Table 4. Associations of genetically determined milk intake with hay fever and asthma (N=361302).

	unadjusted					Adjusted for age, sex, and PCs				+smoking, alcohol, and BMI
	OR	LCI	UCI	P	OR	SE****	LCI	UCI	P	OR	LCI	UCI	p
Hay fever
Lactase genotype
GG (non-persistence)	1 (ref)				1 (ref)					1 (ref)
GA (persistence)	0.989	0.956	1.022	0.514	1.001		0.968	1.036	0.939	1.000	0.967	1.035	0.967
AA (persistence)	0.956	0.925	0.988	0.007	0.983		0.951	1.016	0.304	0.983	0.951	1.016	0.305
AA vs. GA/GG	0.965	0.951	0.981	<0.001	0.982		0.966	0.997	0.022	0.982	0.967	0.998	0.026
Per milk-increasing allele	0.972	0.960	0.985	<0.001	0.986	0.006	0.974	0.999	0.036	0.987	0.974	0.999	0.041
Genotype × milk*				0.047					0.044				0.048
Drinking vs. not drinking milk (genetically determined)					0.791		0.636	0.982	0.033
Per glass of genetically determined higher milk intake*****						0.810		0.667	0.983	0.033
Hay fever, no-milk drinkers**
Lactase genotype
GG (non-persistence)	1 (ref)				1 (ref)					1 (ref)
GA (persistence)	1.030	0.929	1.145	0.568	1.033		0.930	1.149	0.535	1.039	0.934	1.155	0.479
AA (persistence)	1.033	0.933	1.143	0.529	1.062		0.958	1.177	0.253	1.069	0.963	1.185	0.210
AA vs. GA/GG	1.007	0.957	1.060	0.785	1.032		0.980	1.088	0.229	1.035	0.982	1.090	0.203
Per milk-increasing allele	1.010	0.970	1.051	0.635	1.029	0.022	0.987	1.072	0.177	1.031	0.989	1.075	0.148
Hay fever, milk drinkers***
Lactase genotype
GG (non-persistence)	1 (ref)				1 (ref)					1 (ref)
GA (persistence)	0.989	0.955	1.025	0.549	1.002		0.967	1.038	0.911	1.001	0.966	1.037	0.965
AA (persistence)	0.954	0.921	0.987	0.007	0.980		0.946	1.014	0.246	0.979	0.945	1.014	0.232
AA vs. GA/GG	0.963	0.947	0.979	<0.001	0.978		0.962	0.994	0.008	0.978	0.962	0.995	0.009
Per milk-increasing allele	0.970	0.957	0.983	<0.001	0.984	0.007	0.970	0.997	0.016	0.984	0.970	0.997	0.017
Per glass of genetically determined higher milk intake*****						0.775		0.632	0.949	0.014
Asthma
Lactase genotype
GG (non-persistence)	1 (ref)				1 (ref)					1 (ref)
GA (persistence)	0.976	0.933	1.021	0.286	0.976		0.934	1.021	0.295	0.971	0.928	1.05	0.198
AA (persistence)	0.944	0.904	0.986	0.009	0.944		0.904	0.987	0.010	0.937	0.896	0.979	0.004
AA vs. GA/GG	0.964	0.944	0.984	<0.001	0.964		0.944	0.984	<0.001	0.960	0.941	0.981	<0.001
Per milk-increasing allele	0.969	0.953	0.986	<0.001	0.969	0.008	0.953	0.986	<0.001	0.966	0.950	0.982	<0.001
Genotype × milk*				0.615					0.594				0.495
Drinking vs. not drinking milk (genetically determined)					0.587		0.442	0.779	0.001
Per glass of genetically determined higher milk intake*****						0.620		0.481	0.799	0.001

Note: ‘Genetically determined’ refers to (1) an additive model with a per allele (A) milk-increasing effect, and (2) major homozygotes (AA) vs. heterozygotes (GA) and minor homozygotes combined (GG). AA: N=205376, GA: N=133909, GG: N=22017.

Abbreviations: BMI, body mass index; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; OR, odds ratio; LCI, lower confidence interval; UCI, upper confidence interval; PC, principal component; SE, standard error.

^*rs4988235 genotype × drinking milk (no/yes) interaction test.

^**N=28854.

^***N=335107.

^****Used in IV-analyses.

^*****SNP-milk intake estimates, N=2298. SNP-outcome estimates: N_{hay fever} =361302. N_{hay fever}, _{milk drinkers}=335107. N_asthma=361302.