Diabetes & The Body

Ketonuria In Diabetes

Ketosis and ketonuria occur in:

• Metabolic abnormalities such as diabetes, or glycogen storage disease
• Dietary conditions such as starvation, fasting, high protein, or low carbohydrate diets, prolonged vomiting, and anorexia
• Conditions in which metabolism is increased, such as hyperthyroidism, fever, pregnancy or lactation

Ketones are end products of fatty acid metabolism. It is usually formed in the liver and is completely metabolized so that only negligible amounts appear in the urine. But when there is a lack of sufficient carbohydrates in the body, fat becomes the predominant body fuel instead of carbohydrates. This results in the production of excessive amounts of ketones. A finding of ketones in the urine indicates that the body is using fat as the major source of energy.

It has been observed that 3 ketone bodies appear in the urine when fats are burned. They include acetone, acetoacetic acid and beta-hydroxybutyric acid. As is the case with glucose test, acetone can be tested by a dipstick or by a tablet. The results are generally expressed as small, moderate, or large amounts of acetone. The guidelines say that a small amount is when the reading is under 20mg/dl; a moderate amount is a value of 30-40mg/dl, and a finding of 80mg/dl or greater is reported as a large amount.

In acutely ill patients, presurgical patients, and pregnant women doctors make it a point to do screening for ketonuria with enough frequency so that the diagnosis is not missed. Typically, doctors are of the opinion that any diabetic patient who has elevated levels of blood and urine glucose should be tested for ketonuria. Similarly, ketonuria screening should be done when a patient switches from insulin to oral hypoglycemic agents.

According to doctors, the development of ketonuria in a span of 24 hours after insulin withdrawal generally suggests a poor response to the oral hypoglycemic agents.

Urine ketones appear before there is any significant increase in blood ketones, and hence urine ketone measurement is particularly helpful. It has to be noted that during pregnancy, early detection of ketonuria is vital, as studies have associated ketoacidosis with intrauterine death.

In persons without diabetes, ketonuria is generally observed during acute illness or severe stress. It has been observed that 15% of hospitalized patients may have ketonuria, even though they do not have diabetes. In a diabetic patient, ketone bodies in the urine suggest that the patient is not adequately controlled. The immediate response of the healthcare professional should focus mainly on adjustments of medication, diet, or both. In the nondiabetic patient, ketonuria reflects a reduced carbohydrate metabolism and excessive fat metabolism. The identification of the underlying cause of such a phenomenon may need further investigations and thorough analysis of the metabolic process in the patient.