Role of Lipid Peroxidation Products, Plasma Total Antioxidant Status, and Cu-, Zn-Superoxide Dismutase Activity as Biomarkers of Oxidative Stress in Elderly Prediabetics

Abstract

The relationship between hyperglycemia and oxidative stress in diabetes is well known, but the influence of metabolic disturbances recognized as prediabetes, in elderly patients especially, awaits for an explanation. Methods. 52 elderly persons (65 years old and older) with no acute or severe chronic disorders were assessed: waist circumference (WC), body mass index (BMI), percentage of body fat (FAT), and arterial blood pressure. During an oral glucose tolerance test (OGTT) fasting (0′) and 120-minute (120′) glycemia and insulinemia were determined, and type 2 diabetics (n = 6) were excluded. Subjects were tested for glycated hemoglobin HbA1c, plasma lipids, total antioxidant status (TAS), thiobarbituric acid-reacting substances (TBARS), and activity of erythrocyte superoxide dismutase (SOD-1). According to OGTT results, patients were classified as normoglycemics, (NGT, n = 18) and prediabetics, (PRE, n = 28). Results. Both groups did not differ with their lipids, FAT, and TBARS. PRE group had higher WC (P < 0.002) and BMI (P < 0.002). Lower SOD-1 activity (P < 0.04) and TAS status (P < 0.04) were found in PRE versus NGT group. Significance. In elderly prediabetics, SOD-1 and TAS seem to reflect the first symptoms of oxidative stress, while TBARS are later biomarkers of oxidative stress.

The impact of high density lipoprotein on oxidant-antioxidant balance in healthy elderly subjects

“…Our previous study showed a significant positive correlation between SOD -1 and TAS in normoglycemic patients, while no such correlation was observed in hyperglycemic ones. 30 In this study, we found a similar strong positive correlation between SOD -1 and TAS in the high HDL -C group, whereas in the low HDL -C group, a disintegration between intra-and extracellular antioxidant state was observed. In the low HDL -C group, a positive correlation between TAS and Tg levels might reflect the mobilizing effect of Tg on plasma antioxidant capacity associated with a decrease in HDL -C levels.…”

How does thiol/disulfide homeostasis change in prediabetic patients?

“…The negative correlation between age and thiol levels, and the positive correlation between disulfide forms determined in our study shows that oxidative stress levels increase with age [18,23,26,27].…”

“…Many previous studies have shown that oxidative stress levels increase in prediabetic patients [12,13]. These have been associated with the increase of oxidant radicals [13] or the decrease of antioxidant capacity [18]. There are a limited number of studies showing the thiol/disulfide homeostatic status in prediabetic patients [12].…”

Impact of glycaemia, dyslipidemia and anxiety level on oxidative stress in prediabetic and diabetic patients

“…It is observed that greater SOD activity in newly detected type 2 diabetic patients than normal glucose tolerance patients (Siddiqui et al, 2019). It is also reported that decreased erythrocytic superoxide dismutase activity in elderly prediabetic patients (Dzięgielewska-Gęsiak et al, 2014). The increase in the total SOD activity suggests an adaptive reaction, maybe due to the increased generation of superoxide anion radical, which would lead to an increase in the formation of H2O2 (Bandeira et al, 2012).…”