Diabetes Mellitus Flashcards
What is diabetes mellitus?
Group of metabolic diseases of multiple aetiologies characterised by hyperglycaemia with disturbances in carbohydrates, fat and protein metabolism from defects in insulin secretion, action or both
What are the symptoms of hyperglycaemia?
Polydipsia, polyuria, blurred vision, weight loss and infections
What happens if there is metabolic decompensation in diabetes?
Diabetic ketoacidosis
Hyperosmolar hyperglycaemic state
How is diabetes diagnosed?
Measure blood glucose or HbA1c
Fasting glucose >7mmol/l and random >11.1 mmol/l
OGTT 2hr after 75g CHO >11.1mmol/l
HbA1c > 48mmol/l
How many tests are needed in diagnosing diabetes?
One diagnostic lab glucose or HbA1c plus symptoms
2 without symptoms
What is the criteria for intermediate hyperglycaemia?
Impaired fasting glucose 6.1-7mmol/l
Impaired glucose tolerance 2hr glucose > 7.8 and 11mmol/l
HbA1c 42-47 mmol/mol
What is intermediate hyperglycaemia?
Group with higher risk of future diabetes and adverse outcomes such as cardiovascular disease
What is normoglycaemia?
Glucose levels associated with low risk of developing diabetes and cardiovascular disease
What is HbA1c?
Glycated haemoglobin
Gives indication of blood glucose levels over last 8-12 weeks
When can HbA1c not be used for diagnosis?
Children and young people
Pregnancy
Short duration of diabetes symptoms
Acutely ill
Patients on medication which could cause rapid rise in glucose
Acute pancreatic disease or surgery
Renal failure
HIV
What is involved in exam and initial assessment?
BMI
Ketones
Signs of complication - foot exam and retinal screening
What is type I diabetes characterised by?
Insulin deficiency
So there is increased lipolysis, raised glucose production and reduced glucose uptake
How does type I diabetes give diabetic ketoacidosis?
Hyperglycaemia
Ketonemia
What are the conterregulatroy hormones?
Glucagon
Cortisol
Catecholamines
Growth hormones
What does development of type I diabetes require?
Genetic pre-deposition
Plus trigger - viral infection
What are some clinical presentations of type I diabetes?
Thirst, tiredness, polyuria, weight loss, blurred vision and abdominal pain
On exam - ketones on breath, dehydration, increased resp. rate, tachycardia, hypotension and low grade infection
What are some key aspects of clinical diagnosis for type I diabetes?
Younger age
May be slim
Short duration of hyperglycaemic episodes
Other autoimmune condition
FH of autoimmune condition
Elevated ketones
What tests can be done at a later date to confirm diagnosis of type I diabetes?
Autoantibodies GAD, IA2 and ZNT8
C peptide - would expect undetectable c peptide in someone with longstanding t1d and low levels if recently diagnose. High would not have t1d
Genetics t1 genetic risk score
Describe genetics in type II diabetes
More inheritable than type I
Polygenic
What are the symptoms and signs of type II diabetes mellitus?
May have none
Thirst, tiredness, polyuria, weight loss, blurred vision, symptoms of complication
Not ketonic, usually overweight, low grade infections and complications
What are key aspects of making a diagnosis of diabetes mellitus?
Older age and overweight
FH of t2d
May have no symptoms
No ketones
What are risk factors for type II diabetes mellitus?
Overweight
FH
Gestational diabetes
Inactive lifestyle
Previous high blood glucose
What are some other types of diabetes?
Recognised genetic syndrome - MODY
Gestational diabetes
Secondary diabetes
What is MODY?
Maturity onset diabetes in the young
Autosomal dominant
Impaired beta cell formation
Single gene defect
What causes monogenic diabetes?
Glucokinase mutations
Transcription factor mutations
Describe glucokinase mutations
Onset at birth
Stable hyperglycaemia
Diet treatment
Complications are rare
Describe transcription factor mutations
Young adult onset
Progressive hyperglycaemia
1/3 diet, 1/3 OHA and 1/3 insulin
Complications are frequent
Can respond to tablets
Describe secondary diabetes mellitus
Drug therapy - corticosteroids
Pancreatic destruction
Recognised genetic syndromes - DIDMOAD
Rare endocrine disorders - Cushing’s, acromegaly and pheochromocytoma
Describe gestational diabetes
Hyperglycaemia of pregnancy
Increasing insulin resistance in pregnancy
Associated with FH of t2d
Develops 2/3rd trimester
More common if overweight and less active
What is the immediate test for type I diabetes?
Finger prick capillary glucose test
If result more than 11mmol/l
What are the 4 Ts of type I diabetes?
Toilet, thirsty, tired and thinner
What is important about insulin administration?
Needle size, location, rotation, technique and time
Describe the insulin therapy regimens
Basal bolus
Rapid (short) bolus acting to cover CHO at meals 1 unit per 10g of CHO
Basal long acting insulin in background - twice daily
What type of insulin is given twice a day?
Rapid acting mixed with intermediate acting
Before breakfast and evening meal
What insulin is given 3 times a day?
Rapid acting mixed with intermediate acting BB
Rapid acting BT
Intermediate acting at bedtime
What is the regime for multiple daily injections?
Short acting BB BL and BT
Intermediate before bed or long acting once a day
What are the symptoms of diabetic ketoacidosis?
Nausea and vomiting
Abdominal pain
Sweet smelling breath
Drowsiness
Rapid breathing and deep sighing
Coma
What are the initial investigations for DKA?
Rapid A, B, Cs
IV access
Vital signs
Clinical assessment
Urinalysis - ketones
ECG
Glucose and venous blood gas
What is the management for DKA?
Hour 1 - 1000ml/hr 0.9% saline and reduce to 500ml/hr at hour 3/4 and possible add KCl
Hours rate reduce rate of saline
Hour 1 start actrapid 6 units/hr
Check lab glucose, U+E, and bicarbonate
What are the complications of type I diabetes?
Hyper and hypokalaemia
Hypoglycaemia
Cerebral oedema
Aspiration pneumonia
Arterial and venous thromboembolism
ARDS
Describe hypoglycaemia
Blood glucose <4mmol/l
Mild can be self treated
Severe requires assistance
Loss of awareness and autonomic symptoms
What are the causes of hypoglycaemia?
Too much insulin
Inappropriate timing of insulin
Injection site problem
CHO intake or fasting problem
Exercise and alcohol
What are the risk groups for hypoglycaemia?
Tight glycaemic control
Impaired awareness
Extremes of age
Malabsorption
Hypoadrenalism
Renal impairment
Pancreatectomy
What is the treatment for mild hypoglycaemia?
Give 15-20mg of quick acting carbohydrate
Recheck glucose level in 10-15mins
What is the treatment for moderate hypoglycaemia?
Give 1.5-2 tubes of glucose gel
Recheck after 10-15 mins
What is the treatment for severe hypoglycaemia?
Stop IV insulin
Give IV glucose over 10-15mins
If low after 10 mins then repeat IV glucose
