Plasma Lipid Peroxidation and Antioxidiant Nutrients in Type 2 Diabetic Patients
Thavatchai Peerapatdit MD*, Natchai Patchanans MSc**, Atip Likidlilid MSc**, Saiphon Poldee MSc**, Charn Sriratanasathavorn MD***
Affiliation : * Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, ** Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, *** Her Majesty’s Cardiac Center, Faculty of Medicine Siriraj Hospital, Mahidol University
Background and Objective : Observation shows diabetic patients to be more prone to oxidative stress be-
cause of hyperglycemia. The elevation of free radical production by this hyperglycemic production may
exacerbate cardiovascular complication in diabetes. This study aims to investigate the oxidative stress re-
lated parameters in type 2 DM. Since the effects of glycemic control and cardiovascular complications in DM
on these parameters has been not fully determined, the comparison between plasma MDA (malondialdehyde)
and antioxidant nutrients with their age-matched normal healthy group may be used to determine the suscep-
tibility of oxidative stress in this type of DM.
Materials and Methods : MDA and antioxidant nutrients (vitamin A, C, E and β-carotene) were analyzed in
plasma of 19 subjects with poorly controlled type 2 DM (fasting plasma glucose [FPG] >180 mg/dl), 26
subjects with fairly controlled type 2 DM (FPG ≤ 180 mg/dl), and 20 subjects with type 2 DM complicated
coronary heart disease (CHD) who were matched for age and gender. Twenty healthy subjects with normal
plasma glucose level (FPG < 110 mg/dl) and matched for age and gender served as a control group. In all
groups of DM these oxidative stress parameters were compared to a normal group.
Results : The plasma MDA levels were significantly higher in all types of DM compared to age-matched normal
control. Plasma antioxidant vitamin C and E significantly lower only in poorly controlled and CHD compli-
cated type 2 DM, respectively. The mean of plasma vitamin E level was lowest in type 2 DM complicated with
CHD. No significant differences in both plasma vitamin A and β-carotene were noted between any types of DM
and age-matched normal healthy group. The positive correlation between MDA and FPG was demonstrated
in most group of patients with their normal subjects except in fairly controlled type 2 DM and negative
correlation between vitamin E and FPG was also demonstrated in type 2 DM with CHD.
Conclusion : These findings suggested that diabetic patients were susceptible to oxidative stress and higher
plasma glucose level had an association with free radical-mediated lipid peroxidation. The lowest level of
vitamin E in type 2 DM complicated with CHD indicated that oxidative stress played an important role in
cardiovascular complication and vitamin E supplementation may be necessary for treatment and prevention
in this group of diabetics.
Keywords : Lipid peroxidation, Antioxidants, Atherosclerosis, Oxidative stress, Type 2 diabetes
