Point-of-Care Capillary Blood Ketone Measurements and the Prediction of Future Ketoacidosis Risk in Type 1 Diabetes.

Objective: Rather than during illness while diabetic ketoacidosis (DKA) is developing, we aimed to determine if levels of routine point-of-care capillary blood ketones could predict future DKA.

Research design and methods: We examined previously collected data from placebo-assigned participants in an adjunct-to-insulin medication trial program that included measurement of fasted capillary blood ketone levels twice per week in a 2-month baseline period. The outcome was 6- to 12-month trial-adjudicated DKA.

Results: DKA events occurred in 12 of 484 participants at a median of 105 (interquartile range 43, 199) days. Maximum ketone levels were higher in patient cases compared with in control patients (0.8 [0.6, 1.2] vs. 0.3 [0.2, 0.7] mmol/L; P = 0.002), with a nonparametric area under the receiver operating characteristic curve of 0.77 (95% CI 0.66-0.88). Ketone levels ≥0.8 mmol/L had a sensitivity of 64%, a specificity of 78%, and positive and negative likelihood ratios of 2.9 and 0.5, respectively.

Conclusions: This proof of concept that routine capillary ketone surveillance can identify individuals at high risk of future DKA implies a role for future technologies including continuous ketone monitoring.