Case-Based Review of Carbohydrate Metabolism Flashcards
What clinical differences are most likely to be noticed between use of GLP-1 agonists and DPP-4 inhibitors?
GLP-1 agonists are more potent, both in terms of A1c lowering ability and ability to promote weight loss.
How can you clinically distinguish between glycogen phosphorylase deficiency, glucose 6-phosphatase deficiency, and debranching enzyme deficiency?
They all present with hepatomegaly, but debranching enzyme deficiency will not present with hypoglycemia; glycogen phosphorylase deficiency will present with more severe hypoglycemia, but not as severe as glucose 6-phosphatase deficiency (because in phosphorylase deficiency you can still have gluconeogenesis, unlike in glucose 6-phosphatase deficiency).
What happens in debranching enzyme deficiency?
You can still break down glycogen, but the little remnants at the branch points will remain and damage the liver.
What molecular pathway mediates the movement of GLUT4 transporters to the surface of skeletal muscle?
PI-3 kinase
MAP kinase represents the ____________ pathway of insulin.
mitogenic
____________ deficiency leads to the accumulation of lactate. Why?
Niacin; because it is a necessary cofactor for pyruvate dehydrogenase. Without it, you have increased pyruvate and thus increased lactate.
Doubly labeled water tells you _____________. How can this tell you more information?
energy expenditure; if a person is weight-stable, then energy expenditure equals energy intake
How many calories are in a gram of carbohydrate?
4 kcal
What is Dr. Bessesen’s “magic number” for how many calories per kilogram that a person should eat?
30 kcal/kg
Fat provides ______ calories per gram.
9 kcal
How are fatty acids involved in gluconeogenesis?
They are broken down to acetyl co-a that provides the energy needed to convert carbons from proteins and triglycerides (via glycerol) to glucose.
True or false: fructose increases serum free fatty acid levels.
False.
True or false: fructose does not stimulate insulin release.
True.
The key regulated step in the TCA cycle is ________________.
pyruvate to acetyl co-a (by pyruvate dehydrogenase)
Pyruvate kinase takes you from _______________.
PEP to pyruvate
