Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Islamic Republic of Iran.
Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Islamic Republic of Iran.
Public Health Nutr. 2019 Feb;22(2):295-306. doi: 10.1017/S1368980018002112. Epub 2018 Oct 22.
High Na intake has been associated with different health problems. However, serious controversies exist over studies investigating associations of Na intake with mortality from all-causes and CVD. The present systematic review and meta-analysis was done to investigate, for the first time, the dose-response association of dietary Na intake with all-cause and CVD mortality among prospective studies.
Relevant papers published up to August 2017 were searched in MEDLINE, EMBASE and Google Scholar databases. Prospective cohort studies on the association of dietary Na intake with all-cause or/and CVD mortality were included. Linear and non-linear dose-response associations between Na intake and CVD and all-cause mortality were examined.
Overall, twenty publications met inclusion criteria. A significant non-linear association (P<0·001) was found between Na intake and CVD mortality risk among studies assessing urinary Na excretion, with a relatively steep slope at Na intakes above 2400mg/d. However, the association was not significant in studies using dietary Na intake (P=0·61). Additionally, the non-linear association of Na intake with all-cause mortality was also non-significant. No linear association (effect size; 95 % CI; I 2) was seen between 100mg/d increment in Na intake and CVD mortality (1·01; 0·97, 1·05; 98·4 %) or all-cause mortality (1·01; 1·00, 1·02; 89·2 %). Following subgroup analyses, the association between Na intake and CVD mortality was observed only among studies conducted in the USA (0·99; 0·99, 1·00; 20·0 %).
The study showed a direct association between urinary Na excretion and CVD mortality which was more considerable at intakes above 2400mg/d. In contrast, no significant association was found between Na intake and all-cause mortality. Further long-term prospective studies on different populations are required to confirm these findings.
高钠摄入与多种健康问题有关。然而，关于钠摄入量与全因和心血管疾病死亡率之间关联的研究存在严重争议。本系统评价和荟萃分析首次调查了饮食钠摄入量与前瞻性研究中全因和心血管疾病死亡率之间的剂量反应关系。
在 MEDLINE、EMBASE 和 Google Scholar 数据库中搜索截至 2017 年 8 月发表的相关论文。纳入了关于饮食钠摄入量与全因或/和心血管疾病死亡率之间关系的前瞻性队列研究。检查了钠摄入量与心血管疾病和全因死亡率之间的线性和非线性剂量反应关系。
共有 20 篇出版物符合纳入标准。在评估尿钠排泄的研究中，钠摄入量与心血管疾病死亡率之间存在显著的非线性关联（P<0·001），在钠摄入量高于 2400mg/d 时斜率较陡。然而，在使用饮食钠摄入量的研究中，这种关联并不显著（P=0·61）。此外，钠摄入量与全因死亡率之间的非线性关联也不显著。在 CVD 死亡率（1·01；0·97，1·05；98·4%）或全因死亡率（1·01；1·00，1·02；89·2%）方面，100mg/d 钠摄入量的增加与线性关联（效应大小；95%置信区间；I 2）无关。在亚组分析后，仅在美国进行的研究中观察到钠摄入量与心血管疾病死亡率之间的关联（0·99；0·99，1·00；20·0%）。
该研究表明，尿钠排泄与心血管疾病死亡率之间存在直接关联，在摄入量高于 2400mg/d 时更为显著。相反，没有发现钠摄入量与全因死亡率之间存在显著关联。需要对不同人群进行进一步的长期前瞻性研究来证实这些发现。
