Fig. 1

An overview of the study design. (A) Flow chart of the bidirectional MR, sensitivity analyses, and mediation analysis. (B) Schematic chart of the basic principles of MR. MR, Mendelian randomization; PA, physical activity; LSB, leisure sedentary behaviors; GERD, gastroesophageal reflux disease; LOO, leave one out; IVs, instrumental variables