(4)
Decreased skin temperature.
(5)
Decreased capillary and venous filling.
(6)
Thick and ridged toenails.
1-67. DIAGNOSIS
Simple screening tests that determine blood and urine glucose levels are used to
aid in the diagnosis of diabetes mellitus.
a. Fasting Blood Sugar. The fasting blood sugar (FBS) test measures the
amount of sugar present in the blood after a patient has been fasting for a prescribed
amount of time (generally 6-8 hours). An elevated fasting blood sugar level indicates
the possibility of diabetes and the need for further investigation.
b. Two-Hour Post-Prandial Blood Sugar. The two-hour post-prandial blood
sugar (two percent ppBS) is a common diagnostic test to determine how well sugar is
metabolized by the body. A patient remains fasting for 6-8 hours, a fasting blood
specimen is drawn, and the patient is given a high carbohydrate meal. The meal
contains a measured amount of carbohydrates. The patient must eat the entire meal
within 15 minutes. Two hours after completion of the meal, another blood sugar level is
drawn. In a person with normal metabolism, the blood sugar level has returned to
normal range within two hours after the meal. An elevated blood sugar level indicates
the possibility of diabetes and the need for further investigation.
c. Glucose Tolerance Test. The glucose tolerance test (GTT) test is
performed when a patient is found to have an elevated blood sugar level or sugar in the
urine. This test is used to evaluate the body's use of glucose. During this test, blood
and urine specimens are collected at timed intervals following the ingestion of a
measured amount of glucose. The test normally proceeds in this manner:
(1) The patient may be required to follow a prescribed high carbohydrate
diet for three days prior to the test date.
(2) The patient must fast for the required period of time prior to the start of
the test, normally 6-12 hours.
(3)
Blood and urine are collected while the patient is fasting.
(4) The patient is given a measured amount of glucose solution to drink,
which must be consumed quickly.
(5) Blood and urine are collected at timed intervals after the ingestion of the
glucose drink. Intervals are normally at 1/2 hour, 1 hour, 2 hours, and even up to 6
hours following the ingestion of the glucose drink.
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