Hypoglycemia

How do you treat mild hypoglycemia?

Administration of glucose

Her's Disease Enzyme Deficiency How does it cause hypoglycemia?

Enzyme deficiency - Liver phosphorylase Causes inhibition of glucose production from glycogen. Because gluconeogenesis is not inhibited it causes mild hypoglycemia

How can postprandial hypoglycemia be prevented?

Frequent SMALL meals.

How do you treat severe hypoglycemia? How does this help?

Injections of glucagon and epinephrine. These two hormones cause increased release of glucose from the liver (from glycogen) as well as increased lipolysis and gluconeogenesis.

How does glucagon affect glycogenolysis and gluconeogenesis?

It increases both.

What two enzyme deficiencies are the cause of a common hereditary defect in beta oxidation? How does it lead to hypoglycemia?

MCAD deficiency causes build up of medium chain fatty acyl CoA. Deficiency in the CPT-1 in the liver also causes inability of beta oxidation in the liver. Beta oxidation in the liver provides energy for the liver to undergo gluconeogenesis. Without this energy gluconeogenesis is inhibited.

How does the body respond as blood glucose levels decrease?

There is a decrease in secretion of insulin and increase in the secretion of glucagon and epinephrine. As levels continue to drop growth hormone and cortisol are released. If levels continue to drop adrenergic and/or neuroglycopenic symptoms can develop.

What is insulin-induced hypoglycemia? What is it caused by?

This results from patients accidentally, or on purpose, injecting too much insulin.

Hypoglycemia is classified as blood glucose levels below what amount?

55-40 mg/dL

What are some common adrenergic symptoms of hypoglycemia? When do these symptoms usually occur?

Anxiety, heart palpitations, tremors, and sweating. These symptoms usually occur when the blood glucose level drops abruptly and epinephrine release is stimulated.

Why does a slow decline in blood glucose levels not cause release of epinephrine?

Because the slow decline slowly deprives the brain of glucose and as a result the brain fails to trigger the release of epinephrine.

Classical Galactosemia Enzyme Deficiency How does it cause hypoglycemia?

Enzyme deficiency - galactose 1-P uridyltransferase Caused by the trapping of galatose-1-P in the liver, nerves, lens, and kidneys. Trapping of inorganic phosphate inhibits glycogen degradation.

Von Gierke Disease Enzyme deficiency How does it cause hypoglycemia?

Enzyme deficiency - glucose-6-phosphatase Glucose-6-phosphatase is the last enzyme in the livers production of glucose from both gluconeogenesis and glycogenolysis. As a result, the liver cannot maintain normal blood glucose levels during fasting and SEVERE hypoglycemia occurs.

Hereditary Fructose Intolerance Enzyme Deficiency How does it cause hypoglycemia?

Enzyme defiency - Aldolase B Fructose-1-P is formed in the liver but is unable to continue through metabolism. As fructose-1-P levels build up the inorganic phosphate is unable to be utilized for glycogen degradation and causes hypoglycemia.

What is factitious hypoglycemia?

Facticious hypoglycemia is the result of a patient suffering from Munchhausen syndrome. In this syndrome the patient is attempting to gain attention.

What are two methods that cause factitious hypoglycemia? How can they be differentiated?

Insulin injection - this patient will have high insulin levels but low levels of C-peptide and proinsulin. This is because insulin overproduction isn't occurring, only increased levels as a result of injection. Sulfonylurea ingestion - this drug causes the pancreatic beta cells to produce increased amounts of insulin. These patient will present with increased insulin, C-peptide, and proinsulin as this drug is causing overproduction of insulin.

How does cortisol affect glycogenolysis and gluconeogenesis?

It has no affect on glycogenolysis but increases gluconeogenesis by inducing PEP carboxykinase.

What is insulinoma and how can it affect blood glucose levels?

It is a tumor of the pancreatic islet cells that causes increased production of insulin, even during fasting, and blocks the action of the fasting state hormones.

What is postprandial hypoglycemia? What is it caused by?

It is the second most common form of hypoglycemia caused by exaggerated insulin release after a meal which can cause mild adrenergic symptoms.

How does high alcohol intake cause hypoglycemia?

The metabolism of alcohol requires the conversion of NAD+ to NADH. As the NADH/NAD+ ratio increases it leads to inhibition of gluconeogenesis because of the requirement of NAD+ for gluconeogenesis to occur.

Cori Disease Enzyme Deficiency How does it cause hypoglycemia?

Enzyme deficiency - debranching enzyme Causes inhibition of glycogen breakdown (limit dextrinosis) but because gluconeogenesis can still be performed it only results in mild hypoglycemia.

What are some common neuroglycopenia symptoms of hypoglycemia? When do these symptoms usually occur?

Headache, confusion, slurred speech, coma, and death. These symptoms are the result of a slow decline in blood glucose level, often below 40 mg/dL.

How does epinephrine affect glycogenolysis and gluconeogenesis?

Increases glycogenolysis but has no affect on gluconeogenesis.