We extracted DNA from blood samples by using magnetic bead technology (Medical Solutions, Nottingham). Medical Solutions used SNPLex (Applied Biosciences) to determine the following single nucleotide polymorphisms, chosen because their association with diabetes risk has been replicated and the effect size has been estimated with precision from large scale meta-analysis (web table A): ADAMTS9 rs4607103, CALPN10 rs3792267, CDC123 (CAMK1D) rs12779790, CDKN2B rs10811661, FTO rs1421085 (which is complete LD with rs993050630), HHEX rs1111875, HNF1A (TCF2) rs1800574, IGF2BP2 rs440296, JAZF1 rs864745, KCNJ11 rs521, NOTCH2 rs10923931, PPARG rs1801282, SLC30A8 rs13266634, TCF2(HNF1B) rs4430796, TCF7L2 rs12255372, THADA rs7578597, and TSPAN8 (LGR57) rs7961581. Single nucleotide polymorphisms in BCL11A rs10490072, CDKAL1 rs17036101, TCF7L2 rs7901695, and VEGFA rs9472138 were genotyped by using the 50K IBC CVD chip (web table B).31 All single nucleotide polymorphisms were in Hardy-Weinberg equilibrium (χ2, P>0.05).
