MEN/Hypoglycemia Flashcards
Multiple Endocrine Neoplasia
general
Also known as Familial Endocrine Adenomatosis
Rare group of autosomal dominant inherited syndromes that cause a predisposition to the development of hormone-producing tumors in two or more different endocrine glands
Tumors can be benign or malignant
Multiple Endocrine Neoplasia (MEN)
types
MEN 1
MEN 2A
MEN 2B
MEN 4
Major forms are type 1, 2, and 4
MEN 1
general
Develop tumors, or excessive growth and activity, of two or more of the following glands:
Parathyroid glands
Pancreas
Pituitary gland
Thyroid gland (less often affected)
Adrenal glands(less often affected)
PPP
MEN 1
almost all have
Almost all patients have tumors of the parathyroid glands
Most of the tumors are noncancerous
Hyperparathyroidism is usually the first clinical manifestation (kidney stones)
MEN 1
Other common tumors
Gastrinomas
Secrete excessive amounts of gastrin → stimulates overproduction of stomach acid (peptic ulcers with bleeding/perforation)
Insulinomas
Secrete insulin (hypoglycemia)
Tumor with the highest frequency for malignancy
Pituitary adenomas (secretory or non-secretory)
Lipomas and facial angiofibromas (non-endocrine)
MEN 2A
general
Develop tumors or excessive growth and activity in two or three of the following glands:
Adrenal glands
Thyroid gland
Parathyroid glands
Pheochromocytoma
Overactive parathyroid glands → hypercalcemia (kidney stones)
ATP
MEN 2A
Almost everyone develops
medullary thyroid cancer
Patients with MEN and diabetes should NOT receive therapy with a glucagon-like peptide 1 (GLP-1) agonist because it may increase the risk for development of medullary thyroid cancer
MEN 2A
Other common tumors
Pheochromocytomas
Neuroendocrine tumor of the adrenal glands that secretes catecholamine hormones → increased adrenaline (high blood pressure, tachycardia, headache, sweating)
Often bilateral and noncancerous
MEN 2B
General
Associated with Marfan-like habitus
Thin-build, long extremities, loose joints
Development of:
Medullary thyroid cancer
Develop at an early age, grow faster, and spread more rapidly than those in MEN 2A
Pheochromocytomas
Neuromas (mucous membranes)
Glistening bumps around the lips, tongue, and lining of the mouth
Eyelids and lips may thicken, and the lips may turn inside out (become everted)
MEN 4
general
Most recently discovered type
Exhibits signs and symptoms similar to type 1, but is caused by a different gene mutation
Development of:
Parathyroid adenoma → hyperparathyroidism
Pituitary adenoma
Pancreatic neuroendocrine tumor
Gonadal, renal, and/or adrenal tumors
MENs
Dx
Genetic testing: patient and family members
Hormone levels (blood and urine)
Imaging studies to access tumors
MENs
Tx
No cure for any type
Tumor removal if possible
Total thyroidectomy for all those at risk for medullary thyroid cancer
Hypoglycemia
general
Medical emergency in which blood glucose levels are lower than normal (< 70 mg/dL)
Common in patients with diabetes (type I > type 2)
Often the result of inadequate oral intake with insulin administration
After 5 years with diabetes, patients lose their glucagon response (glucagon: ↑ glucose in the blood)
hypoglycemia
can occur in patients without diabetes
Defined by clinical features and not by a defined limit for the glucose level
Occurs with eating less and exercising more, alcohol consumption, medications, hypermetabolic states like sepsis and burns, and tumors (insulinomas)
Glucose Homeostasis
Normal range
Serumglucose levels - normal range of 71–99 mg/dL
Maintained by the coordinated balance between insulin, glucagon, and the sympatheticnervous system
Glucose Homeostasis
With ↓ glucose levels
At ~80 and ~68
At ~80 mg/dL:insulin secretion decreases
At ~68 mg/dL:glucagon,norepinephrine, and epinephrine aresecreted
Glucagon hormone
mobilizes glycogen from the liver - raising blood glucose
Norepinephrine
acts systemically to cause the adrenergic symptoms of hypoglycemia, including tachycardia and diaphoresis
Epinephrine acts on multiple organs
Stimulates glycogenolysis and gluconeogenesis in the liver
Decreases insulin secretion and increases glucagon secretion in pancreatic islet cells
Increaseslipolysis in adipose tissue, which provides glycerol for gluconeogenesis
Decreasesglucose uptake by muscle cells
At ~66-58 mg/dL:
Growth hormone and cortisol are secreted
Increaseslipolysis in adipose tissue
Increasesketogenesis andgluconeogenesis in the liver
Medications causing Hypoglycemia
Insulin
Meglitinides (repaglinide, nateglinide)
Sulfonylureas (glipizide, glimepiride, glyburide)
Beta-blockers
Ethanol
Quinolones
Salicylates
MAO inhibitors
Signs and symptoms may not occur until plasma glucose concentrations drop below 55 mg/dL
hypoglycemia
Sx
Initial symptoms occur with a blood glucose of ~60 mg/dL
Cognitive/behavioral impairment will occur at ~50 mg/dL
Low blood glucose triggers the release of epinephrine (adrenaline) → “fight-or-flight” symptoms
If blood glucose levels continue to fall and the brain goes without glucose → neuroglycopenic symptoms
Includes: (mild → severe)
Feeling shaky/anxious
Sweaty and pale (pallor)
Tachycardic
Light-headed
Impaired vision (blurry)
Numbness/tingling in the lips, tongue, or cheeks
Confused
Clumsiness
Seizures
Coma
Death
Whipple Triad
asscoiated with NON-diabetics
Triad associated withhypoglycemia in nondiabeticpatients:
Confirmedglucoseconcentration ≤ 70 mg/dL
Signs and symptoms associated withhypoglycemia
Resolution of symptoms after the management ofhypoglycemia
Nondiabeticpatients who exhibit theWhipple triadrequire further workup to determine the etiology of a possible hypoglycemic disorder
hypoglycemia
Dx
Levels of hypoglycemia
Requires a reliable means of measuring blood glucose
Hospital point-of-care testing
Laboratory measurement
Level of Hypoglycemia
Level 1: 54-70 mg/dL
Level 2: < 54 mg/dL
Level 3: severe event characterized by altered mental status and/or physical status
hypoglycemia
Tx
Mild-moderate hypoglycemia
“15-15 rule”
1. Check blood glucose
2. Eat 15 g of a simple carbohydrate
Simple carbohydrates
Glucose tablets
4 oz of juice or regular soda
1 tablespoon of sugar or honey
Hard candies
3. Recheck blood glucose in 15 minutes
Repeat until blood sugar levels are ≥ 70 mg/dL
Identify the underlying cause and make corrections as needed
Severe hypoglycemia
Tx (3)
Amp of D50 IV (25 g of dextrose monohydrate in 50 mL of water)
1 mg of glucagon IM
3 mg of glucagon intranasally
Repeat point-of-care bloodglucosemeasurement in 15 minutes
Dose may be repeated ifglucoselevel is still low
Onceglucoseis corrected and mental status is regained, normal oral intake should be restarted
Add dextroseto maintenance fluids if the patient is unable to tolerate oral intake
Hypoglycemia
