Hypoglycemia/insulinoma Flashcards
Describe three things in Whipples Triad
– 1) symptoms/signs consistent with hypoglycemia
– 2) Low measured plasma glucose concentration
– 3) Resolution of symptoms/signs with increasing plasma glucose
Define hypoglycemia
Plasma glucose low enough to cause signs or symptoms including impairment of brain function. Typically < 70 mg/dl and whipples triad
What are some defenses against hypoglycemia?
release of glucagon by alpha cells to increase gluconeogenesis
decrease glucose clearance in kidney
decrease insulin
incrase ACh and NE
response of following hormones during HYPOglycemia
insulin
glucagon
epi
cortisol growth hormone
How does epinephrine increase glucose levels?
causes increase gluconeogeneis by liver
inhibits insulin release from beta cells
increase glycolysis from muscle and lipolysi from fat
What are Neurogenic symptoms of Hypoglycemia
• Tremor • Palpitations • Anxiety/arousal • Sweating • Hunger
Neuroglycopenic sypmptoms of Hypoglycemia
• Cognitive impairment • Behavioral Changes • Psychomotor abnormalities • Visual changes • Seizures • Coma
What drugs can cause hypoglycemia?
insulinoma, nesidioblastosis, post gastric bypass
defiicency of which hormone can cause hypoglycemia?
cortisol
Critical illness such as _____ can cause hypoglycemia
liver/kidney/heart fail
sepsis
severe malnourishtmet
• Insulin secreting tumors of pancreatic origin that cause hypoglycemia
Insulinoma
- Occurs in 1‐4 people per million
- 1‐2% of all pancreatic neoplasms
- 90%: benign, solitary, intrapancreatic, < 2 cm
insulinoma
Where in the pancrease are insulinomas located?
Evenly distributed throughout the pancreas
When workig up a pt for insulinoma when do we get imaging?
Diagnosis made per hormonal studies when hypoglycemic. Imaging helps to localize an insulinoma after the diagnosis is made.
What is the gold standard test to dx insulinoma?
Supervised fast
- Provoke hormonal responses that maintain euglycemia
- Normally symptomatic hypoglycemia should not occur after a prolonged fast given gluconeogenesis
What are the parameters necesseary to dx Insulinoma in a supervised fast?
• End Points for the test
glucose ≤ 45 mg/dl
– Signs/symptoms of hypoglycemia
Glucose ≤ 55 mg/dl + Whipple’s triad
Both proinsulin and C‐peptide are secreted with_____ insulin (including sulfonylureas) Neither Proinsulin or C‐peptide is contained within_____ pharmacologic insulin
endogenous
exogenous
what is the cutoff plasma glucose for insulinoma and regular people during fasting
55
you should be able to maintain euglycemia for up to 72 hours
YOu perform fasting test on pt. they have below normal glucose and INcreased insulin, what does this indicate?
isulin above 3 micro = insulinomas/ exogenous insulin/ sylfonlurease or autoimmune
**need to get C peptide!
Why do we order a C-peptide on pts with hypoglycemia and elevated insulin during a fasting test?
to tell if the insulin is endogeous (high C-peptide)= insluinoma or sulfynrueas
or exogenous (low C peptide)
Why do you need to ourder a sulfonulurea screen in pt with suspect insulinoma?
because both as the same lab values of hypoglycemia, incresaed insluin and increased C peptide
