Table 2. Levels of renal biomarkers at baseline and 6 months after the beginning of the study in compared groups.

Variable	Insulin-treated group (Control) n = 21		Insulin-vildagliptin-treated group (VIG) n = 23		p*	p**
	0 months	6 months	0 months	6 months
Serum urea, mmol/L	5.6 [4.8; 6.5]	-	5.0 [4.0; 5.9]	-	0.08	NA
Serum creatinine, μmol/L	82.0 [74.0; 89.0]	80.0 [74.0; 90.5]	82.0 [71.0; 92.0]	84.0 [67.0; 94.0]	0.69	0.72
eGFRcreat, mL/min/1.73 m 2	77.0 [67.5; 84.4]	78.2 [65.3; 88.3]	69.8 [62.7; 95.0]	72.8 [61.8; 94.7]	0.62	0.86
Serum cystatin C, mg/L	0.87 [0.81; 1.01]	0.86 [0.79; 0.99]	0.84 [0.76; 0.93]	0.75 [0.69; 0.82]	0.12	0.01
eGFRcys, mL/min/1.73 m 2	89.9 [73.8; 100.8]	94.6 [71.5; 100.1]	90.6 [81.9; 104.1]	100.9 [95.1; 107.6]	0.29	0.049
eGFRcreat-cys, mL/min/1.73 m 2	80.0 [73.0; 91.0]	79.0 [66.5; 93.5]	79.0 [75.0; 101.0]	90.0 [77.0; 104.0]	0.44	0.18
Urinary albumin/creatinine ratio (UACR), mg/g Cr.	26.7 [20.1; 70.4]	27.2 [12.6; 89.1]	28.6 [15.0; 61.4]	24.0 [16.4; 47.3]	0.69	0.63
Urinary collagen type IV/creatinine (uCol IV/Cr), μg/g Cr.	3.76 [2.39; 7.15]	4.25 [2.48; 6.03]	3.25 [1.72; 6.90]	1.73 [1.41; 4.12]	0.29	0.21
Urinary NGAL/creatinine (uNGAL/Cr), μg/g Cr.	14.0 [5.3; 24.2]	16.6 [6.8; 27.9]	19.6 [8.6; 38.8]	15.7 [8.1; 38.3]	0.28	0.48

eGFRcreat: estimated glomerular filtration rate based on serum creatinine by CKD-EPI equation; eGFRcys: eGFRbased on serum cystatin C by CKD-EPI equation; eGFRcreat-cys: eGFR based on serum creatinine and cystatin C by CKD-EPI equation. – : not measured. NA: not applicable.

Data are reported as median [25th percentile; 75th percentile]. The difference with P<0.01 for comparison between the levels of renal biomarkers at baseline and 6 months after initiation of the study in the Wilcoxon signed-rank test is indicated in bold. p*– comparisons made between baseline values in the studied groups (by Mann-Whitney U-test). p** – comparisons made between studied groups by repeated measures in the General Linear Models (both measurements in each group are taken into account).