Table 5.

Correlations of each urinary pteridine derivative with urinary pteridines, DNA/RNA oxidation products and 15-isoprostane F_2t.

Variable	Pteridines	DNA/RNA oxidation products	15-Isoprostane F2t
Pterin-6-carboxylic acid	0.509**	0.408**	0.264**
	0.548**	0.413**	0.310**
Neopterin	0.654**	0.531**	0.413**
	0.663**	0.521**	0.437**
Xanthopterin	0.276**	0.112	0.078
	0.269**	0.105	0.035
Isoxanthopterin	0.031	0.174	− 0.104
	0.017	0.161	− 0.133
Biopterin	0.712**	0.505**	0.505**
	0.688**	0.476**	0.511**
Pterin	0.278*	0.401**	0.199*
	0.309**	0.396**	0.204*

Shown are Pearson’s correlation coefficients in univariate analysis (upper lines) and standardized partial regression coefficients in multivariate analysis (lower lines) between each pair of the variables. In multivariate analysis, age, history of smoking, BMI and eGFR were used as other explanatory variables.

Asterisks denote significant correlations (*p < 0.05; **p < 0.01).