Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN) - Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125, Modena, Italy.
Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, Boston, MA, 02118, USA.
Eur J Epidemiol. 2018 Sep;33(9):789-810. doi: 10.1007/s10654-018-0422-8. Epub 2018 Jul 5.
In 2007, supplementation with the trace element selenium in a trial was unexpectedly found to be associated with an excess risk of type 2 diabetes. Given the concerns raised by these findings and the large number of recent studies on this topic, we reviewed the available literature with respect to this possible association. In this paper, we assessed the results of both experimental and nonexperimental epidemiologic studies linking selenium with type 2 diabetes incidence. Through a systematic literature search, we retrieved 50 potentially eligible nonexperimental studies and 5 randomized controlled trials published through June 11, 2018. To elucidate the possible dose-response relation, we selected for further analysis those studies that included multiple exposure levels and serum or plasma levels. We computed a pooled summary risk ratio (RR) of diabetes according to selenium exposure in these studies. We also computed a RR for diabetes incidence following supplementation with 200 µg/day of selenium compared with placebo in trials. In the nonexperimental studies, we found a direct relation between selenium exposure and risk of diabetes, with a clear and roughly linear trend in subjects with higher plasma or serum selenium levels, with RR at 140 µg/L of selenium exposure compared with a referent category of < 45 µg/L equal to 3.6 [95% confidence interval (CI) 1.4-9.4]. A dose-response meta-analysis focusing on studies with direct assessment of dietary selenium intake showed a similar trend. In experimental studies, selenium supplementation increased the risk of diabetes by 11% (RR 1.11, 95% CI 1.01-1.22) compared with the placebo-allocated participants, with a higher RR in women than in men. Overall, results from both nonexperimental and experimental studies indicate that selenium may increase the risk of type 2 diabetes across a wide range of exposure levels. The relative increase in risk is small but of possible public health importance because of the high incidence of diabetes and the ubiquity of selenium exposure.
2007 年，一项关于微量元素硒补充剂的试验意外发现，其与 2 型糖尿病风险增加有关。鉴于这些发现引起的关注以及最近关于这个主题的大量研究，我们对有关这种可能关联的现有文献进行了回顾。在本文中，我们评估了将硒与 2 型糖尿病发病率联系起来的实验和非实验性流行病学研究的结果。通过系统的文献搜索，我们检索到 50 项可能符合条件的非实验性研究和 5 项随机对照试验，这些试验的发表时间截至 2018 年 6 月 11 日。为了阐明可能的剂量-反应关系，我们选择了进一步分析那些包括多个暴露水平和血清或血浆水平的研究。我们根据这些研究中的硒暴露计算了糖尿病的汇总风险比（RR）。我们还计算了试验中与安慰剂相比每天补充 200μg 硒后糖尿病发病率的 RR。在非实验性研究中，我们发现硒暴露与糖尿病风险之间存在直接关系，在血清或血浆硒水平较高的人群中，这种关系明显且大致呈线性趋势，与暴露于 140μg/L 硒相比，参考组的 RR 为 <45μg/L 时为 3.6（95%置信区间 1.4-9.4）。一项侧重于直接评估饮食硒摄入量的研究的剂量-反应荟萃分析显示出类似的趋势。在实验研究中，与安慰剂分配的参与者相比，硒补充剂使糖尿病的风险增加了 11%（RR 1.11，95%置信区间 1.01-1.22），女性的 RR 高于男性。总体而言，非实验性和实验性研究的结果表明，硒可能会在广泛的暴露水平范围内增加 2 型糖尿病的风险。风险的相对增加虽然很小，但由于糖尿病的高发病率和硒暴露的普遍性，可能具有重要的公共卫生意义。
