to approximate normality and adjusting for age and age2 in men and women separately) and combined the results using the regression coefficients and standard errors estimated from each study (Supplementary Fig. 2; Pearson correlation r = 0.91). Both meta-analysis procedures were implemented in the freely available METAL software package. The genomic control parameter λ was 1.10 in our initial meta-analysis without using genomic control correction in any study except SardiNIA, which, given our large sample size, suggests only a modest impact of unmodeled relatedness or population stratification in our results. The P values we report have all subsequently been corrected for this unmodeled relatedness or population stratification by application of a genomic control correction to all input studies as well as to the meta-analysis results.
