Figure 1.

Overview of the MR design assumptions and study methodology. Assumption 1 states that the genetic variants proposed as instrumental variables should be strongly associated with the relevant risk factor; assumption 2 states that the genetic variants used should not be associated with potential confounders; and assumption 3 states that the selected genetic variants should only influence outcome risk through the relevant risk factor and not through other possible pathways. BMI, body mass index; WHR, waist-to-hip ratio; WHR_adjBMI, waist-to-hip ratio adjusted for body mass index; UVMR, Univariable Mendelian randomization analysis; MVMR, Multivariable Mendelian randomization analysis.