Methodological considerations with the use of urine samples for assessment of mercury excretion and markers of renal damage.
OBJECTIVE
To provide recommendations for design and analysis of studies using urine specimens to evaluate renal function or mercury excretion in children.


METHODS
An analysis of mercury, albumin, γ-glutamyl transpeptidase (γ-GT) and N-acetyl-β-D-glucosaminidase (NAG) concentrations was carried out.


RESULTS
Mercury concentration and creatinine-corrected renal markers were higher in daytime compared with overnight samples. Excretion rates increased with urinary flow rate. γ-GT and NAG concentrations decreased with storage time at -20°C. Differences by age, sex and race were noted.


CONCLUSIONS
We recommend use of these creatinine-corrected markers and collection of timed overnight urine samples, stored at -70°C, with control for urinary flow rate, age, sex and race in statistical models.
Trachtenberg
Felicia
F
New England Research Institutes, Watertown, MA 02472, USA. ftrachtenberg@neriscience.com
Barregard
Lars
L
Maserejian
Nancy
N
McKinlay
Sonja
S
D000704:Analysis of Variance; D002648:Child; D006801:Humans; D007668:Kidney / Q000502:physiology*; D007677:Kidney Function Tests; D008628:Mercury / Q000652:urine*; D013048:Specimen Handling
D008628:Mercury