Urinalysis - The Carter Center

levels (hyperglycemia) and accompanying glycosuria and may be
accompanied by changes in fat metabolism.
Glucose is the sugar most commonly found in the urine, although
other sugars , such as lactose, fructose , galactose, and pentose, may
be found under certain condition. Normally, urine doesnot contain a
sufficient amount of sugar to react with any of the popular enzyme
or reducing tests. When sugar appears in the urine, it shows the
abnormality caused by disease diabets mellitus.Hence urine sugar
tests are extremly usefull in monitoring the treatment of diabetes.
Clinical Significance
The presence of detectable amount of glucose in the urine is
known as glycosuria. Normally almost all the glucose, which passes
from the blood into the glomerular filtrate, is reabsorbed back into the
circulation by the kidney tubules
( proximal convoluted tubules ). Usually less than 15 - 20 mg/dl (0.8
mmol) is excreted in the urine. But this amount cannot be detected
by the routine laboratory tests. The term glycosuria is usually used to
describe the presence of more than the normal amount ( 15- 20 mg /dl )
of glucose in the urine.
The occurrence of glucose in the urine is not normal if more than 15 - 20
mg/dl. The blood glucose concentration normally lies between 65 and
110 mg/dl. After a meal it may increase to 120 - 160 mg/dl. If the blood
glucose concentration becomes too high (usually greater than 170 - 180
mg/dl), the excess glucose will not be reabsorbed into the blood and
glucose start appearing in urine. The lowest blood glucose
concentration that will result in glycosuria is termed as the renal
threshold. The most common condition in which the renal threshold for
glucose exceeds is diabetes mellitus.
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