Flashcards in Diabetes Deck (24)
What is insulin?
• Produced in the β-cells in pancreatic islets of Langerhans
• A protein, production is stimulated by presence of glucose in blood
• Acts at membrane receptors on peripheral tissues
• 1st line of treatment for T1DM, 3rd line for T2DM
• Sideeffects (when injected)
– Weight gain
– Lipohypertrophy at injection sites
What is the insulin feedback loop?
1. glucose meal eaten, so high blood glucose.
2. beta cells in the pancreas release insulin into the blood.
3. in the liver the insulin acts to convert glucose to glycogen, fats and proteins.
4. in muscle and other tissues insulin causes them to use the glucose as an energy source or convert it to glycogen, fats and proteins.
5. causing blood glucose levels to fall and less insulin to be produced.
1. low blood glucose.
2. alpha cells in the pancreas release glucagon into the blood.
3. the liver converts it to glucose.
4. blood glucose levels rise and less glucagon is produced.
What other types of diabetes are there?
• Gestational diabetes – (4% all pregnant women)
• Monogenic diabetes (MODY) – genetic defects of β cell function
• Pancreatic disease – e.g. cystic fibrosis, pancreatitis, haemochromatosis
• Drugs – e.g.steroids
• Genetic defects of insulin action – e.g.lipoatrophicdiabetes
• Associated with other endocrine illness – e.g.Cushing’s,Acromegaly
• Associated with other genetic syndromes – e.g. mitochondrial diabetes
What's the diagnostic tests for diabetes?
if presenting with symptoms if one of these tests is positive then patient has diabetes. if no symptoms two tests must be positive.
1. Fasting serum glucose (mmol/L): >7.0
2. Serum glucose 2 hours following 75g oral glucose load (mmol/L) >11.1
What are the classic symptoms of T1DM?
• Polyuria (bedwetting) • Polydypsia (thirst) • Weight loss
• Dehydration • Ketoacidosis • Coma
What's the aetiology of T1DM?
Genetic disposition, then environmental exposure.
What are the symptoms of T2DM?
• Non-symptomatic – Diagnosed on routine screening
• E.g. Glucose in urine leading to OGTT • Metabolic symptoms
– Polyuria, polydypsia, (weight loss) • Less dramatic than in T1DM
• Non-metabolic – Present with complications eg Candidiasis: oral, vaginal
Urinary tract infections
Poor healing of wounds
What are the acute complications of diabetes?
• DKA (diabetic ketoacidosis)
• HONK (hyperosmolar non- ketotic coma)
What are the chronic complications of diabetes?
• Microvascular – Retinopathy
– Nephropathy – Neuropathy
• Macrovascular – Cardiovascular
– Cerebrovascular –Peripheral vascular disease
What is hypoglycaemia?
• Acute low blood sugar
• CBG < 4.0 on blood glucose meter
• Caused by a mismatch of glucose supply or usage to medication
– e.g. a missed/ delayed meal, exercise, alcohol • Occurs as a result of treatments used in diabetes
– sulphonylurea tablets and insulin • Symptoms result of neuroglycopenia
– Impaired supply of glucose to the brain • Can develop ‘hypoglycaemic unawareness’
For an unconscious/unsafe to swallow patient give 1mg IM Glucagon
What are hyperglycaemic comas?
For T1DM: DKA (diabetic ketoacidosis)
For T2DM: HONK (hyperosmolar non-ketotic coma)
What's the presentation of DKA?
• Vomiting • Thirst • Polyuria • Abdominal pain
• Weakness • Lethargy
• Tachycardia • Dehydration • Hyperventilation (Kussmaul’s) • Ketotic breath • Hypotension
• Impaired consciousness/Coma
What are the causes of DKA?
• Surgery • Infection • Inadequate insulin • Pregnancy • Other acute illness e.g. appendicitis
How should you treat DKA?
If insulin deficient: iv insulin
If starving: iv dextrose
If underlying disorder: find out what it is and treat it
If dehydrated: iv saline and K+
How does HONK present? (if there's a risk of clotting make sure to give heparin)
• Similar presentation to DKA • No ketosis • No acidosis
• Significant dehydration
• 50% mortality
What are the microvascular complications of diabetes?
Retinopathy (losing eyesight)
Nephropathy (kidney problems)
What are the macrovascular complications of diabetes?
Stroke (FAST) : Face, Arms, Speech, Time
Peripheral vascular disease
What's the second line of treatment for T2DM, after diet and exercise?
Drugs. Usual sequence; – Metformin + sulphonylurea + newer drug
What do sulphonylureas do?
• Increase insulin secretion from the pancreas
– Hypoglycaemia – Weight gain
• Examples – Gliclazide, Tolbutamide, Glibenclamide
What does metformin do?
• Improves insulin resistance and reduces hepatic glucose output
• Main side effects: – GI upset
– Vitamin B12 malabsorption – Lactic acidosis
• Contraindicated in renal failure • Does not cause hypoglycaemia as a side effect
What do Thiazolidinediones do?
• Insulinsensitiser • No hypoglycaemia
• Side effects – Weight gain
– Fluid retention
– Peripheral oedema
– Increased risk of fractures
– Anaemia – Liver toxicity
What's incretin therapy?
Gut hormone based therapies eg DPP-4inhibitors,
GLP-1 analogues( Incretin mimetics).
Help bring plasma glucose levels back down to normal.
The incretin effect is reduced in T2DM.
What's bariatric surgery?
It's for T2DM, look up what it is though.