Table 4.

Mendelian randomization estimates for the associations between three measures of arsenic metabolism efficiency and asthma-associated traits among those with low inferred rice consumption (n = 10,087).

Metabolite	Ever-smokers		Never-smokers
	Odds ratio (95%CI)	p-value	Odds ratio (95%CI)	p-value
	n = 3947		n = 6140
Lifetime asthma
%iAs	1.07 (0.95–1.21)	0.2754	1.14 (0.92–1.41)	0.2120
%MMA	1.04 (0.95–1.14)	0.3960	1.10 (0.94–1.28)	0.2294
%DMA	0.97 (0.92–1.03)	0.3374	0.95 (0.86–1.04)	0.2215
Current asthma
%iAs	1.09 (0.93–1.28)	0.2858	0.90 (0.66–1.21)	0.4808
%MMA	1.06 (0.94–1.19)	0.3510	0.92 (0.73–1.16)	0.4924
%DMA	0.97 (0.90–1.03)	0.3152	1.05 (0.92–1.20)	0.4674
Past asthma
%iAs	1.07 (0.90–1.28)	0.4509	1.06 (0.95–1.18)	0.3037
%MMA	1.03 (0.91–1.18)	0.6270	1.05 (0.97–1.14)	0.2178
%DMA	0.98 (0.90–1.06)	0.5512	0.97 (0.93–1.02)	0.2461
FEV1 below LLN
%iAs	1.13 (0.99–1.28)	0.0617	0.96 (0.86–1.08)	0.4976
%MMA	1.10 (1.01–1.21)	0.0367*	0.98 (0.90–1.07)	0.6839
%DMA	0.95 (0.90–1.00)	0.0414*	1.01 (0.96–1.07)	0.6026
FVC below LLN
%iAs	0.98 (0.85–1.11)	0.7103	0.99 (0.88–1.11)	0.8596
%MMA	0.98 (0.89–1.08)	0.6520	1.00 (0.92–1.09)	0.9822
%DMA	1.01 (0.96–1.07)	0.6773	1.00 (0.95–1.05)	0.9256
FEV1/FVC below LLN
%iAs	1.13 (0.97–1.32)	0.1057	0.89 (0.75–1.05)	0.1707
%MMA	1.08 (0.97–1.21)	0.1515	0.93 (0.82–1.06)	0.2825
%DMA	0.95 (0.89–1.01)	0.1246	1.05 (0.97–1.13)	0.2388
PEF below LLN
%iAs	0.98 (0.83–1.16)	0.8151	1.04 (0.88–1.24)	0.6296
%MMA	1.02 (0.90–1.15)	0.8038	1.01 (0.89–1.14)	0.9350
%DMA	1.00 (0.93–1.07)	0.9527	0.99 (0.92–1.07)	0.8244

Low inferred consumers of rice are those below the 80th percentile of consumption for grains.

The reported coefficients are interpreted as the expected increase in the odds of the trait for a one percentage point increase in the arsenic metabolite.

LLN Lower limit of normal, FEV₁ forced expiratory volume in one second (mL), FVC forced vital capacity (mL), PEF peak expiratory flow (mL/s), %iAs percent of inorganic arsenic, %MMA percent of monomethylarsenate, %DMA percent of dimethylarsinate.