Glutathione and Glutathione Peroxidase in Type 1 Diabetic Patients
Atip Likidlilid MSc*, Natchai Patchanans MSc*, Saiphon Poldee MSc*, Thavatchai Peerapatdit MD **
Affiliation : * Department of Biochemistry, Faculty of Medicine, Siriraj Hospital, Mahidol University ** Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University
Objective : Diabetic (DM) patients are claimed to be under oxidative stress because of hyperglycemia. The
influence of free radical production by this hyperglycemic induction may involve cardiovascular complica-
tions in diabetes. The present study aimed to compare the glutathione (GSH) level and glutathione peroxidase
(GPx) activity in type 1 DM and a normal healthy group.
Materials and Methods : GSH level and GPx activity were determined in red cells of 20 subjects of type 1 DM
containing fasting plasma glucose (FPG) > 140 mg/dL. Twenty healthy normal subjects with normal plasma
glucose level (FPG < 110 mg/dL) and matched for gender and age served as the control group. These oxida-
tive stress parameters of type 1 DM were compared to a control group by unpaired student’s t-test. The
association of these parameters with FPG was performed by Pearson product moment correlation.
Results : The level of red cell GSH was significantly lower in type 1 DM (p = 0.011) but red cell GPx activity
was significantly increased (p = 0.003) when compared to age-matched normal control. The decrement of red
cell GSH may be due to the higher rate of consumption of GSH, increasing GPx activity or a reduction of
pentose phosphate pathway, stimulated by insulin, resulting in lowered GSH recycle. The correlation between
FPG and GSH in type 1 diabetic patients compared with healthy normal subjects was also observed and it was
found that there was a negative correlation, but not found between FPG and GPx activity.
Conclusion : The present finding suggested that type 1 DM patients were susceptible to oxidative stress and
higher blood glucose level had an association with free-radical-mediated lipid peroxidation. Therefore, any
means that can reduce oxidative stress may be beneficial for slow progression of cardiovascular complication
in type 1 diabetic patients.
Keywords : Type 1 diabetes, Oxidative stress, Glutathione, Glutathione peroxidase, Cardiovascular complication
