Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Department of Environmental Health Engineering, School of Health, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran; Health Sciences Research Center, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran.
Social Determinants of Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Environmental Health Engineering, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran.
J Affect Disord. 2020 Mar 1;264:234-241. doi: 10.1016/j.jad.2019.12.027. Epub 2019 Dec 19.
Lithium at therapeutic doses has protective effects against suicide in clinical practice. This meta-analysis aimed to investigate the relationship between lithium concentration in drinking water and suicide mortality in the general population.
A systematic search was conducted in Web of Knowledge, PubMed, ScienceDirect, and Scopus to find papers reporting the crude relationship between drinking water lithium and suicide incidence in the general population until June 2019. The pooled effect measure was expressed as odds ratio (OR) and 95% confidence interval (CI) using the random-effects model.
We retrieved 308 English original articles, of which 13 ecologic studies with a total sample size of 939 regions and one cohort study with a sample size of 3,740,113 people were eligible for the meta-analysis. A significant relationship was found between the lithium concentration in drinking water and reduced suicide mortality (OR= 0.42; 95% CI: 0.27-0.67; p-value <0.01). Ten studies reported gender-specific responses to lithium, with the pooled estimates as follows: OR= 0.54; 95% CI: 0.35-0.84; p-value <0.01 for men, OR= 0.70; 95% CI: 0.48-1.01; p-value =0.057 for women, and OR= 0.63; 95% CI: 0.47-0.83; p-value <0.01 for total.
The study was limited to the assessment of the crude relationship between lithium exposure and suicide rate without considering the role of confounders.
Lithium in drinking water is dose-dependently associated with reduced suicide mortality at least in ecological studies. However, we need well-designed clinical trials to confirm the protective effect of drinking water lithium intake against suicide.
在临床实践中，治疗剂量的锂对自杀有保护作用。本荟萃分析旨在研究饮用水中锂浓度与普通人群自杀死亡率之间的关系。
系统检索 Web of Knowledge、PubMed、ScienceDirect 和 Scopus 以查找截至 2019 年 6 月报告普通人群饮用水锂与自杀发生率之间原始关系的论文。使用随机效应模型，汇总效应量表示为比值比（OR）和 95%置信区间（CI）。
我们检索到 308 篇英文原始文章，其中 13 项生态学研究的总样本量为 939 个地区，1 项队列研究的样本量为 3740113 人，符合荟萃分析的条件。饮用水中锂浓度与自杀死亡率降低之间存在显著相关性（OR=0.42；95%CI：0.27-0.67；p<0.01）。有 10 项研究报告了锂对性别特异性的反应，汇总估计值如下：男性 OR=0.54；95%CI：0.35-0.84；p<0.01，女性 OR=0.70；95%CI：0.48-1.01；p=0.057，总人群 OR=0.63；95%CI：0.47-0.83；p<0.01。
该研究仅限于评估锂暴露与自杀率之间的原始关系，而没有考虑混杂因素的作用。
饮用水中的锂与自杀死亡率降低至少在生态学研究中呈剂量依赖性相关。然而，我们需要精心设计的临床试验来证实饮用水锂摄入对自杀的保护作用。
