What is the significance of tracing ketones in Urinalysis (UA)?

From the Guidelines

Trace ketones in a urinalysis (UA) should prompt further evaluation, especially in individuals with diabetes, to rule out diabetic ketoacidosis (DKA), as recommended by the most recent guidelines 1. The presence of ketones in urine indicates that the body is breaking down fat for energy instead of using glucose, which can be a sign of insufficient insulin or carbohydrate intake. According to the latest guidelines, individuals prone to ketosis, such as those with type 1 diabetes or a history of DKA, should measure ketones in urine or blood if they have unexplained hyperglycemia or symptoms of ketosis 1.

Key Considerations

• Patients with trace ketones should increase their fluid intake to 2-3 liters per day and consider consuming some carbohydrates if they've been following a low-carb diet.
• If the patient has diabetes, they should check their blood glucose levels more frequently and follow their sick-day management plan if applicable, as recommended by the American Diabetes Association 1.
• For non-diabetic patients, trace ketones may result from fasting, intense exercise, low-carbohydrate diets, or pregnancy, but if accompanied by symptoms like persistent vomiting, extreme thirst, confusion, or abdominal pain, medical attention should be sought immediately.

Clinical Significance

Ketones appear in urine when the body lacks sufficient insulin or carbohydrates, causing it to metabolize fat and produce ketone bodies (acetoacetate, beta-hydroxybutyrate, and acetone) as an alternative energy source. While trace amounts are generally not concerning, persistent or increasing ketone levels require medical evaluation to prevent complications such as DKA, as highlighted in the recent guidelines 1.

From the FDA Drug Label

If instructed by your doctor, test your ketones and report the results to your doctor.

Trace ketones in UA: If instructed by the doctor, patients should test their ketones and report the results. This is usually done in cases of illness, especially with nausea and vomiting, as it may cause insulin requirements to change. 2

From the Research

Trace Ketones in Urine

• Ketones in urine can be an indicator of diabetic ketoacidosis (DKA), a life-threatening complication of type 1 and type 2 diabetes 3
• The urine ketone dip test (UKDT) is a highly sensitive test for the detection of ketonemia in patients with DKA and diabetic ketosis (DK) 4
• The sensitivity of the UKDT for the detection of ketonemia in all patients with DKA or DK was 97% (95% CI, 94% to 99%) 4
• Urinary acetoacetate or capillary beta-hydroxybutyrate can be used for the diagnosis of ketoacidosis in the Emergency Department setting 5
• Ketonuria equal to or less than one cross or a 3-beta-hydroxybutyrate value lower than 3 mmol/l enabled ketoacidosis to be excluded (negative predictive value 100%) 5

Methods of Ketone Measurement

• There are multiple methods available for ketone measurement, including urine ketone assessment and capillary blood ketone measurement 6
• The development of point-of-care devices that can reliably measure the capillary blood ketone β-hydroxybutyrate (BOHB) has widened the spectrum of applications of ketone measurement 6
• The imprecision of capillary blood ketone measures at higher values and the lack of availability of routine laboratory-based assays for BOHB prompt further discussion on the role of capillary blood ketone assessment in ketoacidosis 6

Diagnosis and Management of DKA

• A diagnosis of DKA is confirmed when all of the three criteria are present - 'D', either elevated blood glucose levels or a family history of diabetes mellitus; 'K', the presence of high urinary or blood ketoacids; and 'A', a high anion gap metabolic acidosis 7
• Early diagnosis and management are paramount to improve patient outcomes, and the mainstays of treatment include restoration of circulating volume, insulin therapy, electrolyte replacement and treatment of any underlying precipitating event 7