Table 6

Mean lung function and prevalence of COPD by vitamin D receptor genotype

Genotype	Genotype	FEV₁ (l)			FVC (l)			FEV₁/FVC ratio			COPD
Genotype	Genotype	N	Mean	SD	N	Mean	SD	N	Mean	SD	Total N	N	%
Apa1	gg	1117	2.46	0.68	1113	3.45	0.93	1113	0.717	0.09	1113	193	17.3
	ga	1279	2.41	0.68	1278	3.39	0.92	1278	0.714	0.09	1278	238	18.6
	aa	373	2.42	0.65	372	3.40	0.89	372	0.717	0.09	372	68	18.3

Fok1	gg	1769	2.43	0.68	1765	3.41	0.92	1765	0.717	0.09	1765	305	17.3
	ga	871	2.43	0.67	869	3.41	0.92	869	0.715	0.09	869	163	18.8
	aa	98	2.50	0.70	98	3.55	1.00	98	0.709	0.07	98	20	20.4

Cdx2	aa	791	2.42	0.66	789	3.40	0.93	789	0.716	0.08	789	147	18.6
	ca	1349	2.44	0.68	1346	3.41	0.89	1346	0.716	0.09	1346	231	17.2
	cc	636	2.45	0.68	635	3.44	0.94	635	0.715	0.08	635	119	18.7

COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; 25(OH)D, 25 hydroxy vitamin D.