Relationships between obesity and functional outcome after ischemic stroke: a Mendelian randomization study

Most previous studies suggested obesity deteriorates the functional outcome after ischemic stroke. But there are researches claiming that obesity is associated with lower mortality, recurrence, and readmission rates, which is known as the obesity paradox. Our current research aimed to investigate the correlation between genetically obesity and the post-stroke outcome with the Mendelian randomization (MR) method. The UK Biobank and the GIANT consortium provided instrumental variables for body mass index (BMI, 806,834 individuals) and waist-to-hip ratio (WHR, 697,734 individuals). Data of functional outcome after ischemic stroke were obtained from the Genetics of Ischemic Stroke Functional Outcome network (6012 individuals). Inverse-variance weighted approach was utilized as the primary analyses. Sensitivity analyses involved the utilization of different MR methods. The heterogeneity among genetic variants was assessed by I2 and Q value statistics. In univariable analysis, there was a significant connection between genetic susceptibility to WHR and worse functional outcome (modified Rankin Scale 3) after ischemic stroke (OR [95