.
- Excessive iodine supplementation.
- Tumour (hypothalamic, pituitary).
Hyperthyroidism: Signs and Symptoms
- Nervousness, irritability, hyperactivity, unexplained weight loss.
- Insomnia, palpitations, muscle weakness, frequent bowel & bladder movements, diarrhoea, fatigue.
- Heat sensitivity, increased sweating.
- Signs:Goitre, exophthalmos, tachycardia, tremor, brisk tendon reflexes, lid lag.
Hyperthyroidism
• Allopathic:Carbimazole, radioactive iodine, β-Blockers, surgery.
Barnes Temperature Test
- Prepare the thermometer before going to bed.
- On waking, before getting out of bed, with as little movement as possible, place the thermometer under your arm.
- Leave it in position for 10 minutes.
- Test for 5 consecutive days and make a note of the 3 lowest readings. If menstruating do the test starting the second day of menses.
- 36.6 -36.8OC (97.8 -98.2OF) is normal. Below 36.6OC (97.8OF) = Might indicate hypothyroidism. Above 37OC (98.6OF) = Might indicate hyperthyroidism.
Hyperparathyroidism
• Hyperparathyroidism is characterised by elevated blood levels of parathyroid hormone and improper calcium regulation.
Hyperparathyroidism: Causes
• Usually a tumourof the parathyroid gland.
Hyperparathyroidism: Signs and Symptoms
- Often no/few symptoms.
- Hypercalcaemia -> increased risk of kidney stones, osteoporosis (or osteopenia), low energy, depression.
- In some cases: nausea, vomiting, constipation, anorexia, muscle paralysis.
Hypoparathyroidism
Hypoparathyroidism is characterised by hypo-metabolism and reduced serum levels of parathyroid hormone (PTH).
Hypoparathyroidism: Causes
Usually surgery or radiation (treating thyroid).
Hypoparathyroidism: Signs and Symptoms
Hypocalcaemia -> Muscle cramps & spasms (“tetany”), tingling lips, fingers and toes, dry hair, brittle nails, dry scaly skin, cataracts, weakened tooth enamel (in children).
Cushing Syndrome/Disease
Syndrome
• A cortisol excess from any cause (glucocorticoid drugs, adrenal, tumour).
Disease
• Excess production of ACTH causing excess glucocorticoid production from the adrenal cortex.
Cushing Syndrome/Disease: Causes
Syndrome
- Corticosteroid therapy
- Adrenal adenoma
- Pituitaryadenoma (Cushing’s disease)
Disease
1. Pituitary tumour
Cushing Syndrome / Disease: Signs and Symptoms
- Central weight gain, moon face, buffalo hump, insulin resistance.
- Depression, insomnia, psychosis, poor libido, hirsutism, amenorrhoea (also releases some androgens).
- Easy bruising, thin skin, abdominal stretch marks(due to protein taken from collagen and lowered immunity).
- Reduced immunity.
- Muscular weakness, back pain.
- Bone fractures, osteoporosis.
- Hypertension.
Cushing Syndrome / Disease: Treatment
• Drugs inhibiting cortisol production, surgery (for tumours).
Cushing Syndrome / Disease: Complications
• Lowered immunity, fragile skin, bone fractures, diabetes mellitus.
Addison’s Disease
Adrenal insufficiency: hypo-functioning of the adrenal cortex causing a deficiency of mineralocorticoids and glucocorticoids.
Addison’s Disease: Causes
- Atrophy of the adrenal gland (often autoimmune) (85%).
* Secondary to a disease or abrupt cessation of steroids.
Addison’s Disease: Signs and Symptoms
- Weakness, fatigue and hypotension.
- Hyperpigmentation of skin and mucous membranes.
- Diarrhoea, weight loss, anorexia, malaise, muscle weakness, depression, increased thirst.
- Impotence/amenorrhoea, nausea/vomiting.
- Adrenal failure leads to lack of adrenal hormone production and a failure of the normal negative feedback mechanism.
- The hypothalamus produces an excess of corticotrophin releasing hormone (CRH), which causes the pituitary to erroneously produce melanocyte stimulating hormone.
- This causes the skin colour to darken, hence hyperpigmentation.
Addisonian Crisis
• A complication of Addison’s disease when the individual has no capacity to cope with stress (e.g. psychological, infection etc.)
Addisonian Crisis: Signs and Symptoms
- Severe lethargy and low blood pressure(low sodium).
- Hypoglycaemic, syncope (fainting).
- Severe pain, renal failure, fever.
Diabetes Mellitus
- A metabolic disorder associated with hyperglycaemia, characterised by a deficiency of insulin due to impaired production or insulin resistance.
- Causes a disruption of carbohydrate & fat metabolism & elevated blood glucose levels -> hyperglycaemia.
Types of Diabetes Mellitus
Type I: Autoimmune
Type II: Insulin resistance
Secondary (1-2% of cases): Due to certain medications (cortisone), pancreatitis
Gestational: During pregnancy as a result of placental hormones (i.e. human placental lactogen). Usually disappears after delivery, but elevated rish of Type II years later
Type I Diabetes
Previously called juvenile-onset or insulin-dependent (IDDM).
Type I Diabetes: Causes
- An auto-immune condition causing destruction of pancreatic ß-cells.
- Likely due to the environment in genetically susceptible people.
- Viruses (e.g. polio, rotavirus), dietary factors –infant exposure to dairy products (cow’s milk and the milk protein β casein), vitamin D deficiency, omega-3 deficiency, early exposure to gluten.
Type I Diabetes: Signs and Symptoms
- Glycosuria (sweet urine), polyuria (lots of urine), polydipsia (thirst).
- Weight loss, weakness, fatigue, and mental status changes.
- Blurred vision, slow healing of cuts/infections.
- Ketoacidosis: Fruity smelling breath (exhaled acetone), shortness of breath.
Type I Diabetes: Treatment
Insulin
Type II Diabetes
- Previously called adult-onset or non–insulin-dependent diabetes.
- Cells have developed insulin resistance and glucose cannot enter cells.
- Hyperglycaemia develops when pancreatic beta cells can no longer secrete insulin to compensate for insulin resistance.
- 1/3 adults over 65 and increasing numbers of children have impaired glucose tolerance.
Type II Diabetes: Causes
- Genetic: strong hereditary link, American Indians, Hispanics, African American & Asians.
- Lifestyle: Obesity & weight gain, poor diet, lack of exercise. Other risk factors include: history of gestational diabetes.
Type II Diabetes: Signs and Symptoms
- Polydipsia (excessive thirst).
- Polyuria (excess urination).
- Polyphagia (excessive appetite)
- Often asymptomatic because of mild hyperglycaemia (unlike in type I diabetes).
- Initial symptoms are often complications, indicating the disease has been present for some time.
- Ketoacidosis in rare, severe cases (same complications as type I).
Type II Diabetes: Diagnosis
- Fasting / random blood glucose test.
- Oral glucose tolerance test.
- Glycated Haemoglobin (HbA1c) > 48mmol/mol = diabetes.
- Urine test (assistsdiagnosis only).
Type II Diabetes: Treatment
- Diet (low GI & GL), exercise, oral anti-hyperglycaemics(e.g. metformin), insulin, or both.
- Statins & anti-hypertensives to prevent complications.
Diabetic Complications
Chronic hyperglycaemia causes complications: micro and macro-vascular disease:
• Heart disease, hypercholesterolaemia, hypertension.
• Retinopathy.
• Nephropathy (diabetic kidney disease).
• Peripheral neuropathy.
Ketoacidosis
- When glucose supply is low or when cells cannot utilise glucose, the mitochondria can use ketones to make energy.
- Ketones are derived from the break down of fatty acids.
- Ketones (or keto-acids) are acidic and can be toxic if they accumulate to excessive levels.
- May result in coma or death.
- Ketones can be tested using a urine dipstick.
- Breath smells fruity (acetone) & increased thirst are key signs.
Hypoglycaemia
• Hypoglycaemia can affect diabetics in
response to treatment (e.g. insulin or
other glucose lowering drugs).
Hypoglycaemia: Signs and Symptoms
- Shaking and trembling.
- Sweating.
- Pins and needles in the lips and tongue.
- Extreme hunger and irritability.
- Headache.
- Slurred speech, confusion, tiredness.
- Ketoacidosis & coma.
Histamine
Secreted by: Basophils, mast cells
Action: Inflammation - vasodilation and increased blod vessel permeability
Prostaglandins, Leukotrienes and Thromboxane
Secreted by: most tissues
Action: Chemical messengers involved in many different body processes
Serotonin
Secreted by: intestines and brain
Action: Blood clotting, temperature regulation, appetite, sleep
Dopamine
Secreted by: Brain mostly
Action: Muscle tone and some movements
Erythropoietin
Secreted by: Kidneys
Action: Red blood cell production
CCK
Secreted by: GI Tract
Action: Stimulates bile and pacreatic juice secretion
