Continuous Monitoring of Breath Acetone, Blood Glucose and Blood Ketone in 20 Type 1 Diabetic Outpatients Over 30 Days

Although breath acetone (BA) has been identified as a breath biomarker for some abnormal metabolic status, such as diabetic ketoacidosis, diabetes under insulin treatments, on a ketogenic diet, heart congestion failure, and post intense exercises, many intra-individual biological parameters also influence the breath acetone concentration. Therefore, it would be insightful to study longitudinal variations of breath acetone concentration in given individuals that have no baseline effect resulting from individual physiological heterogeneity. We carried out a daily-based continuous monitoring of BA, blood glucose (BG), and blood ketone (BK) in 20 type 1 diabetic (T1D) outpatients and 5 healthy volunteers over a period of 30 days. 600 breath samples from the T1D outpatients and the healthy subjects were collected and tested. BA was measured using a cavity ringdown BA analyzer. Simultaneous BG and BK levels were also measured using a standard BG/ketone meter. Our findings include: (1) The T1D subjects have elevated mean BA concentrations as compared to the controls. (2) There exists a positive correlation (R=0.57, P<0.05) between the individual mean BA concentration and the individual mean BK in the 20 T1D outpatients. (3) Some adverse or abnormal physiological conditions such as diabetic ketoacidosis, low body mass index or a special daily activity (e.g., exercises) can be identified via an abnormal BA concentration. This study suggests that continuous monitoring BA is useful in monitoring some abnormal physiological status such as T1D outpatients with very high BG or ketone bodies.