Oxidative stress and antioxidant status in patients with late-onset gestational diabetes mellitus

The relationship between late-onset gestational diabetes mellitus [GDM] and oxidative stress is not well known, and the importance of the oxidant/antioxidant equilibrium in the clinical evolution and its complications require elucidation. The aim of the study was to evaluate the relationships between maternal levels of markers of oxidative stress in women with late-onset GDM that, potentially, may have considerable clinical implications in the pathogenesis and/or the evolution of GDM. Pregnant women (n = 78; 53 with GDM, 25 controls), between the 24th and 29th week of gestation, were enrolled. Both groups were analysed for demographic data, perinatal and obstetrics outcomes together with the levels of the marker’s oxidative stress and antioxidant status. Control versus patient results in the univariate analysis were the following: pre-gestational body mass index [BMI] 23.31 ± 4.2 vs. 27.13 ± 4.6 kg/m² (P = 0.001); weeks at delivery 39.2 ± 3.05 vs. 38.9 ± 1.8 (P = 0.09); Caesarean delivery 12.5 vs. 43% (P = 0.004); macrosomia 4 vs. 9.4% (P = 0.6); lipoperoxides [LPO] 2.06 ± 1.00 vs. 3.14 ± 1.55 μmol/mg (P = 0.001); catalase 3.23 ± 1.41 vs. 2.52 ± 1.3 nmol/min/ml (P = 0.03); superoxide dismutase [SOD] 0.11 ± 0.04 vs. 0.08 ± 0.01 U/ml (P = 0.0003); glutathione peroxidase [GPX] 0.03 ± 0.006 vs. 0.025 ± 0.006 nmol/min/ml (P = 0.01); glutathione reductase [GSH] 0.004 ± 0.002 vs. 0.004 ± 0.004 nmol/min/ml (P = 0.9)]; and glutathione transferase [GST] 0.0025 ± 0.0012 vs. 0.0027 ± 0.00017 nmol/min/ml (P = 0.7). Multivariate analysis showed catalase might have a protective effect against GDM development and LPO seems to be a risk factor for the disease. These data suggest an increase in oxidative stress and a decrease in antioxidative defence in women with late-onset GDM and, as such, may have considerable clinical implications in the pathogenesis and/or the course of the pregnancy in these patients.     

Oxidative stress and antioxidant status in type 1 diabetes mellitus

OBJECTIVES: To test the hypothesis that type 1 diabetes is associated with increased oxidative stress and/or antioxidant status by investigating concentrations of 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) in urine and plasma and malondialdehyde (MDA) in plasma as indicators of lipid peroxidation in vivo, and antioxidant status in diabetic subjects compared with healthy control subjects. DESIGN AND SUBJECTS: Thirty-eight subjects with type 1 diabetes mellitus and 41 healthy age- and sex-matched control subjects were included in the study. Blood and urine samples were obtained and analysed for 8-iso-PGF2alpha with a newly developed radioimmunoassay, as well as for MDA, total antioxidant capacity (TAOC) and serum tocopherol levels. RESULTS: None of the variables of lipid peroxidation showed any significant difference between the two groups. Similarly, there were no significant correlations between the levels of 8-iso-PGF2alpha or MDA, and degree of glycemic control (HbA1c). Total antioxidant capacity in plasma was 16% lower amongst the subjects with type 1 diabetes than in the control group (P < 0.0005). Lipid corrected levels of alpha-tocopherol in serum were significantly increased in type 1 diabetic subjects (P < 0.05), as were gamma-tocopherol levels (P < 0.005). CONCLUSIONS: In spite of lower total antioxidant defence, our results do not support the oxidative stress hypothesis for type 1 diabetes mellitus. The higher tocopherol levels suggest that no vitamin E supplementation is necessary for subjects with type 1 diabetes mellitus.     

Oxidative stress and antioxidant capacity in patients with chronic pancreatitis with and without diabetes mellitus

Aim

To determine oxidant stress and antioxidant capacity in chronic pancreatitis (CP) patients with and without diabetes mellitus.

Methods

This study is a secondary data analysis of our earlier study on 127 (male?=?86) patients with CP, grouped as those with diabetes (case; n?=?23) and those without diabetes (control). Markers of antioxidant status included vitamins A and E, total antioxidant capacity (TAC; measured as ferric-reducing ability of plasma [FRAP]), and total glutathione (T-GSH). Markers for oxidative stress included lipid peroxidation, measured as thiobarbituric acid reactive substances (TBARS) and serum superoxide dismutase (s-SOD).

Results

Patients with diabetes were older (mean [SD] age 36.4 [9.7] vs. 29.3 [10.0] years; p?=?0.032), had longer duration of CP [4 (0.3?C21) vs. 3 (0.3?C24) years; p?=?0.07), and had a lower TAC (269.8 [92.4] vs. 355.5 [128.6] ??moles Fe⁺² liberated; p?=?0.003) compared to those without diabetes. In multiple logistic regression analysis taking all exploratory variables, FRAP (<270 ??moles Fe⁺² liberated) was associated with diabetes independent of duration of CP, age of patients, and TBARS levels. However, oxidative stress levels were not different between diabetic and nondiabetic patients.

Conclusions

Diabetes was found to be associated with longer duration of CP and with low antioxidant capacity. Further studies will be needed to evaluate a causal association.     

糖尿病中的氧化损伤与抗氧化研究进展

活性氧簇(ROS)引起的氧化损伤在糖尿病并发症的发病机制中起重要作用,最新研究显示线粒体ROS增加可能是糖尿病并发症发病的共同基础。ROS催化脂质、蛋白质／氨基酸及DNA 所形成的某些化学性质相对稳定的产物,有望成为反映氧化损伤的理想生物标志。近来发现噻唑烷二酮类药物、瑞格列奈、他汀类药物、血管紧张素转换酶抑制剂、血管紧张素Ⅱ受体拮抗剂和钙通道阻滞剂兼有较强的抗氧化活性,有助于防治糖尿病并发症。     

Oxidative stress in non-insulin-dependent diabetes mellitus (NIDDM) patients

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia. The oxidative stress in diabetes was greatly increased due to prolonged exposure to hyperglycemia and impairment of oxidant/antioxidant equilibrium. Proteins and lipids are among the prime targets for oxidative stress. In the present study, the oxidative stress was evaluated in 55 diabetic patients and 40 healthy subjects by measuring the levels of protein oxidation, lipid peroxidation and some enzymatic and nonenzymatic antioxidants. The oxidative products of protein (PCG) and lipid peroxidation (MDA) and nitric oxide levels in plasma of NIDDM patients were significantly increased. However, the levels of enzymatic (GPx, SOD, catalase in RBC) and nonenzymatic (β-carotene, retinol, vitamin C & E and uric acid) antioxidants of RBC showed a significant decrease in NIDDM patients compared to normal subjects. Serum protein analysis by polyacrylamide gel electrophoresis (PAGE) showed the significant difference in the ceruloplasmin, transferrin, albumin, retinal binding protein, etc. in diabetic patients compared to healthy controls. In conclusion, the results suggest that increased protein oxidation, lipid peroxidation and NO levels, decreases the levels of enzymatic and nonenzymatic antioxidants and playing a major role in diabetic complications.     

Oxidative stress markers in coronary artery disease patients with diabetes mellitus

Coronary artery disease (CAD) is the major cause of morbidity and mortality. Diabetes is one of the powerful and independent risk factor for CAD. Hyperglycemia and hypercholesterolemia initiate the oxidative stress and complications like atherosclerosis which induces poor prognosis in diabetic CAD patients. The aim of the present study was to assess oxidative stress by comparing the levels of malondialdehyde and comet tail length in diabetic CAD patients, non-diabetic CAD patients and healthy controls. The study included 400 subjects of which 200 were healthy controls, 100 were diabetic CAD patients, and 100 were non-diabetic CAD patients. Fasting and postprandial glucose levels, glycosylated hemoglobin, serum lipid levels, malondialdehyde, and DNA damage were estimated in all subjects by using commercially available kits and standard protocols. FBS (185.60 ± 6.0 mg/dL), PPG (250 ± 7.06 mg/dL), HbA1c (10.65 ± 2.01 %), TC (280.72 ± 5.25 mg/dL), TG (195.11 ± 5.99 mg/dL), LDL (163.28 ± 5.68 mg/dL), MDA (9.74 ± 2.33 n moles/mL), and comet tail length (21.60 ± 5.69 μm) were significantly high in diabetic CAD patients (p < 0.05) compared to non-diabetic CAD patients and controls. Fasting and postprandial blood sugar levels significantly correlated with oxidative stress markers like MDA (r = 0.553, r = 0.557, p < 0.01) and comet tail length (r = 0.489, r = 0.626, p < 0.01) in diabetic CAD patients compared to non-diabetic CAD patients. Our study showed that diabetic CAD patients with increased levels of oxidative stress markers (MDA and DNA damage) might have the poor prognosis than non-diabetic CAD patients.     

Insulin resistance,glucose intolerance and diabetes mellitus in obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is a highly prevalent disorder, which conveys an increased risk of cardiovascular disease and death. Type 2 diabetes mellitus (T2DM), glucose intolerance and insulin resistance (IR) are common in subjects with OSA, but a shared intimate relationship with obesity makes discerning an independent link challenging. Nonetheless, mechanistic studies suggest that OSA could contribute to impaired glucose metabolism via the effects of sleep fragmentation, sympathetic excitation and intermittent hypoxia (IH) on pancreatic B-cell function, insulin sensitivity, and systemic inflammation. In particular, emerging data suggest that IH may have an important detrimental effect on adipose tissue function and inflammation. Similarly, data from population—and clinic-level studies suggest that OSA is independently related with the prevalence and incidence of T2DM and IR, and may also lead to worse glycaemic control in diabetics. However, the ability of continuous positive airway pressure (CPAP) therapy to make a meaningful impact on T2DM or IR remains uncertain. In this review we explore the available evidence linking OSA with IR, glucose intolerance and T2DM, and discuss potential pathobiological mechanisms by which sleep disordered breathing can affect metabolic health.     

Oxidative stress and enzymatic antioxidant status in patients with hypothyroidism before and after treatment.

The present study was designed to investigate the relationship between the serum levels of oxidant-antioxidant system (malondialdehyde (MDA) level, Paraoxonase (PON1) activity, nitric oxide (NO) level and superoxide dismutase (SOD) activity) and thyroid hormone status in hypothyroidism pre and posttreatment. The study group comprised 33 patients with primary hypothyroidism. 18 of these patients were reevaluated after euthyroid state i.e. at least 6 months of thyroxine replacement. The patients were compared with 26 normal healthy controls. Serum MDA level, PON1 activity, NO level and SOD activity were measured according to an enzymatic spectrophotometric method. MDA levels were found higher in patients with hypothyroidism before the treatment than the controls. MDA levels were also found to be decreased after the treatment in patients with hypothyroidism. However MDA were found still higher than the controls after the treatment. PON1 activity was found to be lower in patients pretreatment when compared to posttreatment hypothyroidism and controls. Posttreatment of hypothyroidism mean PON1 activity significantly increased compared to pretreatment level but it was still significantly lower than control level. NO level was higher in pretreatment hypothyroidism when compared to controls. SOD activity was not found different in patients before treatment when compared to controls. SOD activity was significantly higher in after treatment when compared to both pretreatment and control levels. In conclusion, increased ROS levels in hypothyroidism may result in a pro-oxidation environment, which in turn could result in decreased antioxidant PON1 activity, increased MDA and NO levels. As a result, lipid peroxidation may have a role in the pathogenesis of the atherosclerosis in hypothyroidism.     

Oxidative stress: Changes in pregnancy and with gestational diabetes mellitus

Pregnancy is susceptible to oxidative stress and antioxidant defenses can be altered in response to elevated levels of oxidative stress. Limited data in gestational diabetes mellitus (GDM) suggest that products of lipid peroxidation may be increased and antioxidant enzyme activities decreased, although the results have been inconsistent. As in type 2 diabetes mellitus (T2DM), glycemic levels in patients with GDM correlate with concentrations of lipid peroxides. The effects of supplementation with antioxidants or antioxidant-rich food in T2DM are controversial. Whether or not increased antioxidant intake can reduce the complications of GDM in both mother and fetus has not been explored.     

Oxidative stress and diabetes mellitus: Pathogenesis of long-term complications

Oxidative stress is increased in diabetes mellitus and may play an important role in the pathogenesis of the typical long-term complications of human diabetes, like neuropathy and microangiopathy. Protein glycation and glucose autoxidation can generate free radicals that can catalyze lipid peroxidation. Other potential mechanisms of oxidative stress include the reduction of anti-oxidant defense. The role of endothelium-dependent vasodilatation and LDL oxidation in the pathogenesis of macrovascular disease in diabetes is described in relation to oxidative stress. Furthermore, the several members of the anti-oxidant system are discussed. Short-term use of anti-oxidants may improve glucose metabolism and protein glycation. However, without the results from intervention studies of long-term anti-oxidant use, e.g. on the development of diabetic vascular complications, there is presently no indication for anti-oxidant supplementation in diabetes mellitus.     

Prevalence and predictors of postpartum glucose intolerance in Italian women with gestational diabetes mellitus

Aims

To determine the prevalence of both prediabetes and type 2 diabetes mellitus (T2DM) by postpartum oral glucose tolerance test (ppOGTT) in Italian women diagnosed with gestational diabetes mellitus (GDM), and identify antepartum predictors of glucose intolerance.

Methods

Retrospective study of 454 Caucasian women that underwent a 75 g OGTT between 6 and 12 weeks postpartum in Calabria (Southern Italy) between 2004 and 2012. Prediabetes and T2DM were diagnosed according to the American Diabetes Association (ADA) criteria. Data were examined by univariate analysis and multiple regression analysis.

Results

290 women (63.9%) were normal, 146 (32.1%) had prediabetes (85 impaired fasting glycemia; 61 impaired glucose tolerance), and 18 (4.0%) had T2DM. Of the continuous variables, pre-pregnancy body mass index (BMI), age at pregnancy, fasting plasma glucose (FPG) at gravid OGTT, and week at diagnosis of GDM were associated with prediabetes and T2DM, whereas the parity was associated with T2DM only. For categorical traits, pre-pregnancy BMI ≥25 and previous diagnosis of polycystic ovary syndrome (PCOS) emerged as the strongest predictors of prediabetes whereas the strongest predictors of T2DM were FPG ≥100 mg/dl (5.6 mmol/l) at GDM diagnosis and pre-pregnancy BMI ≥25. Moreover, FPG at GDM screening was a good predictor of T2DM after receiver-operating-characteristic analysis.

Conclusions

Our findings confirm the high prevalence of glucose intolerance in the early postpartum period in women with previous GDM. PCOS emerges as a new strong antepartum predictor of prediabetes.     

Erythrocyte susceptibility to oxidative stress and antioxidant status in patients with type 1 diabetes

In this study, malondialdehyde (MDA) level as an index of erythrocyte susceptibility to oxidative stress and antioxidant defense system (glutathione level (GSH), glutathione peroxidase enzyme activity (GPx) in erythrocytes and ferric reducing ability of plasma (FRAP) as the total plasma antioxidant capacity were measured in 35 patients with type 1 diabetes and 28 age and sex-matched normal subjects. MDA level was significantly elevated in diabetic patients (650.9+/-144.3 nmol/g versus 476.5+/-138.5 nmol/g Hb, P<0.001). The level of MDA was positively correlated with duration of diabetes (r= 0.29, P<0.05) and HbA(1C) (r= 0.39, P<0.05) and negatively with FRAP (r= -0.3, P<0.05). The level of GSH and FRAP were lower in patients than controls (7.05+/-1.6 micromol/g versus 8.24+/-0.9 micromol/g Hb, and 389.05+/-82.3 micromol/l versus 520.4+/-124.1 micromol/l, respectively, P<0.001). GPx activity was not significantly different between the two groups. GSH and FRAP were negatively correlated with HbA(1C) (r= -0.334, P<0.01 and r= -0.5, P<0.01, respectively). In conclusion, there seems to be an increased susceptibility to oxidative stress and decreased antioxidant defense in patients with type 1 diabetes, which may be due to poor glycemic control.     

Comparison of lymphomononuclear cell energy metabolism between healthy, impaired glucose intolerance and type 2 diabetes mellitus patients

Diabetes mellitus (DM) is a complex disease that affects many systems. The most important cells of the immune system are lymphomononuclear (LMN) cells. Here, we aimed to evaluate the energy metabolism of LMN cells in patients with diabetes and impaired glucose tolerance. We measured LMN cell energy metabolism in patients with type 2 diabetes mellitus, impaired glucose tolerance (IGT) and healthy subjects. Cells were freshly isolated from peripheral blood and the subgroups were determined by flow cytometric method. Lactate production and glycogen utilization were significantly increased in the LMN cells of patients with type 2 DM and IGT when compared with healthy volunteers. No statistical difference was observed between the patients with type 2 DM and IGT. There was a significant correlation between fasting plasma glucose and lactate production in LMN cells. LMN cells changed their energy pathway in a diabetic state and preferred anaerobic glycolysis. Prediabetic range also affected energy metabolism in LMN cells. This abnormal energy production might cause dysfunction in LMN cells and the immune system in diabetic and prediabetic patients. In conclusion, we concluded that impaired glucose metabolism could change energy metabolism.     

Gestational diabetes mellitus in Korea: prevalence and prediction of glucose intolerance at early postpartum

To determine the prevalence of glucose intolerance in Korean women with gestational diabetes mellitus (GDM) between 6 and 8 weeks postpartum and identify which antepartum variables were predictive of postpartum diabetes and impaired glucose tolerance (IGT), we prospectively performed 75 g oral glucose tolerance test (OGTT) between 6 and 8 weeks postpartum in women with GDM. WHO criteria were used for classification of glucose tolerance postpartum. Of 392 women with GDM were detected during the study period, 311 women participated in this study. Of the 311 participants, 119 (38.3%) women were found to have persistent glucose intolerance; 47 (15.1%) had diabetes and 72 (23.2%) had IGT. The prevalence of postpartum IGT and diabetes increased in parallel with the metabolic severity during pregnancy. Multiple logistic regression analysis revealed that pre-pregnancy weight, gestational age at diagnosis of GDM, 2-h glucose and 3-h insulin concentrations of diagnostic OGTT were independently associated with postpartum diabetes. Pre-pregnancy weight, 2-h glucose and 1-h insulin concentrations were independently associated with postpartum IGT. Our results support the importance of postpartum testing in Korean women with GDM, and demonstrated that impaired beta-cell function and pre-pregnancy obesity were associated with glucose intolerance at early postpartum.     

Oxidative stress,antioxidant status and lipid profile in pulmonary tuberculosis patients before and after anti-tubercular therapy

BackgroundPulmonary tuberculosis (PTB) is a highly infectious dreadful disease caused by mycobacterium tuberculosis (MTB). Numerous studies reported free radicals activity, antioxidant status and lipid profile in PTB patients, but previous studies have lacunae in comparing the biochemical variables between before and after anti-tubercular therapy (ATT) supplementation to PTB patients. Hence, the present study was carried out to investigate oxidative stress markers, antioxidant status, lipid profile, liver function markers, and glycoprotein components in pulmonary tuberculosis patients (PTB) patients before and after 60 days of ATT.MethodsThis is a case-control study carried out with 100 healthy subjects and 110 PTB patients. All the patients diagnosed with sputum test and were positive for acid fast bacilli (AFB) were included for the study. An informed consent was obtained from all the patients.ResultsOur study found increased levels of oxidative stress markers, decreased enzymatic and non-enzymatic antioxidants, altered lipid profile in PTB patients as compared to healthy subjects before treatment and these levels were restored after clinical improvement with ATT. We also found increased concentrations of liver function parameters and components of glycoprotein in PTB patients. ATT refurbished lipid levels, antioxidant status and oxidative stress markers with decrease in liver function enzymes and glycoproteins in PTB patients.ConclusionCo-supplementation of antioxidants, along with ATT and inclusion of nutritious diet could be useful to reduce the pathogenesis of PTB and is warranted as a future study for the management of PTB.