Table 2. Concentrations of trace elements in urine among DKD stages.

Elements	NDKD (ng/mL)	Mid DKD (ng/mL)	End DKD (ng/mL)	P value*
Iron	785.0 (506.1–1154.0)	645.5 (421.2–1024.3)	328.9 (191.5–566.3)	<0.001
Copper	209.0 (110.6–373.3)	223.6 (132.2–405.2)	305.8 (183.9–435.2)	<0.001
Chromium	72.7 (59.6–89.2)	76.2 (59.3–94.0)	74.7 (53.3–93.6)	0.266
Cobalt	0.55 (0.42–0.79)	0.54 (0.36–0.78)	0.34 (0.22–0.53)	<0.001
Zinc	558.5 (323.4–833.1)	609.5 (397.5–904.0)	473.1 (249.8–786.5)	0.002
Selenium	20.3 (13.6–28.6)	18.5 (11.0–26.0)	17.6 (10.0–21.5)	<0.001
Vanadium	44.8 (31.4–65.9)	46.3 (30.2–69.4)	46.7 (32.2–67.7)	0.767
Nickel	11.4 (8.10–15.8)	9.03 (5.92–13.42)	5.15 (2.69–7.66)	<0.001
Manganese	1.55 (0.95–2.46)	1.86 (1.04–3.36)	2.79 (1.67–4.33)	<0.001

Note: Trace elements are described using median (IQR). The concentrations of trace elements in urine were corrected for specific gravity ().

^* VP values were calculated using the Wilcoxon rank-sum test for continuous variables.

DKD, diabetic kidney diseaseNDKD, non-DKD