To evaluate the effects of lipoic acid combined with valsartan on oxidative stress and inflammation in patients with early diabetic nephropathy.

A total of 128 patients with early diabetic nephropathy who were hospitalized at the People′s Hospital of Weifang from December 2016 to June 2017 were randomly divided into four groups according to their admission time: control group, lipoic acid group, valsartan group, and lipoic acid + valsartan group. All the groups were given routine treatment. The lipoic acid group, valsartan group, and lipoic acid + valsartan group were additionally given intravenous infusion of lipoic acid, oral valsartan, and lipoic acid plus valsartan, respectively. The levels of glucose metabolism, urinary protein, oxidative stress, and inflammation were compared between before and after treatment using paired samples t test, and between groups using LSD-t test.

After treatment, urinary albumin, urinary albumin/creatinine ratio, malondialdehyde (MDA), high sensitivity C-reactive protein (hs-CRP), and 8-iso-prostaglandin F2α (8-iso-PGF2α) were significantly lower in the lipoic acid group, valsartan group and lipoic acid + valsartan group than in the control group [(20.36±4.32) mg/L, (23.35±5.38) mg/L, (16.48±3.37) mg/L vs (44.57±7.78) mg/L, t=19.815, 17.373, 22.992, P<0.001 for all; (42.13±21.52) mg/g, (45.78±16.47) mg/g, (34.62±23.58) mg/g vs (74.72±15.33) mg/g, t=10.029, 8.906, 12.026, P<0.001 for all; (4.71±0.78) mol/ml, (5.17±0.84) mol/ml, (3.87±1.31) mol/ml vs (5.96±0.96) mol/ml, t=6.514, 4.128, 10.848, P<0.001 for all; (2.24±0.98) mg/L, (2.35±1.17) mg/L, (1.76±1.26) mg/L vs (2.93±1.15) mg/L, t=5.769, 4.999, 7.721, P<0.001 for all; (34.98±6.51) ng/L, (36.78±9.46) ng/L, (30.19±13.25) ng/L vs (44.38± 12.27) ng/L, P<0.001, =0.001, <0.001]. Superoxide dismutase (SOD) was significantly higher in all treatment groups than in the control group [(78.62±5.31) U/ml, (75.28±9.24) U/ml, (83.31±6.18) U/ml vs (72.13±7.35) U/ml, t=4.879, 2.365, 8.412, P<0.001, =0.019, <0.001]. Urinary albumin, urinary albumin/creatinine ratio, MDA, hs-CRP, and 8-iso-PGF2α in the combination group were significantly higher than those in patients treated with valsartan or lipoic acid alone (t=3.177, 5.619, P=0.002, <0.001; t=1.996, 3.120, P=0.047, <0.001; t=4.333, 6.719, P=0.002, <0.001; t=1.981, 2.478, P=0.049, =0.007; t=2.039, 2.806, P=0.043, =0.006; t=3.533, 6.047, P=0.001, <0.001).

Lipoic acid combined with valsartan can improve the oxidative stress and inflammatory state in patients with early diabetic nephropathy.