Endocrinology Flashcards
What is type 1 diabetes?
This is a disease where the pancreas stops being able to produce insulin. What causes the pancreas to stop producing insulin is unclear, there may be a genetic component and it may be triggered by certain viruses- coxsackie B virus and enterovirus.
What does the body ideally want to keep the blood glucose concentration at?
4.4 and 6.1mmol/l
How does insulin reduce blood sugar?
It reduces blood sugar in two ways…
Causes cells to take up glucose and use it as fuel
Secondly, it causes liver and muscle to take up glucose and store it as glycogen.
What is the role of glucagon?
It is a hormone that increases blood sugar levels. It is produced by the alpha cells in the islets of langerhans in the pancreas.
It tells the liver to break down glycogen to glucose (glycogenolysis). It also tells the liver to convert protein and fats into glucose (gluconeogenesis).
What is ketogenesis and when does it occur?
Ketogenesis occurs when there is an insufficient supply of glucose and glycogen stores are exhausted
It is where the liver takes fatty acids and converts them to ketones (water soluble fatty acids) that can be used as fuel. Ketones can cross the blood brain barrier and be used by the brain.
How do type 1 diabetics present?
About 25-50% of new type 1 diabetic children present in DKA. This is the result of a situation where the pancreas can no longer produce enough insulin to maintain basic blood glucose regulation.
Remaining present with:
Polyuria
Polydypsia
Weight loss
Less typical presentations= secondary enuresis (bed wetting in a previously dry child) and recurrent infections.
When a new diagnosis of diabetes is established, what bloods should be taken to exclude other pathology.
You need to get a baseline idea of the child’s overall health
Baseline bloods-FBC, U and Es, formal laboratory glucose
Blood cultures in patients with suspected infection (fever)
HbA1C allows doctors to get a picture of how long they had diabetes before presenting
Thyroid function tests and thyroid peroxidase antibodies to test for associated autoimmune thyroid disease
Tissue transglutaminase (anti TTG) antibodies for associated coeliac disease.
Insulin antibodies, anti GAD antibodies, islet cell antibodies to test for antibodies associated with destruction of the pancreas and the development of type 1 diabetes.
What is the basis for the management?p of type 1 diabetes?
Monitor daily carbohydrate intake
Subcutaneous insulin regimes
Monitor blood sugar levels on waking, at each meal and before bed
Monitor for and management of complications
What should you suspect if a patient is not responding to their insulin?
Suspect lipodystrophy- this is when a patient is injecting insulin into the same spot, causing subcutaneous fat to harden and the absorption of insulin to decrease.
What is the usual insulin regime for patients?
Basal bolus- give a long acting insulin (lantus) which acts as a constant background insulin throughout the day.
Bolus is the short acting (actrapid) typically given 3 times a day 30 mins before carbohydrates, it is also injected according to the number of carbohydrates the patient has as a snack.
What is an insulin pump and when would one be used?
Small devices that continuously infuse insulin at different rates to control blood sugar levels. They are an alternative to basal bolus regimes. The pump pushes insulin through a cannula that is inserted under the skin. The cannula is replaced every 2-3 days and the insertion sites are rotated to prevent lipodystrophy and absorption issues.
To qualify you have to be over 12 and have difficulty controlling HbA1C.
What are the benefits/disadvantages of using insulin pumps?
Benefits= better blood glucose control, less injections, more flexibility with eating
Disadvantages= risk of infection, difficulties using the pump and having it attached at all times
What are the short term complications of T1DM?
Hypoglycaemia
Hyperglycaemia (and DKA)
What is hypoglycaemia in T1D caused by?
Too much insulin
Not enough carbohydrates
Not processing carbs properly (this would happen in diarrhoea/vomiting/sepsis)
What are the symptoms of hypoglycaemia?
Hunger Tremor Sweating Irritability Dizziness Pallor
More severe= reduced consciousness, coma, death
How is hypoglycaemia treated?
Needs to be treated with a combination of rapid acting glucose- lucozade and slower acting (biscuits or toast)
What are the options for treating severe hypoglycaemia?
IV dextrose and intramuscular glucagon.
If a cannula is sited, what dextrose solution is given?
2mg/kg/hour bolus followed by a 5mg/kg/hour infusion.
What are the other causes of hypoglycaemia, other than diabetes?
. hypothyroidism . Glycogen storage disease . Growth hormone deficiency . Liver cirrhosis . Alcohol and fatty acid oxidation defects
What damage does chronic exposure to hyperglycaemia cause?
Damages endothelial cells of blood vessels. This leads to leaky malfunctioning vessels which are unable to regenerate.
As well as this it leads immune suppression and therefore an optimal environment for the infectious organisms to thrive.
What are the macrovascular complications of chronic exposure to hyperglycaemia?
Coronary artery disease
Peripheral ISCHAEMIA
Stroke
Hypertension
What are the microvascular complications of exposure to high blood glucose?
Peripheral neuropathy
Retinopathy
Kidney disease- glomerulosclerosis
What are the infection related complications of hyperglycaemia?
UTI
Pneumonia
Skin and soft tissue infections (particularly in feet)
Fungal infections- oral and vaginalis candidiasis