Endocrine Abstracts

Aims: Studies have suggested that breath gases, including acetone, may be related to simultaneous blood glucose (BG) and blood ketone levels in adults with types 2 and 1 diabetes. We aimed to study these relationships in children and young people with type 1 diabetes to assess the efficacy of a simple breath test as a non-invasive means of diabetes monitoring.

Methods: Gases were collected in breath bags and measurements were compared with capillary BG and ketone levels taken at the same time on a single visit to a routine hospital clinic in 113 subjects (59 males, age 7 years 11 months–18 years 3 months) with type 1 diabetes. Gases were also collected at the same time as a capillary blood ketone level in five young people admitted as inpatients with poor BG control or in diabetic ketoacidosis, in order to assess the correlation at higher ketone levels for comparison.

Results: A significant relationship was found between blood β-hydroxybutyrate level and breath acetone (Spearman’s rank correlation ρ=0.364, P<0.0001) in the clinic measurements. These patients were well-controlled and this relationship was apparent over the low concentrations of the blood ketones seen (0–0.4 mmol/l). A weak positive relationship was found between blood glucose and breath acetone (ρ=0.16, P=0.1). Young people presenting in DKA or with poor BG control had elevated levels of both blood ketones and breath acetone, with the latter having increased in some cases to over 100 parts/million. However there was no direct correlation.

Conclusions: Single breath measurements of acetone do not provide a good measure of blood glucose levels in this cohort. However within the limited range of blood ketones observed in well-controlled patients in a clinic, breath acetone levels were found to increase with blood β-hydroxybutyrate levels. Young people being treated for DKA had very high levels of breath acetone, although the changing situation during treatment may mean that there is a time-lag between blood and breath. This might suggest a potential to develop breath gas analysis to provide an alternative to blood testing for ketone measurement, for example to assist with the diagnosis of type 1 diabetes or the prevention of diabetic ketoacidosis.