tolerance tests may be needed to confirm a diagnosis of diabetes in addition to a test for
glucose in the urine. The reason is that glucose in the urine is not always an indication
that the person has diabetes. Also, not all diabetics excrete glucose in the urine.
a. Urine Tests.
(1)
Glucose tests. These are common methods of tests for glucose in the
urine:
(a) Tes-tape. Dip a strip of Tes-tape into the urine specimen. The
tape will turn green or blue if glucose is present in the urine. Use only the end of the
tape that you have not touched with your fingers. Be sure the tape has not previously
been exposed to light or air.
(b) Clinitest. Put ten drops of water in a test tube. Add two or five
drops of urine (depending on the type of Clinitest used). Put in one tablet of Clinitest.
The liquid in the tube will change colors. A Clinitest color chart will show you how to
grade the color chart to grade the resulting color of the urine specimen in the test tube.
(c)
Diastix. Dip a plastic strip in urine. You can read the strip in thirty
seconds.
(2) Ketones. Ketone bodies are present in the urine of diabetic patients. A
doctor will decide whether it is necessary to test for ketones. Two tests are Ketostix
strips which test the urine for ketones and Keto-Diastix which tests the urine for glucose
and ketones. Testing for ketones is especially important when the patient has a fever,
is vomiting, or has glucose in his urine.
b. Blood Tests. Common tests include the following:
(1) Fasting blood glucose. The patient fasts for eight hours. Then, a single
specimen of blood is taken in the morning. Eighty to 120 mg/dl is the normal range.
(2) Postprandial glucose. Two hours after the patient has eaten a high-
carbohydrate meal, a single sample of blood is taken. The normal range is 140 to 160
mg/dl.
(3) Oral glucose tolerance test (OGTT). After the patient has fasted for
about eight hours, a blood sample and a urine specimen are taken. The patient
consumes an oral glucose solution after which blood is drawn at 30 minutes, 1 hour, 2
hours, and 3 hours. A urine specimen is also collected at each of these times. Be sure
to label all specimens with the time of collection. In the nondiabetic patient, the blood
glucose level returns to normal after two to three hours; the urine sample is negative for
glucose. In the diabetic patient, however, the blood glucose levels return to normal
more slowly; the urine tests positive for glucose.
MD0583
3-5
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