Figure 2. Mendelian Randomization of Birth Weight and Risk of Type 2 Diabetes (T2D).

For type 2 diabetes, the data were analyzed from 49 studies from the Cohorts for Heart and Aging Research in Genomic Epidemiology Birth Gene Study where standardized analytic methods were used in individual study. This study included 41 155 patients with T2D and 80 008 controls. Data from the Diabetes Genetics Replication and Meta-analysis (DIAGRAM) Consortium included 34 840 patients with T2D and 114 981 controls, overwhelmingly of European descent. Summary results of 7 single-nucleotide polymorphisms (SNPs) for birth weight identified in genome-wide association studies were extracted from the Early Growth Genetics Consortium.²³ Summary results for risk of T2D were extracted from the DIAGRAM Consortium.¹⁷ Summary results of 43 SNPs for birth weight were extracted from the Early Growth Genetics birth weight genome-wide association study.¹³ Summary results for risk of T2D were extracted from the DIAGRAM Consortium.¹⁷ We used the standard deviation value (543 g) from the birth weight genome-wide association study of the EGG Consortium.¹³ Results are standardized to a 1-SD lower birth weight owing to genetic risk score. ARI indicates absolute risk increase; OR, odds ratio