IRS1 and sarcopenia: In this first large-scale GWA meta-analysis study for lean mass that included most of the cohorts worldwide with lean mass phenotypes, we identified and successfully replicated five GWS loci (in/near HSD17B11, VCAN, ADAMTSL3, IRS1, and FTO genes) for whole body lean mass and three of these (in/near VCAN, IRS1, and ADAMTSL3 genes) for appendicular lean mass, both important for sarcopenia diagnosis.