Real-World Ketone Testing Patterns Among People Using FreeStyle Libre.

Area of Science:

• Endocrinology
• Diabetes Management
• Metabolic Monitoring

Background:

• Ketone testing is crucial for managing diabetes, especially during hyperglycemia.
• Current ketone testing behaviors and their relation to glucose control are not well understood.

Purpose of the Study:

• To describe ketone testing patterns in individuals using FreeStyle Libre (FSL) readers.
• To assess glucose control in relation to ketone testing in a real-world dataset.

Main Methods:

• Analysis of over 2.5 million historical glucose and ketone readings from FSL users.
• Categorization of ketone excursions and evaluation of glucose levels 24 hours pre- and post-ketone testing.
• Assessment of ketone test frequency and retesting within 72 hours.

Main Results:

• 92.4% of users never performed a ketone test; only 5% tested when glucose exceeded 250 mg/dL.
• Elevated ketones (≥3.0 mmol/L) were associated with higher preceding glucose levels.
• Testing for ketones ≥1.5 mmol/L was delayed by 5-8 hours after glucose exceeded 250 mg/dL; retesting was rare.

Conclusions:

• Most FSL users do not adhere to standard-of-care recommendations for ketone monitoring.
• Current ketone testing methods have limitations in adherence and timely retesting.
• Continuous ketone monitoring integration could improve adherence and address current testing limitations.