Table 2. Comparison of biochemical parameters and biomarkers of kidney injury in the study subjects.

	Control group (n = 92)	Group A (n = 40)	Group B (n = 33)	Group C (n = 19)
Blood lead (μg/L)	33 [29, 38.75]	122.5 [95.25, 158.50]*	135 [93, 164.5]*	111 [76, 142]*
Urinary KIM-1/Cr (ng/g)	13.85 [9.20, 20.84]	27.25 [18.84, 40.24]*	36.16 [19.45, 54.79]*	28.34 [20.40, 50.70]*
Urinary NAG/Cr (U/g)	13.10 ± 5.98	20.51 ± 6.72*	18.42 ± 6.74*	19.99 ± 11.95*
Urinary α1-MG/Cr (mg/g)	4.35 [3.07, 7.09]	5.28 [3.82, 8.36]	6.87 [4.19, 8.88]*	7.85 [3.99, 9.26]*
Urinary β2-MG/Cr (mg/g)	0.13 [0.10, 0.21]	0.20 [0.15, 0.27]*	0.19 [0.12, 0.34]*	0.19 [0.13, 0.32]*

Note: Normally distributed data were presented as mean ± SD. Non-normally distributed data were presented using median (25th, 75th percentile). *p < 0.05 compared with control group.