Diabetes Mellitus Flashcards Preview

ESA 1 - Metabolism > Diabetes Mellitus > Flashcards

Flashcards in Diabetes Mellitus Deck (41)
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What is diabetes mellitus? 

A group of metabolic disorders characterised by chronic hyperglycaemia 


What is diabetes mellitus due to? 

Insulin deficiency, insulin resistance, or both 


At what age is type 1 diabetes onset most common?

Teenage years



Describe the age related rate of type 1 diabetes after teenage years?

It is mostly similar up until old 


Does the rate of diabetes mellitus type 1 vary between countries?

Yes, substantially


What does the strong seasonal variation of type 1 diabetes onset suggest? 

A link with viral infection acting as a trigger


What is the mechanism of onset of type 1 diabetes?

  1. Genetic predisposition to the disease interacts with environmental triggers to produce immune activation
  2. Immune activation leads to the production of killer lymphocytes, macrophages and antibodies that attack and progressively destroy ß-cells



What is the genetic predisposition to type 1 diabetes associated with? 

The genetic markers HLA DR2 and HLA DR4


How does a patient present with type 1 diabetes? 

  • Polyuria
  • Polydipsia
  • Weight loss



What is polyuria? 

Excess urine production


What produces the polyuria in type 1 diabetes? 

Large quantities of glucose in the blood are filtered by the kidney, so not all of it is reabsorbed. The extra glucose in the nephron places an extra osmotic load on it, meaning that less water is reabsorbed to maintain osmotic pressure


What is polydipsia? 

Thirst and drinking a lot, due to polyuria


Why does type 1 diabetes cause weight loss? 

Fat and protein are metabolised because insulin is absent


Describe the typical patient presenting with type 1 diabetes

A lean young person with a recent history of viral infection


How can type 1 diabetes be diagnosed? 

By measurement of plasma glucose levels 


Why is blood glucose raised in type 1 diabetes? 

Due to lack of insulin


How does a lack of insulin cause a rise in plasma glucose? 

  • Decreased uptake of glucose into adipose tissue and skeletal muscle
  • Decreased storage of glucose as glycogen in muscle and liver
  • Increased gluconeogenesis in liver



What will high blood glucose lead to the appearance of? 

Glucose in the urine - glycosuria


What will happen if type 1 diabetes is not dealt with rapidly?

The individual will progress to a life-threatening crisis - diabetic ketoacidosis


In what populations is type 2 diabetes relatively common? 

All those enjoying an affulent lifestyle 


What is the estimated prevalence of type 2 diabetes in the UK?

About 2% of the population 


In whom is type 2 diabetes most common in? 

Older and overweight people 


What % of their ß-cells to patients with type 2 diabetes retain at diagnosis? 

About 50%


What happens to the ß-cell levels in patients with type 2 diabetes over time?

The levels fall, ultimately to none, and patients develop disorders of insulin secretion or insulin resistance, and so blood glucose is raised 


What is the difference between type 1 and 2 diabetes in terms of age distribution

  • Type 1 is the commenest type in the young
  • Type 2 affects a large number of usually older individuals



What is type 1 diabetes characterised by? 

The progressive loss of all or most of the pancreatic ß-cells 


What is type 2 diabetes characterised by? 

The slow progressive loss of ß-cells, but with disorders of insulin secretion and tissue resistance 


Describe the prognosis of type 1 diabetes

It is rapidly fatal if not treated


Describe the difference in treatment between type 1 and 2 diabetes

Type 1 diabetes must be treated with insulin, whereas type 2 diabetes may not initially need treatment with insulin, but all do eventually


Describe the progression of type 1 diabetes from its onset

  1. People can be found with the relevant HLA markers and auto-antibodies, but without glucose or insulin abnormalities
  2. They may then develop impaired glucose tolerance
  3. They may then develop diabetes (sometimes initially diet controlled) 
  4. They will eventually become totally insulin dependant