Over 90% of diabetic patients have
Type 2 diabetes. Although an elevated mean breath
acetone concentration has been found to exist in
Type 1 diabetes (T1D), information on breath
acetone in
Type 2 diabetes (T2D) has yet to be obtained. In this study, we first used gas chromatography-mass spectrometry (GC-MS) to validate a ringdown breath-
acetone analyzer based on the cavity-ringdown-spectroscopy technique, through comparing breath
acetone concentrations in the range 0.5-2.5 ppm measured using both methods. The linear fitting of R = 0.99 suggests that the
acetone concentrations obtained using both methods are consistent with a largest standard deviation of ±0.4 ppm in the lowest concentration of the range. Next, 620 breath samples from 149 T2D patients and 42 healthy subjects were collected and tested using the breath analyzer. Four breath samples were taken from each subject under each of four different conditions: fasting, 2 h post-breakfast, 2 h post-lunch, and 2 h post-dinner. Simultaneous
blood glucose levels were also measured using a standard diabetic-management
blood-glucose meter. For the 149 T2D subjects, their exhaled breath
acetone concentrations ranged from 0.1 to 19.8 ppm; four different ranges of breath
acetone concentration, 0.1-19.8, 0.1-7.1, 0.1-6.3, and 0.1-9.5 ppm, were obtained for the subjects under the four different conditions, respectively. For the 42 healthy subjects, their breath
acetone concentration ranged from 0.1 to 2.6 ppm; four different ranges of breath
acetone concentration, 0.3-2.6, 0.1-2.6, 0.1-1.7, and 0.3-1.6 ppm, were obtained for the four different conditions. The mean breath
acetone concentration of the 149 T2D subjects was determined to be 1.5 ± 1.5 ppm, which was 1.5 times that of 1.0 ± 0.6 ppm for the 42 healthy subjects. No correlation was found between the breath
acetone concentration and the
blood glucose level of the T2D subjects and the healthy volunteers. This study using a relatively large number of subjects provides new data regarding breath
acetone in diabetes (T1D and T2D) and suggests that an elevated mean breath
acetone concentration also exists in T2D.