Chap 18, Endocrine System, Laboratory Tests

Question 1

Fasting plasma glucose (FPG)

Answer 1

Also known as fasting blood sugar test. Measures circulating glucose level in a patient who has fasted at least 8 hours.

This test can diagnose diabetes and pre-diabetes (blood glucose is highter than normal but not high enough for diagnosis of diabetes). A normal result is 99 mg/dL or lower. Pre-diabetes levels are 100 to 125 mg/dL and diabetes is 126 mg/dL and above. A casual non-fasting plasma glucose level of 200 mg/dL plus the presence of signs and symptoms such as increased urination, increased thirst, and unexplained weight loss can also diagnose diabetes. An oral glucose tolerance test is used to diagnose pre-diabetes and gestational diabetes.

The glycosylated hemoglobin (HbA1c) test (A1c for short), by measuring the percentage of red blood cells with glucose attached, monitors long-term glucose control (past 3 months). A high level indicates poor glucose control in diabetic patients.

Question 2

Serum and urine tests

Answer 2

Measurement of hormones, electrolytes, glucose, and other substances in serum (blood) and urine as indicators of endocrine function.

Question 3

Thyroid function tests

Answer 3

Measurement of T3, T4 and TSH in the bloodstream.