Endocrine Labs Flashcards
Normal fasting gluscose
<100
Diabetic fasting glucose
> 125
Impaired glucose tolerance fasting glucose
between 100 and 125
A1C normal range
4.0-5.6
What can make A1C inappropriately low
Hemolysis
Blood transfusion
Blood loss
Vitamin C
Aspirin
Splenomegaly
Hypertriglyceridemia
What can make A1C inappropriately high
Iron deficiency
Vitamin B12 deficiency
Alcohol
Uremia
Hyperbilirubinemia
Splenectomy
Fructosamine
Measures glycemia over last two weeks
200-285
Good alternative if A1C isn’t accurate
Most sensitive and specific test for autimmune diabetes
Glutamic acid decarboxylase (GAD60)
Albumin-creatinine ratio
Assesses inappropriate protein loss through kidneys
How to test for urine ketones
Color changing paper
Color decided by acetoacetate
How to test for serum ketones
Dilution with acetoacetate and beta-hydroxybutyrate
1:8 dilution is positive for ketonemia
Normal beta hydroxybutyrate
(0.4-0.5)
beta hydroxybutyrate less than 0.4mmol/L
DKA
Normal TSH range
0.5-5.0
Normal free T3 range
2.3-4.1 pg/mL
More unstable so harder to measure in free form
Normal free T4 range
0.8-1.8 ng/fL
Thyroid binding globulin range
1.1-2.1 mg/dL
Carries T4 and T3 to targets
Thyroglobulin range
3-40 ng/mL
Thyroglobulin
Sotred in follicular coolloid
Monitors thyroid cancer recurrence
Thyroglobulin antibodies
Hashimotos thyroiditis
Grave’s disease
Thyroid peroxidase antibodies
Directed against enzyme needed for iodination of thyroid hormone
Found in hashimotos and graves
TSH receptor antibodies
Stimulate or inhibit thyroid function
Found in graves disease
What is measured to monitor thyroid cancer
Thyroglobulin/thyroglobulin antibodies
Calcitonin
Diabetes insipidus
No ADH
Patient is dehydrated bc peeing dilute urine all the time
Urine osmolality is low and serum osmolality is high
Normal urine osmolality
50-1200
Nromal serum osmolality
275-295
SIADH
Making too much ADH
Urine osmolality >100
Urine sodium >30
Test for SIADH
Water loading and measuring urine and serum osmolality
Test for diabetes insipidus
Water deprivation study
Oxytocin
Unbound polypeptide from post pit
Prolactin
<20 in men
<25 in women
controls lactation (lactotroph)
Inhibits dopamine
Human growth hormone
Growth
Low levels
Somatotroph
Insulin-like growth factor (IGF-1)
Marker for growth hormone
We measure this not GH
Elevated GH
Gigantism in children and acromegaly in adults
What to do if IGF-1 is high
Oral glucose suppression and then remeasure.
What to do if growth hormone is low
Arginine stimulation test.
Stimulates release of growth hormone and samples collected every thirty minutes for two hours
Adrenocorticotropic hormone (ACTH)
Acts on adrenal gland to release cortisol
Follicle stimulating hormone
Stimulates sertoli cells to make sperm and inhibin
Stimulates follicle growth
Lutenizing hormone
Stimulates leydig cells of testes to secrete androgen
Stimulates ovulation
What usually comes with hyperaldosteronism
Hypertension, hypokalemia, decreased renal perfusino, fluid overload
Elevated aldosterone to renin ratio
Cortisol
Regulated by ACTH from ant pit
Highest in morning
Stress
24 hr urinary cortisol
Good test to get levels without worrying about diurnal variations
Dexmethasone suppression test
Used to decide if Cortisol is th problem or if it is CRH or ACTH
Catecholemines
Dopamine, epi, norepi
Made in adrenal madulla
Perferred test for neuroendocrine tumors
Plasma free metanephrines and normetanephrines
Normal calcium range
8.5-10.2
Corrected calcium
Normal (albumin - paientalbumin) x 0.8 + serum calcium
Ionized calcium regular range
4.8-5.3
Parathyroid hormone normal range
14-65
Regulates ionized calcium
Vitamin D
Fat soluble vitamin needed for calcium absorption
Vitamin D2
ergocalciferol from plants
VitaminD3
Cholecalciferol from animal source or UV light
Normal testosterone levles
Men 200-1000
Women (15-70)
