Research
Influence of mercury exposure on blood pressure, resting heart rate and heart rate variability in French Polynesians: a cross-sectional study
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* Corresponding author: Éric Dewailly eric.dewailly@crchul.ulaval.ca
1 Axe Santé des Populations et Environnement, Centre de Recherche du CHUQ, 2875 Boulevard Laurier, Québec, G1V 2M2, Canada
2 Department of Social and Preventive Medicine, Laval University, 1050 avenue de la Médecine, Quebec, G1V 0A6, Canada
3 Quebec Heart and Lung Institute, Laval Hospital Research Centre, 2725 Chemin Sainte-Foy, Québec, G1V 4G5, Canada
4 Faculty of Pharmacy, Laval University, 1050 avenue de la Médecine, Quebec, G1V 0A6, Canada
5 Département Épidémiologie et Biostatistiques, École des Hautes Études en Santé Publique, Hôtel-Dieu, 1, place Notre-Dame, Paris Cedex 4, 75181, France
6 Université Paris 13, GISCOP93, UFR SMBH, 74, rue Marcel Cachin, Bobigny Cedex, 93017, France
7 Unité de maladies non transmissibles (LMNT), Institut Louis Malardé, rue du 5 mars 1797, Papeete, 98713, Polynésie Française
Environmental Health 2011, 10:99 doi:10.1186/1476-069X-10-99
Published: 13 November 2011Abstract
Background
Populations which diet is rich in seafood are highly exposed to contaminants such as mercury, which could affect cardiovascular risk factors
Objective
To assess the associations between mercury and blood pressure (BP), resting heart rate (HR) and HR variability (HRV) among French Polynesians
Methods
Data were collected among 180 adults (≥ 18 years) and 101 teenagers (12-17 years). HRV was measured using a two-hour ambulatory electrocardiogram (Holter) and BP was measured using a standardized protocol. The association between mercury and HRV and BP parameters was studied using analysis of variance (ANOVA) and analysis of covariance (ANCOVA)
Results
Among teenagers, the high frequency (HF) decreased between the 2nd and 3rd tertile (380 vs. 204 ms2, p = 0.03) and a similar pattern was observed for the square root of the mean squared differences of successive R-R intervals (rMSSD) (43 vs. 30 ms, p = 0.005) after adjusting for confounders. In addition, the ratio low/high frequency (LF/HF) increased between the 2nd and 3rd tertile (2.3 vs. 3.0, p = 0.04). Among adults, the standard deviation of R-R intervals (SDNN) tended to decrease between the 1st and 2nd tertile (84 vs. 75 ms, p = 0.069) after adjusting for confounders. Furthermore, diastolic BP tended to increase between the 2nd and 3rd tertile (86 vs. 91 mm Hg, p = 0.09). No significant difference was observed in resting HR or pulse pressure (PP)
Conclusions
Mercury was associated with decreased HRV among French Polynesian teenagers while no significant association was observed with resting HR, BP, or PP among teenagers or adults