Diagnosis and Monitoring Diabetes

• Urine Tests

Urine testing is part of most physicians routines in giving complete physical examinations. Urine tests are basic diagnostic tools that can give physicians valuable information about how your body is working.
In a form of urine testing known as semi quantitative your doctor may use either a tablet or one of several brands of paper or plastic strips to determine the approximate sugar or ketone level in your urine. Only a small sample of urine is needed, and the test takes only a few seconds. The paper or plastic strips are coated with chemicals that change colors according to sugar and ketone concentration. For example, one type of strip ranges from yellow through green to dark blue. With this test a color closer to dark blue indicates a high concentration of sugar in the urine. However, if you are taking certain medications, aspirin, or vitamin C, these substances may int4erfere with the dyes on the strips and distort the readings. Your physician will ask you about medications you are taking so that test results can be interpreted properly.
An advantage of semiquantitative urine testing is that it is fast and can be done easily by your doctor. The disadvantage of urine tests, in general, however, is that they are less accurate and harder to interpret than blood tests. Because the point at which your kidneys begin to spill glucose into your urine may differ from the point in other people, urine test readings may not always accurately reflect the level of glucose in your blood.
Another urine test your physician may do is known as a quantitative measurement in a timed sample. This test might be ordered by your physician after a high or low reading has been found with a semiquantitative test. One advantage of this type of test is that only glucose and ketones are measured, and other chemicals in your blood that might have caused false higher or lower readings with the chemically coated paper strips used in semiquantitative testing are removed. Another advantage is that the exact concentration, rather than a range, of glucose and ketones in the urine is measured.
Because the urine must be collected very accurately in such tests, (whereas only a small sample in necessary for the semiquantitative tests), it is inconvenient. If the physician orders a 24-hour sample, this means that all urine during that period must be collected and brought to the point at which the patient's kidneys actually begin to spill sugar and ketones into the urine, this may or may not be an accurate reflection of glucose levels.