Diabetes

Question 1

What is insulin?

Answer 1

• 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
– Hypoglycaemia
– Lipohypertrophy at injection sites

Question 2

What is the insulin feedback loop?

Answer 2

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.
   OR
6. low blood glucose.
7. alpha cells in the pancreas release glucagon into the blood.
8. the liver converts it to glucose.
9. blood glucose levels rise and less glucagon is produced.

Question 3

What other types of diabetes are there?

Answer 3

• 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

Question 4

What’s the diagnostic tests for diabetes?

Answer 4

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

Question 5

What are the classic symptoms of T1DM?

Answer 5

• Polyuria (bedwetting) • Polydypsia (thirst) • Weight loss

* Dehydration • Ketoacidosis • Coma

Question 6

What’s the aetiology of T1DM?

Answer 6

Genetic disposition, then environmental exposure.

Question 7

What are the symptoms of T2DM?

Answer 7

• 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
Interigo
Urinary tract infections
Poor healing of wounds
Foot ulcers

Question 8

What are the acute complications of diabetes?

Answer 8

• Hypoglycaemia
• DKA (diabetic ketoacidosis)
• HONK (hyperosmolar non- ketotic coma)

Question 9

What are the chronic complications of diabetes?

Answer 9

• Microvascular – Retinopathy
– Nephropathy – Neuropathy
• Macrovascular – Cardiovascular
– Cerebrovascular –Peripheral vascular disease

Question 10

What is hypoglycaemia?

Answer 10

• 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

Question 11

What are hyperglycaemic comas?

Answer 11

For T1DM: DKA (diabetic ketoacidosis)

For T2DM: HONK (hyperosmolar non-ketotic coma)

Question 12

What’s the presentation of DKA?

Answer 12

Symptoms:
• Vomiting • Thirst • Polyuria • Abdominal pain
• Weakness • Lethargy
Signs:
• Tachycardia • Dehydration • Hyperventilation (Kussmaul’s) • Ketotic breath • Hypotension
• Impaired consciousness/Coma

Question 13

What are the causes of DKA?

Answer 13

• Surgery • Infection • Inadequate insulin • Pregnancy • Other acute illness e.g. appendicitis

Question 14

How should you treat DKA?

Answer 14

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+

Question 15

How does HONK present? (if there’s a risk of clotting make sure to give heparin)

Answer 15

• Similar presentation to DKA • No ketosis • No acidosis
• Significant dehydration
• 50% mortality

Question 16

What are the microvascular complications of diabetes?

Answer 16

Retinopathy (losing eyesight)
Nephropathy (kidney problems)
Peripheral neuropathy

Question 17

What are the macrovascular complications of diabetes?

Answer 17

Myocardial infarction
Stroke (FAST) : Face, Arms, Speech, Time
Peripheral vascular disease

Question 18

What’s the second line of treatment for T2DM, after diet and exercise?

Answer 18

Drugs. Usual sequence; – Metformin + sulphonylurea + newer drug

Question 19

What do sulphonylureas do?

Answer 19

• Increase insulin secretion from the pancreas
• Mainsideeffects:
– Hypoglycaemia – Weight gain
• Examples – Gliclazide, Tolbutamide, Glibenclamide

Question 20

What does metformin do?

Answer 20

• 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

Question 21

What do Thiazolidinediones do?

Answer 21

• Insulinsensitiser • No hypoglycaemia
• Side effects – Weight gain
– Fluid retention
– Peripheral oedema
– CCF
– Increased risk of fractures
– Anaemia – Liver toxicity

Question 22

What’s incretin therapy?

Answer 22

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.

Question 23

What’s bariatric surgery?

Answer 23

It’s for T2DM, look up what it is though.

Question 24

How could diabetes affect dentistry?

Answer 24

• Think about the time of day you treat people on insulin/sulphonylureas
– Can they safely be told not to eat/ drink hot drinks until the anaesthetic wears off?
• Think about undiagnosed diabetes in the patient presenting with recurrent dental abcesses, oral candida
• Gingivitis/ gum disease is more common in patients with diabetes
Short operations in T1DM:
Half normal morning dose, First on the list, Monitor sugars, Cover antibiotics
Long operations in T1DM:
• Needs to be in hospital
• First on list
• Insulin sliding scale + IV glucose and K+
• Cover with antibiotics
Short operations in T2DM:
• No tablets in morning • First on the list
• Monitor sugars • Cover antibiotics
• Start tablets again when eating
Long operations in T2DM:
• No insulin morning • First on list • Keep eye on blood sugar • Cover with antibiotics
• Start insulin when eating may need small amount if not