Enhanced oxidative stress and platelet activation combined with reduced antioxidant capacity in obese prepubertal and adolescent girls with full or partial metabolic syndrome

The Response of Antioxidant Enzymes and Antiapoptotic Markers to an Oral Glucose Tolerance Test (OGTT) in Children and Adolescents with Excess Body Weight

Oxidative stress and apoptosis are involved in the pathogenesis of obesity-related diseases. This observational study investigates the antioxidant and apoptotic markers response to an oral glucose tolerance test (OGTT) in a population of overweight children and adolescents, with normal (NGT) or impaired glucose tolerance (IGT). Glucose, insulin, and C-peptide concentrations, as well as oxidative stress (SOD, GPx3) and apoptotic markers (Apo1fas, cck18), were determined at T = 0, 30, 60, 90, 120, and 180 min after glucose intake during OGTT. The lipid profile, thyroid function, insulin-like growth factor1, leptin, ghrelin, and adiponectin were also measured at baseline. The 45 participants, with a mean age of 12.15 (±2.3) years old, were divided into two subcategories: those with NGΤ (n = 31) and those with IGT (n = 14). The area under the curve (AUC) of glucose, insulin, and C-peptide was greater in children with IGT; however, only glucose differences were statistically significant. SOD and GPx3 levels were higher at all time points in the IGT children. Apo1fas and cck18 levels were higher in the NGT children at most time points, whereas Adiponectin was lower in the IGT group. Glucose increased during an OGTT accompanied by a simultaneous increase in antioxidant factors, which may reflect a compensatory mechanism against the impending increase in oxidative stress in children with IGT.

Insulin Resistance-Induced Platelet Hyperactivity and a Potential Biomarker Role of Platelet Parameters: A Narrative Review

Background

Insulin has an inhibitory effect on platelets; however, this is compromised in circumstances of Insulin Resistance (IR), leading to platelet hyperactivity. Platelet parameters such as mean platelet volume, platelet count, and platelet distribution width are simple and accessible potential biomarkers for the early diagnosis and prognosis of IR. Therefore, the aim of this review is to provide insight on the current status of knowledge regarding IR-induced platelet hyperactivation and the potential biomarker role of platelet parameters.

Methods

This narrative review included articles published in the English language. Searches were carried out at the electronic databases PubMed and Google Scholar. The search strategy was done by combining key words and related database-specific subject terms (Mesh terms) with the appropriate Boolean operators.

Conclusion

Increasing insulin sensitivity in insulin resistant patients would possibly cause substantial reduction in platelet activation, which in turn reduce complications related with platelet hyperactivation. The standard methods to measure IR are not frequently employed in clinical practice due to their expensiveness and complexity. Thus, early detection of IR using a simple and more widely available biomarkers such as mean platelet volume, platelet count and platelet distribution width would be beneficial. Particularly in developing countries where resource scarcity is a major constraint of the health sector, utilizing such easy and affordable biomarkers may have a crucial role.

Metabolic syndrome, adiposity, diet, and emotional eating are associated with oxidative stress in adolescents

Background

Metabolic syndrome (MS), a condition related to adiposity and oxidative stress, can develop in adolescence, a critical stage in life that impacts health in adulthood. However, there is scarce scientific research about the relationship between lifestyle factors, emotion management, and oxidative stress in this phase of life.

Aim

To analyze whether nutritional parameters, lifestyle factors, emotion management, and MS in adolescents are associated with oxidative stress measured by the biomarker 8-isoprostane.

Methods

A cross-sectional study was carried out in 132 adolescents (48.5% girls, aged 12 ± 0.48 years) and data were collected on nutritional parameters (anthropometric measurements, biochemical analyzes, and blood pressure), lifestyle factors (physical activity, sleep, and diet), and emotion management (self-esteem, emotional eating, and mood). 8-isoprostane was analyzed in spot urine samples. The study population was categorized in three groups (healthy, at-risk, and with MS) using the International Diabetes Federation definition of MS in adolescents. To capture more complex interactions, a multiple linear regression was used to analyze the association between 8-isoprostane and the aforementioned variables.

Results

Urinary 8-isoprostane levels were significantly higher in the MS group compared to the healthy group (1,280 ± 543 pg./mg vs. 950 ± 416 pg./mg respectively). In addition, univariable analysis revealed positive significant associations between 8-isoprostane and body mass index, waist circumference, waist-to-height ratio, body fat percentage, blood lipid profile and glucose, emotional eating, and refined cereal intake. Conversely, a negative significant association was found between 8-isoprostane and sleep duration and fish intake. The multiple linear regression analysis revealed associations between 8-isoprostane and LDL-c (β = 0.173 value of p = 0.049), emotional eating (low β = 0.443, value of p = 0.036; high β = 0.152, value of p = 0.470), refined cereal intake (β =0.191, value of p = 0.024), and fish intake (β = -0.187, value of p = 0.050).

Conclusion

The MS group, LDL-c, emotional eating, and high refined cereals and low fish intakes were associated with higher levels of oxidative stress in an adolescent population.

The Relationship Between Vitamin-D Deficiency and Protein Oxidation Among Obese Children

Aim: The aim of the study is to examine the relationship between obesity, Vitamin-D deficiency, and protein oxidation. Methods: Thiol-disulfide homeostasis, Vitamin-D, ischemia modified albumin, insulin, and lipid levels were compared among obese, pre-obese and normal-weight healthy children. Results: A total of 136 children (69 boys and 67 girls) were included in the study. The vitamin-D levels of obese children were lower than those of pre-obese and normal weight (p < 0.05). In the normal weight group, total thiol and native thiol were lower in the pubertal period than in adolescence; were higher in those with sufficient Vitamin-D level than those with insufficient and deficient Vitamin-D (p < 0.05). Vitamin-D level was lower in pre-obese girls than boys (p < 0.05). Those with high triglycerides had high disulfide/total thiol, disulfide, and disulfide/native thiol and low native thiol/total thiol (p < 0.05). Conclusion: Thiol-disulfide homeostasis is negatively affected by low vitamin D levels, pubertal period and high triglyceride levels.

Cross-species Association Between Telomere Length and Glucocorticoid Exposure

CONTEXT

Chronic exposure to glucocorticoids (GCs) or stress increases the risk of medical disorders, including cardiovascular and neuropsychiatric disorders. GCs contribute to accelerated aging; however, while the link between chronic GC exposure and disease onset is well established, the underpinning mechanisms are not clear.

OBJECTIVE

We explored the potential nexus between GCs or stress exposure and telomere length.

METHODS

In addition to rats exposed to 3 weeks of chronic stress, an iatrogenic mouse model of Cushing syndrome (CS), and a mouse neuronal cell line, we studied 32 patients with CS and age-matched controls and another cohort of 75 healthy humans.

RESULTS

(1) Exposure to stress in rats was associated with a 54.5% (P = 0.036) reduction in telomere length in T cells. Genomic DNA (gDNA) extracted from the dentate gyrus of stressed and unstressed rats showed 43.2% reduction in telomere length (P = 0.006). (2) Mice exposed to corticosterone had a 61.4% reduction in telomere length in blood gDNA (P = 5.75 × 10-5) and 58.8% reduction in telomere length in the dentate gyrus (P = 0.002). (3) We observed a 40.8% reduction in the telomere length in patients with active CS compared to healthy controls (P = 0.006). There was a 17.8% reduction in telomere length in cured CS patients, which was not different from that of healthy controls (P = 0.08). For both cured and active CS, telomere length correlated significantly with duration of hypercortisolism (R2 = 0.22, P = 0.007). (4) There was a 27.6% reduction in telomere length between low and high tertiles in bedtime cortisol levels of healthy participants (P = 0.019).

CONCLUSION

Our findings demonstrate that exposure to stress and/or GCs is associated with shortened telomeres, which may be partially reversible.

Blunted Reducing Power Generation in Erythrocytes Contributes to Oxidative Stress in Prepubertal Obese Children with Insulin Resistance

Childhood obesity, and specifically its metabolic complications, are related to deficient antioxidant capacity and oxidative stress. Erythrocytes are constantly exposed to multiple sources of oxidative stress; hence, they are equipped with powerful antioxidant mechanisms requiring permanent reducing power generation and turnover. Glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) are two key enzymes on the pentose phosphate pathway. Both enzymes supply reducing power by generating NADPH, which is essential for maintaining the redox balance within the cell and the activity of other antioxidant enzymes. We hypothesized that obese children with insulin resistance would exhibit blunted G6PDH and 6PGDH activities, contributing to their erythrocytes’ redox status imbalances. We studied 15 control and 24 obese prepubertal children, 12 of whom were insulin-resistant according to an oral glucose tolerance test (OGTT). We analyzed erythroid malondialdehyde (MDA) and carbonyl group levels as oxidative stress markers. NADP+/NADPH and GSH/GSSG were measured to determine redox status, and NADPH production by both G6PDH and 6PGDH was assayed spectrophotometrically to characterize pentose phosphate pathway activity. Finally, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GR) activities were also assessed. As expected, MDA and carbonyl groups levels were higher at baseline and along the OGTT in insulin-resistant children. Both redox indicators showed an imbalance in favor of the oxidized forms along the OGTT in the insulin-resistant obese group. Additionally, the NADPH synthesis, as well as GR activity, were decreased. H₂O₂ removing enzyme activities were depleted at baseline in both obese groups, although after sugar intake only metabolically healthy obese participants were able to maintain their catalase activity. No change was detected in SOD activity between groups. Our results show that obese children with insulin resistance present higher levels of oxidative damage, blunted capacity to generate reducing power, and hampered function of key NADPH-dependent antioxidant enzymes.

The Significance of Thiol/Disulfide Homeostasis and Ischemia-modified Albumin Levels in Assessing Oxidative Stress in Obese Children and Adolescents

OBJECTIVE

There is an association between obesity and several inflammatory and oxidative markers in children. In this study, we analyzed thiol/disulfide homeostasis and serum ischemia-modified albumin (IMA) levels for the first time in order to clarify and determine the oxidant/antioxidant balance in metabolically healthy and unhealthy children.

METHODS

This study included obese children and healthy volunteers between 4-18 years of age. The obese patients were divided into two groups: metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO). Biochemical parameters including thiol/disulfide homeostasis, and IMA concentrations were analyzed.

RESULTS

There were 301 recruits of whom 168 (55.8%) were females. The obese children numbered 196 (MHO n=58 and MUO n=138) and healthy controls numbered 105. No statistically significant difference could be found in ages and genders of the patients among all groups (p>0.05, for all). Native thiol (SH), total thiol (SH+SS), and native thiol/total thiol (SH/SH+SS) ratio were statistically significantly lower in the MUO group than the control group (p<0.001, p=0.005, and p=0.005; respectively). Disulfide (SS), disulfide/native thiol (SS/SH), disulfide/total thiol (SS/SH+SS) and IMA levels were statistically significantly higher in the MUO group than the control group (p=0.002, p<0.001, p<0.001, and p=0.001, respectively).

CONCLUSION

Chronic inflammation due to oxidative stress induced by impaired metabolic parameters in MUO children caused impairment in thiol redox homeostasis. Our data suggested that the degree of oxidant imbalance in obese children worsened as obesity and metabolic abnormalities increased. It is hypothesized that thiol/disulfide homeostasis and high serum IMA levels may be reliable indicators of oxidant-antioxidant status in MUO children.

Obesity: Perceived Self-Efficacy, Emotional Regulation and Stress

Abstract Obesity increases the risk of non-transmissible chronic illnesses decreasing the quality of life and life expectancy. This investigation aims to define a psychological profile for the treatment of the target population evaluating the levels of self-efficacy perceived, difficulty in emotional regulation and stress. Eighty-six adults participated, including 63 women and 23 men who pertained to OBEMOB in Temuco. The results indicate that the level of stress, trust in problem solving skills, as well as ability to solve problems and unexpected situations differs according to the type of obesity (p<0.05). In addition, there is a negative relation between general self-efficacy and difficulty of emotional regulation (rho=-0.419) while stress and BMI demonstrate a positive relation (rho=0,380).

Childhood adversity, mental health, and oxidative stress: A pilot study

Childhood adversity is a potent risk factor for mental health conditions via disruptions to stress response systems. Dysregulations in oxidative stress systems have been associated with both childhood adversity and several psychological disorders (e.g., major depressive disorder) in adult populations. However, few studies have examined associations between childhood adversity, oxidative stress, and mental health in pediatric populations. Childhood adversity (Adverse Childhood Events [ACE]), oxidative stress [F2t-isoprostanes (IsoPs)], and mental health pathology were assessed in 50 adolescent females recruited primarily through the Department of Youth Services. Standard ordinary least squares regression models were run co-varying for age, race/ethnicity, adolescent nicotine use, study condition, and parent history of ACEs. Adolescents who reported experiencing four or more ACEs had significantly elevated IsoP levels. Further, internalizing symptom scores across diagnoses were significantly associated with elevated IsoPs, whereas no externalizing symptoms scores, except Attention Deficit Hyperactivity Disorder, were related to altered oxidative stress. Results indicate that IsoPs may be a global marker of childhood adversity and mental health symptomatology, particularly within internalizing symptom domains. A limitation is that body mass index was not collected for this sample. Future studies are needed to replicate and extend these findings in larger, more diverse samples.

Obesity and cardio-metabolic risk factors in Ecuadorian university students. First report, 2014-2015

OBJECTIVE

Overweight and obesity are risk factors for developing cardiovascular disease. The objective of this study was to determine the prevalence of obesity and risk factors associated with metabolic syndrome and cardiovascular disease in university students.

METHODS

883 students from the Faculty of Medical Sciences of the Central University of Ecuador were included, who were surveyed with demographic data, smoking habits and physical activity. Body mass index, abdominal circumference and blood pressure were determined. Blood chemistry and lipid profile were performed. Central tendency and dispersion measures, average comparisons (Student's T) and Pearson's correlation were calculated to study quantitative variables and χ2 distributed statistic for the comparison of qualitative variables.

RESULTS

The prevalence of overweight and obesity was 25.5%. The body mass index was similar in both sexes (23.15 women / 23.57 men), waist circumference was higher in women. Men had higher than normal levels in blood pressure and elevated triglycerides while women had high cholesterol.

CONCLUSIONS

One of four students presents some degree of overweight or obesity and an important percentage of altered levels of plasma lipids and blood pressure. Blood glucose levels were found in normal ranges.

Dynamic thiol/disulphide homeostasis as a novel indicator of oxidative stress in obese children and its relationship with inflammatory-cardiovascular markers

Objective:

Childhood obesity is an important cause of cardiovascular risk with chronic inflammation. Oxidative stress may contribute to the pathogenesis of obesity-related cardiovascular pathologies. We aimed to evaluate thiol/disulphide homeostasis as a novel and sensitive marker of oxidative stress and to evaluate its relationship with some inflammatory and cardiovascular markers in obese children.

Methods:

In this case-controlled study, 65 children with exogenous obesity and 64 healthy children, as a control group, were included. In both groups, thiol/disulphide homeostasis parameters and inflammatory (white blood cells, platelets, mean corpuscular volume, neutrophil/lymphocyte ratio, and high-sensitivity C-reactive protein) and cardiovascular (epicardial adipose tissue thickness and left ventricular mass index) markers were studied. Correlation analyses of thiol/disulphide homeostasis parameters with body mass index standard deviation scores (BMI SDS) and inflammatory and cardiovascular markers were performed. Receiver-operating characteristic analysis was performed to determine the sensitivity, specificity, and optimal cut-off values of thiol/disulphide homeostasis parameters.

Results:

Native thiol, total thiol, and native thiol/total thiol ratios (antioxidant parameters) were lower (p<0.05) and disulphide/native thiol and disulphide/total thiol ratios (oxidant parameters) were higher in the obese group than in the control group (p<0.01). A positive correlation of oxidant parameters with BMI SDS and inflammatory markers was found. However, a negative correlation of antioxidant parameters with BMI SDS and inflammatory markers was found. The specificities of disulphide/native thiol and disulphide/total thiol ratios were higher in the obese group.

Conclusion:

The impairment in thiol/disulphide homeostasis, which is indicative of oxidative stress, is associated with inflammation in obesity. In addition, cardiovascular involvement may also contribute to this impairment.

[Comprehensive diagnosis in patients with morbid obesity; candidates for bariatric surgery and suggestions for preoperative treatment]

OBJECTIVE

The purpose of the study was to analyze and describe the psychological, metabolic, anthropometric and physical condition of obese candidates for bariatric surgery. This is in order to determine the preoperative intervention.

MATERIAL AND METHODS

The population is made up of 24 obese candidates for bariatric surgery; five men and 19 women between 21 and 60 years old. The sample type is non-probabilistic, with non-randomised subjects chosen conveniently and volunteers. Psychological, anthropometric, metabolic and physical condition variables were evaluated.

RESULTS

The average age of participants corresponds to 41.0 years old. Low levels of empathic joy were observed. Anxiety symptoms presented an intermediate level: 62,5 % presented minimal depression, 29,1 % presented slight depression, and 8,4 % presented considerable depression. Body weight averaged 99.1 kg, height 1.6 meters, Body Mass Index (BMI) 39.3, the percentage of fat mass and contour waist averaged 41.1 118.0 centimeters in that order. With regards to plasma levels (mg / dl), the following were obtained: total cholesterol 192.9, 120.0 LDL cholesterol, HDL cholesterol, 43.3, 182.3 triglycerides, glycerin to 105.9; and distance covered in 6 minutes was 511.9 meters.

CONCLUSIONS

The results provide information to determine best Preoperative intervention strategies; changing the lifestyles of patients, keeping the postoperative weight.

Classifying oxidative stress by F2-isoprostane levels across human diseases: A meta-analysis

The notion that oxidative stress plays a role in virtually every human disease and environmental exposure has become ingrained in everyday knowledge. However, mounting evidence regarding the lack of specificity of biomarkers traditionally used as indicators of oxidative stress in human disease and exposures now necessitates re-evaluation. To prioritize these re-evaluations, published literature was comprehensively analyzed in a meta-analysis to quantitatively classify the levels of systemic oxidative damage across human disease and in response to environmental exposures.

In this meta-analysis, the F₂-isoprostane, 8-iso-PGF_2α, was specifically chosen as the representative marker of oxidative damage. To combine published values across measurement methods and specimens, the standardized mean differences (Hedges’ g) in 8-iso-PGF_2α levels between affected and control populations were calculated.

The meta-analysis resulted in a classification of oxidative damage levels as measured by 8-iso-PGF_2α across 50 human health outcomes and exposures from 242 distinct publications. Relatively small increases in 8-iso-PGF_2α levels (g<0.8) were found in the following conditions: hypertension (g=0.4), metabolic syndrome (g=0.5), asthma (g=0.4), and tobacco smoking (g=0.7). In contrast, large increases in 8-iso-PGF_2α levels were observed in pathologies of the kidney, e.g., chronic renal insufficiency (g=1.9), obstructive sleep apnoea (g=1.1), and pre-eclampsia (g=1.1), as well as respiratory tract disorders, e.g., cystic fibrosis (g=2.3).

In conclusion, we have established a quantitative classification for the level of 8-iso-PGF_2α generation in different human pathologies and exposures based on a comprehensive meta-analysis of published data. This analysis provides knowledge on the true involvement of oxidative damage across human health outcomes as well as utilizes past research to prioritize those conditions requiring further scrutiny on the mechanisms of biomarker generation.

•

Oxidative damage is highly variable in human conditions as measured by F₂-isoprostanes.

•

Respiratory tract and urogenital diseases have the highest F₂-isoprostanes.

•

Cancer and cardiovascular diseases have surprisingly low F₂-isoprostanes.

Reduced antioxidant capacity and increased subclinical inflammation markers in prepubescent obese children and their relationship with nutritional markers and metabolic parameters

OBJECTIVE

There are associations between some inflammatory and oxidative markers and obesity in adults, but whether prepubescent children of different weights also have such markers has not been studied. We investigated multiple inflammatory markers and levels of erythrocyte oxidant/antioxidant enzymes in prepubescent children of different weights.

METHODS

Children aged 2-11 years were divided into three groups: 80 were underweight, 90 were obese but otherwise healthy, and 80 were healthy age- and sex-matched children of normal-weight. We analyzed inflammatory markers and the total oxidant status, total antioxidant status (TAS), and total thiol level were also determined, and the oxidative stress index was calculated as an indicator of the degree of oxidative stress.

RESULTS

The obese group exhibited higher levels of fasting glucose, insulin, total cholesterol, triglycerides, the homeostatic model assessment of insulin resistance (HOMA-IR), and the homeostatic model assessment of β-cell function (HOMA-β), C-reactive protein (CRP), neutrophils, and neutrophil/lymphocyte ratio (NLR), as well as lower TAS and total thiol levels than the other two groups (all P < 0.001). Moreover, TAS and total thiols were negatively correlated with age in the obese group (r = -0.212, P = 0.001; r = -0.231, P < 0.001, respectively). CRP levels in plasma were positively correlated with the body mass index (BMI), insulin and glucose levels, HOMA-IR, HOMA-β, WBC and neutrophil counts, and the NLR, and were negatively correlated with TAS and total thiol levels in the overall studied population.

DISCUSSION

The coexistence of increased obesity-related subclinical inflammation and decreased antioxidant capacity can be observed even in prepubescence, and may eventually increase the risk of long-term vascular damage.

Enhanced oxidative stress and platelet activation in patients with Cushing's syndrome

OBJECTIVE

Cushing Syndrome (CS) is implicated by increased cardiovascular risk (CVR) leading to increased morbidity and mortality. Oxidative stress (OS) and platelet activation (PA) are associated with increased CVR. However, scarce data of OS in CS exist. Our objective was to determine the oxidant-antioxidant balance in CS.

DESIGN

Fourteen patients with CS at diagnosis and fourteen healthy subjects (NS) were evaluated OS by measuring plasma 15-F2t -Isoprostane (15-F2t -IsoP), PA by thromboxaneB2 levels (TXB2 ), and antioxidant reserve measuring total antioxidant capacity (TAC) and serum vitamin E.

RESULTS

15-F2t -IsoP and TXB2 levels were significantly higher (P < 0·01) in CS, while vitamin E levels were higher in NS (P < 0·03). 15-F2t -IsoP levels were significantly higher (P < 0·01) in complicated vs not-complicated CS and NS and significantly higher (P < 0·03) in CS not-complicated vs NS. TXB2 levels were significantly reduced (P < 0·03) in NS vs complicated and not-complicated CS. A negative correlation between Vitamin E and UFC was observed in CS (P < 0·05 r = -0·497). TXB2 correlated with glucose, HbA1c and T-score (P < 0·05 r = 0·512, P < 0·03 r = 0·527 and P < 0·01 r = 0·783, respectively) and HDL (P < 0·01 r = -0·651). 15-F2t -IsoP correlated with triglicerides, HbA1c and diastolic pressure (P < 0·01 r = 0·650, P < 0·03 r = 0·571 and P < 0·05 r = 0·498, respectively) and HDL (P < 0·03 r = -0·594).

CONCLUSIONS

This study emphasizes the major role of OS in CS. As our findings demonstrated that enhanced OS and PA take place in this rare metabolic disorder which is associated with increased CVR, it could be suggested that these biochemical alterations can further contribute in the pathogenesis of atherosclerosis, increased CVR and mortality in CS.

Cancer metabolism and oxidative stress: Insights into carcinogenesis and chemotherapy via the non-dihydrofolate reductase effects of methotrexate

Methotrexate has been in use as an anti-cancer agent for over 60 years. Though inhibition of dihydrofolate reductase is its best known mechanisms of action, its non-dihydrofolate reductase dependent mechanisms disrupt metabolic pathways resulting in a depletion of NAD(P)H and increasing oxidative stress. These mechanisms highlight a novel dependence of cancer cells on their metabolic abnormalities to buffer oxidative stress and chemotherapeutic agents interfere with these cellular abilities. Mitochondria appear to play a significant role in maintaining cancer cell viability and alterations in metabolism seen in cancer cells aid this mitochondrial ability. Further research is needed to understand the effects of other chemotherapeutic agents on these pathways.

•

Methotrexate inhibits multiple enzymes beyond dihydrofolate reductase.

•

Mitochondria serve a critical role in buffering cellular oxidative stress.

•

Metabolic derangements seen in cancer fuel this mitochondrial rescue function.

•

Methotrexate toxicity occurs secondary to a handicapping of this buffering function.

•

Many chemotherapeutic agents appear to have mechanisms affecting these pathways.

Lycopene supplementation reduces TNF-α via RAGE in the kidney of obese rats

Background:

The kidney is a target organ for injuries caused by advanced glycation end products (AGEs) in obesity. The receptor of AGEs (RAGE) is proinflammatory and appears to have a role in the pathogenesis of renal disease due to obesity.

Objective:

The aim was to verify the effect of obesity on renal damage and the effect of lycopene on these complications

Design and Methods:

Male Wistar rats were randomly assigned to receive a control diet (C, n=7) or a high-fat diet plus sucrose (HD+S, n=14) for 6 weeks. After this period, the HD+S animals were randomized into two groups: HD+S (n=7) and HD+S supplemented with lycopene (HD+S+L, n=7). The animals received maize oil (C and HD+S) or lycopene (HD+S+L) for a 6-week period.

Results:

The HD+S and HD+S+L animals demonstrated insulin resistance (OGTT glucose after 150 min; C: 117.6±3.9<HD+S: 138.1±5.1=HD+S+L: 137.8±5.2 mg dl⁻¹; P=0.01); however, no changes were seen in fasting glucose, plasma lipids, blood pressure or renal function. Renal concentrations of RAGE and TNF-α increased in the HD+S group and lycopene supplementation restored these to control group values (RAGE: C: 3.1±0.3=DH+S+L: 3.1±0.3<DH+S: 3.6±0.4 μg g⁻¹; P=0.014; TNF-α: C: 227.8±2.7=DH+S+L: 227.4±2.2<DH+S: 238.7±3.0 pg/ml; P=0.014).

Conclusions:

Lycopene may be beneficial in the prevention and treatment of oxidative stress and inflammation in the kidney due to obesity.

Behavior of the total antioxidant status in a group of subjects with metabolic syndrome

AIMS

Our purpose was to examine the total antioxidant status (TAS) in subjects with metabolic syndrome (MS) subdivided according to the presence or not of diabetes mellitus.

METHODS

We enrolled 106 subjects (45 women, 61 men) with MS subsequently subdivided in diabetics (14 women, 29 men) and nondiabetics (31 women, 29 men). TAS was obtained using an Assay kit which relies on the ability of plasma antioxidant substances to inhibit the oxidation of 2,2'-azino-bis(3-ethylbenzthiazoline sulfonic acid) to the radical ABTS·+.

RESULTS

In the group of MS subjects a significant decrease in TAS (p<0.05) in comparison with normal controls was evident. This difference was present between normal subjects and nondiabetic subjects with MS (p<0.001) but not between normal and diabetic subjects with MS. Examining the linear regression among TAS, age, anthropometric profile, blood pressure values and glycometabolic pattern, conflicting data were found.

CONCLUSIONS

Although we know that TAS includes several enzymatic and non enzymatic antioxidants, we retain that the difference observed in the two subgroups of subjects with MS must be looked in particular into two pathophysiological aspects regarding bilirubin and uric acid.

Autophagy, myocardial protection, and the metabolic syndrome

Autophagy is a housekeeping process that helps to maintain cellular energy homeostasis and remove damaged organelles. In the heart, autophagy is an adaptive process that is activated in response to stress including acute and chronic ischemia. Given the evidence that autophagy is suppressed in energy-rich conditions, the objective of this review is to examine autophagy and cardioprotection in the setting of the metabolic syndrome. Clinical approaches that involve the induction of cardiac autophagy pharmacologically to enhance the heart's tolerance to ischemia are also discussed.

Moderate weight loss decreases oxidative stress and increases antioxidant status in patients with metabolic syndrome

Background. Oxidative stress is enhanced in metabolic syndrome (MetS) and believed to contribute to accelerated atherosclerosis. Weight loss is associated with lowered oxidative stress. Methods. We performed a cross-sectional study in 92 consecutive patients with metabolic syndrome and 80 without. A dietary intervention with moderately low-calorie diet (600 calories/day negative energy balance) was carried out in 53 of metabolic syndrome patients. Oxidative stress, assessed by sNOX2-dp and urinary 8-iso-PGF2α, and antioxidant status, assessed by serum levels of vitamin E and adiponectin, were measured before and after 6 months. Results. Serum vitamin E/cholesterol ratio was significantly lower in metabolic syndrome compared to controls (P < 0.001) and decreased by increasing the number of metabolic syndrome components (P < 0.001). After six months, 23 and 30 patients showed >5% (group A) or <5% (group B) weight loss, respectively. Urinary 8-iso-PGF2α (−39.0%), serum sNOX2-dp (−22.2%), adiponectin (+125%), and vitamin E/cholesterol ratio (+129.8%) significantly changed only in A group. Changes in body weight and in serum adiponectin were independent predictors of vitamin E/cholesterol ratio variation. Conclusion. Our findings show that in metabolic syndrome moderate weight loss is associated with multiple health benefits including not only oxidative stress reduction but also enhancement of antioxidant status.

A phytochemical approach to experimental metabolic syndrome-associated renal damage and oxidative stress

The aim of this study was to evaluate the effect of DTS-phytocompound on oxidant-antioxidant balance and protein damage in the kidneys of rats administered high doses of fructose. Adult male Wistar rats were divided into four groups. Group A received a control diet, whereas groups B and C were fed a high-fructose diet (60 g/100 g), the latter with additional DTS (50 mg/kg per day) for 60 days. Lipo- and nitro-peroxidation together with α-smooth muscle actin (α-SMA) expression in the glomerular and interstitial tissue of the kidneys were measured after 60 days. Fructose-fed rats showed significantly higher lipoperoxidation, 2,4-dinitrophenol and 3-nitrotyrosine protein adducts, and upregulation of α-SMA in the kidney. DTS significantly decreased such redox unbalance in renal tissue, while partially downregulating α-SMA (p<0.01). These data suggest the potential clinical benefit of DTS in protecting the kidneys from metabolic syndrome-associated changes; gender-related analysis is under way.

Different impacts of cardiovascular risk factors on oxidative stress

The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCH) with and without insulin resistance. Oxidative stress markers (oxidized/reduced glutathione ratio, 8-oxo-deoxyguanosine and malondialdehide) together with the activity of antioxidant enzyme triad (superoxide dismutase, catalase, glutathione peroxidase) and activation of both pro-oxidant enzyme (NAPDH oxidase components) and AGTR1 genes, as well as antioxidant enzyme genes (CuZn-SOD, CAT, GPX1, GSR, GSS and TXN) were measured in mononuclear cells of controls (n = 20) and patients (n = 90) by assessing mRNA levels. Activity of some of these antioxidant enzymes was also tested. An increase in OS and pro-oxidant gene mRNA values was observed in patients compared to controls. The hypertensive group showed not only the highest OS values, but also the highest pro-oxidant activation compared to those observed in the other groups. In addition, in HT a significantly reduced antioxidant activity and mRNA induction of antioxidant genes were found when compared to controls and the other groups. In FH and FCH, the activation of pro-oxidant enzymes was also higher and antioxidant ones lower than in the control group, although it did not reach the values obtained in hypertensives. The thioredoxin system was more activated in patients as compared to controls, and the highest levels were in hypertensives. The increased oxidative status in the presence of cardiovascular risk factors is a consequence of both the activation of pro-oxidant mechanisms and the reduction of the antioxidant ones. The altered response of the main cytoplasmic antioxidant systems largely contributes to OS despite the apparent attempt of the thioredoxin system to control it.