MAGIC (the Meta-Analyses of Glucose and Insulin-related traits Consortium) represents a collaborative effort to combine data from multiple GWAS to identify additional loci that impact on glycemic and metabolic traits.
MAGIC investigators have initially studied fasting glucose, fasting insulin, 2h glucose and HBA1c, as well as performed meta-analysis of more sophisticated measures of insulin secretion and sensitivity. Through these efforts, dozens of loci influencing these traits have been idenfified, a subset of which also influence risk of type 2 diabetes.
The 2hr glucose datasets were generated by a meta-analysis of nine GWAS in 15,234 non-diabetic individuals and a follow-up of 29 independent loci in 6,958-30,620 individuals. Trait values for 2hr glucose are untransformed and are adjusted for BMI in addition to age, sex and study-specific covariates.
The fasting insulin and fasting glucose datasets were generated by performing a meta-analysis of up to 21 genome-wide association studies (GWAS) informative for fasting glucose, fasting insulin and indices of β-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 non-diabetic participants. Fasting glucose trait values are not transformed. Trait values for Fasting insulin, HOMA-IR, HOMA-B and fasting proinsulin have been naturally log transformed. All datasets are adjusted for age, sex and study-specific covariates.
The fasting proinsulin datasets were generated by a meta-analysis of GWAS data in 10,701 non-diabetic adults of European ancestry. Fasting proinsulin values are adjusted for fasting insulin, age, sex and study-specific covariates.
Glucose results accounting for BMI are from an analysis of 29 studies in up to 58,074 non-diabetic participants and the insulin results accounting for BMI are from an analysis of 26 studies in up to 51,750 non-diabetic participants. Details of the analyses accounting for BMI are within the zip file containing the data.
The HbA1c association results were available in up to 46,368 non-diabetic adults of European descent from 23 GWAS and combined using inverse-variance meta-analysis. HbA1c trait values are untransformed and adjusted for age, sex and study-specific covariates.
Meta-analysis results files for glucose-stimulated insulin secretion (GSIS) indices during an oral glucose tolerance test in up to 5318 non-diabetic participants from 9 cohorts.
The GWAS discovery results for 9 traits from up to 7 cohorts are included in these files. Results from all traits are ln-‐transformed and are adjusted for age, sex, BMI and study-‐specific covariates.
Results for fasting glucose are from models adjusted for age and sex, and from up to 133,010 non-diabetic participants from 66 studies. Fasting insulin results are for ln-transformed fasting insulin as the outcome and are adjusted for age, sex and are reported both with and without BMI adjustment. These results are from up to 108,557 individuals from 56 studies. Results for 2h-glucose are from models adjusted for age and sex and from up to 42,854 individuals from 20 studies.