Lactate determination in exercise testing using an electrochemical analyser: with or without blood lysis?

Area of Science:

• Exercise Physiology
• Biomedical Engineering
• Analytical Chemistry

Background:

• Lactate measurement is crucial in exercise testing.
• Discrepancies exist between spectrophotometric and electrochemical lactate assays.
• Practical application of electrochemical lactate analyzers requires validation.

Purpose of the Study:

• Compare spectrophotometric and electrochemical lactate measurement methods.
• Evaluate lactate thresholds derived from lysed and non-lysed blood samples.
• Assess the utility of electrochemical analyzers in exercise testing.

Main Methods:

• Bland-Altman statistical analysis was employed.
• Progressive exercise tests to exhaustion were conducted.
• Lactate concentrations were measured using spectrophotometry and electrochemistry on lysed and non-lysed samples.
• Lactate thresholds were derived using a log-log transform technique.

Main Results:

• Spectrophotometric and electrochemical methods showed close agreement for lysed blood lactate.
• Electrochemical measurements of non-lysed blood yielded systematically lower lactate values.
• Lactate thresholds derived from lysed spectrophotometric and electrochemical measurements were not significantly different.
• Lactate thresholds derived from lysed spectrophotometric and non-lysed electrochemical measurements were also not significantly different.

Conclusions:

• Electrochemical lactate analyzers are suitable for lactate threshold determination.
• Sample lysis is not necessary when using electrochemical analyzers with the log-log transform technique.
• This validates a simpler approach for exercise lactate threshold assessment.