a Department of Nutrition, School of Public Health , Iran University of Medical Sciences, Hemaat Highway , Tehran , Iran.
b Department of Community Nutrition , School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences , Tehran , Iran.
Crit Rev Food Sci Nutr. 2019;59(2):196-206. doi: 10.1080/10408398.2017.1363710. Epub 2017 Oct 16.
The prevalence of metabolic syndrome (MetS) has been greatly increased, worldwide. In recent years, investigators have proposed that sodium might contribute to the development of metabolic syndrome; however, the published data were conflicting. The present systematic review aimed to summarize the evidence from observational studies in this regard. We conducted a systematic search for relevant observational studies investigating the association between sodium status and MetS, published until June 2017 in electronic databases including PubMed, EMBASE, Scopus and Google Scholar. Summary effects were derived using random effects model. After screening the records, seventeen publications with 66,274 participants were eligible to be included in the systematic review and meta-analysis. The analysis revealed that subjects with MetS have significantly higher levels of sodium compared to healthy controls (Hedges' g = 0.21, 95% CI: 0.12, 0.29, I = 68.6). Subgroup analyses revealed that the difference was significant when the sodium status was assessed using urinary sodium levels. The random effects meta-regression analysis also revealed that body sodium level increases with the number of MetS components. Furthermore, participants with highest dietary/urinary or serum sodium levels had 37% higher chance of developing MetS when compared with participants with the lowest sodium levels (OR = 1.37 95%CI: 1.31, 1.42, I = 86.9). The current meta-analysis revealed that higher sodium input into the body is directly associated with the likelihood of MetS. Prospective cohort studies and well-designed randomized clinical trials considering the effect of sodium restricted diets on the risk of MetS as an outcome are necessary to represent the causal association.
代谢综合征（MetS）的患病率在全球范围内大幅增加。近年来，研究人员提出，钠可能导致代谢综合征的发生；然而，已发表的数据存在矛盾。本系统评价旨在总结这方面观察性研究的证据。我们对截至 2017 年 6 月，在电子数据库（包括 PubMed、EMBASE、Scopus 和 Google Scholar）中发表的研究钠状态与 MetS 之间关联的观察性研究进行了系统检索。使用随机效应模型得出综合效应。筛选记录后，有 17 项研究共 66274 名参与者符合纳入系统评价和荟萃分析的标准。分析显示，患有 MetS 的患者的钠水平明显高于健康对照组（Hedges'g=0.21，95%CI：0.12，0.29，I=68.6）。亚组分析显示，当使用尿钠水平评估钠状态时，差异具有统计学意义。随机效应荟萃回归分析还显示，随着 MetS 成分数量的增加，体内钠水平增加。此外，与钠水平最低的参与者相比，钠摄入量/尿钠或血清钠水平最高的参与者患 MetS 的可能性增加 37%（OR=1.37，95%CI：1.31，1.42，I=86.9）。本荟萃分析显示，体内摄入更多的钠与发生 MetS 的可能性直接相关。需要前瞻性队列研究和精心设计的随机临床试验来评估钠限制饮食对 MetS 风险的影响，以代表因果关系。
