  A pilot study of exhaled volatile compounds and their correlation with blood
glucose levels in eight children with type 1 diabetes is reported. Five paired
blood and breath samples were obtained from each child over a 6 hour period.
The blood glucose concentration ranged from 41.4 to 435.6 mg/dL. Breath samples
were collected in Tedlar bags and immediately evacuated through thermal
desorption tubes packed with Carbopack B and C. The VOCs were later recovered
by thermal desorption and analysed using gas chromatography mass spectrometry.
The study identified 74 volatile compounds present in at least 10% of the
patient samples. Of these 74 volatiles 36 were found in all patient samples
tested. Further analysis of the 36 compounds found that none showed significant
overall correlation with blood glucose levels. Isoprene showed a weak negative
correlation with blood glucose levels. Acetone was found to have no correlation
with blood glucose levels for the patients studied. Some patients showed
significant individual correlation between the relative peak areas of certain
compounds and blood glucose levels. However, there was no consistent pattern
observed within these results across all 8 patients. Additional breath samples
were collected in Tedlar bags and analysed using SIFTMS for 3 of the patients
and a healthy control. The levels of 24 volatiles are reported and were found
to be generally consistent with previously reported SIFT-MS data. In agreement
with the GCMS data, no compounds exhibited a significant overall correlation
with blood glucose level.
