The effect of BMI and type 2 diabetes on socioeconomic status: a two-sample multivariable Mendelian randomization study
To assess the independent causal effect of BMI and type 2 diabetes (T2D) on socioeconomic outcomes applying two-sample Mendelian randomization (MR) analysis.
RESEARCH DESIGN AND METHODS
We carried out univariate and multivariate two-sample MR to jointly assess the effect BMI and T2D on socioeconomic outcomes. We used overlapping genome-wide significant single nucleotide polymorphisms (SNPs) for BMI and T2D as instrumental variables. Their causal impact on household income and regional deprivation was assessed using summary-level data from the UK Biobank.
In the univariate analysis, higher BMI was related with lower income (marginal effect of 1-SD increase in BMI [β=-0.092 (95% CI: -0.138; -0.047)] and higher deprivation [β=0.051 (95% CI: 0.022; 0.079)]. In the multivariate MR, the effect of BMI controlling for diabetes was slightly lower for income and deprivation. Diabetes was not associated with these outcomes.
High BMI, but not diabetes, shows a causal link with socioeconomic outcomes.