Evidence map›Paper›PMID 24561639›Full record

ArticleNeurotoxicology and teratology

Negative confounding by essential fatty acids in methylmercury neurotoxicity associations.

Anna L Choi, Ulla B Mogensen, Kristian S Bjerve, Frodi Debes, Pal Weihe, Philippe Grandjean, Esben Budtz-Jørgensen

Open access · greenAbstract read
In one paragraph

Article in Neurotoxicology and teratology. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 26 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
26citing papers in PubMed, 1 pooled it
6.8field-weighted citation impact, top 3% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

26 citing papers in PubMed, 1 synthesis or guideline pooled it, 66 citations in OpenAlex.

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  19. Managing mercury exposure in northern Canadian communities.CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne · 2016
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 4 institutions in 3 countries.

Anna L ChoiDepartment of Environmental Health, Harvard School of Public Health, Boston, MA, USA. Electronic address: achoi@hsph.harvard.edu.
Ulla B MogensenDepartment of Biostatistics, University of Copenhagen, Copenhagen, Denmark.
Kristian S BjerveDepartment of Medical Biochemistry, St. Olavs Hospital, Trondheim University Hospital, N-7021 Trondheim, Norway; Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
Frodi DebesFaroese Hospital System, Torshavn, Faroe Islands.
Pal WeiheFaroese Hospital System, Torshavn, Faroe Islands.
Philippe GrandjeanDepartment of Environmental Health, Harvard School of Public Health, Boston, MA, USA; Institute of Public Health, University of Southern Denmark, Odense, Denmark.
Esben Budtz-JørgensenDepartment of Biostatistics, University of Copenhagen, Copenhagen, Denmark.
University of Copenhagen · DKUniversity of the Faroe Islands · FOSt Olav's University Hospital · NOUniversity of Southern Denmark · DK

Funding

MERCURY-ASSOCIATED NEUROBEHAVIORAL DEFICIT IN CHILDRENU01ES009797 · NIEHS · HARVARD UNIVERSITY (SCH OF PUBLIC HLTH) · PI GRANDJEAN, PHILIPPE ADAM · 2000 to 2004
$2.1M
Mercury-Associated Neurobehavioral Deficit in ChildrenR01ES009797 · NIEHS · HARVARD SCHOOL OF PUBLIC HEALTH · PI GRANDJEAN, PHILIPPE ADAM · 2007 to 2011
$2.0M
Effects of perinatal endocrine disrupters in childrenR01ES011681 · NIEHS · HARVARD UNIVERSITY (SCH OF PUBLIC HLTH) · PI GRANDJEAN, PHILIPPE ADAM · 2001 to 2004
$1.3M
NIEHS NIH HHS ES009797NIEHS NIH HHS ES011681NIEHS NIH HHS R01 ES009797NIEHS NIH HHS R01 ES011681NIEHS NIH HHS U01 ES009797
6 · The paper itself

Abstract

backgroundMethylmercury, a worldwide contaminant of fish and seafood, can cause adverse effects on the developing nervous system. However, long-chain n-3 polyunsaturated fatty acids in seafood provide beneficial effects on brain development. Negative confounding will likely result in underestimation of both mercury toxicity and nutrient benefits unless mutual adjustment is included in the analysis.

methodsWe examined these associations in 176 Faroese children, in whom prenatal methylmercury exposure was assessed from mercury concentrations in cord blood and maternal hair. The relative concentrations of fatty acids were determined in cord serum phospholipids. Neuropsychological performance in verbal, motor, attention, spatial, and memory functions was assessed at 7 years of age. Multiple regression and structural equation models (SEMs) were carried out to determine the confounder-adjusted associations with methylmercury exposure.

resultsA short delay recall (in percent change) in the California Verbal Learning Test (CVLT) was associated with a doubling of cord blood methylmercury (-18.9, 95% confidence interval [CI]=-36.3, -1.51). The association became stronger after the inclusion of fatty acid concentrations in the analysis (-22.0, 95% confidence interval [CI]=-39.4, -4.62). In structural equation models, poorer memory function (corresponding to a lower score in the learning trials and short delay recall in CVLT) was associated with a doubling of prenatal exposure to methylmercury after the inclusion of fatty acid concentrations in the analysis (-1.94, 95% CI=-3.39, -0.49).

conclusionsAssociations between prenatal exposure to methylmercury and neurobehavioral deficits in memory function at school age were strengthened after fatty acid adjustment, thus suggesting that n-3 fatty acids need to be included in analysis of similar studies to avoid underestimation of the associations with methylmercury exposure.

Indexed as

Food ContaminationAttentionChildCohort StudiesDenmarkFatty Acids, EssentialFatty Acids, Omega-3FemaleFetal BloodHumansInfant, NewbornMaleMental RecallMethylmercury CompoundsNeuropsychological TestsNeurotoxinsFatty Acids, EssentialFatty Acids, Omega-3Methylmercury CompoundsNeurotoxinsMethylmercury compoundsNegative confoundingNeuropsychological measuresOmega-3 fatty acidsPrenatal exposure delayed effectsStructural equation modeling

Identifiers

PMID24561639
PMCPMC4051703
OpenAlexW2073676483

What OpenQuestion holds

Textmetadata
LicenceTDM
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.