Table 2.

Odds ratios for serum homocysteine and arsenic exposure predicting arsenic-induced skin lesions in conditional logistic regression models (552 matched pairs).

Predictor	Level/unit	Model 1a OR (95% CI)	Model 2b OR (95% CI)
Serum Hcys	< 10 μM	ref.	ref.
	10–15 μM	1.47 (1.03, 2.10)	1.53 (1.06, 2.20)
	15–20 μM	1.82 (1.21, 2.73)	1.87 (1.24, 2.82)
	> 20 μM	2.38 (1.51, 3.76)	2.48 (1.57, 3.94)
Well water As	< 10 μg/L	ref.	ref.
	10–50 μg/L	1.59 (1.03, 2.45)	1.65 (1.06, 2.57)
	50–100 μg/L	2.06 (1.32, 3.21)	2.08 (1.32, 3.28)
	100–200 μg/L	2.41 (1.58, 3.67)	2.30 (1.49, 3.55)
	>200 μg/L	4.35 (2.79, 6.79)	4.35 (2.76, 6.85)
Urinary InAs (%)c	< 11.1%	ref.	--
	11.1 – 15.0%	0.99 (0.72, 1.36)	--
	> 15.0%	1.34 (0.98, 1.83)	--
Urinary MMA (%)c	< 11.5%	ref.	--
	11.5 – 15.4%	0.85 (0.62, 1.17)	--
	> 15.4%	1.11 (0.81, 1.52)	--
Urinary DMA (%)c	< 69.6%	ref.	ref.
	69.6 – 76.3%	0.79 (0.58, 1.07)	0.78 (0.57, 1.06)
	> 76.3%	0.72 (0.52, 0.98)	0.68 (0.49, 0.94)

^aModel 1 included listed predictor, adjusted for wAs (categorical), age (continuous), and education (categorical);

^bModel 2 included predictors serum Hcys (categorical), wAs (categorical) and urinary %DMA (categorical), adjusted for age (continuous), and education (categorical);

^cCutoffs based on tertiles in control group