What causes elevated ketone levels in urine?

From the Guidelines

Elevated ketone levels in urine are primarily caused by the body breaking down fat for energy instead of carbohydrates, often due to insufficient insulin, and can be caused by uncontrolled diabetes, prolonged fasting or starvation, high-protein low-carbohydrate diets, excessive alcohol consumption, and intense physical exercise. This occurs when there is insufficient insulin to help cells use glucose, forcing the body to use fat as an alternative fuel source. Common causes include:

• Uncontrolled diabetes (particularly type 1) 1
• Prolonged fasting or starvation
• High-protein low-carbohydrate diets
• Excessive alcohol consumption
• Intense physical exercise During pregnancy, morning sickness with frequent vomiting can also lead to ketonuria 1. Certain metabolic disorders and conditions causing persistent vomiting or diarrhea may result in elevated ketones as well. For diabetic patients, ketone testing is important when blood glucose levels exceed 240 mg/dL or during illness 1.

Key Considerations

• Ketone testing is crucial for individuals prone to ketosis, such as those with type 1 diabetes or a history of diabetic ketoacidosis (DKA), especially when they have unexplained hyperglycemia or symptoms of ketosis 1.
• The presence of ketones may indicate impending or established ketoacidosis, a condition that requires immediate medical attention 1.
• Treatment depends on the underlying cause but typically involves addressing the primary condition, ensuring adequate carbohydrate intake, proper insulin management for diabetics, and maintaining hydration. Severely elevated ketones can lead to diabetic ketoacidosis, a medical emergency requiring immediate attention 1.

From the FDA Drug Label

Inadequate dosing or discontinuation of treatment may lead to hyperglycemia and, in patients with type 1 diabetes, diabetic ketoacidosis... High amounts of sugar and ketones in your urine

Elevated ketone levels in urine can be caused by:

• Inadequate dosing of insulin
• Discontinuation of insulin treatment
• Hyperglycemia (high blood sugar)
• Diabetic ketoacidosis (a serious complication of diabetes) 2
• Untreated high blood sugar (hyperglycemia) 2

From the Research

Causes of Elevated Ketone Levels in Urine

Elevated ketone levels in urine can be caused by several factors, including:

• Insulin deficiency, which can lead to diabetic ketoacidosis (DKA) 3, 4, 5
• Low carbohydrate availability, such as during fasting or prolonged exercise 4
• Type 1 diabetes, where the body is unable to produce enough insulin 3, 6
• Dehydration, which can occur due to excessive urine production and insufficient fluid intake 3
• Certain medical conditions, such as hyperosmolar nonketotic coma and alcoholic ketoacidosis 7

Diabetic Ketoacidosis (DKA)

DKA is a serious complication of diabetes that can cause elevated ketone levels in urine. It is characterized by:

• High blood glucose levels
• Insulin deficiency
• Dehydration
• Electrolyte imbalance
• Acidosis 3, 7, 5

Measurement of Ketones

Ketones can be measured in various bodily fluids, including:

• Urine: using point-of-care tests that measure acetoacetate and beta-hydroxybutyrate 4
• Blood: using point-of-care tests that measure beta-hydroxybutyrate 4
• Breath: using devices that measure acetone, although currently no device is FDA-cleared for this purpose 4
• Interstitial fluid: using new technology that measures beta-hydroxybutyrate 4

Other Factors

Other factors that can contribute to elevated ketone levels in urine include:

• Poorly controlled diabetes 6
• Inadequate insulin therapy 6
• Certain medications, such as SGLT2 inhibitors and immune checkpoint inhibitors 4