Vinceti Marco, Grioni Sara, Alber Dorothea, Consonni Dario, Malagoli Carlotta, Agnoli Claudia, Malavolti Marcella, Pala Valeria, Krogh Vittorio, Sieri Sabina
Centro di Ricerca in Epidemiologia Ambientale, Genetica e Nutrizionale (CREAGEN), University of Modena and Reggio Emilia, Modena, Via Campi, 287, 41125 Modena, Italy.
Epidemiology and Prevention Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133 Milano, Italy.
J Trace Elem Med Biol. 2015 Jan;29:145-50. doi: 10.1016/j.jtemb.2014.07.017. Epub 2014 Aug 4.
Epidemiologic studies, particularly randomized controlled trials, have shown a direct relation between dietary and environmental exposure to the metalloid selenium and risk of type 2 diabetes. We investigated the association between baseline toenail selenium levels and diabetes occurrence in a case-control study nested in ORDET, a population-based female cohort in Northern Italy. After a median follow-up of 16 years, we identified 226 cases of type 2 diabetes cases and 395 age-matched control women with available toenail samples at baseline. The multivariate odds ratios of diabetes in increasing a priori defined categories of toenail selenium exposure were 1.09 (95% confidence interval 0.61, 1.96), 0.71 (0.38, 1.34) and 1.14 (0.46, 2.80) compared with the lowest category. The results were not substantially altered when quartile distribution of toenail selenium in controls was used to define exposure categories. Spline regression analysis did not show homogeneous risk trends. Overall, we did not find an association between toenail selenium and subsequent development of diabetes. Since the diabetogenic activity of selenium is strongly supported by experimental studies and some observational investigations, our null results might be explained by the limitations of overall selenium toenail content to assess environmental exposure to selenium species of etiologic relevance in the study population.
流行病学研究，尤其是随机对照试验，已表明饮食和环境中接触类金属硒与2型糖尿病风险之间存在直接关联。在一项嵌套于意大利北部基于人群的女性队列研究ORDET中的病例对照研究中，我们调查了基线时 toenail 硒水平与糖尿病发生之间的关联。经过16年的中位随访，我们确定了226例2型糖尿病病例以及395名在基线时有可用 toenail 样本的年龄匹配对照女性。与最低类别相比， toenail 硒暴露的先验定义类别增加时，糖尿病的多变量优势比分别为1.09（95%置信区间0.61, 1.96）、0.71（0.38, 1.34）和1.14（0.46, 2.80）。当使用对照中 toenail 硒的四分位数分布来定义暴露类别时，结果没有实质性改变。样条回归分析未显示出均匀的风险趋势。总体而言，我们未发现 toenail 硒与糖尿病后续发生之间存在关联。由于实验研究和一些观察性调查有力支持了硒的致糖尿病活性，我们的阴性结果可能是由于 toenail 总硒含量在评估研究人群中与病因相关的硒物种的环境暴露方面存在局限性所致。
