ARIC participants were genotyped using the Affymetrix 6.0 array (Affymetrix Inc, Santa Clara, CA, USA). Genotyping in the Rotterdam Study was done using the Illumina 550K and 610K quad array (Illumina Inc, San Diego, CA, USA). Genotyped variants were imputed to the Haplotype Reference Consortium (r1.1 2016) (21 (link)). Haplotype phasing and imputation was performed using the Michigan Imputation Server, which is available at https://imputationserver.sph.umich.edu .
A recent GWAS based on individuals of European ancestry identified 403 independent genetic variants associated with type 2 diabetes (5 (link)). Using the 403 genetic variants identified in this study, we created weighted polygenic score by multiplying the risk allele dosage with the effect estimates reported in the GWAS of type 2 diabetes. An additive weighted polygenic score was calculated by summing the weighted dosages for each individual (22 (link)). Separately in ARIC and the Rotterdam Study, all individuals were categorized into low (quintile 1), intermediate (quintiles 2–4), and high (quintile 5) genetic risk categories, with the low genetic risk category as the reference.
A recent GWAS based on individuals of European ancestry identified 403 independent genetic variants associated with type 2 diabetes (5 (link)). Using the 403 genetic variants identified in this study, we created weighted polygenic score by multiplying the risk allele dosage with the effect estimates reported in the GWAS of type 2 diabetes. An additive weighted polygenic score was calculated by summing the weighted dosages for each individual (22 (link)). Separately in ARIC and the Rotterdam Study, all individuals were categorized into low (quintile 1), intermediate (quintiles 2–4), and high (quintile 5) genetic risk categories, with the low genetic risk category as the reference.
