Association of Age-Related Macular Degeneration with Erythrocyte Antioxidant Enzymes Activity and Serum Total Antioxidant Status

Table 2

Conditional effect of decrease in GPx activity on AMD at different levels of SOD.

SOD^* ( values)	Effect of decrease of GPx
	(95% CI)		OR	Probability of AMD
10th percentile (−1.31)	−0.02 (−0.79–0.74)	0.953	0.98	0.49
25th percentile (−0.73)	0.55 (0.00–1.09)	0.049	1.73	0.63
50th percentile (−0.06)	1.20 (0.63–1.76)	<0.001	3.31	0.77
75th percentile (0.59)	1.83 (0.98–2.67)	<0.001	6.22	0.86
90th percentile (1.28)	2.50 (1.27–3.73)	<0.001	12.16	0.92

GPx = glutathione peroxidase; SOD = superoxide dismutase; = regression coefficient; 95% CI = 95% confidence intervals; = level of statistical significance; OR = odds ratio for AMD at unit decrease in standardized GPx values; probability = probability of AMD predicted by logistic regression of decrease of GPx values.
Values of GPx, SOD, and CAT were standardized before the logistic regression analysis and expressed as values; arithmetic mean was subtracted and the difference was divided by standard deviation.