Table 3 Associations of SNPs in IL6 with rate of decline of FEV₁ in the LHS and association with COPD in the NETT-NAS

Bin	SNP ID	SNP in gene	LD (r² with rs1800795)		Rate of FEV₁ decline study in the LHS				COPD case-control study in the NETT-NAS
Bin	SNP ID	SNP in gene	LHS	NETT-NAS	Fast decline MAF %	Non-decline MAF %	p Value‡ genotype based	p Value‡ additive	NETT MAF %	NAS MAF %	p Value§ genotype-based	p Value§ additive
1	rs1800797†	-598G/A	NA	0.93					0.41	0.35	0.06	0.02
1	rs1800795*†	-174G/C	–	–	0.45	0.40	0.006	0.041	0.42	0.36	0.03	0.01
1	rs2069832†	615A/G	NA	0.98					0.42	0.37	0.10	0.09
1	rs1474348†	1090G/C	NA	0.97					0.41	0.36	0.10	0.04
1	rs1474347†	1306G/T	NA	0.98					0.42	0.36	0.06	0.03
2	rs1554606*†	1889G/T	0.84	0.87	0.47	0.43	0.011	0.103	0.44	0.38	0.02	0.01
2	rs2069845*	3331G/A	0.89	NA	0.47	0.42	0.007	0.078
3	rs2069825*	-1479CT/–	0.90	NA	0.44	0.37	<0.001	0.023
4	rs2069840*†	1754C/G	0.36	0.33	0.32	0.37	0.005	0.064	0.35	0.36	0.30	0.70
5	rs1818879*	5909G/A	0.32	NA	0.29	0.34	0.012	0.035
6	rs2069827*†	-1363G/T	0.12	0.14	0.08	0.08	0.786¶	0.669	0.09	0.09	0.90	0.40
Other	rs2069849†	4338C/T	NA	0.02					0.03	0.02	0.20	0.20

COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 s; LD, linkage disequilibrium; LHS, Lung Health Study; MAF, minor allele frequency; NAS, Normative Aging Study; NETT, National Emphysema Treatment Trial; SNP, single nucleotide polymorphism.
*Genotyped in the LHS.
†Genotyped in the NETT-NAS.
‡Adjustment for confounding factors such as age, gender, pack-years of smoking and research centre.
§As the NAS controls were uniformly male smokers with normal lung function, the models were adjusted for age and pack-years.
¶The p values were from a dominant genetic model because the minor allele frequency of this SNP was very low.