Table 6.

Association of elevated blood manganese concentrations (BMC) with ASD status among children with different GSTP1 genotypes based on co-dominant and dominant genetic models using conditional logistic regression models including the mixture index of the four heavy metals. (163 matched pairs)

						Unadjusteda			Adjustedb
Genetic Model	Higher BMC		Ref. BMC		Genotype( s)	Matched Odds Ratio	95% CI for MOR	P value c,d	Matched Odds Ratio	95% CI for MOR	P value e,f
Co- dominan t	BMC > 12pg/L	v s.	BMC < 12pg/L	a t	GSTP1 (Ile/Ile)	2.38	(0.95, 6.00)	0.07	4.58	(1.21, 17.42)	0.03
	BMC > 12pg/L	v s.	BMC < 12pg/L	a t	GSTP1 (Ile/ Val)	0.69	(0.33, 1.46)	0.34	1.26	(0.32, 5.01)	0.74
	BMC > 12pg/L	v s.	BMC < 12pg/L	a t	GSTP1 (Val/Val)	0.62	(0.21, 1.85)	0.39	0.26	(0.05, 1.42)	0.12
Domina nt	BMC > 12pg/L	v s.	BMC < 12pg/L	a t	GSTP1 (Val/*)	0.67	(0.36, 1.26)	0.22	0.67	(0.25, 1.83)	0.44
	BMC > 12pg/L	v s.	BMC < 12pg/L	a t	GSTP1 (Ile/Ile)	2.49	(0.99, 6.25)	0.05	4.27	(1.15, 15.85)	0.03

^aAdjusted for the binary mixture index based on four metals (lead, mercury, cadmium, and arsenic)

^bAdjusted for potential confounders including parental education, place of child’s birth (Kingston parish vs. other parishes), consumption of root vegetables (“yam, sweet potato, or dasheen“), salt water fish, and cakes/buns as well as the binary mixture index based on four metals (lead, mercury, cadmium, and arsenic);

^cFor the unadjusted co-dominant model, the interaction term had P = 0.06 and the binary mixture index had MOR=0.56 with (P=0.04);

^dFor the unadjusted dominant model, the interaction term had P = 0.01 and the binary mixture index had MOR=0.57 with (P=0.04);⁸

^eFor the adjusted co-dominant model, the interaction term had P = 0.03 and the binary mixture index had MOR=1.18 with (P=0.73);

^fFor the adjusted dominant model, the interaction term had P = 0.02 and the binary mixture index had MOR=1.14 with (P=0.78). (In the unadjusted analyses for both co-dominant and dominant models, lower mixture index was significantly associated with ASD, but these findings were not observed in the adjusted models.)

Note: All missing data are the same as those reported in the footnote of Tables 2–4.