W16 59 diabetes and endocrine disease Flashcards
What is a hormone?
Substance produced in one part of the body, secreted into the bloodstream, transported to a different organ/tissue where it acts to modify structure of function.
What are the different types of hormones? Give examples
Peptide hormones: insulin, pituitary hormones, PTH
Steroids: cortisol, testosterone, oestrogen
Tyrosine derivatives: thyroid hormones, epinephrine
What are the major functions of the anabolic (builds up tissue) hormone insulin?
Moves glucose out of the bloodstream for storage/building
Maintains supply of glucose to tissues
Regulates metabolism in muscle
Promotes protein synthesis
Inhibits breakdown of fat
What is Diabetes Mellitus?
A group of metabolic diseases characterised by chronic hyperglycaemia resulting from defects in insulin secretion, insulin action or both. The lack of insulin can lead to damage of blood vessels or nerves after a long time.
What are the non-specific symptoms of DM?
Polyuria - weeing a lot
Polydipsia - very thirsty (glucose is osmotic and when in blood more will be urinated out, taking in more water, so thirst)
Weight loss - cells cant use the glucose so people waste away
Fatigue - low energy as cant use glucose
Glucosuria and hyperglycaemia.
How are diabetes diagnoses made?
Fasting plasma glucose >=7mmol/L
Random plasma glucose >=11.1mmol/L
What is the oGTT?
Oral glucose tolerance test
Diabetes if level >=11.1mmol/L
How is HbA1c a measure of diabetes?
If you have an excess amount of glucose in bloodstream, it will bind to haemoglobin, and correlates. Thus HbA1c, measured. Gives an idea of the average blood glucose over the past 3 months.
What should the HbA1c level be?
If below 5.7% - pt has no diabetes
>6.5% - pt has diabetes
(between need more tests, fasting glucose or oGTT)
What are some oral manifestations/complications of diabetes?
- Compromises the immune system - wound healing impaired; prone to infection; prolonged recovery
- dental caries
- periodontitis - high levels of CRP correlate with inflammation
- xerostomia
- altered taste
- parotid gland enlargement
- mucosal diseases eg lichen planus, lichenoid drug reactions
Main difference between type I and type II diabetes?
Type I - autoimmune destruction of the beta cells in the islets of Langerhands in the pancreas.
Type II - disorders of insulin secretion and insulin action - insulin resistance or beta cell failure.
Treatment of type I diabetes
Insulin replacement necessary - via injections or insulin pump
Monitoring of blood glucose is vital - basal bolus: 4 injections daily; mixed insulin - 2-3 injections daily; long-acting insulin only 1-2 injections daily.
Treatment of type II diabetes
(in order of disease progression)
1. Diet and exercise to promote weight loss (reduces insulin resistance)
2. Oral treatment with drugs - single or combined therapy
3. Insulin - in combination with drugs - full insulin - replacement (when pancreas completely shuts down)
What things should you know about a patient’s diabetes?
Type
Treatment
Level of glycaemic control - when it has been checked last. Poorly controlled diabetes will more likely develop complications.
how should you manage diabetes in practice?
try not to omit meals (increases risk of hypo)
plan breaks for snacks
regular glucose checks during longer procedures
avoid procedures in uncontrolled diabetes
plan ahead with local diabetes team for major procedures
never pause insulin in Type I
Symptoms of hypoglycaemia
dizziness, confusion, eventual loss of consciousness
(some wont even notice)
treatment of hypo
PO (glucogel, lucozade)
IM (glucagon)
IV (dextrose 10% or 20%) - not chocolate as not fast acting
what medical emergencies can arise in diabetics?
hypoglycaemia
hyperglycaemia
What can hyperglycaemia lead to?
Ketoacidossis
Hyperosmolar hyperglycaemia state (HHS)
What is ketoacidosis?
Build-up of ketone bodies in bloodstream, lowers pH. Leads to coma and death. Treat with insulin and IV fluids. More type 1.
What is hyperosomolar hyperglycaemia state (HHS)?
Presentation is very high glucose (more than 30) and dehydration. Treat with fluids. More type 2.
What are some micro vascular complications of diabetes?
Eyes, kidneys, nerves
Retinopathy, nephropathy, neuropathy
Hypertension also contributes to retinopathy and neuropathy.
Why does diabetes cause these complications?
Prolonged exposure to hyperglycaemia becomes toxic when glucose remains in blood.
What are the macrovascular complications of diabetes?
Heart, blood vessels
Cardiovascular disease and stroke
Due to lipid disorders
All contribute to damage of the heart
What things can affect the HPA system? (PG580)
Stress
Cytokines
Diurnal rhythm
What are the different hormones involved in calcium metabolism?
Calcium - most of it in bones
PTH - from parathyroid glands
Vitamin D
When is PTH secreted and what does it stimulate?
Secreted in response to low calcium levels. Stimulates osteoclast activity (bone breakdown) to increase serum calcium.
What does vit D do?
Regulates calcium and phosphate in the body
What is primary hyperparathyroidism?
Autonomous overproduction of PTH - parathyroid adenoma and hyperplasia of all 4 glands
High calcium and PTH
Bones of the mouth become less radiodense (might see in X-rays)
Central giant granulomas from osteoclasts may be present
What are some calcium disorders?
Hypoparathyroidism
Osteomalacia = softening of the bones
What is Hypoparathyroidism?
Low levels of PTH and Ca
Autoimmune or following thyroid/parathyroid surgery
Hypoplasia of the enamel and dentin, short roots, delayed eruption of teeth
What is osteomalacia?
Softening of the bones
Deficit of calcium, phosphate and vitamin D (often vit D)
Can lead to rickets (in children), hypocalcification of dentin enamel and alveolar bone
What is osteoporosis and who is it most commonly presented in?
Bone is less radiodense, can cause pathological fractures
Most common in post-menopausal women
What is the treatment of osteoporosis?
Calcium and vitamin D, bisphosphonates
What are the 2 parts of the pituitary gland?
Anterior lobe - adenohypophysis
Posterior lobe - neurohypophysis
Pituitary stalk = infundibulum
What hormones are secreted by the anterior lobe of pituitary gland?
ACTH
TSH
GH
LH, FSH
Prolactin
What hormones are released by posterior lobe of pituitary?
ADH
Oxytocin
How are hormones released from the different parts of the pituitary gland?
Hormones released in hypothalamus into bloodstream can travel directly to pituitary gland, allowing prompt interaction of the 2 glands
Posterior by nerve stimulation mainly, anterior by bloodstream secretion mainly
What is Cushing’s syndrome?
Cortisol/glucocorticoid excess
What can cause Cushing’s syndrome?
Glucocorticoid medication
Pituitary tumour (producing excess ACTH, disrupts negative feedback)
Adrenal tumour (increased cortisol)
Carcinoma (can disrupt hormone balance by destroying tissues)
What is Cushing’s disease?
Cushing’s syndrome caused by autonomous ACTH production from a pituitary tumour
What are some therapies for Cushing’s disease?
Surgery
Radiotherapy
Glucocorticoid receptor antagonist
Adrenal enzyme inhibitors
What are some dental manifestations of Cushing’s?
Osteoporosis - includes alveolar bone
Gums bleed easily - from fragile vessels and skin
Infections (periodontitis, candidiasis) - due to poor immune response
What is adrenal failure/addisons disease?
Lack of cortisol/glucocorticoids
Vague symptoms of Addisons
Weight loss, tiredness/myalgia, dizziness, anorexia, abdominal pain, pigmentation
Signs (clinical) of Addisons disease
Pigmentation
Postural hypotension
Myopathy
Decreased sodium, increased potassium, increased urea
Decreased glucose
Anaemia
What is the general management of Addisons?
Hydrocortisone (2-3 doses per 24hrs)
Fludrocortisone!
Sick day rules!
Steroid card - to prevent adrenal crisis and make everyone aware
What happens in adrenal crisis? Life threatening complications?
Severe vomitting and diarrhoea followed by dehydration
Low blood pressure and shock
Hypoglycaemia
Loss of consciousness
What can trigger adrenal crisis?
Stressful events, eg dentist
What is the treatment for adrenal crisis?
IV fluids and IV hydrocortisone (synthetic glucocorticoids)
What is acromegaly?
Excessive production of GH from the anterior pituitary gland
Growth hormone is released throughout life. What stimulates its release?
Low glucose, exercise, sleep
What can acromegaly cause?
Accelerated tooth eruption in children
Accelerate growth (if suffering for a long time) - eg broad nose, thick lips, larger maxillary sinuses, enlarged jaw, leonides facies etc
What is thyrotoxicosis?
Diagnosis: High fT3 and fT4, low TSH
What are some causes of thyrotoxicosis?
Grave’s disease, toxic goitre, adenoma, medication
What are some symptoms of thyrotoxicosis?
Weight loss, tachycardia, sweating, tremor
Accelerated tooth development in children
Potential to malocclusion and demineralisation
Avoid epinephrine in local anaesthetics if possible
What is treatment for thyrotoxicosis?
Anti thyroid drugs
Radioactive iodine
Thyroid surgery
What is hypothyroidism?
Diagnosis: low fT3 and fT4, high TSH
What are some causes of hypothyroidism?
Autoimmune, post-surgery, inflammatory, post-radioactive iodine
What are the symptoms of hypothyroidism?
Fatigue, weight gain, cold intolerance, dry skin
Cretinism: maxillary prognathism, delayed tooth development
Excessive dental caries
Macroglossia and swollen lips
Exaggerated response to barbiturates and narcotics
What is the treatment for hypothyroidism?
Levothyroxin
