Non-invasive breath test by residual gas analyzer-mass spectrometry: a new method for detection of pre-diabetes and type 2 diabetes

Background:

The pre-diabetes (PD) and type 2 diabetes (T2D) are diagnosed by means of oral glucose tolerance test (OGTT), glycosylated hemoglobin (HbA1c) test etc.

Aim:

These methods are invasive and need blood samples. The aim of the present study was to diagnose pre-diabetes and type 2 diabetes from breath analysis.

Materials and methods:

After administration of non-radioactive ¹³C-glucose (75 mg) along with 75 gm normal glucose, breath samples were collected at baseline and 0.5h intervals for upto 2h. The breath samples were analyzed by our designed simple residual gas analyzer mass spectrometer (RGA-S) to record the ion currents of different masses in the exhaled breaths.

Results:

From the ion-current measurements of several masses by RGA-MS technique, we found the least enrichment of glucose derived breath ¹³CO₂/¹²CO₂ isotope ratios (45 and 44 masses), expressed as δ_DOB ¹³C‰, for type 2 diabetes followed by pre-diabetes and controls. The optimal diagnostic cut-off points were determined to be δ_DOB ¹³C‰= 28.32‰ and 19.32‰ for screening individuals with control vs. pre-diabetes and pre-diabetes vs. type 2 diabetes respectively.

Conclusion:

Our observations suggest that a simple RGA-MS may serve as an alternative non-invasive point-of-care diagnostic tool for routine clinical practices as well as for large-scale diabetes screening purposes in real-time.