School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, China.
Division of Prevention and Community Health, National Center for Cardiovascular Disease, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Nutr Diet. 2021 Jul;78(3):315-323. doi: 10.1111/1747-0080.12653. Epub 2021 Jan 7.
This study aimed to determine the causal association between salt added to food and body mass index (BMI) by integrating a summary-level genome-wide association study (GWAS) data.
We performed two-sample Mendelian randomisation (MR) analyses using summary statistics of GWAS. Inverse-variance weighted (IVW), maximum likelihood estimation, and random effect model were used to analyse the effect of salt added to food on BMI. A bidirectional MR analysis with BMI as the exposure and salt added to food as the outcome was also performed.
The single nucleotide polymorphisms (SNPs) were selected from the UK Biobank (n = 462 630) and a meta-analysis of 322 154 European-descent individuals. The IVW method estimate indicated that salt added to food was positively associated with BMI (β = 0.1416, SE = 0.0576, P = .0139). Results from maximum likelihood estimation (β = 0.1476, SE = 0.0363, P < .0001) and the random effect model (β = 0.1411, SE = 0.0572, P = .0137) were consistent with the IVW. Bidirectional MR analysis suggested that BMI did not causally affect salt added to food.
Our results provided qualitative evidence supporting a causal relationship between salt intake and BMI.
本研究旨在通过整合汇总水平全基因组关联研究（GWAS）数据，确定食物中添加的盐与体重指数（BMI）之间的因果关系。
我们使用 GWAS 的汇总统计数据进行了两样本孟德尔随机化（MR）分析。采用逆方差加权（IVW）、最大似然估计和随机效应模型分析食物中添加的盐对 BMI 的影响。还进行了双向 MR 分析，以 BMI 为暴露因素，食物中添加的盐为结果因素。
从英国生物库（n=462630）和 322154 名欧洲血统个体的荟萃分析中选择了单核苷酸多态性（SNPs）。IVW 方法估计表明，食物中添加的盐与 BMI 呈正相关（β=0.1416，SE=0.0576，P=0.0139）。最大似然估计（β=0.1476，SE=0.0363，P<0.0001）和随机效应模型（β=0.1411，SE=0.0572，P=0.0137）的结果与 IVW 一致。双向 MR 分析表明，BMI 不会对食物中添加的盐产生因果影响。
我们的结果提供了定性证据，支持盐摄入量与 BMI 之间存在因果关系。
