insulin + diabetes

Question 1

diabetes mellitus

Answer 1

• caused by an insufficiency in the production or action of the pancreatic hormone insulin
• most common endocrine disorder

Question 2

type 1 diabetes

Answer 2

• loss of insulin production
• insulin dependent
• develops in children/young adults
• pancreas produces little or no insulin
• autoimmune disorder

Question 3

type 2 diabetes

Answer 3

• occurs when body is in insulin-resistant state and pancreatic beta cells cannot release sufficient insulin to compensate
• most common form
• diagnosed later in life
• result of lifestyle; obesity, lack of exercise, diet, genes

Question 4

hyperglycaemia

Answer 4

loss of insulin-stimulated glucose uptake
loss of insulin repression of gluconeogenesis and glycogen breakdown

Question 5

dyslipidaemia

Answer 5

loss of insulin repression of lipolysis (defect in production of lipid pathways)

Question 6

gestational diabetes

Answer 6

• can affect up to 25% of women during pregnancy
• usually develops in 2nd trimester and disappears after child is born
• cause not clear thought to be due to hormonal changes that may block action of insulin

Question 7

tests used to diagnose diabetes

Answer 7

• fasting glucose test
• glucose tolerance test
• HbA1c

Question 8

fasting glucose test

Answer 8

• no food or drinks except water for 8-10 hours
  values:
  normal: 3.9 - 5.4 mmol/L
  prediabetes or impaired glucose tolerance: 5.5 - 6.9 mmol/L
  diabetic: >7 mmol/L

Question 9

oral glucose tolerance test

Answer 9

• patient must fast for at least 8 hours
• plasma glucose measured immediately before and 2 hours after drinking 75g glucose dissolved in water
  >11.1 mmol/L indicates diabetes
  7.9 - 11 mmol/l indicates impaired glucose tolerance

Question 10

HbA1c

Answer 10

• HbA1c forms as a result of a slow and irreversible reaction between haemoglobin A (HbA) and glucose
• HbA1c levels measure the average blood glucose levels over the previous 3-4 months (average life-time of RBC)
• HbA1c levels indicate how well blood glucose is being controlled and can be used as diagnostic test for type 2
• > 48 mmol/l indicates type 2
• 42-47 mmol/l indicates a risk of developing diabetes

Question 11

diagnosis of diabetes

Answer 11

• diagnosis is made by classic acute symptoms of hyperglycaemia and an abnormal blood test
• in patients without classic symptoms diagnosis can be made by two abnormal blood tests on separate days

Question 12

acute symptoms of diabetes

Answer 12

• polyuria: excessive urination
• dehydration/increased thirst
• nausea/vomiting
• increased fatigue
• unexplained weight loss
• blurry vision
• poor wound healing because of damaged blood vessels
• genital itching/thrush

Question 13

polyuria in diabetes

Answer 13

excessive urination because the amount of glucose filtered by kidney exceeds maximal capacity for reabsorption, resulting in glucose entering urine and drawing H2O with it by osmotic diuresis

Question 14

diabetic ketoacidosis

Answer 14

• potentially life-threatening complication of type 1
• lack of insulin limits use of glucose as an energy source
• absence of insulin enhances free fatty acids (FFA) release from adipocytes
• FFAs converted to ketone bodies by the liver which can serve as energy source
• ketones cause the pH of the blood to become acidic
• liver continues to synthesise glucose - blood glucose rises
• high glucose in the urine takes water and solutes such as potassium and sodium with it - dehydration

Question 15

treatment of diabetic ketoacidosis

Answer 15

• fluid replacement, insulin, mineral replacement
• usually develops at the time of diagnosis, during illness, during growth spurt/puberty, when insulin hasn’t been taken correctly

Question 16

chronic complications of diabetes

Answer 16

• diabetic retinopathy (blindness)
• diabetic nephropathy (end-stage renal disease)
• diabetic neuropathy (non-traumatic lower extremity amputation)
• stroke
• cardiovascular disease

Question 17

diabetic foot

Answer 17

• nerve damage or poor blood flow to feet increases risk of various complications
• cuts and blisters can become infectious, which heal poorly and may ultimately need to/foot/leg amputation

Question 18

diabetes and pregnancy complications

Answer 18

• increased risk of miscarriage, stillbirth and birth defects when diabetes is not well-controlled
• it increases risk of DKA, retinopathy, pregnancy-induced high BP and pre-eclampsia in mother