MEH Diabetes Mellitus Flashcards
What is diabetes mellitus?
Raised blood glucose level. Over years leads to damage of the small and large blood vessels causing premature death from cardiovascular diseases. Long term/chronic disease
Why is it a major concern?
Major budget use of NHS Cause of blindness Cause of amputation Cause of CVD/PVD/stroke Reduces life expectancy
What is metabolic syndrome (4)?
A cluster of the most dangerous risk factors associated with CVD:
1) Diabetes and raised fasting plasma glucose
2) Abdominal obesity
3) High cholesterol
4) High BP
What are the markers for metabolic syndrome for each of the 4 criteria?
Waist >94cm for men >80cm for women
Plus any 2 of:
Raised triglyceride >1.7mmol/L or on treatment
Reduced HDL cholesterol <1 for men <1.2 for women
Raised BP >135/75 or on treatment
or Raised fasting glucose >5.6mmol or treated diabetes
What causes metabolic syndrome (5)
Central obesity Insulin resistance Genetics Ageing Sedentary lifestyle
What is insulin resistance linked to in particular?
Obesity
Insulin resistance often processes to type 2 diabetes true/false
True
What is the genetic and autoimmune basis of type 1 diabetes?
Mostly genetic –> alleles of HLA DQB1 an MHCII molecule.
Autoantibodies against beta cells destroy them
Environmental role in pathogenesis
How might diabetes mellitus present?
Polyuria
Polydipsia (excessive thirst)
Blurring of vision (change in refraction due to glucose)
Urogenital infections –> thrush
Tiredness
Weakness
Lethargy
Weight loss (due to effect of no insulin)
How do you test for diabetes mellitus?
How do you diagnose?
Fasting glucose
HbA1c - glycated Hb
Oral glucose tolerance test (not used now?)
1 abnormal test and symptoms
or 2 tests if asymptomatic
What are the benefits of using HbA1c over the fasting glucose (2)?
No need to fast
Indicates average of glucose levels over the past 3 months
Why could someone who was newly diagnosed with diabetes type 1 present with vomitting?
Why could they present with hyperventilation?
Could present as diabetic ketoacidosis —> a response is vomitting (would reduce acidosis)
Due to ketoacidosis —> lowers pH –> drive to breath off CO2 to reduce acidity leads to hypeventilation
Why would type I diabetic have ketones in their urine? Why would type II not?
Due to lipid break down due to reduced insulin:anti-insulin ratio –> excess leads to lipolysis. Liver uses triglycerides to make energy due to the lack of insulin to enable plasma glucose to be utilised. This leads to excess ketone formation.
What is Diabetic Ketoacidosis (DKA)?
Major life threatening complication of diabetes indicated by hyperglycaemia hyperketonuria and ketoacidosis (lowered pH)
What are the genetic markers for diabetes type I?
Genetic markers HLA DR3 and HLA DR4.
Why might the patients breath smell of pear drops?
Because acetone (a ketone due to liver fat metabolism) is volatile and can be breathed out via the lungs giving a smell.
What are symptoms of DKA?
prostration, hyperventilation, nausea, vomiting, dehydration and abdominal pain
How do you treat type I diabetes?
Sub cutaneous injections of insulin several times a day
Dietary requirements
Excercise
Psychosocial support
What are the WHO (world health organisation) goals to maintain a health body weight (2)?
Adult to aim for BMI 20-25
For individuals to avoid weight gain greater than 11pounds (5kg) during adult life
Why do some diabetics not comply with medication/insulin/lifestyle changes??
Sometimes asymptomatic so don’t have motivation to alter lifestyle/take medication as feel well.
Literacy difficulties with understanding disease/medication
Inconvenience/effort involved with lifestyle change/perceived costs of exercise/healthy food
Social reasons - esp injecting in public - appropriate places for teenagers etc
What is involved in management of the diabetic patient (5)?
Treatment: insulin/metforming
Lifestyle: food/exercise
Education: about condition/what to do in hypo/hyper/how to control/how to monitor and take medication
Other risk factors: BP, cholesterol, smoking
Surveillance for chronic complications - e.g. neuropathy leading to ulcers on the foot/ischaemic cardiac disease etc
What is hyperosmolar non ketotic syndrome in type 2 diabetes?
hyperglycemia, hyperosmolarity, and dehydration without significant ketoacidosis
Similar to DKA
May need insulin to treat
Present usually with dehydration and sometimes neurological defects
What are the complications associated with hypoglycaemia?
Coma
Brain needs glucose
Can be caused by hypoglycaemic therapy –> need oral or IV glucose.
What are some chronic complications of diabetes?
CVD, PVD, stroke
Capillary: Retinopathy, nephropathy, neuropathy
What causes ‘diabetic foot’?
Neuropathy
Poor blood supply due to peripheral arterial disease
Poor wound healing
Increased risk of infection
Can lead to diabetic foot - which can ulcer, gangrene and end up with amputation
What is the most common cause of loss of pancreatic Beta cells in type I diabetes?
- autoimmune 90%
- idiopathic - 10%
What might you find in the islets of newly diagnosed diabetes?
Chronic inflammation - T lymphocytes and macrophages - Insulitis
What is the trio of symptoms/signs in type 1 diabetes? Is it slow or fast onset often?
Polyuria
Polydypsia
Weightloss
Usually fast onset
What is the mechanism of ketoacidosis in type 1 diabetes?
Perceived starvation by the body due to the plasma glucose not able to be taken up into the cells for use –> so fatty acids are used for energy leading to ketone body formation and ketoacidosis
What is the mechanism of polyuria, glucosuria and dehydration?
> 10mM is the renal threshold where after this glucose will be excreted in the urine
Polyuria as H2O follows glucose
Dehydration as polyuria - leads to polydipsia
What is a normal HbA1c % glycation? What is the target for diabetics %?
4-5.9%
Diabetics 6.5%
What two types of oral medication are used in diabetes type II?
Metformin - inhibits gluconeogenesis in liver
Sulphonylureas - decreases opening probability of kATP channel so increases insulin secretion
What are the two major concerns with metabolic syndrome?
Metabolic syndrome increases the risk of type 2 diabetes 5 fold and heart disease by approximately 3 fold
