The evaluation of the repeatability of the ¹³C-ketoisocaproate breath test for assessing hepatic mitochondrial function

ABSTRACT

The ¹³C-ketoisocaproate (¹³C-KICA) breath test (BT) has been recently proposed as a non-invasive test for assessing hepatic mitochondrial function. Results of the ¹³C-KICA BT can be expressed as different parameters. However, the best parameter for expressing the ¹³C-KICA BT result is uncertain which hinders use of the BT in routine clinical practice. We have investigated the repeatability of different parameters of ¹³C-KICA BT. Thirteen healthy adult subjects (5 men and 8 women) underwent a ¹³C-KICA BT on two occasions separated by a gap of approximately 30 days. There were no significant differences between the repeated measurements for all the test parameters over 30 days. Furthermore, the Bland Altman statistics showed no fixed or proportional bias for any of the test parameters. The cumulative ¹³C-dose enrichment over 60 min had the lowest within-subject variability of 12% compared to all other test parameters. The cumulative ¹³C-dose enrichment over 60 min could be a very useful parameter for the ¹³C-KICA BT to detect impaired hepatic mitochondrial function in patients with chronic liver diseases.

KEYWORDS:

• Breath test
• carbon-13
• ¹³C-ketoisocaproate test
• diagnostic application in human medicine
• in vivo
• liver function
• men
• organ function test

Acknowledgements

The authors will like to thank Sanchia Triggs, Gemma Rood and Jennifer Hedges without whose help this study would not have been possible and Lucinda England for research governance administration. Finally, the authors also would like to thank all the study volunteers.

Disclosure statement

No potential conflict of interest has been reported by the authors.

Additional information

Funding

This study was supported and funded by the National Institute for Health Research, Southampton Biomedical Research Centre, Southampton, United Kingdom and all authors were supported in part by the National Institute for Health Research, Southampton Biomedical Research Centre, Southampton.