Type 1 Diabetes Mellitus Flashcards
Definition of diabetes
Symptoms and random plasma glucose ≥ 11.1 mmol/l
Fasting plasma glucose ≥ 7.0 mmol/l
HbA1c ≥ 48 mmol/mol
What is HbA1c?
Blood test measuring average blood glucose levels over previous 2-3 months. Refers to protein that carries the oxygen. Glucose in blood attaches to haemoglobin to form glycated haemoglobin.
What does OGTT stand for?
Oral Glucose Tolerance Test
How is an OGTT carried out?
Fasting food and drink (except water) for 8 hours/overnight prior to testing. Blood test to measure fasting blood glucose levels. Then give 75g glucose. Blood samples taken at intervals and levels analysed to see effectiveness of processing glucose over time. Elevated blood glucose may indicate diabetes.
Presenting features of diabetes
Thirst
Polyuria
Weight loss
Fatigue (lipid and muscle loss due to unrestrained gluconeogenesis)
Hunger (lack of useable energy source)
Vaginal candidiasis
Chest/skin infections
Blurred vision (altered acuity due to uptake of glucose/water into lens)
The severity of type 1 diabetes mellitus symptoms depends on rate of…
B-cell destruction
Suggestive features of type 1 diabetes mellitus
Onset in childhood/adolescence
Lean body habitus
Acute onset of osmotic symptoms
Prone to ketoacidosis
High levels of islet autoantibodies
Any 2 of what 3 features indicate Type 1 diabetes?
Weight loss
Short history (weeks) of severe symptoms
Moderate or large urinary ketones
Having at least 2 of the 3 key signs calls for immediate…
insulin treatment at any age
Suggestive features of Type 2 diabetes
Usually presents in over 30s
Onset is gradual
Family History
Almost 100% concordance in identical twins
In type 2 diabetes what can help control hyperglycaemia?
Diet
Exercise
Oral medication
Insulin may be required later in disease
If in doubt between Type 1 and Type 2 diabetes, what should you do?
Treat with insulin
Other than diabetes, what other diseases are linked to autoimmunity antibodies
Hypothyroidism
Addisons’ Disease
Coeliac disease
Reduced insulin Type 1 diabetes leads to ___ breakdown and formation of ______ and f___ f____ a____
fat
glycerol
free farry acids
Free fatty acids impair g___ uptake
glucose
Free fatty acids are transported to the liver and provide energy for g______
gluconeogenesis
Free fatty acids are oxidised to form…
ketone bodies (beta hydroxybutyrate, acetoacetate and acetone)
Absence of insulin and rising counterregulatory hormones leads to increasing h_______ and rising k____
hyperglycaemia
ketones
Glucose and ketones escape in the urine but lead to an o___ d____ and falling circulating blood volume
osmotic diuresis
Ketones cause a_____ and v_____
anorexia and vomiting
Ketoacidosis creates a vicious circle of increasing d______, h_____ and increasing acidosis eventually leads to circulatory collapse and death
dehydration, hyperglycaemia
Definition of Diabetic Ketoacidosis (DKA)
Hyperglycaemia (plasma glucose usually <50 mmol/l)
Raised plasma ketones (urine ketones > 2+)
Metabolic acidosis - plasma bicarbonate < 15 mmol/l
Clinical symptoms of DKA
Develop over few days
Polyuria
Polydipsia
Nausea and vomiting
Weight loss
Weakness
Abdominal pain
Drowsiness / confusion
Clinical signs of DKA
hyperventilation (Kussmaul breathing - deep, rapid, consistent pace)
Dehydration (average fluid loss 5-6 litres)
Hypotension
Tachycardia
