variable in the linear regression model in MACH2QTL [33] (http://www.sph.umich.edu/csg/abecasis/MACH/download/). To account for the clear gender dimorphism in these traits, analyses were performed in men and women separately, apart from the SardiNIA and deCODE studies for which, due to family relatedness between men and women, a combined analysis of men and women together was also performed, which accounted both for relatedness and gender in a single test [12]. For these GWAS analyses the software packages MACH2QTL [33], Merlin [39] and SNPTEST [34] were used.
