Oxidative Stress In Adolescents Research Articles

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

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

Improved glycemic control either alone, or combined with antioxidant supplementation, fails to restore blood glutathione or markers of oxidative stress in adolescents with poorly controlled type 1 diabetes

In earlier studies, we showed that adolescents with type 1 diabetes mellitus (T1DM) have significant glutathione (GSH) depletion and that GSH is reciprocally related to glycemic control. In both the general population and in those with diabetes, the use of over-the-counter antioxidant supplements is widespread. We hypothesized that improved glycemic control, alone or in combination with dietary antioxidants, would restore blood GSH pool. The study included 41 participants who were 15.8 ± 2.4 years of age (mean ± standard deviation) and with poorly controlled T1DM (hemoglobin A1c [HbA1c] 8.2 ± 0.6%). Erythrocyte GSH, and 3-nitrotyrosine, F2-isoprostane, and 8-hydroxy-2′-deoxy-guanosine (as markers of protein, lipid, and DNA oxidative stress, respectively) were determined in the postabsorptive state after blood glucose was maintained overnight near euglycemia. Participants were then randomized to a mix of antioxidants (vitamin C, selenium, zinc, vitamin E, β-carotene) or placebo for 3 to 6 months, and diabetes management was intensified using CSII (n = 30) or multiple daily injections (n = 11) coupled with CDE phone calls and visits with a Nutritionist. A second, identical study was performed when/if a drop in HbA1c ≥0.5% was achieved. HbA1c levels dropped similarly in both groups (from 8.9 ± 1.0% to 7.9 ± 0.9% and 8.5 ± 0.6% to 7.7 ± 0.7% in placebo and antioxidant group, respectively). Neither total nor reduced GSH was altered by improved metabolic control. Markers of protein, lipid, and DNA oxidation remained unaltered. We conclude that, in youngsters with T1DM, neither a significant improvement in diabetes control over a 3-month period nor the regimen of dietary antioxidant supplied in the current study can mitigate oxidative stress. These findings suggest that, in adolescents with T1DM, (1) more sustained improvement of diabetes control may be needed to alleviate oxidative stress and (2) the putative benefit of antioxidant supplements remains to be proven.

Evaluation of thiol disulfide balance in adolescents with vitamin B12 deficiency

BackgroundVitamin B12 is an important vitamin for metabolism and affects many mechanisms in the body including neuronal migration, DNA synthesis, neurotransmitter synthesis, brain and cognitive development. Increased oxidative stress in the body leads to the damage of the child development, but also plays a crucial role in the pathogenesis of many diseases encountered in the childhood period. Our aim is to investigate whether or not B12 deficiency is associated with dynamic thiol/disulfide homeostasis in adolescent patients.MethodsThis is a case-controlled observational study consisting of 45 adolescent patients with vitamin b12 deficiency and a control group consisting of 45 healthy adolescent. Patients between 11 and 18 ages who applied to the outpatient clinic for the first time with one of the complaints of headache were selected due to their decreased school performance, dizziness, and fatigue. Hemogram, vitamin B12, homocysteine levels and oxidative stress parameters such as native and total thiol disulfide levels and ratios of disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol were measured from the patients.ResultsVitamin B12 level was found to be significantly lower in vitamin B12 deficiency group (p < 0.001). The serum disulfide level was found to be 27.5 ± 8.38 in the case group and 20.5 ± 8.36 in the control group (p < 0.001). In the multiple linear regression analysis, it was determined that the independent variables of native thiol, homocysteine and disulfide levels effected of vitamin B12 levels (p < 0.001, p < 0.001, p < 0.005 respectively; R2 = 0.62).ConclusionThe results obtained in terms of the effect of vitamin B12 deficiency on oxidative stress in adolescents are remarkable. The increase in oxidative stress parameters in the patient group may also suggest that oxidative stress plays a vital role in vitamin B12 deficiency in adolescence.

Relationship of Circadian Rhythm in Behavioral Characteristics and Lipid Peroxidation of Brain Tissues in Mice.

This study aimed to explore the relationship among several indices of circadian rhythms and lipid peroxidation of brain tissue in mice. After entrainment of 4-week-old mice, one group was disrupted their circadian rhythms for three days and the other group for seven days (n = 10, respectively). After a recovery period, the Y-maze test, the elevated plus maze test, the tail suspension test, and the forced swimming test were conducted. To assess lipid peroxidation in brain tissue, thiobarbituric acid reactive substances were measured in the cortex, hippocampus, and cerebellum. When circadian rhythms were disrupted and adapted back to their original rhythm, the recovery time of the 7-day disruption group (median 3.35 days) was significiantly faster than one of the 3-day disruption group (median 4.87 days). In the group with a 7-day disruption, mice that had recovered their rhythms early had higher malondialdehyde levels in their hippocampus compared to those with delayed recovery. The entrainment of circadian rhythms was negatively correlated with the malondialdehyde level of brain tissue. The behavioral test results showed no differences depending on the disruption durations or recovery patterns of circadian rhythms. These results suggest that disruption types, recovery patterns, and the entrainment of circadian rhythms are likely to affect oxidative stress in adolescents or young adult mice. Future study is needed to confirm and specify these results on the effects of circadian rhythms on oxidative stress and age-dependent effects.

Oxidative balance disorders as a factor of formation and progression of hypoandrogenism in boys

Objective — to study the features of the state of oxidative balance (processes of free radical oxidation and antioxidant protection) in boys with hypoandrogenism (HA). Materials and methods. Examinations involved 103 adolescent boys agreed 14 to 17 years with the delayed sexual development. Serum levels of total testosterone (TT), conjugated dienes (CD), thiobarbituric acid­reactive substance (TBARS), carbonylated proteins, reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activity were determined. The coefficient of oxidative stress was calculated. Results and discussion. The following indicators have been revealed in patients with the delayed sexual development vs the comparison group: increased CD levels in 84.0 % of patients, elevated levels of carbonylated proteins in 53.7 % of adolescents, one third had raised TBARS levels; 63.0 % of patients demonstrated the increased GSH levels. Decreased activity of GPx and CAT was registered in more than half of the patients. Such changes indicate an imbalance in the ratio of free radical oxidation (FRO) and antioxidant protection, which leads to the state of OS in adolescents with delayed puberty.It was found that the redox balance in adolescents with delayed puberty significantly depends on the degree of androgen deficiency. Half of the patients with a degree I and II HA and 24.5 % of boys with degree III HA had elevated TBARS levels, which is more common in adolescents with normative values of TT. At the highest degree of androgen deficiency, the frequency of normative values of carbonylated proteins decreased. Most boys had elevated levels of CD (80 %), regardless of the degree of HA. An increase in SOD activity was found in patients with degree III HA. Low SOD activity was registered in 28.6 % of patients with degree II HA and 29.6 % with degree III HA, which is much less common compared to patients with normal TT levels. Most patients with HA, regardless of degree, were characterized by low GPx activity. Decreased CAT activity was registered in 76.9 % of patients with degree II HA. The majority of patients with HA (from 60.9 to 90 %) showed elevated levels of GSH, regardless of degree. The progression of HA in adolescents is characterized by the accumulation of products of free radical oxidation of lipids and an imbalance in the enzymatic and low molecular parts of the antioxidant system. This is typical for HA II and III degrees. The largest number of correlations was found in patients with degree III HA, testifying the formation of oxidative stress due to the activation of lipid peroxidation with simultaneous tension of the antioxidant defense system. Conclusions. The progression of HA is accompanied by the accumulation of products of free radical oxidation of lipids with simultaneous depletion of the enzymatic part of the antioxidant defense system. The activating effect of testosterone deficiency on the formation of oxidative stress in adolescents with the highest degree of androgen deficiency has been proven. This makes it possible to assess the state of oxidative balance as a factor in the formation and progression of HA in adolescents.

The effects of Mediterranean diet on hepatic steatosis, oxidative stress, and inflammation in adolescents with non-alcoholic fatty liver disease: A randomized controlled trial.

Non-alcoholic fatty liver disease (NAFLD) has become the most common liver disease in children and adolescents. The optimal dietary strategy to improve hepatic stetatosis and reduce oxidative stress and inflammation in adolescents is unknown. This study was conducted to evaluate the effect of Mediterranean diet (MD) versus low-fat diet (LFD) on hepatic steatosis, inflammation, and oxidative stress in adolescents with obesity and NAFLD. Adolescents diagnosed with NAFLD between the ages of 11-18 years were randomized to either a MD or conventional LFD (control diet) for 12 weeks. Dietary status, anthropometry, body composition, and biochemical parameters were evaluated. Hepatic steatosis was determined by ultrasonography. A total of 44 participants completed the study. At the end of the study, severity of hepatic steatosis, serum transaminase levels, and insulin resistance decreased significantly in both groups with no significant differences between groups except for aspartate aminotransferase (AST). The amount of decrease in AST levels in the MD group was greater than the LFD group (p < 0.05). In the MD group, serum total antioxidant capacity, paraoxanase-1, and glutathione peroxidase levels increased (p < 0.05); it did not change in the LFD group compared to baseline (p > 0.05). C-Reactive Protein (CRP) levels decreased only in the MD group (p=0.008), interleukine-6 decreased only in the LFD group (p=0.031). Consumption of MD and LFD for 12 weeks in adolescents with obesity and NAFLD reduced BMI, fat mass, hepatic steatosis, and insulin resistance, improved high transaminase levels, and had positive effects on inflammation and oxidative stress. Registered under ClinicalTrials.gov Identifier no. NCT04845373.

Osteopontin's relationship with malnutrition and oxidative stress in adolescents. A pilot study.

Osteopontin (OPN) is a protein involved in inflammatory illnesses such as fibrosis and cancer; its overexpression in cardiovascular diseases promotes the biomineralization of blood vessels and other soft tissues. Moreover, there is an active component of oxidative stress related with those diseases. The present study relates serum OPN levels with nutritional condition and oxidative stress in a group of adolescents. Anthropometric measurements were performed, and fasting blood samples were analyzed to determine OPN concentrations, blood chemistry parameters (glucose, triglycerides, total cholesterol, urea, uric acid, and creatinine) and oxidative stress biomarkers (Paraoxonase-1, Glutathione S-Transferase, Catalase, NAD(P)H Quinone Oxidoreductase, free carbonyl groups and malondialdehyde). Adolescents were categorized according to body mass index (BMI) and metabolic syndrome (MetS) criteria. We found increased OPN serum concentrations in overweight and obese adolescents, as well as in adolescents with MetS. Rises in OPN correlated with arm circumference and biomarkers of lipid peroxidation; with regard to serum glucose there was a trend to positive correlation. Our results suggest that serum OPN is associated to nutritional status and could be considered as an early biomarker of low-grade inflammation and probably the early biomineralization of soft tissues in adolescence.

Positive Association between Urinary Concentration of Phthalate Metabolites and Oxidation of DNA and Lipid in Adolescents and Young Adults

Phthalate has been used worldwide in various products for years. Little is known about the association between phthalate exposure and biomarkers of oxidative stress in adolescents and young adults. Among 886 subjects recruited from a population-based cohort during 2006 to 2008, 751 subjects (12–30 years) with complete phthalate metabolites and oxidation stress measurement were enrolled in this study. Nine urine phthalate metabolites, 8-hydroxydeoxyguanosine (8-OHdG), and 8-iso prostaglandin F2α (8-isoPGF2α) were measured in urine to assess exposure and oxidative stress to DNA and lipid, respectively. Multiple linear regression analysis revealed that an ln-unit increase in mono-methyl phthalate (MMP) concentration in urine was positively associated with an increase in urine biomarkers of oxidative stress (in μg/g; creatinine of 0.098 ± 0.028 in 8-OHdG; and 0.253 ± 0.051 in 8-isoPGF2α). There was no association between other eight phthalate metabolite concentrations and oxidative stress. In conclusion, a higher MMP concentration in urine was associated with an increase in markers of oxidative stress to DNA and lipid in this cohort of adolescents and young adults. Further studies are warranted to clarify the causal relationship between exposure to phthalate and oxidative stress.

Preliminary Report of Inflammatory Markers, Oxidative Stress, and Insulin Resistance in Adolescents of Different Ethnicities.

Higher fasting glucose and hemoglobin A1C levels are seen more often in African American (AA) and Hispanic (H) youth, even after adjusting for body mass index (BMI), pointing to other factors that might be promoting abnormal glucose tolerance, such as inflammatory mediators. Our study compared markers of inflammation and oxidative stress in adolescents of different ethnicities. This was a cross-sectional cohort study of healthy Caucasian (C), H, and AA adolescents. Fasting urine for F2-isoprostanes and plasma for adiponectin, soluble vascular cell adhesion molecule (s-VCAM 1), interleukins (ILs), and tumor necrosis factor-α were collected and analyzed. Insulin resistance was measured by homeostasis model assessment of insulin resistance (HOMA-IR). Multivariable regression analyses were used to assess the effect of the biomarkers on HOMA-IR. Seventy adolescents were enrolled (26 C, 20 A, and 24 H); 32 were male (46%) and 27 (39%) were obese. Exploratory analysis showed that for every 1 U increase in BMI z-score, IL-8 rose by 0.53 (0.05, 1.00), P = 0.03. On regression analyses, for every unit increase in BMI z-score, HOMA-IR increased by 0.67 U (P = 0.001); for every unit increase in IL-8, HOMA-IR decreased by 0.21 U (P = 0.04). None of the other biomarkers was significantly associated with HOMA-IR. Higher insulin resistance was associated with increasing BMI z-scores and lower IL-8. This pilot study demonstrates the need to further evaluate inflammatory markers as an independent risk factor for the development of diabetes and to explore if there is a cause and effect relationship between IL-8 and insulin resistance. This could prove valuable for early identification of insulin resistance and as targets for intervention.

Comparative study of the effect of obesity on lipid profiles levels, insulin resistance and oxidative stress in adolescents

Introduction: Obesity is associated with social and medical risks that especially make it a problem. The study is to determine whether the lipid abnormalities observed in obese adolescents are associated with insulin resistance & oxidative stress. Methods: We evaluated the relationship between lipid levels and insulin resistance and oxidative stress in 30 female obese adolescents who were obese (body mass index > 25 Kg/m). Insulin resistance was assessed by fasting insulin and glucose level, Lipid profile was studied including, total cholesterol, HDL, LDL, and oxidative stress by estimating vitamin-c and Malandialdehyde. Results: All the parameters except serum HDL level showed significant increase in obese adolescents persons while HDL level was significantly decreased. Conclusion: The study indicates elevation of glucose, lipid profile levels and oxidative stress in obese adolescents. This is due to hyperinsulinaemia leads to insulin resistance. Insulin resistance may be responsible, for changes in lipid and lipoprotein concentration. childhood weight requires special early attention because insulin resistance, inflammation and dyslipidemia increase the risk of cardiovascular disease

Efficacy of selected treadmill training programme on oxidative stress in adolescents with Down syndrome

The aim of this study was to assess the efficacy of an electronic treadmill exercise training programme on malondialdehyde (MDA) as a marker for lipid peroxidation and the antioxidant enzyme glutathione peroxidase (GPx) in adolescents with Down syndrome. The study was carried out on 30 adolescent males with Down syndrome, ranging in age from 15 to 18 years, with 30 healthy subjects as a control group. Clinical examination, anthropometric measurements and determination of GPx activity and MDA before and after exercise were done. A treadmill training programme was performed for 12 weeks. Our data showed a significant increase in GPx activity and decrease in serum level of MDA in Down syndrome individuals after treadmill exercise for 3 months. Exercise promotion for adolescents with Down syndrome requires attention to motivators and facilitators of exercise adherence as it may limit risk of increased neurological consequences associated with oxidative stress and improve quality of life.

434 Relationship between Obesity and 8-Hydroxy 2- Deoxy Guanosine as an Oxidative Marker in Obese Adolescents of Giza

Background and AimThis study was conducted to assess the relationship between obesity markers (Body mass index “BMI”, fat percentage) and DNA oxidative marker 8-hydroxyl guanosine (OHG), as a predictor for...

PP217-MON PSYCHIATRIC DISORDERS IN OBESE MEXICAN CHILDREN

Rationale: Assessing the relationship between obesity markers (Body mass index [BMI], fat percentage) and DNA oxidative marker 8-hydroxyl guanosine (OHG), as a predictor for future clinical problems in obese adolescents. Methods: The study was conducted on 103 adolescents aged 13 18 years (22 boys, 81 girls). BMI was calculated as body weight (kg) divided by height squared (m2) and obesity was defined as BMI of 95 percentile. Fat percentage was determined by using Biological impedance technique. Oxidative stress markers as 8-hydroxyl guanosine, superoxide and gluthione were measured. The adolescents were divided according to BMI into two groups. Group I with BMI >95 percentile and less than 97 percentile (obese) and Group II with BMI >97 percentile (severely obese). Results: Significant differences were detected between the two groups of the study as regard obesity markers (BMI, fat %) and oxidative stress markers (lipid oxidation, superoxide dismutase enzyme activity, glutathione peroxidase enzyme activity, 8-hydroxyl guanosine) (p < 0.0005). Significant positive correlations were detected between obesity markers and oxidative stress markers among severely obese adolescent (group II). Obesity is highly associated with states of oxidative stress in adolescents, with a positive relation with 8-hydroxy-guanosine and obesity markers and other oxidative markers. Conclusion: 8-hydroxy-guanosine might play an important role in the prediction of future development of some clinical diseases.

Effects of a physical activity program on markers of endothelial dysfunction, oxidative stress, and metabolic status in adolescents with metabolic syndrome.

The metabolic syndrome (MetS) is a precursor of diabetes. Physical activity (PA) improves endothelial dysfunction and may benefit patients with MetS. Aims. To evaluate the effect of a physical activity (PA) program on markers of endothelial dysfunction and oxidative stress in adolescents with (MetS). Methods. We carried out a cohort study of 38 adolescents with and without MetS (18 females and 20 males). All participants completed a 3-month PA program. All variables of the MetS as well as markers of endothelial dysfunction and oxidative stress tests were evaluated. Results. Females with and without MetS showed significant differences for almost all components of the MetS, whereas males were significantly different in half of the components. After the PA program, components of the MetS were not different from baseline values except for HDL-C levels. Some baseline endothelial dysfunction markers were significantly different among adolescents with and without MetS; however, after the PA program, most of these markers significantly improved in subjects with and without MetS. Conclusion. PA improves the markers of endothelial dysfunction in adolescents with MetS although other changes in the components of the MetS were not observed. Perhaps the benefits of PA on all components of MetS would appear after a PA program with a longer duration.

Evidence of unexpected oxidative stress in airways of adolescents born very pre-term

Prematurity and its main respiratory complication, bronchopulmonary dysplasia (BPD), are potentially associated with lifelong respiratory morbidities and/or lung function abnormalities. The mechanisms behind these long-term respiratory problems are still unclear. We assessed airway oxidative stress in adolescents born very pre-term (≤ 32 gestational weeks) by measuring 8-isoprostane concentration in exhaled breath condensate (EBC). In addition, the study protocol included spirometry and measurement of exhaled nitric oxide fraction (F(eNO)). The study groups included 34 ex-pre-term adolescents with BPD, 18 ex-pre-term adolescents without BPD and 34 healthy controls born at term. Regardless of a history of BPD, the ex-premature adolescents had higher EBC 8-isoprostane levels (median (interquartile range) BPD 9.5 (7.3-12.2) pg·mL(-1); pre-term non-BPD 10 (8.1-16) pg·mL(-1)) than the controls (3.2 (1.9-6.5) pg·mL(-1)) (p<0.001). Forced expiratory volume in 1 s was lower in the BPD group (mean ± sd Z-score -2.1 ± 1.58) than in the pre-term non-BPD individuals (-1.13 ± 1.15), who showed in turn significantly lower values than the controls (0.18 ± 0.83; p<0.001). F(eNO) was similar in the three groups (p=0.55). Our data show that, after premature birth, evidence of oxidative stress in the airways may be detected into adolescence, suggesting that long-term respiratory abnormalities after pre-term birth may be associated with an ongoing airway disease and not just a stabilised structural lung damage.

Experimental evidence that phenylalanine is strongly associated to oxidative stress in adolescents and adults with phenylketonuria

Few studies have looked at optimal or acceptable serum phenylalanine levels in later life in patients with phenylketonuria (PKU). This study examined the oxidative stress status of adolescents and adults with PKU. Forty PKU patients aged over fifteen years were enrolled, and were compared with thirty age-matched controls. Oxidative stress markers, anti-oxidant enzyme activities in erythrocytes, and blood anti-oxidant levels were examined. Nitric oxide (NO) production was also examined as a measure of oxidative stress. Plasma thiobarbituric acid reactive species and serum malondialdehyde-modified LDL levels were significantly higher in PKU patients than control subjects, and correlated significantly with serum phenylalanine level ( P < 0.01). Plasma total anti-oxidant reactivity levels were significantly lower in the patient group, and correlated negatively with phenylalanine level ( P < 0.001). Erythrocyte superoxide dismutase and catalase activities were higher and correlated significantly with phenylalanine level ( P < 0.01). Glutathione peroxidase activity was lower and correlated negatively with phenylalanine level ( P < 0.001). The oxidative stress score calculated from these six parameters was significantly higher in patients with serum phenylalanine of 700–800 μmol/l. Plasma anti-oxidant substances, beta-carotene, and coenzyme Q 10 were also lower (P < 0.001), although the decreases did not correlate significantly with the phenylalanine level. Serum nitrite/nitrate levels, as stable NO products, were higher together with low serum asymmetric dimethylarginine, as an endogenous NO inhibitor. Oxidative stress status is closely linked with serum phenylalanine levels. Phenylalanine level in should be maintained PKU below 700–800 μmol/l even in adult patients.

Fruit and Vegetable Consumption and Its Relation to Markers of Inflammation and Oxidative Stress in Adolescents

Background Fruits and vegetables, foods rich in flavonoids and antioxidants, have been associated with lower risk of stroke, coronary heart disease, and markers of inflammation and oxidative stress in adults. Markers of inflammation and oxidative stress are predictors of coronary heart disease risk; however, it is unknown whether these markers are related to dietary flavonoid and antioxidant intake in youth. Objective To determine whether greater intakes of fruit and vegetables, antioxidants, folate, and total flavonoids were inversely associated with markers of inflammation and oxidative stress in 285 adolescent boys and girls aged 13 to 17 years. Design In this cross-sectional study conducted between February 1996 and January 2000, diet was assessed by a 127-item food frequency questionnaire. Height and weight measurements were obtained and a fasting blood sample drawn. Spearman partial correlation analyses evaluated the relation of intakes of fruit and vegetables, antioxidants, folate, and flavonoids with markers of inflammation (C-reactive protein, interleukin-6, tumor necrosis factor-α, and 15-keto-dihydro-PGF 2α metabolite and oxidative stress (urinary 8-iso prostaglandin F 2α, an F 2-isoprostane), adjusting for age, sex, race, Tanner stage, energy intake, and body mass index. Results Urinary F 2-isoprostane was inversely correlated with intakes of total fruit and vegetables, vitamin C, beta carotene, and flavonoids. Serum C-reactive protein was significantly inversely associated with intakes of fruit ( r=−0.19; P=0.004), vitamin C ( r=−0.13, P=0.03), and folate ( r=−0.18; P=0.004). Serum interleukin-6 was inversely associated with intakes of legumes, vegetables, beta carotene, and vitamin C. Serum tumor necrosis factor-α was inversely associated with beta carotene ( r=−0.14, P=0.02) and luteolin ( r=−0.15, P=0.02). Conclusion Study results show that the beneficial effects of fruit and vegetable intake on markers of inflammation and oxidative stress are already present by early adolescence and provide support for the Dietary Guidelines for Americans “to consume five or more servings per day” of fruits and vegetables to promote beneficial cardiovascular health.

Glycemic control in adolescents with type 1 diabetes mellitus improves lipid serum levels and oxidative stress

Atherosclerosis begins in childhood, and diabetes is a risk factor for coronary heart disease. Dyslipidemia is prevalent in children with type 1 diabetes mellitus (T1DM), with an association between elevated hemoglobin A1c (HbA1c), serum lipid levels, and oxidative stress. Our aim was to examine the effect of metabolic control on serum lipid levels and oxidative stress in adolescents with T1DM. Twenty-six adolescents (13 boys and 13 girls), aged 15.65 +/- 1.5 yr, with disease duration of 5.9 +/- 2.8 yr and average HbA1c 10.8 +/- 1.9% were assigned to intensive insulin therapy for 3 months. Comparisons for HbA1c, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein cholesterol, total triglycerides (TG), total cholesterol (TC), apolipoprotein AI, apolipoprotein AII, apolipoprotein B (ApoB), and thiobarbituric acid reactive substances (TBARS) were done between patients whose HbA1c improved by 0.5% or more (GR1) and the rest of the cohort (patients whose HbA1c improved by <0.5%, did not change, or increased) (GR2). ApoB (p = 0.047) and TBARS (p = 0.01) were significantly lower at the end of the study in GR1. In GR2, TC (p = 0.01) and LDL (p = 0.03) were significantly higher at study end. Overall, significant beneficial changes in TC (p = 0.006), TG (p = 0.04), LDL (p = 0.02), ApoB (p = 0.015), and oxidative stress (p = 0.001) were found in GR1 compared with GR2. We provide direct evidence for the beneficial effect of tight metabolic control on serum lipids and oxidative stress in adolescents with T1DM, indicating that tight metabolic control may reduce cardiovascular risk in these patients.

The effect of oral alpha-lipoic acid on oxidative stress in adolescents with type 1 diabetes mellitus

Oxidative stress has been implicated in the pathophysiology of diabetic complications. Alpha-lipoic acid (LA), a potent antioxidant, has been shown to be an effective treatment for diabetic neuropathy when given intravenously. Recently, an oral controlled-release formulation of alpha-lipoic acid (CRLA) was developed, and a pharmacokinetic study demonstrated that CRLA maintained significant plasma levels for 67% longer than a common quick-release formulation. To determine if CRLA is an effective antioxidant in type 1 diabetes mellitus (T1D) by measuring its effects on markers of oxidative damage and total antioxidant status. Forty pubertal and postpubertal adolescents with T1D underwent a double-blind, randomized, placebo-controlled study of CRLA for 3 months. 8-hydroxy-2'-deoxyguanosine, 2-thiobarbituric acid-reactive substances, protein carbonyl, total reactive antioxidant potential, hemoglobin A1c (HbA1c), and spot random urine collected for albumin to creatinine ratio were measured before and after treatment. There was no significant change in any measurement of oxidative damage, total antioxidant status, HbA1c, or microalbuminuria prevalence after treatment with either placebo or CRLA. In this pilot study, CRLA was not an effective treatment for decreasing oxidative damage in T1D, although efficacy may have been limited by issues with compliance.

Roles of Paraoxonase and Oxidative Stress in Adolescents with Uraemic, Essential or Obesity-Induced Hypertension

Background/Aims: Paraoxonase 1 (PON1) is associated with high-density lipoproteins in the plasma, and is capable of hydrolysing oxidized lipids and preventing the oxidation of low-density lipoproteins. Oxidative stress and the PON1 (activity and Q192R polymorphism) were analysed in adolescent patients with essential (n = 49) or obesity-induced hypertension (n = 79), uraemic patients (n = 20), and also in obese normotensive patients (n = 60) and age-matched controls (n = 57). Methods: The PON1 activity was measured via paraoxon hydrolysis. The PON1 genotype was determined by real-time PCR. The levels of oxidized and reduced glutathione, the end-products of nitric oxide, cysteine, homocysteine and lipid peroxidation in the plasma were measured and related to the PON1 status. Results: There were no significant differences between the patient groups and the control group in the genotype distributions and the allele frequencies of the Q192R polymorphism. The PON activity was significantly lower (p < 0.001) in the uraemic hypertensive group than in the controls. The MDA concentration was significantly higher in the uraemic hypertensive (p < 0.001) and obese hypertensive (p < 0.05) patients. The plasma NO_x concentrations were significantly lower (p < 0.001) and the ratio MDA/NO_x were significantly higher in all four patient groups. The GSH levels were significantly lower in the patients with hypertension (p < 0.001) and obesity-induced hypertension (p < 0.05) than in the controls, while the GSSG level (p < 0.01) and the ratio GSSG/GSH (p < 0.05) was significantly higher in the uraemic hypertensive group. The plasma homocysteine level was significantly higher (p < 0.001) in the uraemic hypertensive patients as compared with the controls. Conclusions: We found no significant correlation between the biochemical parameters and neither genotypes nor enzyme activities. The PON1 status and the levels of certain biochemical parameters are independently associated with the hypertension in hypertensive and obese hypertensive patients, and the elevated levels of lipid peroxides and plasma homocysteine may contribute to the increased risk of cardiovascular complications in patients on haemodialysis.