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Associations of Prenatal Mercury Exposure and PUFA with Telomere Length and mtDNA Copy Number in 7-Year-Old Children in the Seychelles Child Development Nutrition Cohort 2

Stajnko, Anja LU ; Pineda, Daniela LU orcid ; Klus, Jonathan K ; Love, Tanzy M ; Thurston, Sally W ; Mulhern, Maria S ; Strain, J J ; McSorley, Emeir M ; Myers, Gary J and Watson, Gene E , et al. (2025) In Environmental Health Perspectives 133(2).
Abstract

BACKGROUND: Telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) variations are linked to age-related diseases and are associated with environmental exposure and nutritional status. Limited data, however, exist on the associations with mercury exposure, particularly early in life.

OBJECTIVE: We examined the association between prenatal mercury (Hg) exposure and TL and mtDNAcn in 1,145 Seychelles children, characterized by a fish-rich diet.

METHODS: Total mercury (THg) was determined in maternal hair at delivery and cord blood. TL and mtDNAcn were determined relative to a single-copy hemoglobin beta gene in the saliva of 7-y-old children. Linear regression models assessed associations between THg and relative TL... (More)

BACKGROUND: Telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) variations are linked to age-related diseases and are associated with environmental exposure and nutritional status. Limited data, however, exist on the associations with mercury exposure, particularly early in life.

OBJECTIVE: We examined the association between prenatal mercury (Hg) exposure and TL and mtDNAcn in 1,145 Seychelles children, characterized by a fish-rich diet.

METHODS: Total mercury (THg) was determined in maternal hair at delivery and cord blood. TL and mtDNAcn were determined relative to a single-copy hemoglobin beta gene in the saliva of 7-y-old children. Linear regression models assessed associations between THg and relative TL (rTL) and relative mtDNAcn (rmtDNAcn) while controlling for maternal and cord serum polyunsaturated fatty acid (PUFA) status and sociodemographic factors. Interactions between THg and child sex, PUFA, and telomerase genotypes were evaluated for rTL and rmtDNAcn.

RESULTS: Higher THg concentrations in maternal hair and cord blood were associated with longer rTL [


β
=
0.009

; 95% confidence interval (CI): 0.002, 0.016 and


β
=
0.002

; 95% CI: 0.001, 0.003, respectively], irrespective of sex, PUFA, or telomerase genotypes. Maternal serum n-6 PUFA and n-6/n-3 ratio were associated with shorter [


β
=
-
0.24

; 95% CI:


-
0.33

,


-
0.15

and


β
=
-
0.032

; 95% CI:


-
0.048

,


-
0.016

, respectively] and


n
-
3

PUFA with longer (


β
=
0.34

; 95% CI: 0.032, 0.65) rTL. Cord blood n-6 PUFA was associated with longer (


β
=
0.15

; 95% CI: 0.050, 0.26) rTL. Further analyses revealed linoleic acid in maternal blood and arachidonic acid in cord blood as the main drivers of the n-6 PUFA associations. No associations were observed for THg and PUFA with rmtDNAcn.

DISCUSSION: Our results indicate that prenatal THg exposure and PUFA status are associated with rTL later in childhood, although not consistently aligned with our initial hypothesis. Subsequent research is needed to confirm this finding, further evaluate the potential confounding of fish intake, and investigate the underlying molecular mechanisms to verify the use of rTL as a true biomarker of THg exposure. https://doi.org/10.1289/EHP14776.

(Less)
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type
Contribution to journal
publication status
published
subject
keywords
Humans, Female, Seychelles, Child, Pregnancy, Mercury/blood, Telomere/drug effects, Prenatal Exposure Delayed Effects, Fatty Acids, Unsaturated, Male, DNA, Mitochondrial, DNA Copy Number Variations, Hair/chemistry, Cohort Studies, Fetal Blood/chemistry, Environmental Pollutants/blood, Environmental Exposure/statistics & numerical data
in
Environmental Health Perspectives
volume
133
issue
2
article number
027002
publisher
National Institute of Environmental Health Sciences
external identifiers
  • scopus:85218027999
  • pmid:39903555
ISSN
1552-9924
DOI
10.1289/EHP14776
language
English
LU publication?
yes
id
79c338a4-46d0-4c69-9b8e-bb702dac2213
date added to LUP
2025-02-11 15:38:47
date last changed
2025-07-26 12:10:05
@article{79c338a4-46d0-4c69-9b8e-bb702dac2213,
  abstract     = {{<p>BACKGROUND: Telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) variations are linked to age-related diseases and are associated with environmental exposure and nutritional status. Limited data, however, exist on the associations with mercury exposure, particularly early in life.</p><p>OBJECTIVE: We examined the association between prenatal mercury (Hg) exposure and TL and mtDNAcn in 1,145 Seychelles children, characterized by a fish-rich diet.</p><p>METHODS: Total mercury (THg) was determined in maternal hair at delivery and cord blood. TL and mtDNAcn were determined relative to a single-copy hemoglobin beta gene in the saliva of 7-y-old children. Linear regression models assessed associations between THg and relative TL (rTL) and relative mtDNAcn (rmtDNAcn) while controlling for maternal and cord serum polyunsaturated fatty acid (PUFA) status and sociodemographic factors. Interactions between THg and child sex, PUFA, and telomerase genotypes were evaluated for rTL and rmtDNAcn.</p><p>RESULTS: Higher THg concentrations in maternal hair and cord blood were associated with longer rTL [<br>
 <br>
 <br>
 β<br>
 =<br>
 0.009<br>
 <br>
 ; 95% confidence interval (CI): 0.002, 0.016 and <br>
 <br>
 <br>
 β<br>
 =<br>
 0.002<br>
 <br>
 ; 95% CI: 0.001, 0.003, respectively], irrespective of sex, PUFA, or telomerase genotypes. Maternal serum n-6 PUFA and n-6/n-3 ratio were associated with shorter [<br>
 <br>
 <br>
 β<br>
 =<br>
 -<br>
 0.24<br>
 <br>
 ; 95% CI: <br>
 <br>
 <br>
 -<br>
 0.33<br>
 <br>
 , <br>
 <br>
 <br>
 -<br>
 0.15<br>
 <br>
 and <br>
 <br>
 <br>
 β<br>
 =<br>
 -<br>
 0.032<br>
 <br>
 ; 95% CI: <br>
 <br>
 <br>
 -<br>
 0.048<br>
 <br>
 , <br>
 <br>
 <br>
 -<br>
 0.016<br>
 <br>
 , respectively] and<br>
 <br>
 <br>
 n<br>
 -<br>
 3<br>
 <br>
 PUFA with longer (<br>
 <br>
 <br>
 β<br>
 =<br>
 0.34<br>
 <br>
 ; 95% CI: 0.032, 0.65) rTL. Cord blood n-6 PUFA was associated with longer (<br>
 <br>
 <br>
 β<br>
 =<br>
 0.15<br>
 <br>
 ; 95% CI: 0.050, 0.26) rTL. Further analyses revealed linoleic acid in maternal blood and arachidonic acid in cord blood as the main drivers of the n-6 PUFA associations. No associations were observed for THg and PUFA with rmtDNAcn.<br>
 </p><p>DISCUSSION: Our results indicate that prenatal THg exposure and PUFA status are associated with rTL later in childhood, although not consistently aligned with our initial hypothesis. Subsequent research is needed to confirm this finding, further evaluate the potential confounding of fish intake, and investigate the underlying molecular mechanisms to verify the use of rTL as a true biomarker of THg exposure. https://doi.org/10.1289/EHP14776.</p>}},
  author       = {{Stajnko, Anja and Pineda, Daniela and Klus, Jonathan K and Love, Tanzy M and Thurston, Sally W and Mulhern, Maria S and Strain, J J and McSorley, Emeir M and Myers, Gary J and Watson, Gene E and Shroff, Emelyn and Shamlaye, Conrad F and Yeates, Alison J and van Wijngaarden, Edwin and Broberg, Karin}},
  issn         = {{1552-9924}},
  keywords     = {{Humans; Female; Seychelles; Child; Pregnancy; Mercury/blood; Telomere/drug effects; Prenatal Exposure Delayed Effects; Fatty Acids, Unsaturated; Male; DNA, Mitochondrial; DNA Copy Number Variations; Hair/chemistry; Cohort Studies; Fetal Blood/chemistry; Environmental Pollutants/blood; Environmental Exposure/statistics & numerical data}},
  language     = {{eng}},
  number       = {{2}},
  publisher    = {{National Institute of Environmental Health Sciences}},
  series       = {{Environmental Health Perspectives}},
  title        = {{Associations of Prenatal Mercury Exposure and PUFA with Telomere Length and mtDNA Copy Number in 7-Year-Old Children in the Seychelles Child Development Nutrition Cohort 2}},
  url          = {{http://dx.doi.org/10.1289/EHP14776}},
  doi          = {{10.1289/EHP14776}},
  volume       = {{133}},
  year         = {{2025}},
}