Axe santé des populations et environnementale, Centre de recherche du CHUQ, Édifice Delta 2, 2875, boulevard Laurier, 6e étage, Sainte-Foy, Québec, Canada G1V 2M2.
Environ Res. 2013 Jan;120:102-8. doi: 10.1016/j.envres.2012.08.002. Epub 2012 Sep 5.
Epidemiological evidence suggests a negative impact of methylmercury (MeHg) on cardiovascular risk factors such as blood pressure (BP) and heart rate (HR). This issue is of concern in Arctic populations such as in the Inuit of Nunavik since this contaminant is accumulated in fish and marine mammals, which still represent the subsistence diet of this population.
We examined the associations between MeHg and BP and resting HR among Inuit adults.
The "Santé Quebec" health survey was conducted in 1992 in the 14 villages of Nunavik and a complete set of data was obtained for 313 Inuit adults≥18 years. Blood samples were collected in order to determine total mercury, lead, total polychlorinated biphenyls (PCBs), n-3 polyunsaturated fatty acids (PUFAs), fasting glucose and lipid profile while socio-demographic variables were obtained through questionnaires. Anthropometric measurements as well as BP and resting HR were obtained using standardised protocols. Pulse pressure (PP: systolic BP minus diastolic BP) was also calculated. Multiple linear regression was used in order to determine the change in the dependent variables associated with the quartiles of MeHg concentration, taking the quartile 1 as reference.
The mean age of the participants was 38±14 years and the sample was composed of 132 men (42.2%) and 181 women (57.8%). MeHg geometric mean was 15.4 μg/L (95%CI: 13.9-17.0) and levels ranged from 0.8 to 112.0 μg/L. Resting HR increased linearly across quartiles of blood MeHg concentration after adjusting for confounders (p for trend=0.02). An increase of 6.9 beats per minute (bpm) between the 4th and 1st quartile was observed after adjusting for confounders. No significant association was observed between blood MeHg and systolic BP, diastolic BP or PP.
MeHg was associated with increasing resting HR after considering traditional risk factors as well as other contaminants (lead and total PCBs) and n-3 PUFAs. In contrast, no significant association with blood pressure was observed in this study.
流行病学证据表明，甲基汞（MeHg）对血压（BP）和心率（HR）等心血管危险因素有负面影响。在北极地区的人群中，如努纳武特的因纽特人，这个问题尤为关注，因为这种污染物会在鱼类和海洋哺乳动物中积累，而这些动物仍然是该人群的主要食物来源。
我们研究了因纽特成年人血液中 MeHg 与 BP 和静息 HR 之间的关联。
“魁北克健康调查”于 1992 年在努纳武特的 14 个村庄进行，共有 313 名≥18 岁的因纽特成年人完成了完整的数据采集。采集血样以测定总汞、铅、总多氯联苯（PCBs）、n-3 多不饱和脂肪酸（PUFAs）、空腹血糖和血脂谱，同时通过问卷获得社会人口统计学变量。采用标准议定书获取人体测量数据以及 BP 和静息 HR。还计算了脉压（PP：收缩压减去舒张压）。采用多元线性回归确定与 MeHg 浓度四分位的因变量变化，四分位 1 作为参考。
参与者的平均年龄为 38±14 岁，样本由 132 名男性（42.2%）和 181 名女性（57.8%）组成。MeHg 的几何平均值为 15.4μg/L（95%CI：13.9-17.0），范围从 0.8 到 112.0μg/L。在调整混杂因素后，静息 HR 随血液 MeHg 浓度四分位的变化呈线性增加（趋势检验 p 值=0.02）。在调整混杂因素后，第 4 四分位和第 1 四分位之间的心率增加了 6.9 次/分钟（bpm）。血液 MeHg 与收缩压、舒张压或脉压之间未见显著相关性。
在考虑传统危险因素以及其他污染物（铅和总 PCBs）和 n-3 PUFAs 后，血液 MeHg 与静息 HR 升高相关。相比之下，在这项研究中，血液 MeHg 与血压之间没有显著相关性。
