Endocrine Labs

Question 1

What are common signs of hypothyroidism?

Answer 1

Fatigue/Sluggishness
Weight gain
Cold intolerance
Dry skin, brittle hair
Constipation
Slow heart/respiration
Menstrual irregularities

Question 2

What are common signs of hyperthyroidism?

Answer 2

Anxiety, irritable, difficulty sleeping
Weakness in arms and legs
tremors
hot skin, perspiration
weight loss
frequent bowel movements
irregular heart beat

Question 3

What 5 test are used to evaluate thyroid function?

Answer 3

TSH
Total T4
Total T3
Free T4
Free T3

Question 4

Which test is used most commonly?

Answer 4

TSH

Question 5

If TSH test results are normal, what other tests should be ordered?

Answer 5

None

Question 6

If symptoms don’t make sense with a normal TSH result, what test should be ordered?

Answer 6

Free T4

Question 7

What do elevated TSH levels indicate?

Answer 7

hypothyroidism

Question 8

What do low TSH levels indicate?

Answer 8

hyperthyroidism

Question 9

When elevated TSH results are presented, what test should be ordered and why?

Answer 9

Free T4

to determine the degree of hypothyroidism

Question 10

When low TSH results are presented, what test should be ordered and why?

Answer 10

Free T4 (and possibly Free T3)
to determine the degree of hyperthyroidism

Question 11

What test is used to monitor therapy of patients who have hypothyroidism?

Answer 11

TSH

Question 12

After adjusting thyroid medication, how long does it take for the TSH to equilibrate?

Answer 12

4-6 weeks

Time your retesting appropriately.

Question 13

How do we treat a patient with hyperthyroidism?

Answer 13

Refer!

Question 14

How do we treat a patient with hypothyroidism?

Answer 14

give Levothyroxine (T4)

Question 15

What are Total T3 and Total T4 tests used for?

Answer 15

Not used often!
Measure both protein bound and unbound T3 and T4.
Both increase with hyperthyroid and decrease with hypothyroid.

Question 16

What are Free T3 and Free T4 tests used for?

Answer 16

Confirming TSH results.

Free T3 has a more dramatic elevation than T4 in patients with hyperthyroidism.

Question 17

Are Free T3 and T4 tests used to routinely monitor therapy?

Answer 17

Rarely.

Question 18

If labs don’t make sense, such as high TSH and high FT4, what is the plan?

Answer 18

Problem may be in the pituitary gland. Refer!

Question 19

If lab results indicate high TSH and low FT4, what is the diagnosis?

Answer 19

Hypothyroidism. Start Levothyroxine.

Question 20

If the lab results indicate high TSH and normal FT4, what is the diagnosis?

Answer 20

Subclinical hypothyroidism.

Treat if the patient is symptomatic or TSH is greater than 10, or planning pregnancy.

Question 21

What are the main lab tests to diagnose or screen for diabetes mellitus?

Answer 21

Fasting blood glucose level (FBG)
Glycosylated hemoglobin (Hb A1C)
Oral glucose tolerance test (OGTT)

Question 22

Which type of diabetes is screening recommended for?

Answer 22

Type 2 DM

Question 23

Why might a random blood glucose level be tested?

Answer 23

To diagnose a patient with symptoms of diabetes, if the results are greater than 200mg/dl.

Question 24

When screening a patient for diabetes, and the test comes back positive, what test should be given for confirmation?

Answer 24

The same test you just used. Do NOT use a different test.

Question 25

How well is the specificity and sensitivity of the DM tests?

Answer 25

Good specificity, but poor sensitivity. | Trust the positive, not the negative.

Question 26

For a fasting blood glucose test, how long should the patient fast in advance?

Answer 26

8 hours | Can use glucose on CMP, if patient has fasted

Question 27

What levels does a fasting blood glucose test confirm DM?

Answer 27

greater than or equal to 126 mg/dl, on TWO separate tests.

Question 28

What is a normal value for fasting blood glucose tests?

Answer 28

less than 100 mg/dl

Question 29

What is considered to be "impaired glucose tolerance?"

Answer 29

Patients with FBG tests between 100 and 126. | They are at risk!

Question 30

How long should a patient fast for Hb A1C?

Answer 30

Does not require fasting.

Question 31

What does the Hb A1C test reflect?

Answer 31

The average blood sugar levels for the 3 month period before the test.

Question 32

What levels does an Hb A1C test confirm DM?

Answer 32

greater than 6.5% on TWO separate tests.

Question 33

What are considered normal levels of an Hb A1C test?

Answer 33

between 5.0 and 6.0%

Question 34

What Hb A1C levels indicate a patient who is at risk for developing DM?

Answer 34

6.0 - 6.4%

Question 35

What conditions might affect the results of an Hb A1C test?

Answer 35

Changes to RBCs, such as anemia, chronic blood loss, toxicities, renal failure, and pregnancy.

Question 36

How long must a patient fast for an Oral glucose tolerance test?

Answer 36

8 hours

Question 37

How is an OGTT performed?

Answer 37

Patient first drinks 75 g of glucose solution, wait 2 hours, draw blood after 2 hours.

Question 38

What levels of an OGTT test indicate diagnosis of DM?

Answer 38

greater or equal to 200 mg/dl

Question 39

What are normal OGTT levels?

Answer 39

under 140 mg/dl

Question 40

What OGTT levels indicate impaired glucose tolerance?

Answer 40

between 140 and 200 mg/dl

Question 41

How is a patient with DM normally monitored?

Answer 41

Eye exams, Foot exams, Dental exams, monitoring Blood Pressure, Weight, Diet, Exercise, and Smoking cessation.

Question 42

What lab exams are used to monitor patients with DM?

Answer 42

``` Annual urine albumin tests Annual Lipid panels Annual liver function tests (CMP) Biannual Hb A1C in stable patients (quarterly in unstable) ```

Question 43

What does a positive albumin urine test indicate?

Answer 43

If patient does NOT have HTN, you should start them on an ACE inhibitor! This provides protection to the kidney! (a patient who already has HTN should already be on an ACE inhibitor)