Hypoglycemic Disorders Flashcards
What blood sugar level is considered hypoglycemic
<65 mg/dL
Insulin secretion is inhibited when blood glucose decreases to what level?
~80 mg/dL
Hormones secreted during Hypoglycemia (4 total)
Glucagon
Epi
GH
Cortisol
What blood sugar is associated with AMS, seizures and coma
<50 mg/dL
Signs/symptoms of Hypoglycemia
Sweats Tremors Palpitations Tired Faint/Dizzy AMS Seizures Coma
What is “Whipple’s Triad”
1) Symptoms of Hypoglycemia
2) Lab confirmation of Hypoglycemia
3) Resolves with glucose
Purpose of “Whipple’s Triad”
To help establish suspicion of hypoglycemia
What are the 2 rough categories for classifying FASTING Hypoglycemia
Insulin Mediated
Non-Insulin Mediated
Examples of causes of Hypoglycemia in NEONATES/CHILDREN (Low vs. High Insulin)
Low Insulin: Metabolism errors, Hormone deficiency, Prematurity, Sepsis)
High Insulin: Maternal Diabetes, Congenital Hyperinsulinism, Insulinoma
Examples of causes of Hypoglycemia in ADULTS (Low vs. High Insulin)
Low Insulin: Hormone deficiency (GH and Cortisol), Liver or Renal failure, Sepsis or Drugs (alcohol, quinine, etc.)
High Insulin: Insulinoma and Drugs (insulin)
Which drugs can cause Hypoglycemia
Alcohol (high NADH/NAD+ ratio inhibiting gluconeogenesis)
Quinine (anit-malarials)
Salicylates (aspn)
Psychiatric illness characterized by the surreptitious use of diabetic medication (usually Insulin or Sulfonylureas) by patients for secondary gain, such as taking a family member’s insulin or seeking attention
Factitious Hypoglycemia
Drugs commonly used in Factitious Hypoglycemia
Insulin
Sulfonylureas
How can you tell the difference between Insulinoma and Exogenous Insulin overuse/abuse?
Insulinoma: elevated C-peptide
Exogenous: low C-peptide
- Factitious Sulfonylurea ingestion can also cause elevated C-peptide, but sulfonylurea screen would be POSITIVE.
Signs/Symptoms of Insulinoma
80% Neuroglycopenia (low blood sugar in brain)
20% weight gain
10% seizures
Insulinomas can occur with which MEN
MEN1
Treatment for Insulinomas
- Surgery (tx of choice)
- Medical therapy:
- Diazoxide (inhibit insulin secretion by opening ATP-dependent K+ channels)
- Somatostatin (-reotide)
Insulin secretion inhibitor; used for Insulinomas
Diazoxide
Somatostatin
When would you prefer medical therapy for Insulinoma vs. surgery
When there are multiple tumors or incomplete resections
Episodes of Hypoglycemia shortly after meals (~2 hours); thought to be due to rapid gastric emptying, triggering rapid overproduction of incretins and insulin; treat with small, frequent meals and Acarbose (delay absorption)
Postprandial Hypoglycemia (due to post-Gastrectomy or early type 2 DM)
Treatment for Postprandial Hypoglycemia
Small, frequent meals (avoid rapid emptying)
Acarbose (delay absorption)
Blood glucose levels are slightly higher (3-5%) in (veins/arteries)
Arteries
- Normal, healthy level of HbA1c
- Prediabetes HbA1c
- Diabetes HbA1c
- 4-5.6%
- 5.7-6.4%
- > 6.4%
What is HbA1c
Hemoglobin A1c: glycosylated hemoglobin during states of hyperglycemia
What is the utility of a HbA1c measurement?
Glucose measurements are only “snap shots” of glucose levels. Since HbA1c is based on hemoglobin, which survive for 120 days, can give a longer view (~4 months) of glucose levels
What can be used to evaluate diabetes if a A1c might not be reliable?
Fructosamine (glycated albumin)
- albumin half life is about 21 days so it can give average of 3 weeks glucose level
