# Discrepancy of Beta-Hydroxybutyrate Measurements between a Blood Meter and GC-MS Methods in Healthy Humans

## TL;DR

This study compares blood meters and GC-MS for measuring ketones in blood and finds that blood meters underestimate ketone levels compared to GC-MS.

## Contribution

The study reveals that blood meters fail to detect L-β-hydroxybutyrate, leading to underestimation of ketone levels compared to GC-MS.

## Key findings

- Blood meters showed significantly lower β-hydroxybutyrate levels than GC-MS at baseline and after KS consumption.
- The blood meter's inability to detect L-β-hydroxybutyrate suggests a need for improved ketone measurement devices.

## Abstract

Ketone salt (KS) supplementation induces temporary nutritional ketosis to achieve potential exercise performance and health benefits. Racemic KS includes both D/L isomers of β-hydroxybutyrate, yet commercially available measurement devices (i.e., blood meters) only measure the D variant. The aim of this study was to investigate the efficacy of a blood meter to measure serum β-hydroxybutyrate in comparison with gas chromatography–mass spectrometry (GC-MS) before and 30 min after consuming a placebo or racemic KS. In this triple-blinded cross-over study, 16 healthy adults were administered either a placebo or KS drink, and the circulating β-hydroxybutyrate concentration was measured at baseline (PRE) and 30 min following consumption (POST) using a blood ketone meter and by GC-MS. Compared to the placebo, both GC-MS and the blood meter obtained significantly greater β-hydroxybutyrate levels from PRE to POST time-points after consuming KS. Additionally, GC-MS results showed significantly higher levels of β-hydroxybutyrate with both the placebo and KS at PRE and POST time-points, as compared to the blood meter. These results indicate that (1) even in the absence of KS, the blood meter yields significantly lower β-hydroxybutyrate values than GC-MS, and (2) the inability of the blood meter to measure L-β-hydroxybutyrate values POST KS warrants the further development of publicly available ketone measurement apparatuses.