chemical pathology: hypoglycaemia Flashcards
What organ in the body is glucose dependent
Brain
Who is at higher risk for hypoglycaemia & why
Children due to limited capacity of hepatic gluconeogenesis relative to brain size
What is neuroglycopenia
Inadequate supply of glucose to the brain
Why does hypoglycaemia occur
Failure/interference in normal physiological response to hypoglycemia
What is the physiological response in hypoglycaemia
Elevated levels of cortisol, glucagon, GH & catecholamines
0 insulin
Increased muscle & fat breakdown for energy
What is the three main cause for hypoglycemia
- Secondary to other causes: hepatic failure, severe malnutrition, sepsis & drugs
- Increased uptake & use of glucose: hyperinsulinism
- Failure of hepatic gluconeogenesis: ethanol
How does ethanol cause hypoglycemia
Sustained heavy drinking + low carb/sugar intake causes change in NADH:NAD ratio (increasing NADH) that prevent gluconeogenesis
What is important when treating hypoglycemia
Take blood before giving glucose infusion
What is the four reasons why diabetics have increased risk of hypoglycaemia
- Tightly controlled type 1 diabetics
- Hypoglycemia unawareness develop over time
- Beta blockers use
- Type 2 high intake of sulfonylureas
What is the three instances when hypoglycaemia occur in diabetic patients
- Taking medication with decrease food intake/exercise
- Wrong dose of medication
- Excessive alcohol use
What is hyperinsulinism
Hypoglycemia with detectable insulin, no ketones & low FFA
How to detect endogenous or exogenous insulin
Endogenous: C peptide
Exogenous: C peptide absent
What is the two causes of hyperinsulinism in neonates
- Babies of diabetic mothers with transient hyperinsulinism
- Congenital hyperinsulinism
What is the three causes of hyperinsulinism in adults
- Insulinomas
- Sulphonylureas
- Exogenous
