The storage stability and concentration of acetoacetate differs between blood fractions.
BACKGROUND
Plasma concentrations of 3-hydroxybutyrate (3HB) are measured more often than acetoacetate (AcAc) which may be due to the reported storage instability of AcAc. The aims of the study were to compare the storage stability of AcAc in different blood fractions over time (90days) when stored at -80°C and to determine the postprandial concentration of AcAc in whole blood, plasma and red blood cells.


METHODS
Blood was collected from fasting subjects (n=5): whole blood, plasma and red blood cells were isolated and deproteinised in perchloric acid, and supernatants were stored at -80°C until analysis. Postprandial concentrations of AcAc in whole blood, plasma and red blood cells were determined at regular intervals over 420min, after subjects (n=23) had consumed a mixed test meal.


RESULTS
Storing deproteinised plasma at -80°C resulted in no significant change in AcAc concentration over 60days. In contrast, whole blood AcAc concentrations significantly decreased by 51% (p=0.018) within 30days. The concentration of AcAc in fasting and postprandial plasma was notably higher than that of whole blood and red blood cells.


CONCLUSIONS
Our data demonstrates that plasma for AcAc analysis can be stored for longer than previously suggested provided that plasma is deproteinised and stored at -80°C.
Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford OX3 7LE, UK.
Catriona A
CA
McNeil
Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford OX3 7LE, UK.
Camilla
C
Pramfalk
Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford OX3 7LE, UK.
Sandy M
SM
Humphreys
Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford OX3 7LE, UK. Electronic address: leanne.hodson@ocdem.ox.ac.uk.
Leanne
L
Hodson
D020155:3-Hydroxybutyric Acid / Q000097:blood; D000090:Acetoacetates / Q000097:blood*; D001774:Blood Chemical Analysis / Q000379:methods*; D003080:Cold Temperature; D004912:Erythrocytes / Q000737:chemistry; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D010949:Plasma / Q000737:chemistry; D019518:Postprandial Period; D013048:Specimen Handling / Q000379:methods*; D013997:Time Factors
D000090:Acetoacetates; D005230:Fatty Acids, Nonesterified; D007328:Insulin; C016635:acetoacetic acid; D020155:3-Hydroxybutyric Acid
Acetoacetate; Blood fractions; Deproteinised; Storage stability