Hypoglycemia/insulinoma Flashcards Preview

Endocrine > Hypoglycemia/insulinoma > Flashcards

Flashcards in Hypoglycemia/insulinoma Deck (16):
1

in 72 hour fast, proinsulin level >5pmol/L consistent with

insulinoma

2

action of cortisol and growth hormone in response to hypoglycemia

limit glucose utilization and enhance glucneogensis (if hypoglycemia persists)

2

end points for 72 hour fast

glucose

glucose < 55 + whipples triad

signs/symptoms of hypoglycemia

>72 horus

 

3

critical timing for measurements of hypoglycemia

must be taken while patient is experiencing hypoglycemia

4

level for hypoglycemia if on insulin or sulfonylurea

5

Whipple's triad for hypoglycemia

Symptoms/signs consistent

low plasma glucose (typically <70)

resolution of symptoms with feeding

6

physiologic defenses against hypoglycemia

reduction in insulin

increase glucagon

increase in epinephrine

7

action of epinephrine in response to hypoglycemia

increase substrate for gluconeogenesis at beta-2 adrenergic receptors

 

inhibit insulin secretion at Alpha 2 

7

measurements and indications for mixed meal test

measure glucose, proinsulin, insulin, C peptide pre-meal (fasting) and every 30 minutes post meal

 

Used to evaluate patients with postprandial symptoms (clarify if insulin mediated)

often after Gastric Bypass

8

Patients with insulin mediated hypoglycemia response to IV glucagon at end of supervised fast

 

mechanism

increase in plasma glucose (response to insulin)

 

hyperinsulin secretion permits retention of glycogen whtin liver

(normal patients would have no remaining glycogen)

9

neuroglycopenic symptoms of hypoglycemia

cognitive impairment

behavior changes

psychomotor abnormalities

visual changes

seizures

coma

11

lab value cut offs to distinguish patients with insulinomas from normal in 72 hour fast

glucose 3microU/ml

12

action of glucagon in response to hypoglycemia

increased glycogenolysis and gluconeogenesis at liver

14

order of hormonal response to hypoglycemia

1. decrease insulin

2. increase glucagon

3. increase epinephrine

4. Cortisol and growth hormone

15

neurogenic (autonomic) symptoms of hypoglycemia

tremor

palpitations

anxiety/arousal

sweating

hunger

16

Beta hydroxybutyrate levels in fasting insulinoma patient

low levels when fasting (