Intensity-specific effect of physical activity on urinary levels of 8-hydroxydeoxyguanosine in middle-aged Japanese

Association between oxidative balance score and inflammatory markers in middle-aged and older Japanese people

PURPOSE

This study aimed to investigate the association between oxidative balance score (OBS), wherein higher OBSs indicate lower oxidative stress, and high-sensitivity C-reactive protein (hs-CRP), as well as inflammatory scores, in a large cohort of Japanese adults.

METHODS

In total, 9703 individuals aged 40-69 years participated in a baseline survey of a population-based cohort study in Saga, Japan (2005-2007). OBSs were calculated from 11 prooxidant and antioxidant lifestyle factors, including dietary intake, physical activity, alcohol consumption, and smoking status. Lifestyle data, including dietary intake, were obtained using a self-administered questionnaire. Adjusted geometric means of serum hs-CRP levels were calculated based on OBS quartiles, and linear trend tests were performed, with adjustments for potential confounders. In addition, an inflammatory cytokine z-score was constructed and assessed alongside individual markers.

RESULTS

After adjusting for multiple confounders in both sexes, the results showed a significant inverse association between OBS and serum hs-CRP levels in both men and women. These results remained unaltered when the OBS evaluation excluded powerful prooxidants, serum ferritin, or smoking. There was also an association between OBS and lower inflammatory z-score, indicating reduced overall systemic inflammation.

CONCLUSIONS

These findings suggest that a higher OBS, indicating a greater predominance of antioxidants over prooxidant exposure, is associated with lower hs-CRP levels and reduced systemic inflammation, regardless of sex.

The Association between Oxidative Balance Score and Urinary Levels of 8-Hydroxydeoxyguanosine among Japanese Adults

The oxidative balance score (OBS), wherein higher OBSs indicate lower oxidative stress, was designed to assess a composite measure of multiple pro-oxidant and antioxidant effects on an individual's oxidative stress status. This study aimed to evaluate whether OBSs were inversely associated with urinary levels of 8-hydroxydeoxyguanosine (8-OHdG)-an oxidative stress marker-among Japanese adults. This cross-sectional study was based on data obtained during 2010-2012. Overall, 7552 participants from the J-MICC Study Saga who answered a self-administered food frequency questionnaire were recruited for the final analysis. OBSs were calculated from 11 pro-oxidant and antioxidant lifestyle factors, including dietary intake, physical activity, and alcohol and smoking status. Urinary 8-OHdG values were corrected by creatinine level (ng/mg creatinine). Our findings revealed a higher total OBS was significantly associated with lower urinary 8-OHdG/creatinine levels after adjustment for covariates in men and women (p for trend < 0.01 in both sexes). We performed a multiple regression analysis of the association between OBSs and urinary 8-OHdG/creatinine levels stratified by age, body mass index (BMI), and menopausal status and found consistent negative associations in most groups for both sexes. No significant differences in the 60-64 age group for women (standardized β = -0.09, p = 0.13) or BMI < 18.5 kg/m2 for men (standardized β = -0.18, p = 0.17) were observed. A higher OBS had a strong inverse association with urinary 8-OHdG/creatinine levels in men and women among Japanese adults. The OBS might be a useful tool for evaluating the roles of oxidative stress-related lifestyle factors, including diet.

Vaping Dose, Device Type, and E-Liquid Flavor are Determinants of DNA Damage in Electronic Cigarette Users

INTRODUCTION

Despite the widespread use of electronic cigarettes, the long-term health consequences of vaping are largely unknown.

AIMS AND METHODS

We investigated the DNA-damaging effects of vaping as compared to smoking in healthy adults, including "exclusive" vapers (never smokers), cigarette smokers only, and nonusers, matched for age, gender, and race (N = 72). Following biochemical verification of vaping or smoking status, we quantified DNA damage in oral epithelial cells of our study subjects, using a long-amplicon quantitative polymerase chain reaction assay.

RESULTS

We detected significantly increased levels of DNA damage in both vapers and smokers as compared to nonusers (p = .005 and p = .020, respectively). While the mean levels of DNA damage did not differ significantly between vapers and smokers (p = .522), damage levels increased dose-dependently, from light users to heavy users, in both vapers and smokers as compared to nonusers. Among vapers, pod users followed by mod users, and those who used sweet-, mint or menthol-, and fruit-flavored e-liquids, respectively, showed the highest levels of DNA damage. The nicotine content of e-liquid was not a predictor of DNA damage in vapers.

CONCLUSIONS

This is the first demonstration of a dose-dependent formation of DNA damage in vapers who had never smoked cigarettes. Our data support a role for product characteristics, specifically device type and e-liquid flavor, in the induction of DNA damage in vapers. Given the popularity of pod and mod devices and the preferability of sweet-, mint or menthol-, and fruit-flavored e-liquids by both adult- and youth vapers, our findings can have significant implications for public health and tobacco products regulation.

IMPLICATIONS

We demonstrate a dose-dependent formation of DNA damage in oral cells from vapers who had never smoked tobacco cigarettes as well as exclusive cigarette smokers. Device type and e-liquid flavor determine the extent of DNA damage detected in vapers. Users of pod devices followed by mod users, and those who use sweet-, mint or menthol-, and fruit-flavored e-liquids, respectively, show the highest levels of DNA damage when compared to nonusers. Given the popularity of pod and mod devices and the preferability of these same flavors of e-liquid by both adult- and youth vapers, our findings can have significant implications for public health and tobacco products regulation.

8-oxoguanine and 8-oxodeoxyguanosine Biomarkers of Oxidative DNA Damage: A Review on HPLC-ECD Determination

Reactive oxygen species (ROS) are continuously produced in living cells due to metabolic and biochemical reactions and due to exposure to physical, chemical and biological agents. Excessive ROS cause oxidative stress and lead to oxidative DNA damage. Within ROS-mediated DNA lesions, 8-oxoguanine (8-oxoG) and its nucleotide 8-oxo-2'-deoxyguanosine (8-oxodG)-the guanine and deoxyguanosine oxidation products, respectively, are regarded as the most significant biomarkers for oxidative DNA damage. The quantification of 8-oxoG and 8-oxodG in urine, blood, tissue and saliva is essential, being employed to determine the overall effects of oxidative stress and to assess the risk, diagnose, and evaluate the treatment of autoimmune, inflammatory, neurodegenerative and cardiovascular diseases, diabetes, cancer and other age-related diseases. High-performance liquid chromatography with electrochemical detection (HPLC-ECD) is largely employed for 8-oxoG and 8-oxodG determination in biological samples due to its high selectivity and sensitivity, down to the femtomolar range. This review seeks to provide an exhaustive analysis of the most recent reports on the HPLC-ECD determination of 8-oxoG and 8-oxodG in cellular DNA and body fluids, which is relevant for health research.

Moderate-to-vigorous physical activity and sedentary behavior are independently associated with renal function: a cross-sectional study

BACKGROUND

Little is known about whether insufficient moderate-to-vigorous physical activity (MVPA) and longer sedentary behavior (SB) are independently associated with estimated glomerular filtration rate (eGFR) and CKD, whether they interact with known risk factors for CKD, and the effect of replacing sedentary time with an equivalent duration of physical activity on kidney function.

METHODS

We examined the cross-sectional association of MVPA and SB with eGFR and CKD in 66,603 Japanese cohort study in 14 areas from 2004 to 2013. MVPA and SB were estimated using a self-reported questionnaire, and CKD was defined as eGFR<60 mL/min/1.73 m². Multiple linear regression analyses, logistic regression analyses, and an isotemporal substitution model were applied.

RESULTS

After adjusting for potential confounders, higher MVPA and longer SB were independently associated with higher eGFR (P_{for trend MVPA}<0.0001) and lower eGFR (P_{for trend SB}<0.0001), and a lower odds ratio (OR) of CKD (adjusted OR of MVPA≥20 MET·h/day: 0.76 [95%CI: 0.68-0.85] compared to MVPA<5 MET·h/day) and a higher OR of CKD (adjusted OR of SB≥16 h/day: 1.81 [95%CI: 1.52-2.15] compared to SB<7 h/day), respectively. The negative association between MVPA and CKD was stronger in men, and significant interactions between sex and MVPA were detected. Replacing 1 hour of SB with 1 hour of physical activity was associated with about 3 to 4% lower OR of CKD.

CONCLUSIONS

These findings indicate that replacing SB with physical activity may benefit kidney function, especially in men, adding to the possible evidence on CKD prevention.

Health examination results and work environment factors affecting urinary 8-hydroxy-2'-deoxyguanosine levels

OBJECTIVE

Oxidative stress is considered to cause lifestyle-related diseases, including cancer. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) is widely analyzed as an oxidative stress marker. We extensively scrutinized the relationships between 8-OHdG levels and lifestyle choices as carcinogenic factors.

METHODS

In this study, we investigated health examination results and working conditions affecting urinary 8-OHdG levels in 503 male workers.

RESULTS

The urinary 8-OHdG level was positively associated with high blood sugar and leanness in smokers. In addition, urinary 8-OHdG tended to increase with organic solvent or hydrochloric acid exposure, as well as long working hours. On the other hand, the urinary 8-OHdG level was negatively associated with high plasma LDL-cholesterol levels in non-smokers and anemia.

CONCLUSION

According to the results, anemia decreased the oxidative stress, regardless of smoking status, while leanness or high blood sugar increased the oxidative stress in smokers, and the presence of plasma cholesterol contributed to the lower oxidative stress in non-smokers. Certain types of occupational exposure may cause oxidative stress. The measurement of urinary 8-OHdG at annual health checks may be a useful biomarker for preventing lifestyle- and work-related diseases.

Urinary 8-OHdG as a Biomarker for Oxidative Stress: A Systematic Literature Review and Meta-Analysis

Oxidative stress reflects a disturbance in the balance between the production and accumulation of reactive oxygen species (ROS). ROS are scavenged by the antioxidant system, but when in excess concentration, they can oxidize proteins, lipids, and DNA. DNA damage is usually repaired, and the oxidized products are excreted in urine. 8-hydroxy-2-deoxyguanosine is considered a biomarker for oxidative damage of DNA. It is needed to define background ranges for 8-OHdG, to use it as a measure of oxidative stress overproduction. We established a standardized protocol for a systematic review and meta-analysis to assess background ranges for urinary 8-OHdG concentrations in healthy populations. We computed geometric mean (GM) and geometric standard deviations (GSD) as the basis for the meta-analysis. We retrieved an initial 1246 articles, included 84 articles, and identified 128 study subgroups. We stratified the subgroups by body mass index, gender, and smoking status reported. The pooled GM value for urinary 8-OHdG concentrations in healthy adults with a mean body mass index (BMI) ≤ 25 measured using chemical methods was 3.9 ng/mg creatinine (interquartile range (IQR): 3 to 5.5 ng/mg creatinine). A significant positive association was observed between smoking and urinary 8-OHdG concentrations when measured by chemical analysis. No gender effect was observed.

Salivary 8-hydroxyguanine as a lifestyle-related oxidative stress biomarker in workers

Oxidative stress is a risk factor for lifestyle-related diseases, such as cancer. Investigations of the factors that increase or decrease oxidative stress contribute to disease prevention. In the present study, we focused on the 8-hydroxyguanine (8-OHGua) in saliva, as a new oxidative stress biomarker. The relationship between lifestyles and salivary 8-OHGua levels in 541 Japanese subjects was analyzed. The salivary 8-OHGua levels were significantly elevated in older persons, as well as those who smoke, have hypertension, or excess visceral fat. By contrast, statistically significant lower levels of 8-OHGua were observed in persons who moderately exercised or recently drank green tea or coffee. The direct collection of saliva, without any special collecting device, was suitable for the 8-OHGua analysis. The present results suggest that oxidative stress can be measured in a non-invasive manner with easily collectable saliva, and the salivary 8-OHGua may be a useful biomarker for lifestyle-related disease prevention.

[Workers' Lifestyles and Urinary 8-hydroxydeoxyguanosine as an Oxidative Stress Marker]

Oxidative stress in biological components has become recognized as one of the causative factors of various diseases. In this study, we investigated the effects of worker lifestyle and fatigue on the levels of urinary 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative stress. Our results revealed that urinary 8-OHdG level was increased by alcohol intake and decreased by snack intake and adequate sleep time on the day before the survey. A decrease in urinary 8-OHdG level was also observed in parallel with a decrease in workload. Urinary 8-OHdG monitoring is expected to be useful for disease prevention in the future.

Protective effect of exogenous 8-oxo-2'-deoxyguanosine on Drosophila melanogaster larval stages under heat shock

The influence of exogenous 8-oxo-2'-deoxyguanosine on the development of Drosophila melanogaster under normal conditions, and under the influence of short-term heat shock was studied. It was shown that 8-oxo-2'-deoxyguanosine was not toxic at concentrations of up to 1 μM. A tendency to accelerate larval development and fly emergence was observed under the influence of this compound in our experiments. Short-term heat shock causes a 50-80% decrease in the number of larvae that complete development. The addition of exogenous 8-oxo-2'-deoxyguanosine to the food before thermal influence negates this effect and brings the levels of the imago emergence indicators back to the basal level. The obtained results are further evidence of the possible bioregulatory and adaptogen functions of 8-oxo-2'-deoxyguanosine.

Leisure-time physical activity and DNA damage among Japanese workers

BACKGROUND

It remains unclear whether daily physical activity is associated with DNA damage. This cross-sectional study examined the association between leisure-time physical activity and urinary 8-hydroxydeoxyguanosine (8-OH-dG), a biomarker of oxidative DNA damage, or urinary 7-methylguanine (m7Gua), a biomarker of methylating DNA damage.

METHODS

Participants included 501 workers (294 men and 207 women), aged 20-65 years, from municipal offices in Japan. Urinary 8-OH-dG and m7Gua were measured using column-switching HPLC. Physical activity was evaluated using a self-reported questionnaire. The associations between leisure-time physical activity and urinary DNA damage markers were assessed by multiple linear regression analysis, with stratification by occupational physical activity.

RESULTS

After adjusting for covariates, leisure-time physical activity showed a suggestive inverse correlation with urinary 8-OH-dG levels (P for trend = 0.06), and a significant inverse association with urinary m7Gua levels (P for trend = 0.03). In analysis stratified by occupation, inverse correlations were observed in sedentary workers (walking < 30 min/day at work: P for trend = 0.06 and = 0.03 for urinary 8-OH-dG and m7Gua, respectively), but not in physically active workers (walking ≥ 30 min/day at work). In analysis for each intensity of leisure-time physical activity, light-intensity exercise was associated with lower levels of urinary 8-OH-dG (P for trend = 0.03), whereas moderate-to-high-intensity exercise was associated with lower levels of urinary m7Gua (P for trend = 0.02).

CONCLUSIONS

Our results suggest that high levels of leisure-time physical activity are associated with decreased levels of DNA damage in individuals with low physical activity at work.

Predicting the Future Need of Walking Device or Assistance by Moderate to Vigorous Physical Activity: A 2-Year Prospective Study of Women Aged 75 Years and Above

Objective

To examine the association between daily moderate to vigorous physical activity (MVPA) and the change in mobility function among community-dwelling Japanese women aged 75 years and above.

Methods

This prospective study included 330 older women aged 75 years and above who could walk without a walking device or assistance. MVPA and light-intensity physical activity (LPA) were assessed using an accelerometer for seven consecutive days. MVPA was defined as an activity with an intensity of >3 metabolic equivalents. The study outcome was a change in mobility function, defined as the need of walking device or assistance, during the two-year period.

Results

The results of the logistic regression analysis showed that MVPA was inversely associated with a decline in mobility function after controlling for LPA and potential confounders (adjusted odds ratio (OR) = 0.93 per 1 min/d, 95% confidence interval (CI) = 0.88-0.99; P = 0.017), whereas LPA was not when adjusted for MVPA and confounders (adjusted OR = 0.99 per 1 min/d, 95% CI = 0.96-1.01; P = 0.245). The receiver operating characteristics analysis identified a 7.9 min/d of MVPA as the cut-off value.

Conclusions

The results of this study suggest the importance of promoting daily MVPA for preventing mobility limitation in older women aged 75 years and above.

Perceived Stress, Depressive Symptoms, and Oxidative DNA Damage

OBJECTIVE

Psychosocial stress may influence the risk of disease through its association with oxidative DNA damage. We examined whether perceived stress and depressive symptoms were associated with urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG), with mutual interaction on 8-OHdG.

METHODS

This cross-sectional study included 6517 individuals aged 45 to 74 years who participated, between 2010 and 2012, in a follow-up survey of an ongoing cohort study. Perceived stress during the past year was measured using a self-report questionnaire. Depressive symptoms were evaluated using the Zung Self-Rating Depression Scale. Urinary 8-OHdG concentrations were measured using a column switching high-pressure liquid chromatography system coupled to an electrochemical detector.

RESULTS

Higher perceived stress was significantly associated with higher 8-OHdG (2.1% increase per one-category increase of stress; ptrend = .025), even after adjusting for sex, age, supplement use, psychosocial factors, psychotropic medication use, smoking, and body mass index. This association was modestly attenuated after further adjustment for physical activity, suggesting possible mediation or confounding by this factor. Depressive symptoms were not significantly associated with 8-OHdG. No significant interaction was detected between perceived stress and depressive symptoms on 8-OHdG.

CONCLUSIONS

In a general Japanese population, we found a weak positive association between perceived stress and urinary excretion of 8-OHdG, whereas no association was observed between depressive symptoms and 8-OHdG. Further studies are needed to examine whether the association between perceived stress and 8-OHdG is modified by depressive symptoms.

Intensity-specific effect of physical activity on urinary levels of 8-hydroxydeoxyguanosine in middle-aged Japanese

Physical activity (PA) is recommended to both promote and maintain health and prevent cancer by improving the body's DNA repair system, which is considered a mechanism of cancer prevention. However, associations between PA and urinary levels of 8-hydroxydeoxyguanosine (8-OH-dG), which reflects DNA damage, are unclear. This cross-sectional study included 2370 men and 4052 women aged 45-74 years enrolled between 2010 and 2012. Habitual PA was assessed by single-axis accelerometer and urinary 8-OH-dG levels by automated HPLC. Multiple linear regression analysis was used to examine the relationship between log-transformed urinary 8-OH-dG and total PA (TPA) and PA of moderate/vigorous intensity (MVPA; ≥3 metabolic equivalents), with adjustment for age, body mass index, energy intake, alcohol consumption, smoking status, daily coffee drinking, menopause status (in women), and TPA (for MVPA). On multivariate adjustment, urinary 8-OH-dG levels were inversely correlated with TPA (β = -0.020, P < 0.01) in women, and this correlation was not changed by PA intensity. Conversely, urinary 8-OH-dG levels were inversely correlated with MVPA (β = -0.022, P < 0.05) in men, although the correlation with TPA was non-significant. This inverse correlation was clearer in current smokers than in never or former smokers, although the interaction between smoking status and MVPA on urinary 8-OH-dG levels was non-significant. In conclusion, greater TPA in women and greater MVPA in men were correlated with reduction in urinary 8-OH-dG, suggesting sex-specific effects of MVPA and TPA on protection from oxidative DNA damage. Increasing PA may mediate reduction in oxidative stress.