Associations of baroreflex sensitivity, heart rate variability, and initial orthostatic hypotension with prenatal and recent postnatal methylmercury exposure in the Seychelles Child Development Study at age 19 years.

Détails

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Etat: Public
Version: Final published version
ID Serval
serval:BIB_6291011D363A
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Associations of baroreflex sensitivity, heart rate variability, and initial orthostatic hypotension with prenatal and recent postnatal methylmercury exposure in the Seychelles Child Development Study at age 19 years.
Périodique
International Journal of Environmental Research and Public Health
Auteur(s)
Périard D., Beqiraj B., Hayoz D., Viswanathan B., Evans K., Thurston S.W., Davidson P.W., Myers G.J., Bovet P.
ISSN
1660-4601 (Electronic)
ISSN-L
1660-4601
Statut éditorial
Publié
Date de publication
2015
Peer-reviewed
Oui
Volume
12
Numéro
3
Pages
3395-3405
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
Publication Status: epublish
Résumé
BACKGROUND: A few studies have suggested an association between prenatal exposure to methylmercury and decreased heart rate variability (HRV) related to autonomic heart function, but no study has examined this association using baroreflex sensitivity (BRS). In this study we assessed the distribution of BRS and immediate orthostatic hypotension (IOH) in young Seychellois adults and their associations with exposure to prenatal and recent postnatal methylmercury.
METHODS: Subjects in the Seychelles Child Development Study (SCDS) main cohort were evaluated at age 19 years. Non-invasive beat-to-beat blood pressure (BP) monitoring (Finapres, Ohmeda) was performed at rest and during active standing in 95 consecutive subjects. Recent postnatal mercury exposure was measured in subjects' hair at the age of 19 years and prenatal exposure in maternal hair grown during pregnancy. BRS was estimated by sequence analysis to identify spontaneous ascending and descending BP ramps. HRV was estimated by the following markers: PNN50 (relative numbers of normal-to-normal intervals which are shorter by more than 50 ms than the immediately following normal-to-normal intervals); rMSSD (root mean of the squared sum of successive interval differences); LF/HF (low frequency/high frequency component ratio); ratio of the mean expiratory/inspiratory RR intervals (EI ratio); and the ratio between the longest RR interval 30 s after active standing and the shortest RR interval at 15 s (Max30/Min15). IOH was estimated by the deepest BP fall within the first 15 s after active standing up.
RESULTS: Prenatal MeHg exposures were similar in boys and girls (6.7±4.3, 6.7±3.8 ng/g) but recent postnatal mercury levels were higher in males than females (11.2±5.8 vs 7.9±4.3 ng/g, p=0.003). Markers of autonomic heart rate control were within the normal range (BRS: 24.8±7 ms/mm Hg, PNN50: 24.9±6.8%, rMSSD: 68±22, LF/HF: 0.61±0.28) in both sexes. After standing, 51.4% of subjects had a transient systolic BP drop>40 mm Hg, but only 5.3% reported dizziness or had syncope. Prenatal and recent postnatal MeHg levels, overall, were not associated with BRS, E/I ratio, PNN50, rMSSD, LF/HF ratio, Max30/Min15 ratio, and IOH.
CONCLUSIONS: This study provides no support for the hypothesis that prenatal or recent postnatal MeHg exposure from fish consumption is associated with impaired autonomic heart rate control.
Mots-clé
Baroreflex/drug effects, Environmental Exposure/adverse effects, Environmental Pollutants/toxicity, Female, Heart Rate/drug effects, Humans, Hypotension, Orthostatic/chemically induced, Male, Methylmercury Compounds/toxicity, Pregnancy, Prenatal Exposure Delayed Effects/chemically induced, Seychelles, Young Adult
Pubmed
Web of science
Open Access
Oui
Création de la notice
28/04/2015 17:22
Dernière modification de la notice
20/08/2019 14:19
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