The effect of insulin intensive therapy on serum level of oxidative stress in patients with first diagnosed type 2 diabetes mellitus

Abstract

Objective To observe the difference in serum level of oxidative stress between first diagnosed type 2 diabetes mellitus (T2DM) patients and healthy person with normal glucose,compare the difference in serum level of oxidative stress between T2DM patients with continuous subcutaneous insulin injection (CSII) and multiple subcutaneous insulin injection (MSII),and further explore the possible mechanism of CSII superior to MSII.Methods Sixty patients with first diagnosed T2DM were divided into CSII group and MSII group by random digits table,with 30 patients in each group and given 14 days treatment of CSII and MSII respectively.Thirty healthy person were selected with age and sex matched in same period as control group,then fasting plasma glucose (FPG),2-hour postprandial blood glucose (2 h PG),glycosylated serum protein (GA),fasting insulin (FINS),superoxide dismutase (SOD),reduced glutathione (rGSH) and malondialdehyde (MDA) before and after treatment was measured and analyzed.Results The FPG,2 h PG,GA,HOMA model of insulin resistance (HOMA-IR) and MDA before treatment in CSII group and MSII group was higher than that in control group [FPG:(13.81 ± 3.14),(13.58 ±2.10) mmol/L vs.(5.21±0.42) mmol/L; 2 h PG:(21.72 ±4.43),(22.07 ±3.86) mmol/L vs.(6.19 ± 0.47) mmol/L;GA:(28.74 ± 4.40),(28.83 ± 5.01) mmol/L vs.(13.24± 1.26) mmol/L;HOMA-IR:0.45 ±0.13,0.43 ±0.12 vs.0.20 ±0.15;MDA:(4.37 ± 1.13),(4.44 ± 1.07) mmol/L vs.(2.37 ±0.58) mmol/L] (P ＜ 0.01),and the HOMA model 3 cell function index (HOMA-β),SOD and rGSH was lower than that in control group [HOMA-β:0.98 ±0.17,0.96 ±0.12 vs.1.91 ±0.19;SOD:(29.63 ±9.29),(28.07 ±9.62) mU/L vs.(41.00 ± 12.89) mU/L;rGSH:(157.03 ±46.58),(165.23 ±45.66) ng/L vs.(212.00 ± 61.67) ng/L] (P ＜ 0.01).There was no significant difference between CSII group and MSII group (P ＞ 0.05).The FPG,HOMA-β,SOD and MDA after treatment in CSII group was no significant difference compared with that in control group (P ＞ 0.05).But the FPG and MDA after treatment in MSII group was higher than that in control group(P＜ 0.01 or ＜ 0.05),and the HOMA-β and SOD was lower than that in control group (P ＜ 0.01).The FPG,2 h PG,GA and MDA after treatment in CSII group was lower than that in MSII group (P ＜ 0.01 or ＜ 0.05).The HOMA-β was higher than that in MSII group (P ＜ 0.01).Multi-factor analysis results showed that the HOMA-β and FPG (r =-0.919,P ＜ 0.01),2 h PG (r =-0.904,P ＜ 0.01),GA (r =-0.830,P ＜ 0.01) and MDA (r =-0.653,P ＜ 0.01) was negatively correlated,and SOD (r =0.454,P ＜ 0.01) and rGSH (r =0.394,P ＜ 0.01) was positively correlated.Conclusions Oxidative stress level of first diagnosed T2DM is significantly higher than that of healthy people.Two intensive insulin treatment for first diagnosed T2DM can reduce blood glucose level,oxidative stress levels and improve insulin resistance and β cell function.CSII can effectively reduce blood glucose,reduce the level of lipid peroxidation and improve β-cell function compared with MSII. Key words: Diabetes mellitus,type 2; Insulin; Oxidative stress