Oxidative stress, inflammation, and atherosclerotic changes in retinal arteries in the Japanese population; results from the Mima study

Association between Abdominal Obesity and Oxidative Stress in Korean Adults

Background

Obesity causes several changes in the body and is associated with both inflammation and oxidative stress. However, the relationship between abdominal obesity, diacron-reactive oxygen metabolites (d-ROMs), and biological antioxidant potential (BAP) levels in Korean adults has not yet been proved. The aim of this study was to evaluate the association between d-ROMs, BAP levels, and abdominal obesity in the Korean adult population using clinical data.

Methods

A total of 2,367 individuals, aged 18–86 years, were identified from health check-up examination records at a university hospital, between January 2015 and August 2016. Clinical and biochemical parameters, including waist circumference, lipid profile, alcohol drinking status, and smoking status, were investigated. Oxidative stress levels, viz., d-ROM concentration and antioxidant capacity, viz., BAP, were measured.

Results

Subjects with abdominal obesity presented significantly higher levels of d-ROMs compared to those with a normal waist circumference (P<0.001). After adjusting for age, sex, alcohol drinking status; smoking status; and triglyceride, low-density lipoprotein levels were found to have a significant positive correlation with abdominal obesity (P<0.001). BAP did not significantly correlate with abdominal obesity.

Conclusion

We observed a positive association between abdominal obesity and d-ROM concentration. This result indicates that abdominal obesity can increase oxidative stress and may affect the pathways involved in obesity, such as the inflammatory pathway. Such correlation analyses were helpful in revealing the causes, as well as methods to reduce, oxidative stress.

Association between Serum Uric Acid and Oxidative Stress in Korean Adults

Background

Oxidative stress is implicated in the pathogenesis and development of lifestyle-related diseases. In the present study, we evaluated the correlation between the serum uric acid (UA) levels and oxidative status in Korean adults.

Methods

The subjects were 5,093 individuals (2,041 women and 3,052 men) who underwent a health checkup between June 2012 and December 2016. Oxidative stress levels (derivatives of reactive oxygen metabolites [d-ROMs]) and antioxidant potential (biological antioxidant potential [BAP]) were measured. Metabolic markers, including UA, were also examined.

Results

Higher serum UA levels were associated with decreased levels of d-ROMs (P<0.05). The UA levels were positively associated with BAP levels (P<0.001).

Conclusion

Serum UA is related to oxidative status, especially antioxidant capacity, in Korean adults; UA may play a role in antioxidant defense systems in humans.

Shiftwork and the Retinal Vasculature Diameters Among Police Officers

OBJECTIVE

To investigate associations of central retinal arteriolar equivalent (CRAE), a measure of retinal arteriolar width, and central retinal venular equivalents (CRVE), a measure of retinal venular width, with shiftwork in 199 police officers (72.9% men).

METHODS

Shiftwork (day, afternoon, night) was assessed using electronic payroll records. Four digital retinal images per officer were taken. Mean diameters of the retinal vasculature were compared across shifts using analysis of variance (ANOVA)/analysis of covariance (ANCOVA).

RESULTS

Among all officers (mean age = 46.6 ± 6.8 years), shiftwork was not significantly associated with CRAE or CRVE. However, among current and former smokers, night-shift officers had a wider mean (±standard error [SE]) CRVE (230.0 ± 4.5 μm) compared with day shift officers (215.1 ± 3.5 μm); adjusted P = 0.014.

CONCLUSIONS

Night shift schedule in current and former smokers is associated with wider retinal venules. Reasons for this association are not known. Longitudinal studies are warranted.

The effects of exercise load during development on oxidative stress levels and antioxidant potential in adulthood

The objective of this study was to elucidate the impact of physical activity during the growth period as well as on oxidative stress and antioxidative potential in adulthood. The experimental animals used were four-week old male Wistar rats, which were randomly divided into three groups. The exercise loads were as follows: control (CON), treadmill exercise (TE), and jumping exercise (JE). The exercise was performed at the same time of day, at a frequency of five days per week, for eight weeks. Derivatives of reactive oxygen metabolites (d-ROSs) and biological antioxidant potential (BAP) were measured during periods of rest prior to commencement of the experiment and after the experiment. Analysis was conducted using a Wilcoxon signed-rank test and Schaffer's multiple comparison procedure and the significance level was set at p < 0.05. The percent increase in d-ROM levels in the JE group, which experienced short-duration intense exercise loads, was higher than that in the TE group, which experienced moderately intense exercise loads. However, BAP, which is an index of antioxidant potential, markedly decreased in adulthood in the CON group, as compared to that in the developmental period, whereas the exercise groups showed no notable changes in BAP levels. Oxidative stress levels and antioxidant potential are affected differently in adulthood, depending on the intensity of sustained exercise loads experienced during development. Results suggested that in order to increase antioxidant potential, while taking oxidative stress production into account, moderately intense exercise loads are more desirable than highly intense exercise loads.

Serum γ-glutamyltranspeptidase and oxidative stress in subjectively healthy women: an association with menopausal stages

BACKGROUND

Gamma-glutamyltransferase (γ-GT) is used as a marker of alcohol-related pathology, while γ-GT is recently considered to be an oxidative stress marker.

AIM

The present study aimed to investigate the correlation between the oxidative status and γ-GT levels, in association with menopausal stages.

METHODS

In total, 252 women, who were subjectively healthy, were divided into three groups: premenopausal, perimenopausal, and postmenopausal. The circulating oxidative status was evaluated by the diacron-reactive oxygen metabolite (d-ROM) test. In addition to serum γ-GT, routine blood investigations, including lipid, glucose, and inflammatory parameters, were performed.

RESULTS

The median γ-GT level was 17 U/L and the mean d-ROM level was 335 Carr U in all subjects. On multiple regression analysis, independent significant positive correlations were observed between d-ROM and high-sensitivity CRP levels in three groups, while there was a significant positive correlation between d-ROM and γ-GT levels only in the premenopausal group but not in the perimenopausal and postmenopausal groups.

DISCUSSION

The significant relationship between d-ROM and γ-GT at active estrogen stage may indicate a different oxidative stress condition by memopausal stage. The reasons of this relationship should be further explored.

CONCLUSION

A positive relationship between d-ROM and γ-GT levels, both as known as oxidative stress-related markers, could exist in premenopausal women.

A comparative study of time-specific oxidative stress after acute myocardial infarction in patients with and without diabetes mellitus

Background

Oxidative stress is involved in the initiation and progression of atherosclerosis, and hyperglycemia is known to increase oxidative stress, which injures the endothelium and accelerates atherosclerosis. To clarify the relation between oxidative stress, diabetes mellitus (DM), and acute myocardial infarction (AMI), we evaluated and compared time-specific oxidative stress after AMI in patients with and without DM by simple measurement of derivatives of reactive oxygen metabolites (d-ROMs) levels as indices of reactive oxygen species production.

Methods

Sixty-eight AMI patients were enrolled (34 non-DM patients and 34 DM patients). Using the FRAS4 free radical analytical system, we measured d-ROMs levels in each patient at two time points: 1 and 2 weeks after AMI onset.

Results

d-ROM levels decreased significantly between week 1 and week 2 (from 475.4 ± 119.4 U.CARR to 367.7 ± 87.9 U.CARR, p < 0.001) in the non-DM patients but did not change in the DM patients (from 463.1 ± 109.3 U.CARR to 461.7 ± 126.8 U.CARR, p = 0.819). Moreover, significant correlation was found in the total patient group between d-ROMs levels at 1 week and N-terminal prohormone of brain natriuretic peptide (r = 0.376, p = 0.041) and between d-ROM levels at 2 weeks and 2-hour oral glucose tolerance test glucose levels (r = 0.434, p < 0.001).

Conclusions

Exposure to oxidative stress is greater in AMI patients with DM than AMI patients without DM. Our study results suggest that it is the continuous hyperglycemia that increases oxidative stress in these patients, causing endothelial dysfunction and accelerating atherosclerosis. However, long-term follow up study is needed to assess whether the increased oxidative stress affects patient outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0259-6) contains supplementary material, which is available to authorized users.

Effects of Febuxostat on Oxidative Stress

PURPOSE

We previously examined factors that affect the measured derivatives of reactive oxygen metabolites (d-ROMs), an indicator of reactive oxygen species production, and biological antioxidant potential (BAP), an indicator of antioxidant capacity, in typical health checkup examinees and reported the usefulness of measuring both indicators simultaneously. In addition, a positive correlation reportedly exists between d-ROMs and the visceral fat area measured by using computed tomography. A recent study of the relationship between uric acid levels and various obesity-related factors found that visceral fat was the factor most strongly related to uric acid levels. Uric acid is itself a potent endogenous antioxidant, but because reactive oxygen species are produced during uric acid generation, it is suggested that uric acid may have opposing effects. The objective of this study was to analyze the effect of febuxostat, a novel xanthine oxidase inhibitor, on oxidative stress.

METHODS

Study subjects were 43 hyperuricemia outpatients receiving care in the internal medicine department of our institution. The subjects were divided into a new administration group (29 patients) and a switched administration group (14 patients); the latter were allopurinol-treated patients with hyperuricemia who were switched to febuxostat. In addition to measuring the patients' uric acid and creatinine levels and estimated glomerular filtration rate before and after treatment, their d-ROMs and BAP as well as the BAP/d-ROMs ratio were also measured.

FINDINGS

Both groups exhibited significant decreases in uric acid levels, as well as significant decreases in d-ROMs and BAP. No significant changes were observed in the BAP/dROMs ratio or renal function, including creatinine levels and estimated glomerular filtration rate.

IMPLICATIONS

Febuxostat could significantly reduce d-ROMs. However, BAP levels were also significantly reduced concurrently. No changes were observed in the BAP/d-ROMs ratios. This regulatory mechanism is believed to have counteracted changes in the in vivo oxidative stress balance caused by febuxostat administration.

C-reactive protein and reactive oxygen metabolites in subjects with metabolic syndrome

OBJECTIVE

This cross-sectional study investigated the correlation between diacron reactive oxygen metabolites (d-ROMs) and high-sensitivity C-reactive protein (hs-CRP) in subjects with or without metabolic syndrome.

METHODS

Cardiometabolic risk factors, d-ROMs and hs-CRP were determined in 457 women: 123 with metabolic syndrome and 334 without metabolic syndrome. The correlation between d-ROMs and hs-CRP levels was compared between the two groups.

RESULTS

The group with metabolic syndrome had significantly higher d-ROMs and hs-CRP levels than the group without metabolic syndrome. While the d-ROMs level was significantly and positively correlated with the hs-CRP level in both groups, the correlation level between the two groups was significantly different. Multiple linear regression analysis adjusted for other cardiometabolic risk factors also showed significant positive correlation between dROMs and hs-CRP levels in both groups.

CONCLUSION

Subjects with metabolic syndrome may have a closer relationship between inflammation and oxidative stress than subjects without metabolic syndrome, possibly reflecting their increased predisposition to atherosclerosis. Further studies are necessary to confirm the observed relationship.

Correlation Between High-sensitivity C-reactive Protein and Reactive Oxygen Metabolites During A One-year Period Among Asymptomatic Subjects

Background

Inflammation and oxidative stress are associated with human health and the disease status. The present study aimed to investigate the longitudinal correlation between the diacron reactive oxygen metabolites (d-ROMs) level, as an oxidative stress-related marker, and high-sensitivity C-reactive protein (hsCRP), as an inflammatory marker, during a one-year period among asymptomatic subjects.

Methods

The data, including anthropometric and biochemical markers, were collected at baseline and after the one-year period from 71 participants (male/female = 41/30, mean age 50 years). The correlation between the changes of the d-ROMs and hsCRP levels during the study period was examined.

Results

A simple correlation analysis showed a significant and positive correlation to exist between the changes of the d-ROMs and hsCRP levels (r = 0.40, P < 0.01). This significant correlation remained independent in a multiple linear regression analysis adjusted for confounding factors.

Conclusions

The present findings suggest that the relationship between the d-ROMs and hsCRP levels could be prospectively followed, and that monitoring both markers may help to better understand the cooperation of inflammation and oxidative stress in association with health and disease. Further studies are necessary to clarify the biological mechanism(s) responsible for the observed relationship.

Keywords

Oxidative stress; Oxygen reactive species; Inflammation; CRP

Characteristics of reactive oxygen metabolites in serum of early teenagers in Japan

OBJECTIVES

The relationship between the incidence of cardiovascular disease and the state of oxidative stress in blood has been studied to some extent. Several lines of evidence underscore the importance of primary prevention of cardiovascular disease beginning in childhood. However, little is known about the current state of oxidative stress in childhood. This study was carried out to determine the current state of the level of reactive oxygen metabolites (ROM) in serum of early teenagers.

METHODS

This study enrolled 595 healthy junior high school students from the town of Nanbu located in northern Japan. Oxidative stress was evaluated by measuring the serum level of ROM, and antioxidant capacity was evaluated by measuring the serum level of biological antioxidant potential (BAP).

RESULTS

Although the ROM level in female students [308.6 ± 63.1 Carratelli units (U.CARR)] was slightly higher than that in males (299.9 ± 55.2 U.CARR), the difference was not statistically significant. The BAP level in males was significantly higher than that in females. The levels of ROM and BAP detected in males in the first grade were higher than those in the other grades. In females, only first-graders' BAP was higher than that in other grades.

CONCLUSIONS

The current study found that the ROM level in males was negatively correlated with grade. These results suggest the presence of factor(s) that increase oxidative stress in Japanese puberty.

Significance of measuring oxidative stress in lifestyle-related diseases from the viewpoint of correlation between d-ROMs and BAP in Japanese subjects

In recent years, oxidative stress has been postulated to be an important factor in the pathogenesis and development of lifestyle-related diseases. In this study, we investigated the association between the derivatives of reactive oxygen metabolites (d-ROMs), as an index of products of reactive oxygen species (ROS), and biological antioxidant potential (BAP), as an index of antioxidant potential. We also investigated the associations between d-ROMs or BAP and the risk factors for lifestyle-related diseases or metabolic syndrome-associated factors to evaluate their usefulness in preventive medicine. There were 442 subjects who underwent health checkup examination in our facilities. In addition to standard medical checkup items, we analyzed d-ROMs, BAP, brachial-ankle pulse wave velocity, high-sensitivity C-reactive protein level and visceral fat area (VFA) visualized on a computed tomography scan. The mean d-ROM value in females was significantly higher than that in males. There was a positive correlation between the d-ROM and VFA levels. On correlation analysis, there was a negative correlation between the d-ROM and creatinine levels. As factors that influence d-ROMs, the level of VFA was selected, suggesting the significance of oxidative stress measurement with d-ROMs. In addition, there was a positive correlation between d-ROMs and BAP values. Further research is required to resolve whether increased production of ROS or the antioxidant potential that can compensate for such an increase of ROS is more important in vivo.

Relations between serum reactive oxygen metabolites (ROMs) and various inflammatory and metabolic parameters in a Japanese population

AIM

Both oxidative stress and inflammation are known to play roles in the pathogenesis of cardiovascular disease. We investigated the relations between reactive oxygen metabolites (ROMs) and various inflammatory and metabolic parameters in a Japanese population.

METHODS

We analyzed 48 male and 69 female subjects, aged 25 to 65 years, who underwent an annual health checkup in our university. Serum ROM level was assayed using a free radical elective evaluator. We also measured serum concentrations of high-sensitivity C-reactive protein (hsCRP), insulin, and high molecular weight (HMW) adiponectin.

RESULTS

Although the serum ROM level in females (347+/-83 Carr U) was slightly higher than in males (333+/-53 Carr U), this was not statistically significant. In the 48 male subjects, the ROM level negatively correlated with age (r=-0.344, p=0.0161), and positively correlated with the hsCRP level (r=0.306, p=0.0338). In the 69 female subjects, the ROM level negatively correlated with serum creatinine (r=-0.293, p=0.0141), and positively correlated with insulin (r=0.278, p=0.0202), the insulin resistance index (r=0.286, p=0.0170) and hsCRP levels (r=0.487, p<0.0001). Stepwise multiple regression analysis revealed that serum hsCRP, creatinine, and age were independently correlated with the serum ROMs level (R2=0.365; F value highest for hsCRP). When the study subjects were divided into tertiles according to the ROM level, serum hsCRP was significantly different among the three groups: its level was highest in the highest tertile of ROMs (p<0.001).

CONCLUSION

These results suggest that the serum ROM level is closely associated with serum hsCRP in Japanese adult subjects.