Two-sample Mendelian randomization in independent adult samples supports negative effects of BMI (and, secondarily, asthma) on years of schooling, with little evidence for migraine¶

Claim · All claims
Evidence · 1 study · causal r2 · q2
Currency · newest study 2021 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Summary-level MR estimated that a one-unit increase in BMI was associated with 0.16 (IVW) and 0.11 (weighted median) fewer years of schooling, and asthma with 0.02 fewer years; there was little evidence of a causal impact of migraine. → Hughes 2021

Evidence¶

Hughes 2021¶

Hughes, A., Wade, K. H., Dickson, M., Rice, F., Davies, A., Davies, N. M. & Howe, L. D. (2021). Common health conditions in childhood and adolescence, school absence, and educational attainment: Mendelian randomization study. npj Science of Learning 6:1. https://doi.org/10.1038/s41539-020-00080-6

q2 · i? · causal · r2

Two-sample summary-level Mendelian randomization in independent adult GWAS samples (Table 5; 945 SNPs for BMI). The article also reports a negative asthma effect (−0.02, p < 0.001 IVW) and "little evidence of a causal impact of migraine"; MR-Egger indicated pleiotropy for BMI.

"Our analyses supported an influence of BMI, with a one-unit increase in BMI associated with 0.16 (p < 0.001) and 0.11 ( p < 0.001) fewer years of schooling in IVW and weighted median models, respectively."

Discussion¶

Related Claims¶

• Genetic instrumental-variable analysis supports a causal negative effect of higher BMI in childhood and adolescence on GCSE attainment and school absence (ALSPAC cohort) — related
• School absence mediates health–attainment associations, least for ADHD (7.1%) and most for migraine (72.0%) and BMI (39.9%) (ALSPAC cohort) — related
• In multivariate-adjusted phenotypic models, all measured child/adolescent health conditions except migraine and asthma are associated with poorer GCSE attainment at 16 (ALSPAC cohort) — related