We downloaded information on genome-wide significant (P < 5×10−8) associations with the traits “nicotine dependence” and “smoking behaviour” in the NHGRI-EBI GWAS Catalog42. We assessed these top smoking-associated SNPs in our Stage 1 meta-analysis results. We also assessed overlap of smoking and COPD in the publically available summary statistics from the 2010 Tobacco and Genetics Consortium GWAS45. We evaluated our top COPD loci associations from overall meta-analysis with both cigarettes per day and ever-smoking traits. For COPD risk SNPs not directly analyzed in the Tobacco and Genetics Consortium GWAS, we attempted to examine proxy SNPs in LD (r2 > 0.5, 1000 genomes phase1 CEU) with our top COPD loci.
