Diabetes Flashcards
What are the values for normoglycaemia and hypo/hyperglycaemia?
Hypo = <2.5 mmol/L Normo = 3-5 mmol/L (Fasting) Normo = 7-8mmol/L (post-prandial) Hyper = >10mmol/L
Describe the homeostasis of Hyperglycaemia
Glucose Rise in blood
Insulin released from pancreatic B-cells
Increases glucose to Liver, Muscle, Adipocytes, CNS
Lowers blood glucose
Describe the homeostasis of Hypoglycaemia
Fall in blood glucose
Glucagon released from a-cells (IoL)
Stimulates Exogenous glucose production - liver, muscles, adipocytes
Blood glucose rises
What is the half life of insulin?
3-5 minutes
Which endocrine cells make up the Islets of Langerhans and what do they secrete?
β-cells; release insulin α-cell; release glucagon δ-cells; release somatostatin ε-cells; release ghrelin PP-cells; release pancreatic polypeptide
What do insulin secretagogues do?
Used to close K channels
Causes calcium influx and Insulin release
What do Incretins do?
Activate GLP-q receptors on B-cells
Cause cell signalling and insulin release
How does insulin increase glucose transport into cells?
Binds to receptors and activates them
Receptors have endogenous activity
Intrinsic kinase activity activated
Switches on transporters in the cell membrane
Causes more transporters in the cell membrane (Glut4)
Glucose enters the cell via Glut4
What do insulin sensitixers do?
Work on insulin receptor expressing cells
Facilitate process of new transporters
So more glucose into cells
In what ways does insulin promote hypoglycaemia?
Increases the transport of glucose into cells Converts glucose to glycogen (in liver) Decreases glycogen breakdown Increases fat stores Increases protein production
Which tissues are involved in hyperglycaemia?
Increase of food intake = GIT, CNS
Glucose production = Liver, adipocytes
Glucose reabsorption = Kidney
Which tissues are involved in hypoglycaemia?
Glucose utilization - Alll tissues
Deacreased food intake = GIT, CNS
Glucose storage = Liver, Adipocytes
Glucose Loss = kidney
Where is excess glucose strored?
Converted to glycogen and stored in the liver
What are the three underlying pathologies of hyperglycaemia?
Islet cell pathology
Insulin action pathology
Obese, unhealthy diet
What are the 5 mechanisms of therapy for diabetes?
Promote glucose release Delay glucose absorption Promote insulin release Sensitize to the actions of endogenous insulin Replace islets
What are the symptoms of hypoglycaemia?
Autonomic: Hunger, Sweating, Shaking, Increased Heart Rate, Headache, Nausea
Neuroglycopaenic: Confusion, Drowsiness, Odd behaviour, Incoherent speech, Poor co-ordination
Hypoglycaemic coma
Death
Give eamples of two hyperglycaemia inducing therapies
Glucagon Therapy (Hypokit) Diazoxide Therapy
What are the symtpoms of T1DM?
Increased Urination Increased thirst Increased Tiredness Weight loss Look for: oral thrush, buying vitamin drops/food supplements
What are the symptoms of T2DM?
Often unsymptomatic
Symptoms are like T1 but slower onset and less extreme
Increased genital thrush
Slow wound healing
What is the difference in insulin production between T1DM and T2DM?
T1DM - No Insulin
T2DM - Insulin is usually produced but body doesnt respond to it
What are the advantages and disadvantages of metformin?
Advantages:
Cheap
Weight neutral,
Low risk of hypo
Disadvantages: GI SE's (Diarrhoea), Risk of lactic acidosis, TDS as short half life, Caution if egfr<45, C CI if egfr <30
What are the advantages and disadvantages of Sulfonylureas?
Advantages:
OD or BD,
Quickly lowers cBG - fast symptom improvement
Fewer GIT
Disadvantages: Hypos Weight gain Need residual pancreas function Un-predictable in renal impairement and in the elderly
What are the advantages and disadvantages of Pioglitazone?
Advantages:
OD
Low hypo risk
Suitable in renal impairment
Disadvantges:
Associated with Heart failure (fluid retention)
Increases risk of bladder cancer and fractures
Weight gain (fluid)
Liver toxicity - rare
3-6 months to show benefit
What are the advantages and disadvantages of DPP-4 Inhibitors?
Advantages: OD No weight gain Low risk of hypo Some can be used in renal impairment Few side effects
Disadvantages:
GI SE’s, rash, UTI
Pancreatic inflammation (rare)
Don’t work that well
