Hypoglycemic Disorders

Question 1

What blood sugar level is considered hypoglycemic

Answer 1

<65 mg/dL

Question 2

Insulin secretion is inhibited when blood glucose decreases to what level?

Answer 2

~80 mg/dL

Question 3

Hormones secreted during Hypoglycemia (4 total)

Answer 3

Glucagon
Epi
GH
Cortisol

Question 4

What blood sugar is associated with AMS, seizures and coma

Answer 4

<50 mg/dL

Question 5

Signs/symptoms of Hypoglycemia

Answer 5

Sweats
Tremors
Palpitations
Tired
Faint/Dizzy
AMS
Seizures
Coma

Question 6

What is “Whipple’s Triad”

Answer 6

1) Symptoms of Hypoglycemia
2) Lab confirmation of Hypoglycemia
3) Resolves with glucose

Question 7

Purpose of “Whipple’s Triad”

Answer 7

To help establish suspicion of hypoglycemia

Question 8

What are the 2 rough categories for classifying FASTING Hypoglycemia

Answer 8

Insulin Mediated

Non-Insulin Mediated

Question 9

Examples of causes of Hypoglycemia in NEONATES/CHILDREN (Low vs. High Insulin)

Answer 9

Low Insulin: Metabolism errors, Hormone deficiency, Prematurity, Sepsis)

High Insulin: Maternal Diabetes, Congenital Hyperinsulinism, Insulinoma

Question 10

Examples of causes of Hypoglycemia in ADULTS (Low vs. High Insulin)

Answer 10

Low Insulin: Hormone deficiency (GH and Cortisol), Liver or Renal failure, Sepsis or Drugs (alcohol, quinine, etc.)

High Insulin: Insulinoma and Drugs (insulin)

Question 11

Which drugs can cause Hypoglycemia

Answer 11

Alcohol (high NADH/NAD+ ratio inhibiting gluconeogenesis)
Quinine (anit-malarials)
Salicylates (aspn)

Question 12

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

Answer 12

Factitious Hypoglycemia

Question 13

Drugs commonly used in Factitious Hypoglycemia

Answer 13

Insulin

Sulfonylureas

Question 14

How can you tell the difference between Insulinoma and Exogenous Insulin overuse/abuse?

Answer 14

Insulinoma: elevated C-peptide
Exogenous: low C-peptide

• Factitious Sulfonylurea ingestion can also cause elevated C-peptide, but sulfonylurea screen would be POSITIVE.

Question 15

Signs/Symptoms of Insulinoma

Answer 15

80% Neuroglycopenia (low blood sugar in brain)
20% weight gain
10% seizures

Question 16

Insulinomas can occur with which MEN

Answer 16

MEN1

Question 17

Treatment for Insulinomas

Answer 17

1. Surgery (tx of choice)
2. Medical therapy:
   - Diazoxide (inhibit insulin secretion by opening ATP-dependent K+ channels)
   - Somatostatin (-reotide)

Question 18

Insulin secretion inhibitor; used for Insulinomas

Answer 18

Diazoxide

Somatostatin

Question 19

When would you prefer medical therapy for Insulinoma vs. surgery

Answer 19

When there are multiple tumors or incomplete resections

Question 20

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)

Answer 20

Postprandial Hypoglycemia (due to post-Gastrectomy or early type 2 DM)

Question 21

Treatment for Postprandial Hypoglycemia

Answer 21

Small, frequent meals (avoid rapid emptying)

Acarbose (delay absorption)

Question 22

Blood glucose levels are slightly higher (3-5%) in (veins/arteries)

Answer 22

Arteries

Question 23

1. Normal, healthy level of HbA1c
2. Prediabetes HbA1c
3. Diabetes HbA1c

Answer 23

1. 4-5.6%
2. 5.7-6.4%
3. > 6.4%

Question 24

What is HbA1c

Answer 24

Hemoglobin A1c: glycosylated hemoglobin during states of hyperglycemia

Question 25

What is the utility of a HbA1c measurement?

Answer 25

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

Question 26

What can be used to evaluate diabetes if a A1c might not be reliable?

Answer 26

Fructosamine (glycated albumin)

• albumin half life is about 21 days so it can give average of 3 weeks glucose level