These are three in number, namely, acetoacetate (AcAc), 3-beta-hydroxybutyrate (3HB) and the third,least abundant, acetone.
Ketones are always present in the blood in some amount and their levels increase during fasting and prolonged exercise.
Diabetes is the most common pathological cause leading to elevated blood ketones. In diabetic ketoacidosis (DKA), high levels of ketones are produced in response to low insulin levels and high levels of counter-regulatory hormones.
Acyl CoA is produced from break down of fatty acid, when cannot enter the Citric Acid Cycle (Cycle is down) due to lack of insulin sensitivity, get converted & accumulate in the form of ketone bodies.
In acute DKA, the ketone body ratio (3HB:AcAc) rises from normal (1:1) to as high as 10:1. In response to insulin therapy, 3HB levels commonly decrease long before AcAc levels.
The frequently employed nitroprusside test only detects AcAc in blood and urine. This test is inconvenient, does not assess the best indicator of ketone body levels (3HB), provides only a semiquantitative assessment of ketone levels and is associated with false-positive results.
Recently, inexpensive quantitative tests of 3HB levels have become available for use with small blood samples.
These tests offer new options for monitoring and treating diabetes and other states characterized by the abnormal metabolism of ketone bodies.