Urinalysis - The Carter Center

metabolism or absorption, the body metabolizes increasing amounts of
fatty acids, which is then converted into excessive amount of acetyl-CoA.
The extra acetyl-CoA molecules join up in pairs to form acetoacetic acid.
Most of this is reduced to β-hydroxybutyric acid while some is
decarboxylated to acetone. Acetoacetic and β-hydroxybutyric acids are
transported in the blood to the peripheral tissues to serve as an
alternative fuel for cells. In the peripheral tissues these ketone bodies
are reconverted to acetyl- CoA, and oxidized by the tricarboxylic acid
cycle to give energy. Acetone is excreted in the urine.
Clinical Significance
When the rate of formation of ketone bodies is greater than the rate of
their use, their levels begin to rise in the blood, which is called
ketonemia, and eventually in the urine, which is known as ketonuria.
These two conditions are seen most often in cases of starvation and
diabetes mellitus. Ketone bodies can be seen also in the urine during
prolonged vomiting, severe diarrhea, anesthesia, severe liver damage,
high fat intake and low carbohydrate diet.
The excessive production and accumulation of ketone bodies may lead
to ketosis.
Its physiological effect is serious because acetoacetic acid and β-
hydroxybutyric acid contribute excess hydrogen ions to the blood,
resulting in acidosis - a condition that tends to lower the blood pH. If not
corrected in time this may result in death.
Another physiological effect of ketone accumulation concerns the
substance acetone and acetoacetic acid. Both have been found to be
toxic to brain tissue when present in increased amounts in the blood.
So this condition can result in permanent brain damage.
When ketones accumulate in the blood and urine, they do not occur in
equal concentrations. β-hydroxybutric acid is present in the greatest
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