From this initial set of 76 WC- and/or WHR- associated signals, we sought to enrich for variants with specific impacts on central adiposity, by identifying a subset of 23 SNPs for which there was greatest evidence for a disproportionate effect on central adiposity, as opposed to overall adiposity or height. These 23 variants all had strong (i.e. P≤10−5) associations with WC and/or WHR while displaying only weak evidence of an association with overall adiposity (BMI, P>0.01) or adult height (P≥0.005) in the stage 1 GWAS meta-analysis data (Table S2). We also included three variants for reasons of biological candidacy, even though they did not precisely meet all P-value threshold criteria (see Table S2). Given the stage 1 sample size of 38,580, the follow-up P-value threshold of 10−5 provides 80% power to detect a per-allele beta of 0.045 (equivalent, for example, to a per-allele effect on WC of approximately 0.5 cm), given an additive model and MAF of 20%.
