Dietary salt intake is not associated with risk of stroke: A Mendelian randomization study

Previous studies have demonstrated a correlation between dietary salt intake and stroke; however, there was a lack of conclusive evidence regarding a causal connection between them. We undertook a two-sample Mendelian randomization (MR) study to examine their potential association. The genome-wide data for dietary salt intake was sourced from genome-wide association study that involved 462,630 samples. Genetic instruments for stroke were also obtained from genome-wide association study, which included 446,696 samples. Both samples were from European. The inverse variance weighting was used as the main method in MR analysis. We also performed several complementary MR methods, including MR-Egger, position weighted median, simple model, and weighted model. Our results showed that there was no causal relationship between dietary salt intake and stroke, which was genetically determined (fixed-effects inverse variance weighted: odds ratio, 0.95; 95% confidence interval, 0.74-1.21; P  = .67). Neither Cochran Q test (P = .52) nor MR-Egger method (P = .48) found obvious heterogeneity; in addition, the MR pleiotropy residual sum and outliers global test (P = .52) and MR-Egger regression intercept (P = .74) also showed no pleiotropy. The result of our MR study showed that there was no direct causal relationship between dietary salt intake and stroke risk. More studies were required to further confirm the stability of this relationship and to trying applied the findings to the clinic.