Quantitative measurement of ketone bodies in urine using reflectometry.
BACKGROUND
Recently, automated urine test strip readers became available that can report quantitative data. We explored the possibility of measuring all ketone bodies (acetone, acetoacetate, 3-hydroxybutyrate) in urine with these test strips. Monitoring urinary ketone concentrations could offer the advantages of measuring higher values (due to the low renal thresholds) and being less sensitive to fluctuations.


METHODS
We evaluated URISYS 2400 (Roche) quantitative reflectance data for the ketone reflectance field and compared it with biochemical data from urine samples. Using an easy sample pre-treatment with 3-hydroxybutyrate dehydrogenase, we were able to assay 3-hydroxybutyrate as well, which normally does not react on urine test strips.


RESULTS
Within- and between-run reproducibility of the reflectance signal for high- and low-concentration urine pools was 11.0-3.6% and 11.0-5.8% for aceto-acetate, 8.2-9.2% and 10.4-16.1% for acetone, and 5.1-3.0% and 5.6-3.5% for 3-hydroxybutyrate, respectively. The lower limit of detection for acetoacetate was 0.13 mmol/L (CV=3.6%). Fair agreement was obtained between test strip data for ketones andcolorimetrically determined acetoacetate values (r=0.90).


CONCLUSIONS
In urine test strip analysis, quantitative ketone reflectance data allow a simple and fast analysis, offering affordable screening for the detection of ketone body production in diabetes, especially in emergency settings.
Penders
Joris
J
Department of Clinical Chemistry, University Hospital Ghent, Gent, Belgium.
Fiers
Tom
T
Giri
Mimi
M
Wuyts
Birgitte
B
Ysewyn
Larissa
L
Delanghe
Joris R
JR
D020155:3-Hydroxybutyric Acid / Q000652:urine; D000090:Acetoacetates / Q000652:urine; D000096:Acetone / Q000652:urine; D000328:Adult; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000652:urine*; D005260:Female; D006801:Humans; D007332:Insulin Infusion Systems; D007657:Ketone Bodies / Q000652:urine*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D016482:Urinalysis / Q000379:methods* / Q000706:statistics & numerical data
D000090:Acetoacetates; D007657:Ketone Bodies; D000096:Acetone; C016635:acetoacetic acid; D020155:3-Hydroxybutyric Acid