The PLINK version 1.04 was used to analyze genome-wide data obtained in Stage I. A set of 4,305 SNPs with MAF ≥ 0.35 and ≥ 100 kb between two adjacent SNPs was selected to evaluate the population structure. The inflation factor λ was estimated to be 1.024, suggesting that population substructure, if present, should not have any appreciable effect on the results. Odds ratios (OR) and 95% confidence intervals (CI) were estimated from logistic regression analysis. Age was adjusted in the GWA analyses of Stage I data to select promising SNPs. Additional adjustment was made for education in the analyses of Stages II and III data. Finally, multivariate analyses including age, education, study stage, body mass index, age at menarche, and age at first live birth were performed in the pooled analyses of data from all stages. None of the 29 markers genotyped in Stage II showed deviations from Hardy-Weinberg equilibrium (P > 0.05). P-values based on 2-tailed tests are presented.
