Urinary 8-OHdG Levels Research Articles

Central obesity transition increased urinary levels of 8-hydroxydeoxyguanosine in male adults: A 3-year follow up study

ObjectiveAssociation of oxidative DNA damage with gain in anthropometric indices has not been fully elucidated. MethodsIn this study, participants (n = 1151) were derived from the baseline visit of Wuhan residents in the Wuhan-Zhuhai Cohort Study. The participants finished the physical examinations at both baseline and 3-year follow up. Urinary levels of 8-hydroxydeoxyguanosine (8-OHdG) were measured by gradient-elution high performance liquid chromatography method and then calibrated by urinary creatinine (Cr) values. ResultsGeneralized linear models showed that after adjusted for confounding factors, baseline central obesity individuals with a ≥2.5% hip circumference (HC) loss or >5% HC gain had a 0.290 μmol/mol Cr (95% confidence interval (CI): 0.108, 0.472) or 0.553 μmol/mol Cr (95% CI: 0.273, 0.833) increase in urinary 8-OHdG levels compared with those with a −2.5%–2.5% HC gain (both P < 0.05). Moreover, compared with non-central obesity at both baseline and 3-year follow-up, we observed that central obese men at both baseline and 3-year follow-up had a 0.46 μmol/mol Cr (95% CI: 0.16, 0.75) increased in urinary 8-OHdG levels. ConclusionsHC gain showed dose-dependent associations with urinary 8-OHdG levels. Moreover, male central obesity at both baseline and 3-year follow-up had an increased risk for urinary 8-OHdG levels.

Chronic intermittent hypoxia-mediated renal sympathetic nerve activation in hypertension and cardiovascular disease

In sleep apnea syndrome (SAS), chronic intermittent hypoxia (CIH) is believed to activate the sympathetic nerve system, and is thus involved in cardiovascular diseases (CVD). However, since patients with SAS are often already obese, and have diabetes and/or hypertension (HT), the effects of CIH alone on sympathetic nerve activation and its impacts on CVD are largely unknown. We, therefore, examined the effects of CIH on sympathetic nerve activation in non-obese mice to determine whether renal sympathetic nerve denervation (RD) could ameliorate CIH-mediated cardiovascular effects. Male C57BL/6 (WT) mice were exposed to normal (FiO2 21%) or CIH (10% O2, 12 times/h, 8 h/day) conditions for 4 weeks with or without RD treatment. Increased urinary norepinephrine (NE), 8-OHdG, and angiotensinogen levels and elevated serum asymmetric dimethyl arginine levels were observed in the CIH model. Concomitant with these changes, blood pressure levels were significantly elevated by CIH treatment. However, these deleterious effects by CIH were completely blocked by RD treatment. The present study demonstrated that CIH-mediated renal sympathetic nerve activation is involved in increased systemic oxidative stress, endothelial dysfunction, and renin-angiotensin system activation, thereby contributing to the development of HT and CVD, thus could be an important therapeutic target in patients with SAS.

High serum uric acid is associated with oxidation of nucleosides in patients with type 2 diabetes

Uric acid presents different roles in an organism, since it can act as an antioxidant or a pro-oxidant molecule. High serum uric acid levels may cause damage to several structures, including nucleic acids and its components. Therefore, in this study the association between increased serum uric acid concentrations and oxidation of nucleosides was investigated by assessment of urinary 8-hydroxydeoxyguanosine (8-OHdG) in patients with type 2 diabetes (T2D) and in healthy individuals. Urinary 8-OHdG and biochemical parameters were assessed in 61 patients who were initially grouped into 2 groups based on the median serum uric acid levels (<5.3 mg/dL and ≥5.3 mg/dL). Urinary 8-OHdG was higher in patients with T2D and serum uric acid levels ≥5.3 mg/dL, when compared with the patients with serum uric acid levels <5.3 mg/dL; however, co-occurrence of high serum uric acid with high urinary 8-OHdG was not observed in healthy individuals. A significant positive correlation between 8-OHdG and uric acid (r = 0.40, P < 0.01) was observed in patients with T2D. High serum uric acid levels were associated with high urinary 8-OHdG levels in patients with T2D, and this association was independent of gender, hypertension, body mass index, and serum creatinine.

Heavy Exposure of Waste Collectors to Polycyclic Aromatic Hydrocarbons in a Poor Rural Area of Middle China.

Manual collection and open-air incineration of waste materials is a common practice in rural regions of China and beyond. Low-temperature combustion of rubber and plastic waste generates high levels of airborne polycyclic aromatic hydrocarbons (PAHs). We investigated ten urinary hydroxylated PAH metabolites (OH-PAHs), the oxidative damage biomarker (8-hydroxy-deoxyguanosine, 8-OHdG), and four serum biomarkers including gamma-glutamyl transferase (GGT) and alanine aminotransferase (ALT) in 41 waste collectors and 122 control subjects residing in the same or a distant rural village in Henan Province. The level of PAH metabolites in urine (median: 17.24 μg/g Cre) was twice that of controls living in the same area without an occupational history involving waste collection (median: 8.16 μg/g Cre) and thrice that of controls living 30 km away (median: 6.07 μg/g Cre). The concentrations of OH-PAHs were positively associated with urinary 8-OHdG levels (β = 0.283, p < 0.05). Serum GGT and ALT were slightly increased in waste collectors. Urinary 8-OHdG levels were similar in one-year and longer-term workers, suggesting that rubber and plastic waste collection/incineration carries a high PAH exposure risk. These data provide solid baseline information, emphasizing the importance of monitoring the long-term health outcomes of waste collectors and changes in exposure patterns associated with rural development and regulation of waste disposal.

Urinary 8-hydroxydeoxyguanosine is a better biomarker of aging in non-smokers

Objective: The aim of this study is finding an optimal and convenient aging marker. Method: The information of participants’ occupation, family background, life style, physical condition, etc. was obtained by a self-administered questionnaire. Spot urine and saliva samples were collected during the early morning after fasting overnight. 8-hydroxydeoxygunaosine (8-OHdG), 8-iso-prostaglandin F2[Formula: see text] (8-isoPGF2[Formula: see text]), advanced oxidation protein products (AOPPs), malondialdehyde (MDA), and dehydroepian drosterone sulfate (DHEA-S) were measured by ELISA. Results: Around 112 non-smokers (males/females [Formula: see text] 61/51; mean age [Formula: see text] 44.9 years) were eligible and analyzed in this study. The mean urinary 8-OHdG level was [Formula: see text] (ng/mmol, creatinine) and mean 8-isoPGF2[Formula: see text] level was [Formula: see text] (pg/mmoL, creatinine). In saliva, the mean level of AOPPs, MDA, and DHEA-S was [Formula: see text] ([Formula: see text]mol/L), [Formula: see text] ([Formula: see text]mol/L) and [Formula: see text] (ng/mL), respectively. After analysis in multiple regression model, urinary 8-OHdG was influenced by age and tea consumption ([Formula: see text]); urinary 8-isoPGF2[Formula: see text] level was correlated with gender ([Formula: see text]); salivary DHEA-S was related to gender ([Formula: see text]) and marital status ([Formula: see text]); AOPPs and MDA in saliva presented no relationships with those factors. Conclusion: Among healthy non-smokers, urinary 8-OHdG is the best aging biomarker comparing to other markers.

Dietary non-enzymatic antioxidant capacity and DNA damage in a working population.

The aim of this study was to investigate the potential links between dietary non-enzymatic antioxidant capacity (NEAC) in overall diet and separately from foods and beverages and markers of DNA damage. The participants were 513 employees, 20 to 65y of age. Urinary levels of 8-hydroxydeoxyguanosine (8-OHdG) and 7-methylguanine (m7 Gua) were measured using column-switching high-performance liquid chromatography. Dietary NEAC was determined from databases of NEAC measurements obtained by different assays: ferric reducing-antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and total radical-trapping antioxidant parameter (TRAP). Dietary NEAC for each participant was calculated by multiplying the estimated NEAC values with the consumed amount and summing up those values, which was ascertained by a validated brief self-administered diet history questionnaire. Multiple-regression analyses were performed to assess the associations between dietary NEAC and 8-OHdG and m7 Gua, with adjustment for potential confounders. No statistically significant associations were found between overall dietary NEAC or NEAC from either foods or beverages and urinary 8-OHdG levels, after adjustment for potential confounders (overall: FRAP, Ptrend=0.40; ORAC, P=0.27; TRAP, P=0.45). Likewise, no association was found between overall dietary NEAC and m7 Gua levels (FRAP, Ptrend=0.30; ORAC, P=0.65; TRAP, P=0.41). However, we did identify significant inverse association between NEAC from foods, as estimated by TRAP, and m7 Gua levels (Ptrend=0.049). Overall, dietary NEAC was not associated with 8-OHdG or m7 Gua levels. In contrast, dietary NEAC from foods but not beverages may be inversely associated with DNA damage caused by methylation.

Inhalation of hydrogen gas elevates urinary 8-hydroxy-2'-deoxyguanine in Parkinson's disease.

Hyposmia is one of the earliest and the most common symptoms in Parkinson’s disease (PD). The benefits of hydrogen water on motor deficits have been reported in animal PD models and PD patients, but the effects of hydrogen gas on PD patients have not been studied. We evaluated the effect of inhalation of hydrogen gas on olfactory function, non-motor symptoms, activities of daily living, and urinary 8-hydroxy-2′-deoxyguanine (8-OHdG) levels by a randomized, double-blinded, placebo-controlled, crossover trial with an 8-week washout period in 20 patients with PD. Patients inhaled either ~1.2–1.4% hydrogen-air mixture or placebo for 10 minutes twice a day for 4 weeks. Inhalation of low dose hydrogen did not significantly influence the PD clinical parameters, but it did increase urinary 8-OHdG levels by 16%. This increase in 8-OHdG is markedly less than the over 300% increase in diabetes, and is more comparable to the increase after a bout of strenuous exercise. Although increased reactive oxygen species is often associated with toxicity and disease, they also play essential roles in mediating cytoprotective cellular adaptations in a process known as hormesis. Increases of oxidative stress by hydrogen have been previously reported, along with its ability to activate the Nrf2, NF-κB pathways, and heat shock responses. Although we did not observe any beneficial effect of hydrogen in our short trial, we propose that the increased 8-OHdG and other reported stress responses from hydrogen may indicate that its beneficial effects are partly or largely mediated by hormetic mechanisms. The study was approved by the ethics review committee of Nagoya University Graduate School of Medicine (approval number 2015-0295). The clinical trial was registered at the University Hospital Medical Information Network (identifier UMIN000019082).

SIRT6 expression and oxidative DNA damage in individuals with prediabetes and type 2 diabetes mellitus

Sirtuins (SIRTs) is a family of NAD+ dependent histone deacetylases. SIRT6 takes play in glucose homeostasis, genomic stability and DNA repair. Although increased oxidative DNA damage and decreased DNA repair activity were determined in diabetes mellitus, the possible relation between level of oxidative DNA damage and SIRT6 expression has not been investigated so far. We determined SIRT6 expression and urinary 8-hydroxy deoxyguanosine (8-OHdG) levels, marker of oxidative DNA damage, in cases with prediabetes (PreDM) and type 2 diabetes mellitus (T2DM).SIRT6 gene expression was determined in peripheral blood leukocytes of 70 patients with type 2 diabetes, 50 cases in prediabetic stage and 40 healthy subjects. SIRT6 mRNA levels were determined by quantitive real time- polymerase chain reaction. SIRT6 protein was detected by immunocytochemical staining. Urinary 8-hydroxy deoxyguanosine (8-OHdG) levels were measured by ELISA.There was no significant difference between groups for SIRT6 mRNA level. SIRT6 immunopositivity in T2DM group was lower when compared to those in preDM group (P<0.05). SIRT6 positive cell number in T2DM and preDM groups were lower in comparison to control group (P<0.01 for both), however, when study groups were subdivided into two groups according to their age, the difference between preDM and control groups disappeared in both mid-aged and old-aged groups. The urinary 8-OHdG level was found to be higher in the T2DM group in comparison to preDM group (P<0.05). When age is taken into consideration, urinary 8-OHdG level in the T2DM group was found to be higher than those in both preDM and control groups in the old-aged cases but no significant difference was determined between groups in the mid-aged cases. There was no relation between SIRT6 expression and urinary 8-OHDG excretion.It was concluded that SIRT6 may take play in development of T2DM but this effect seems to be independent from repair of oxidative DNA damage.

Elevation in and persistence of multiple urinary biomarkers indicative of oxidative DNA stress and inflammation: Toxicological implications of maleic acid consumption using a rat model.

Maleic acid (MA), an intermediate reagent used in many industrial products, instigated public health concerns in Taiwan when it was used to adulterate an array of starch-based delicacies to improve texture and storage time. Established studies reported that exposure to high concentrations of MA induce renal injury; little is known whether oxidative stress is induced at a relative low dose. This study aims to investigate the effect of oral single dose exposure of MA on the status of oxidative stress and inflammation. Single dose of MA at 0, 6 and 60 mg/kg (control, low- and high-dose groups, respectively) were orally administered to adult male and female rats. Urine samples were collected and analyzed to measure 8-hydroxy-2’-deoxyguanosine (8-OHdG), 8-iso-prostaglandin F2α (8-IsoPGF2α), 8-nitroguanine (8-NO2Gua) and N-acetyl-S-(tetrahydro-5-hydroxy-2-pentyl-3-furanyl)-L-cysteine (HNE-MA) using LC-MS/MS. Results revealed that oral consumption of MA induced oxidative DNA damage and lipid peroxidation, as demonstrated by the statistically significant increases in urinary levels of 8-NO2Gua, 8-OHdG, and 8-isoPGF2α, in high-dosed male rats within 12 h of oral gavage (p < 0.05). Additionally, increases in concentration of these biomarkers persist for days after consumption; male rats appear to be more sensitive to oxidative burden compared to their counterparts. The aforementioned findings could help elucidate the mechanisms through which nephrotoxicity occur.

Abstract P346: Diurnal Variation of Serum Uric Acid Levels and Corresponding Variations of Oxidative Stress Makers in Patients With Hypertension and Stable Coronary Artery Disease

Background: Hyperuricemia has been known as a risk factor of hypertension, stroke and coronary artery disease (CAD). Uric acid (UA) itself has antioxidative activity, but it is also reported that UA can also stimulate oxidative stress. In healthy subjects, it has been shown that UA has diurnal variation; elevate in the early morning. However, it is unclear whether such diurnal variation is observed and whether corresponding diurnal variation of oxidative stress can also be observed even in patients with CAD. Therefore, we investigated presence of diurnal variation of serum levels of UA, oxidative stress makers in patients with hypertension and CAD. Method: We measured serum levels of UA, NOx, and urinary levels of 8-OHdG, serum at 6 p.m., 6 a.m., 12 p.m. in 26 men with CAD. We excluded patients who was taking drugs which can affect UA levels. Result: Overall 20 patients were enrolled. Serum UA levels were 5.67±0.99 mg/dl at 6 p.m., 5.86±0.99 mg/dl at 6 a.m., and 5.73±0.99 mg/dl at 12 p.m., indicating obvious diurnal variation (P=0.0004). Serum UA levels increased significantly from 6 p.m. to 6 a.m. (P=0.002) and decreased significantly from 6 a.m. to 12 p.m. (P=0.002). Urinary level of 8-OHdG were 13.96±4.95 ng/mlCr at 6 p.m., 19.47±9.20 ng/mlCr at 6 a.m., and 16.19±5.52 ng/mlCr at 12 p.m., indicting corresponding diurnal variation to the serum UA level (P=0.013). Similarly, urinary levels of 8-OHdG increased significantly from 6 p.m. to 6 a.m. (P=0.008) and tend to decrease from 6 a.m. to 12 p.m. (P=0.57). Serum NOx levels were 13.19±6.60μM at 6 p.m., 12.11±6.02μM at 6 a.m. and 15.08±6.61μM at 12 p.m. and showed reciprocal diurnal variation to the serum UA and urinary 8-OHdG levels (p=0.0028). Discussion: Serum UA levels showed diurnal variation even in patients with hypertension and CAD. Considering the fact that oxidative stress makers showed corresponding diurnal variations, diurnal variation of serum UA level may play a role in the pathogenesis of CAD.

GS-E3D, a new pectin lyase-modified red ginseng extract, inhibited diabetes-related renal dysfunction in streptozotocin-induced diabetic rats

BackgroundGS-E3D is a newly developed pectin lyase-modified red ginseng extract. The purpose of this study was to investigate the therapeutic effects of GS-E3D on diabetes-related renal dysfunction in streptozotocin-induced diabetic rats.MethodGS-E3D (25, 50, and 100 mg/kg body weight per day) was administered for 6 weeks. The levels of blood glucose and hemoglobin A1c, and of urinary albumin, 8-hydroxy-2′-deoxyguanosine (8-OHdG), and advanced glycation end-products (AGEs) were determined. Kidney histopathology, renal accumulation of AGEs, and expression of α-smooth muscle actin (α-SMA) were also examined.ResultsAdministration of GS-E3D for 6 weeks reduced urinary levels of albumin, 8-OHdG, and AGEs in diabetic rats. Mesangial expansion, renal accumulation of AGEs, and enhanced α-SMA expression were significantly inhibited by GS-E3D treatment. Oral administration of GS-E3D dose-dependently improved all symptoms of diabetic nephropathy by inhibiting renal accumulation of AGEs and oxidative stress.ConclusionThe results of this study indicate that the use of GS-E3D as a food supplement may provide effective treatment of diabetes-induced renal dysfunction.

The polymorphism XRCC1 Arg194Trp and 8-hydroxydeoxyguanosine increased susceptibility to arsenic-related renal cell carcinoma

This study was designed to explore the relationship between X-ray repair cross-complementing group 1 (XRCC1) gene polymorphisms and renal cell carcinoma (RCC) and to investigate whether individuals with an XRCC1 risk genotype, a high level of 8-OHdG or a high urinary total arsenic concentration have a modified odds ratio (OR) of RCC. We recruited 180 RCC patients and 360 age- and sex-matched controls from a hospital-based pool. Image-guided biopsy or surgical resection of renal tumors was performed on RCC patients for pathological verification. Genomic DNA was used to examine the genotype of XRCC1(Arg399Gln), XRCC1(Arg194Trp), XRCC3(Thr241Met) and XPD(Lys751Gln) by PCR-RFLP. Liquid chromatography with tandem mass spectrometry was used to determine urinary 8-OHdG levels. A HPLC-HG-AAS was used to determine the concentrations of urinary arsenic species. Participants with the genotype XRCC1(Arg194Trp) Arg/Trp+Trp/Trp had a significantly higher OR of RCC than those with the Arg/Arg genotype; the OR and 95% confidence interval was 0.66 (0.45–0.97) after multivariate adjustment. The OR of RCC for the combined effect of high urinary 8-OHdG levels and high urinary total arsenic concentration in individuals with a XRCC1(Arg194Trp) Arg/Trp+Trp/Trp genotype was higher than in patients with an Arg/Arg genotype, which was evident in a dose response manner. In conclusion, this is the first study to show that the XRCC1 Arg194 allele is a predicting factor for RCC. The more risk factors (high urinary 8-OHdG levels, high urinary total arsenic concentrations, and XRCC1 Arg194 allele) that were present, the higher the OR of RCC.

Effects of smoking on concentration of urinary 8-hydroxydeoxyguanosine in coke oven workers

Objective: To explore the influence of smoking and polycyclic aromatic hydrocarbons (PAHs) on urinary 8-hydroxydeoxyguanosine (8-OHdG) in coke oven workers and investigate their dose-dependent relationships. Methods: A total of 436 workers exposed to coke oven emissions (COEs) and 132 controls were recruited in this study. Questionnaires were completed in a personal interview. Then their urine samples were also collected and the concentrations of urinary four OH-PAHs and 8-OHdG were determined by high performance liquid chromatography (HPLC) which was used to evaluate the levels of occupational PAHs internal exposure among workers and the DNA damage. Results: The differences of concentrations of urinary 2-NAP (2-hydroxynathalene) , 2-FLU (2-hydroxyfluorene) , 9-PHE (9-hydroxyphenanthrene) , 1-OHP (1-hydroxypyrene) between exposure group and control group were statistically significant (P<0.05) . In exposure group and control group, the level of 8-OHdG in heavy smoking workers were significantly higher than that in other groups (P<0.05) . Multivariate logistic regression analysis revealed high levels of urinary 8-OHdG were associated with a significantly increased risk of having higher urinary1-hydroxypyrene levels[OR=1.43 (95%CI: 1.06-1.94) , P<0.01] and heavy smoking [OR=1.44 (95%CI: 1.08-1.91) , P<0.01], respectively. Trend test showed that linear dose response relationship between smoking, 1-OHP in urine and higher concentrations of 8-OHdG (P<0.05) . Smoking could significant modify the effects of urinary 1-hydroxypyrene, while co-exposure to both heavy smoking and high urinary 1-hydroxypyrene levels[OR=5.64 (95%CI: 2.15-14.80) , P<0.05]. Conclusion: Urinary 1-hydroxypyrene is a useful biomarker for evaluating total PAHs exposure, coke oven workers with heavy smoking present more serious DNA oxditive damage.

Effect of Pycnogenol\xae on attention-deficit hyperactivity disorder (ADHD): study protocol for a randomised controlled trial

BackgroundMethylphenidate (MPH), the first choice medication for attention-deficit hyperactivity disorder (ADHD), is associated with serious adverse effects like arrhythmia. Evidence on the association of ADHD with immune and oxidant-antioxidant imbalances offers potential for antioxidant and/or immunomodulatory nutritional supplements as ADHD therapy. One small randomised trial in ADHD suggests, despite various limitations, therapeutic benefit from Pycnogenol®, a herbal, polyphenol-rich extract.MethodsThis phase III trial is a 10-week, randomised, double-blind, placebo and active treatment controlled multicentre trial with three parallel treatment arms to compare the effect of Pycnogenol® to MPH and placebo on the behaviour of 144 paediatric ADHD and attention-deficit disorder (ADD) patients. Evaluations of behaviour (measured by the ADHD-Rating Scale (primary endpoint) and the Social-emotional Questionnaire (SEQ)), immunity (plasma cytokine and antibody levels, white blood cell counts and faecal microbial composition), oxidative stress (erythrocyte glutathione, plasma lipid-soluble vitamins and malondialdehyde and urinary 8-OHdG levels, as well as antioxidant enzyme activity and gene expression), serum zinc and neuropeptide Y level, urinary catecholamines and physical complaints (Physical Complaints Questionnaire) will be performed in week 10 and compared to baseline. Acceptability evaluations will be based on adherence, dropouts and reports of adverse events. Dietary habits will be taken into account.DiscussionThis trial takes into account comorbid behavioural and physical symptoms, as well as a broad range of innovative immune and oxidative biomarkers, expected to provide fundamental knowledge on ADHD aetiology and therapy. Research on microbiota in ADHD is novel. Moreover, the active control arm is rather unseen in research on nutritional supplements, but of great importance, as patients and parents are often concerned with the side effects of MPH.Trial registrationClinicaltrials.gov number: NCT02700685. Registered on 18 January 2016. EudraCT 2016-000215-32. Registered on 4 October 2016.

Decreased total antioxidant capacity has a larger effect size than increased oxidant levels in urine in individuals with autism spectrum disorder.

Oxidant/antioxidant imbalance may contribute to the pathophysiology of autism spectrum disorder (ASD). We assayed urinary levels of oxidative stress related biomarkers, hexanoyl-lysine (HEL), total antioxidant capacity (TAOC), the DNA methylation biomarker 8-hydroxy-2'-deoxyguanosine (8-OHdG), and plasma levels of superoxide dismutase (SOD), which is major antioxidant enzyme. We examined the relationship between these four biomarkers and social responsiveness in 20 individuals with ASD and in 11 healthy controls. The sex (ASD group, 7/13 vs. control group, 4/7) and age distributions (ASD group, 10.7±5.0years vs. control group, 14.7±6.3years) were not significantly different between the groups. Social responsiveness was assessed using the social responsiveness scale (SRS). We used standardized regression coefficients to measure the effect size. The ASD group exhibited significantly lower urinary TAOC levels and significantly elevated urinary HEL levels than the control group. Urinary 8-OHdG levels and plasma SOD levels were not significantly different between the groups. The ASD group showed significantly higher SRS scores than the control group. Plasma SOD levels correlated significantly with urinary TAOC levels. Standardized regression coefficients revealed that TAOC levels had a larger effect size than HEL levels in urine. This study firstly reveals that an imbalance between urinary HEL and TAOC levels in favor of urinary TAOC levels may contribute to impaired social responsiveness in individuals with ASD. Plasma SOD levels may also affect urinary TAOC levels.

Dose-response relationship between urinary polycyclic aromatic hydrocarbons metabolites and urinary 8-hydroxy-2′-deoxyguanosine in a Chinese general population

Association of exposure to polycyclic aromatic hydrocarbons (PAHs) with increased urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation has been reported in occupational population and children. However, studies on the association between them in general population are limited. A total of 1864 eligible subjects from the baseline Wuhan participants of the Wuhan-Zhuhai Cohort Study (n = 3053) were included in this study, after excluding individuals with certain disease and missing data on urinary monohydroxy PAHs (OH-PAHs) and 8-OHdG levels. Urinary monohydroxy PAHs and 8-OHdG levels were measured by gas chromatography-mass spectrometry and high performance liquid chromatography-electrochemical detection, respectively. Association of urinary OH-PAHs with urinary 8-OHdG was analyzed by multiple linear regression analysis. We found a dose-dependent relationship between urinary PAHs metabolites and urinary 8-OHdG (p < 0.05 for all). Furthermore, more evidence for the association of total concentrations of urinary OH-PAHs with 8-OHdG levels were observed in individuals with normal body mass index or central obesity (p < 0.01 for all). There was a dose-dependent relationship between urinary OH-PAHs levels and urinary 8-OHdG levels among a general Chinese population. Exposure to background PAHs may have a greater influence on urinary 8-OHdG levels in individuals with central obesity.

Phthalate-induced oxidative stress and association with asthma-related airway inflammation in adolescents.

In Belgium, around 8.5% of the children have asthmatic symptoms. Increased asthma risk in children has been reported in relation to exposure to phthalate plasticizers but the underlying mechanisms are largely unknown. The aim of this study was to identify if oxidative stress, assessed by excision of 8-hydroxydeoxyguanosine (8-OHdG) from damaged DNA, is an intermediate marker for the association between phthalate exposure and doctor-diagnosed asthma. In 418 14-15-year-old youngsters, recruited as a representative sample of residents of Flanders (Belgium), personal exposure to phthalates was assessed by measuring phthalate metabolites in urine: mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-n-butyl phthalate (MnBP), mono-benzyl phthalate (MBzP), mono-isobutyl phthalate (MiBP) and mono-ethyl phthalate (MEP). Analysis of 8-OHdG in urine was used as a sensitive biomarker of oxidative stress at the level of DNA. The presence of doctor-diagnosed asthma was elicited by a self-administered questionnaire. Associations were assessed using multiple linear and logistic regression models. Mediation was tested using Baron and Kenny's regression approach. A significant increased risk of a youngster being diagnosed with asthma was found for both urinary MnBP (metabolite of dibutyl phthalate (DBP)) and the sum of the three di(2-ethylhexyl) phthalate metabolites (ΣDEHP=MEHP+MEHHP+MEOHP), with respective odds ratio of 1.84 [95% CI: 1.02, 3.32] for MnBP and 1.94 [95% CI: 1.07, 3.51] for ΣDEHP. In addition, we observed significant associations between all urinary phthalate metabolites and increased urinary levels of 8-OHdG. The associations were stronger in girls than in boys. We did not found evidence that 8-OHdG was associated with doctor-diagnosed asthma. The results of our study are in line with other findings from epidemiological surveys and raise further concern about DEHP and DBP as risk factors for asthma, however, the underlying mechanisms are not yet well understood.

Biomarkers of oxidative stress in electroplating workers exposed to hexavalent chromium.

This study evaluates levels of biomarkers of oxidative DNA damage and lipid peroxidation in 105 male workers at 16 electroplating companies who had been exposed to hexavalent chromium (Cr(VI)). The study participants were 230 non-smoking male workers, comprising 105 electroplating workers who had been exposed to chromium and 125 control subjects who performed office tasks. Personal air samples, spot urine samples, hair samples, fingernail samples and questionnaires were used to quantify exposure to Cr(VI), oxidative DNA damage, lipid peroxidation, and environmental pollutants. Both the geometric mean personal concentrations of Cr(VI) of the Cr-exposed workers and the total Cr concentrations in the air to which they were exposed significantly exceeded those for the control subjects. The geometric mean concentrations of Cr in urine, hair and fingernails, and the urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), and malondialdehyde (MDA) levels in the Cr(VI) exposed workers exceeded those in the control subjects. Daily cumulative Cr(VI) exposure and urinary Cr were significantly correlated with urinary 8-OHdG levels following adjustments for covariates. A ten-fold increase in urinary Cr level was associated with a 1.73-fold increase in urinary 8-OHdG level. Daily cumulative Cr(VI) exposure and urinary Cr level were significantly correlated with urinary MDA level following adjustments for covariates. A ten-fold increase in urinary Cr was associated with a 1.45-fold increase in urinary MDA. Exposure to Cr(VI) increased oxidative DNA injury and the oxidative deterioration of lipids in electroplating workers.

The effect of sunblock against oxidative stress in farmers: a pilot study.

Farmers are frequently exposed to ultraviolet (UV) radiation which causes various diseases by inducing oxidative stress. This study aimed to assess the effects of sunblock on oxidative stress in the body. Eighty-seven farmers were divided into two groups: those who wore sunblock for five days and those who did not. The total antioxidant capacity (TAC) in urine, which is an antioxidant indicator, and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels in urine, an oxidative stress indicator, were measured. The urinary TAC of sunblock users was significantly higher than that of non-users, but urinary 8-OHdG levels were not significantly different. Even after adjustment for potential confounders, urinary TAC was found to be markedly increased with sunblock usage. These results suggest that sunblock is effective in preventing oxidative stress among farmers. In addition, they show that urinary TAC can be used as a good effect marker of oxidative stress caused by UV exposure.

Lifestyle Changes and Oxidative Stress in a High-incidence Area of Amyotrophic Lateral Sclerosis in the Southwestern Kii Peninsula, Japan.

Objective Lifestyle changes may play an important role in the incidence reduction and delay of onset age of amyotrophic lateral sclerosis (ALS) in the Koza/Kozagawa/Kushimoto (K) area. The aim of this study was to evaluate recent lifestyle changes in the K area and to investigate the relationships between lifestyle and oxidative stress among the residents. Methods We conducted a medical checkup for elderly residents in the K area and the control area and evaluated the urinary 8-OHdG levels, cognitive function test scores and metal contents in serum and scalp hair, coupled with a lifestyle questionnaire survey between 2010 and 2015. Results Recent lifestyle changes among the K residents, including a decrease in the Japanese pickle consumption, increase in fresh vegetable consumption and decrease in farm work, were evaluated in this study. Low consumption of Japanese pickles, high consumption of fresh vegetables, rare farm work and low levels of 8-OHdG/creatinine were all associated with high scores in the cognitive function tests. Frequent farm work and consumption of Japanese pickles was associated with high contents of transition metals, such as Mn, Al and V, in the scalp hair. Conclusion These lifestyle changes among residents in the K area may be associated with their oxidative stress.