Diabetes

Question 1

Definition of diabetes

Answer 1

Metabolic disorder characterised by hyperglycaemia due to absolute insulin deficiency . Develops due to destruction of pancreatic beta cells, mostly by immune mediated mechanisms

Question 2

Aetiological factors for diabetes

Answer 2

HLA gene polymorphisms (HLA-DR/DQ alleles)
Environmental factors
Geographical variation
Viruses: rubella, enteroviruses, Cocksaxie
Bacteria
Vitamin D deficiency
Cow's milk
Early introduction of cereals
Associaed autoimmune conditions

Question 3

Symptoms of T1 diabetes

Answer 3

Polyuria (increased micturition and urine volume)
Polydipsia (increased thirst/fluid uptake)
Weight loss
Generalised weakness
Blurred vision
Hyperglycaemia
Diabetic ketoacidosis (DKA)
- dehydration
- nausea + vomiting
- abdominal pain
- tachypnoea
- tachycardia
- lethargy

Question 4

Pathophysiology of T1 diabetes

Answer 4

Usually develops as result of autoimmune pancreatic beta cell destruction
Up to 90% of individuals will have autoantibodies to at least one of 2 antigens:
- glutamic acid decarboxylase
- insulin
- islet auto-antigen 2 (IA-2)
Beta cell destruction proceeds for months-years as insulinitis
When 80-90% beta cells have been destroyed, patient develops hyperglycaemia
T1 = insulin deficiency
- unable to use glucose in peripheral muscle and adipose tissues
- stimulates secretion of counter-regulatory hormones: glucagon, adrenaline, cortisol and growth hormone
- these promote gluconeogenesis, glycogenolysis and ketogenesis in the liver
- patients present with hyperglycaemia and anion gap metabolic acidosis

Question 5

Investigations for T1 diabetes

Answer 5

Random plasma glucose
- 11 mmol/L or higher
Fasting plasma glucose:
- 7 or higher = diabetic
2 hour plasma glucose (OGTT)
- 11.1 mmol/L or higher
Plasma/urine ketones
- medium high quantity
- acidotic if >3
Glycated haemaglobin test (HbA1c)
- average over 6-12 weeks
- 42-47 mmol/mol = pre-diabetic
- 48 mmol/mol or above = diabetic

Could consider fasting C peptide or autoimmune markers

Question 6

Epidemiology of T1 diabetes

Answer 6

5-10% all diabetes cases
About 0.5% prevalence
Significant geographical variation
- more common in Europe and less common in Asia
Higher incidence seen in colder autumn/winter months
Slightly more common in males than females (1.3:1)
T1 incidence increasing by 3% each year worldwide
1 in 20 siblings of affected children will also develop condition

Question 7

What percentage of people in Scotland have diabetes?

Answer 7

5.2% of the population (276 430) people have been diagnosed

Question 8

Name 4 different adipokines and their role in type 2 diabetes

Answer 8

Leptin: tells hypothalamus about the amount of stored fat
Adiponectin: reduces levels of free fatty acids
TNF-alpha
Resistin: enhances hypothalamic stimulation of glucose production