Diabetes Lecture 1: Type 1 Diabetes: Flashcards Preview

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Flashcards in Diabetes Lecture 1: Type 1 Diabetes: Deck (30):

What does GLUTS (glucose transporters do)

Facilitate glucose uptake into tissues


What should the typical glucose levels be maintained at

3 to 8 mM


What happens after the body eats a meal

Increased uptake of glucose into liver and pancreas through low affinity transporter- GLUT-2

Increased uptake of glucose into some tissues (muscle and adipose) following activation of insulin dependent GLUT-4


What does a low Km and high Km value represent

Low Km= high affinity

High Km= low affinity


What is the role of the pancreas

Secretion of insulin and glucagon to regulate glucose levels


What do the alpha and beta cells do

Alpha: secretion of glucagon

Beta: secretion of insulin


If there is low glucose, how does the body react

Glucagon secretion

Increase catabolic pathways
Increase Glycogenolysis (muscle and liver)
Increase Gluconeogenesis (liver and all tissues)
Increase lipolysis (adipose tissue)
Inhibit glycolysis (liver)

Inhibit anabolic pathways- glycogen synthesis and lipid synthesis


If there is high glucose, how does the body react

Insulin secretion

Increase anabolic pathways
Increase fatty acid synthesis (liver, adipose tissue)
Increase glycogen synthesis (liver, muscle)
Inhibition of catabolic pathway- gluconeogenesis, lipolysis (muscle, liver, adipose tissue)


What is diabetes mellitus and how does it arise

A common group of metabolic disorders, characterised by chronic hyperglycaemia

Arises from insulin deficiency, insulin resistance or both


What is type 1 diabetes definition

A polygenic disorder characterised by immune destruction of pancreatic beta cells that leads to complete insulin deficiency


What is type 2 diabetes definition

A polygenic disorder characterised by decrease in beta cell mass, leading to a reduction in secretion and peripheral insulin resistance


What are the non modifiable risk factors of diabetes

Family history (increased if mother, father or sibling have it)

Type 1:
more common in northern european countries

Type 2:
South asian
African or afrocaribbeans

Over 40 more likely to develop type 2 diabetes or 25 if black or asian

Medical conditions:
Polycystic ovary syndrome
Gestational diabetes
Impaired glucose tolerance


What are the modifiable risk factors for diabetes

Weight- type 2 only

Increased waist circumference

Sedentary life style (type 2)

Social deprivation and low income


What are the symptoms of type 1 diabetes

2-4 history of thirst


Weight loss



What are the symptoms of type 2 diabetes

History of thirst


Weight loss


Visual disturbances



What are the clinical signs of diabetes

Glycosuria- glucose in urine

More or equal to 11mmol/l (random plasma glucose)
More or equal to 7mmol/l (fasted plasma glucose)

Impaired glucose tolerance
Excludes certain medications, obesity, liver disease

Complications of diabetes


What are the physiological basis for blood glucose levels being elevated in diabetes, explain in detail

Water drawn from interstitial spaces into the circulation to decrease blood osmolarity

Increase in blood volume is countered by increased urinary output

When reabsorptive capacity of renal tubes is exceeded, there is an increased osmotic pressure in tubules (reduced glucose and water reabsorption)

Therefore fluid and electrolyte losses result from polyuria which stimulates thirst


What are the physiological basis for fluid loss leading to dehydration and weight loss in diabetes, explain in detail

No insulin means cells cannot absorb glucose from blood- must use other sources like glycogen fats and proteins

Breakdown of fat and muscle leads to weight loss

Using fat sources leads to production of ketone bodies- can increase blood acidity known as KETOACIDOSIS


Why do diabetic patients have a reduced life expectancy and mortality rate

Increased cardiovascular disease

Increase renal failure

Increased morbidity and increased risk of blindness


When diagnosing diabetes, what is a good indicator with the HbA1c levels of diabetes

HbA1c level of more than or equal to 6.5% (48mmol/mol)


What is considered normal and impaired fasting blood glucose level

Normal: 2-6 mmol/L

Impaired: 6-7 mmol/L


How do you measure oral glucose tolerance testing

Fasting over night (12 hours, water only), a fasting blood glucose reading is taken

Glucose solution consumed
(75g of oral glucose in 250 to 300mL) within 5 minutes

Blood glucose levels measured at 120 minutes after consumption of glucose


Why is HbA1c level a good indicator

Exposing red blood cells to glucose results in them becoming irreversibly glycated

Therefore can be used to estimate average glucose levels


What is the evidence showing that type 1 diabetes is an autoimmune response

Association of type 1 with other autoimmune disorders (coeliac disease)

Evidence of chronic inflammation in cells and macrophages in islets of newly diagnosed patients

Detection of circulating auto-antibodies before disease onset
- anti-insulin
- anti-islet antibodies


What are the treatment goals

Preserve life

Achieve good glycemic control which avoids long term complications

Avoid iatrogenic side effects (hypoglycaemia)

Alleviate symptoms


How do you manage type 1 diabetes

Insulin replacement

Dietary modification




Psychosocial support


What should the diabetic diet contain

Less fat and saturated fats

Low in simple sugars

High in fibre


How should you treat a type 1 diabetic patient

Provide insulin replacement in a way that mimics insulin secretion pattern seen in normal people- released at slow basal rate all date

Eat meal, rises rapidly before dropping after 2 hours


What are the complications of type 1 diabetic patients

Patient can experience partial remission phase- only requires low levels of insulin for good maintenance of glycemic control


Lipohypertrophy- accumulation of fat at injection sites due to local insulin effects

Insulin allergy


How do you monitor a type 1 diabetic patient

Can monitor capillary blood glucose levels before and/or 2 hours after meals after exercise

Monitor long term glycemic control (doctor led HbA1c levels)

Monitor risk of developing long term complications:
regular eye screening for retinopathy
Cardiovascular disease screening