Author: Barregard L, Trachtenberg F, McKinlay S.
Source: Environ Health Perspect.
Year: 2008
Comment:
While this study does not fully establish a connection between microalbuminuria and children's dental amalgam, it encourages more research about the subject.
Abstract / Excerpt:
“BACKGROUND:
Mercury is nephrotoxic and dental amalgam is a source of mercury exposure.
METHODS:
Children 6-10 years of age (n = 534) with two or more posterior teeth with caries but no prior amalgam restorations, were randomized to one of two treatments–amalgam or resin composite (white fillings)–used for caries treatment during 5 years of follow-up. The primary outcome was change in IQ, but important secondary outcomes were effects on markers of glomerular and tubular kidney function: urinary excretion of albumin, alpha-1-microglobulin (A1M), gamma-glutamyl transpeptidase (gamma-GT), and N-acetyl-beta-d-glucosaminidase (NAG). These markers were measured on several occasions during the trial, together with urinary mercury and covariates. We evaluated the results using repeated-measures analyses.
RESULTS:
There were no significant differences between treatment groups in average levels of renal biomarkers, nor significant effects of number of dental amalgams on these markers. There was, however, a significantly increased prevalence of microalbuminuria (MA) among children in the amalgam group in years 3-5 (adjusted odds ratio 1.8; 95% confidence interval, 1.1-2.9). Most of these cases are likely to be temporary MA, but 10 children in the amalgam group had MA in both years 3 and 5, versus 2 children in the composite group (p = 0.04). There were no differences in the occurrence of high levels of renal tubular markers (A1M, gamma-GT, or NAG).
CONCLUSIONS:
The increase in MA may be a random finding, but should be tested further. The results did not support recent findings in an observational study of an effect of low-level mercury on tubular biomarkers in children.”
Citation:
Barregard L, Trachtenberg F,McKinlay S. Renal effects of dental amalgam in children: the New England children's amalgam trial. Environ Health Perspect. 2008; 116(3):394–9.