Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.
Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton, Canada.
Int J Circumpolar Health. 2021 Dec;80(1):1889879. doi: 10.1080/22423982.2021.1889879.
Indigenous Arctic Canadians have a higher prevalence of gastric neoplasms relative to North Americans of European ancestry. We investigated the hypothesis that low-dose methylmercury exposure from eating fish/whale increases the risk of gastric cancer in Arctic communities. We used intermediate endpoints from an established model of gastric carcinogenesis: intestinal metaplasia, atrophy, and severe chronic gastritis. During 2008-2012, we obtained gastric biopsies from participants of community-driven projects in 3 communities. In 2016, we collected hair samples to measure methylmercury levels and interviewed them about diet. In cross-sectional analysis, logistic regression estimated odds ratios for the estimated effect of hair-methylmercury concentration on the prevalence of each pathology outcome stratified by selenium intake. Among 80 participants, prevalence of intestinal metaplasia, atrophy and severe chronic gastritis was 17, 29 and 38%, respectively. Adjusted Odds of severe chronic gastritis and atrophy were highest at hair-methylmercury concentrations ≥1μg/g when estimated selenium intake was 0, and approached 0 for all methylmercury levels as estimated selenium intake increased. Gastric pathology increased with methylmercury exposure when selenium intake was low. Though limited by small numbers, these findings suggest selenium ingested by eating fish/whale may counter harmful effects of methylmercury exposure in Arctic populations.
与欧洲裔北美人相比，土生土长的北极加拿大人患有胃肿瘤的比例更高。我们研究了一个假设，即食用鱼类/鲸鱼中低剂量的甲基汞暴露会增加北极社区胃癌的风险。我们使用了已建立的胃癌发生模型中的中间终点：肠上皮化生、萎缩和严重慢性胃炎。在 2008-2012 年期间，我们从 3 个社区的社区驱动项目参与者中获得了胃活检。2016 年，我们收集了头发样本以测量甲基汞水平，并对他们的饮食进行了访谈。在横断面分析中，逻辑回归估计了头发甲基汞浓度对每个病理学结果（按硒摄入量分层）的患病率的估计效果的比值比。在 80 名参与者中，肠上皮化生、萎缩和严重慢性胃炎的患病率分别为 17%、29%和 38%。当估计的硒摄入量为 0 时，头发-甲基汞浓度≥1μg/g 时，严重慢性胃炎和萎缩的调整后的比值最高，随着估计的硒摄入量增加，所有甲基汞水平的比值均接近 0。当硒摄入量较低时，胃病理随着甲基汞暴露而增加。尽管受到样本量较小的限制，但这些发现表明，通过食用鱼类/鲸鱼摄入的硒可能会抵消甲基汞暴露对北极人群的有害影响。
