Figure 1
From: Iron status and sarcopenia-related traits: a bi-directional Mendelian randomization study
An overview of the study design includes three key assumptions.MR satisfies the following three conditional assumptions32: (1) there is a strong association between instrumental variables and exposure factors; (2) no confounding factors exist in the association between exposure and outcome, in other words, there is no genetic pleiotropy; and (3) the instrumental variables do not have a direct effect on outcome and can only influence outcome through exposure factors.
