Figure 1. Schematic diagrams depicting different scenarios whereby childhood adiposity may exert an effect on cardiac outcomes in adulthood using a lifecourse Mendelian randomization approach.

A, Univariable Mendelian randomization was conducted to estimate the “total effect” of childhood body size on cardiac outcomes in adulthood. B, Multivariable Mendelian randomization was subsequently applied to estimate “direct effects” of childhood body size on cardiac outcomes (ie, an effect independent of adulthood body size), as well as simultaneously estimating (C) “indirect effects,” which are mediated along the causal pathway involving adulthood body size.