RRM2 attenuates the renal tubular ferroptosis in diabetic kidney disease through PI3K/Akt/Nrf2 pathway

Table 1 Baseline characteristics of the study population

Characteristics	Control (n = 120)	T2DM (n = 194)	P value
Age (years)	56.80 ± 10.41	55.16 ± 9.67	0.158
Sex (male), n (%)	68 (56.7)	101 (52.1)	0.426
BMI (kg/m2)	24.01 ± 1.24	24.55 ± 1.15	< 0.001
Duration (years)	0	9.14 ± 2.01	< 0.001
SBP (mmHg)	123.44 ± 11.21	136.82 ± 15.18	< 0.001
FBG (mmol/L)	4.72 ± 0.66	7.76 ± 1.15	< 0.001
HbA1c (%)	4.98 ± 0.82	7.94 ± 1.17	< 0.001
TG (mmol/L)	1.89 ± 0.79	2.11 ± 0.82	0.021
TC (mmol/L)	5.29 ± 0.47	5.50 ± 0.72	0.002
eGFR (mL/minute/1.73 m2)	105.24 ± 18.35	99.47 ± 22.12	0.017
Scr (μmol/L)	67.92 ± 10.40	82.56 ± 17.46	< 0.001
Urinary NGAL (ng/mL)	6.57 ± 0.92	8.62 ± 1.51	< 0.001
Urinary KIM-1 (ng/mL)	1.01 ± 0.24	1.30 ± 0.36	< 0.001
MDA (nmol/mL)	7.30 ± 1.13	9.14 ± 1.51	< 0.001
GSH (nmol/mL)	10.76 ± 1.75	8.31 ± 1.92	< 0.001
SLC7A11 (pg/mL)	141.36 ± 16.28	125.04 ± 19.26	< 0.001
GPX4 (ng/mL)	175.23 ± 23.89	139.14 ± 20.87	< 0.001
RRM2 (pg/mL)	24.17 ± 3.83	37.39 ± 6.69	< 0.001

Continuous variables are expressed as mean ± SD, and analyzed using t-test or Wilcoxon-Mann-Whitney test. Categorical variables are expressed as frequency (percentage), and analyzed using the χ² test. T2DM: Type 2 diabetes mellitus; BMI: Body mass index; SBP: Systolic blood pressure; FBG: Fasting blood glucose; HbA1c: Glycosylated hemoglobin; TG: Triglyceride; TC: Total cholesterol; eGFR: Estimated glomerular filtration rate; Scr: Serum creatinine; NGAL: Neutrophil gelatinase-associated lipocalin; KIM-1: Kidney injury molecule-1; MDA: Malondialdehyde; GSH: Glutathione; SLC7A11: Solute carrier family 7 member 11; GPX4: Glutathione peroxidase 4; RRM2: Ribonucleotide reductase regulatory subunit M2.