From the Guidelines
Urine ketones do not directly indicate dehydration, though they can sometimes appear alongside it. Ketones in urine primarily indicate that your body is breaking down fat for energy instead of using carbohydrates, which occurs during fasting, low-carbohydrate diets, uncontrolled diabetes, or intense exercise 1. Dehydration is better assessed through other clinical signs such as:
- Dark urine color
- Decreased urine output
- Increased urine concentration (specific gravity)
- Dry mouth
- Thirst
- Dizziness
- Skin turgor changes While ketosis can lead to increased urination and potentially contribute to dehydration, especially in diabetic ketoacidosis, the presence of ketones alone is not a reliable indicator of hydration status 1. If you're monitoring ketones for a medical condition like diabetes, it's essential to also track your hydration status separately through urine color, thirst levels, and other physical symptoms. For accurate assessment of either ketones or hydration status, consult with a healthcare provider who can evaluate multiple clinical parameters together, as recommended by guidelines for the management of diabetes mellitus 1.
From the Research
Urine Ketones and Dehydration
- Urine ketones are not a reliable indicator of dehydration, as they can be present in various conditions, including diabetic ketoacidosis (DKA) and low carbohydrate diets 2.
- A study found that urine specific gravity and ketones are inaccurate tests for dehydration, and their utility has not been established 3.
- Another study found that urine ketones (acetoacetate) and capillary blood ketones (3-beta-hydroxybutyrate) are correlated, but the correlation is poor for high values, making capillary blood ketones a more accurate test for confirming ketoacidosis 4.
- In patients with type 1 diabetes, blood ketone bodies are a better indicator of metabolic control compared to urine ketone detection, and are useful to predict the time required for blood ketone clearing 5.
- Dehydration can occur prior to the onset of significant ketoacidosis, especially in patients using human soluble insulin, due to the renal diuresis and subsequent dehydration caused by high blood glucose levels 6.
Key Findings
- Urine ketones are not a reliable indicator of dehydration.
- Capillary blood ketones are a more accurate test for confirming ketoacidosis.
- Blood ketone bodies are a better indicator of metabolic control compared to urine ketone detection.
- Dehydration can occur prior to the onset of significant ketoacidosis, especially in patients using human soluble insulin.
Relevant Studies
- 6: People with type 1 diabetes using short acting analogue insulins are less dehydrated than those using human soluble insulin prior to onset of diabetic ketoacidosis.
- 2: Update on Measuring Ketones.
- 5: Blood ketone bodies in patients with recent-onset type 1 diabetes (a multicenter study).
- 3: Urine specific gravity and other urinary indices: inaccurate tests for dehydration.
- 4: Correlation between urine ketones (acetoacetate) and capillary blood ketones (3-beta-hydroxybutyrate) in hyperglycaemic patients.