glucose

Question 1

What is the blood glucose level in hypoglycemia for adults?

Answer 1

No consensus
Usually below 4 mmol/L

In adults - <3-3.5
In newborns <2.5

But you can be okay at low levels too so symptoms matter

Question 2

Symptoms of hypoglycemia

Answer 2

Adrenergic - tremors, palpitations, sweating, hunger

Neurohypoglyemic symptoms - somnolence, confusion, incoordination, seizures, coma

Sometimes asymptomatic - loss of hypoglycemia

Question 3

What happens when we have low blood sugar?

Answer 3

You stop producing insulin and produced glucagon

You reduce peripheral (non-essential) uptake of glucose
Increased glycogenolysis and gluconeogenesis
Increase lipolysis

Question 4

What does lipolysis result in?

Answer 4

Increased free fatty acids through beta oxidation

Product = ketone bodies

Question 5

When does lipolysis occur?

Answer 5

Only if there is no insulin.

Question 6

How does the hypothalamus respond to hypoglycemia?

Answer 6

Sympathetic activation
????

Question 7

What do you do to investigate hypoglycemia?

Answer 7

Confirm there is hypoglycemia - this is easier in patients with diabetes, not in patietns without

If not you have to bring them in and monitor blood glucose during fasting in clinic

Question 8

Venous glucose vs capillary blood glucose

Answer 8

capillary blood glucose - point of care analyser, but it’s not very precise at low blood sugar levels, not quality controlled

Venous glucose measurement is better

Question 9

What is added to the preservative

Answer 9

Fluoride oxalate

Question 10

Causes of this without diabetes

Answer 10

Fasting/reactive
Critically unwell
Organ failure - particulalry liver failure as they can’t store glycogen
gluconeogenesis occurs in kidneys

Post-gastric bypass
Drugs
Extreme weight loss
Factititious

Paeds vs adult??

Question 11

Reasons for hypoglycemia in diabetes

Answer 11

Sulphonylureas
Gliclazide

Medications
Missed meals
Excessive alcohol
Strenuous exercise
Co-existing autoimmune conditions e.g. addisons (rare) - do a short synacthen test

Question 12

Medications that can cause hypoglycemia in diabetic patietns - and when

Answer 12

Sulphonylureas
Meglitinides
GLP-1 agonists - only when given in conjunction with INSULIN
Insulin - if there is a mismatch between carbs and insulin
Alcohol

Question 13

Causes of hypoglycemia outside of diabetes?

Answer 13

Insulin levels
C-peptide
Drug screen
Auto-antibodies
Cortisol/GH
FFA/ketones
Lactate

Question 14

What is c-peptide?

Answer 14

It’s a marker of how much insulin the PANCREAS is making

Pro-insulin gets cleaved into pro-insulin and C-peptide

Question 15

What are the combinations of scenarios you can get from insulin/hypoglycemia?

Answer 15

Hypoglycemia hypoinsulinemia

Hyperinsulinemic hypoglycemia, high c-peptide

High insulin and low c-peptide from exogenous insulin

Question 16

What is the appropriate diabetic response?

Answer 16

Hypoglycemic hypoinsulinemia

Question 17

Neonatal hypoglycemia

Answer 17

In inherited metabolic disorders, you might get fatty acid oxidation defect so you might measure this too - see slide

Question 18

List of conditions causing inappropriately high insulin

Answer 18

Islet cell tumours - insulinoma
Drugs - insulin, sulphonylurea
Islet cell hyperplasia (Beckwith Weidermann syndrome, Nesidioblastosis, infant of a diabetic mother)

the excessively high insulin causes

Question 19

When someone has high insulin and high c-peptide, what do you need to check?

Answer 19

Do a sulphonyl urea drug screen and make sure that isn’t causing the hyperinsulinemia

Question 20

How does sulphonylurea

Question 21

Insulinoma is associated with which syndrome?

Answer 21

MEN1

Question 22

Normally if c peptide and insulin are low, what happens to free fatty acids?

Answer 22

They should be high

Question 23

What happens

Answer 23

Non-islet cell tumour hypoglycemia

big IGF-2 - an aberrant protein which binds to the insulin receptor, as though insulin is being produced,

presents in patients with lung cancers and epithelial cells

it’s a paraneoplastic syndrome

Question 24

Genetic causes of hyperinsulinism

Answer 24

Glucokinase activating mechanism

see slide

Question 25

reactive post-prandial hypoglycemia

Answer 25

Due to

Question 26

Why does gastric bypass surgery cause

Answer 26

islet cells hyperplasia

Question 27

19 yo girl, lenugo hair on back, low BMI, BM of 2.5, what’s the cause?

Answer 27

Low glycogen stores as a result of starving