Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
Environ Res. 2021 Jun;197:111190. doi: 10.1016/j.envres.2021.111190. Epub 2021 Apr 16.
Selenium is an essential trace element that shows beneficial or adverse health effects depending on the dose. Laboratory studies suggest that high selenium may contribute to the development of non-alcoholic fatty liver disease (NAFLD). However, human evidence is limited. We evaluated the associations of serum selenium level with serum alanine aminotransferase (ALT) activity and suspected NAFLD prevalence in U.S. adults.
We conducted the cross-sectional analysis in 3827 adults aged 20 years and older without viral hepatitis, hemochromatosis, or alcoholic liver disease who participated in the National Health and Nutrition Examination Survey (NHANES) 2011-2012, 2013-2014, and 2015-2016. Serum selenium was measured using inductively coupled plasma dynamic reaction cell mass spectrometry. Suspected NAFLD cases were defined in the presence of serum ALT >30 international units (IU)/L in men and >19 I.U./L in women in the absence of other identifiable causes of liver disease.
The median (interquartile range) of serum selenium level was 127.9 (117.9, 139.4) μg/L. Non-linear associations of serum selenium with NAFLD prevalence and serum ALT activity were observed in the generalized additive models with penalized splines. After adjustment for sociodemographic variables, lifestyle factors, body mass index, and NHANES survey cycles, positive associations were found at > ~130 μg/L serum selenium with both NAFLD and ALT, whereas the associations were flattened at < ~130 μg/L.
Our findings provide evidence of non-linear associations of serum selenium with ALT activity and NAFLD prevalence. In particular, positive associations were found above serum selenium level of 130 μg/L, whereas no association was observed below this value. This finding requires confirmation in future prospective cohort studies.
硒是一种必需的微量元素，其健康效应取决于剂量，既可能有益，也可能有害。实验室研究表明，高硒可能导致非酒精性脂肪性肝病（NAFLD）的发生。然而，人体证据有限。我们评估了血清硒水平与血清丙氨酸氨基转移酶（ALT）活性及美国成年人疑似非酒精性脂肪性肝病患病率之间的关系。
我们对参加 2011-2012、2013-2014 和 2015-2016 年国家健康与营养调查（NHANES）的 3827 名年龄在 20 岁及以上、无病毒性肝炎、血色病或酒精性肝病的成年人进行了横断面分析。使用电感耦合等离子体动态反应池质谱法测量血清硒。在排除其他可识别的肝病原因的情况下，男性血清 ALT>30 国际单位（IU）/L 和女性血清 ALT>19 IU/L 时定义为疑似非酒精性脂肪性肝病病例。
血清硒水平的中位数（四分位距）为 127.9（117.9，139.4）μg/L。广义加性模型和惩罚样条曲线显示，血清硒与非酒精性脂肪性肝病患病率和血清 ALT 活性之间存在非线性关联。在校正社会人口统计学变量、生活方式因素、体重指数和 NHANES 调查周期后，在>130μg/L 血清硒水平下，发现血清硒与非酒精性脂肪性肝病和 ALT 均呈正相关，而在<130μg/L 血清硒水平下，相关性趋于平稳。
我们的研究结果提供了血清硒与 ALT 活性和非酒精性脂肪性肝病患病率之间存在非线性关联的证据。特别是在血清硒水平>130μg/L 时，发现了正相关，而在这个值以下则没有发现相关。这一发现需要在未来的前瞻性队列研究中得到证实。
