Sakiko Kanbara

Oxidative stress biomarkers and lifestyles in Japanese healthy people

The urinary concentrations of 8-isoprostane and 8-hydroxy-2’-deoxyguanosine (8-OHdG), which are biomarkers of oxidative stress, were measured in 677 Japanese people without any diseases, and their correlations with lifestyle facotrs, lifestyle-related blood biochemical parameters, and dietary intake of antioxidative vitamins were investigated. The mean urinary concentration of 8-isoprostane and 8-OHdG was 0.58 ng/mg creatinine and 8.43 ng/mg creatinine, respectively. Mean urinary 8-isoprostane was significantly different in terms of age, gender, smoking and alcohol consumption but not different in terms of body mass index (BMI) and exercise. By multiple regression analysis, urinary 8-isoprostane was significantly influenced by smoking and age. On the other hand, mean urinary 8-OHdG showed differences only by age group. Multiple regression analysis revealed that urinary 8-OHdG was significantly influenced by age, smoking, body weight, levels of high-sensitivity C-reactive protein (Hs-CRP) and low density lipoprotein-cholesterol in females, although it was significantly influenced by body weight in males. The present study shows that urinary 8-isoprostane is associated with lipid peroxidation related-lifestyles such as smoking, and urinary 8-OHdG is associated with arteriosclerosis related-factors such as Hs-CRP. Our findings suggest that 8-isoprostane and 8-OHdG appear to be prospective biomarkers for early prediction of lifestyle related-disease risk at the population level.

Plasma 3-nitrotyrosine, urinary 8-isoprostane and 8-OHdG among healthy Japanese people

To examine the relation between lifestyle factors and oxidative stress biomarkers, this study analysed plasma 3-nitrotyrosine (3-NT), urinary 8-isoprostane and 8-hydroxy-2’- deoxyguanosine (8-OHdG) of 323 healthy Japanese without any disease. Plasma 3-NT was significantly increased by excessive exercise (p=0.010), but it was not significantly different in terms of sex, age (< 40, ≧40), BMI (<18.5, 18.5–24.9, ≧25.0), smoking (non-smokers, smokers) and alcohol drinking per week (non-drinkers, <10 units, ≧10 units). Urinary 8-isoprostane was significantly associated with alcohol drinking (p <0.01) and sex (p <0.01), although it had no significant relevance to age and exercise. Moreover, urinary 8-OHdG was positively associated with age (p <0.05) and negatively associated with BMI (p <0.05) and fasting insulin (p <0.001). However, it was not related with sex, smoking, alcohol drinking and exercise. In conclusion, the present results suggest that 3-NT, 8-isoprostane and 8-OHdG seem to be useful biomarkers for early prediction of lifestyle-related disease risk at the population level.

C-reactive protein is associated with cigarette smoking-induced hyperfiltration and proteinuria in an apparently healthy population

Although cigarette smoking is known to be an important risk factor for renal disease, the mechanism by which smoking induces progressive renal disease in a healthy population has not been established. We hypothesized that oxidative stress (measured as 8-iso-prostaglandin F2α, 8-iso-PGF2a), inflammation (highly sensitive C-reactive protein (CRP), hs-CRP) and nitric oxide may be associated with an alteration in the estimated glomerular filtration rate (eGFR) and proteinuria in otherwise healthy smokers. A total of 649 eligible subjects were classified according to their smoking status. Plasma NOx was measured using ozone-based chemiluminescence, urinary 8-iso-PGF2a was measured using enzyme immunoassay and serum hs-CRP was measured using a latex aggregation nephelometry method. The levels of 8-iso-PGF2a and hs-CRP increased in current smokers (P=0.001 and P=0.029, respectively), although there was not an increase in the NOx level. The prevalence of a high eGFR increased in light smokers (odds ratio (OR) 1.15 (95% confidence interval (CI), 0.61–2.17)) and heavy smokers (OR 2.33 (95% CI, 1.06–5.10)) when compared with non- and past smokers (P for trend=0.024). The multivariable-adjusted mean values of the eGFR in current smokers, reported from the lowest to the highest quintiles of hs-CRP levels, were 82.1, 85.1, 86.4 and 88.5 ml per min per 1.73 m2 (P for trend=0.027). The mean values of proteinuria were 28.6, 34.6, 37.2 and 39.5 mg g−1 creatinine (P for trend=0.003). The correlation coefficient between hs-CRP and eGFR was increased significantly (P=0.03) across non- (r=0.03), past (r=−0.17), light (r=0.13) and heavy smokers (r=0.31). In conclusion, cigarette smoking is a risk factor for renal function alteration in healthy smokers and is characterized by a high eGFR and a high urinary protein associated with an increase in the hs-CRP. This finding suggests that hs-CRP may help mediate the alteration of renal function in smokers.

Interactive Effects of Job Stress and Body Mass Index on Over-eating

Interactive Effects of Job Stress and Body Mass Index on Over‐eating: Jiro Takaki, et al. Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences

Practicality of Veterans Specific Activity Questionnaire in Evaluation of Exercise Capacity of Community-Dwelling Japanese Elderly

ObjectiveThe aim of this study is to determine whether a questionnaire-based method using the Veterans Specific Activity Questionnaire (VSAQ) is a practical tool for the development of a safe exercise program to prevent a reduction in physical performance.MethodsOne hundred and twenty-one senior residents of Yakage, Okayama, agreed to voluntarily participate in this study. They were asked to complete a questionnaire for information on age, sex, subjective health status, exercise habits and VSAQ. We investigated the relationship between age and exercise capacity predicted by VSAQ (predicted metabolic equivalents (METs)). In addition, for 36 out of the 121 participants, we performed a 6-min walk distance test (6MD) and investigated whether its results correlate with the predicted METs. Furthermore, we prepared a modified VSAQ and examined its practicality in the evaluation of the exercise capacity of Japanese elderly (n=50).ResultsWe found that the predicted METs correlate well with age. Habitual exercise and subjective health status did not affect the predicted METs. A significant correlation was observed between the predicted METs and the results of 6MD (r=0.56, p<0.001). We also found that certain activities included in the original VSAQ are unfamiliar to Japanese elderly; thus, we made a few modifications to the original VSAQ in order to evaluate the physical fitness of Japanese elderly. The number of inadequate answers was reduced by employing the modified VSAQ.ConclusionThese findings imply that the modified VSAQ is useful in evaluating the exercise capacity of Japanese elderly adequately and is a practical scale for safe exercise.

Relationship between ceruloplasmin and oxidative biomarkers including ferritin among healthy Japanese

Serum ceruloplasmin (CP), a marker relevant to copper metabolism, is one of famous inflammation markers with a reduction in Wilson’s disease, whereas serum ferritin is a marker relevant to iron metabolism. Recently, ferritin is pointed out to be related with oxidative stress. However, there is still no population research which showed the relation of CP and ferritin. Therefore, we investigated the relationship between CP and ferritin including oxidative stress biomarkers among healthy Japanese (n = 389). We measured serum CP, ferritin, Fe, high-sensitivity C-reactive protein (hs-CRP), and urinary oxidative stress biomarkers [H2O2, 8-hydroxy-2’-deoxyguanosine (8-OHdG), 8-isoprostane] and so on. Subjects showed that age; 41.7 ± 10.0 (year), CP; 31.9 ± 6.8 (mg/dl), ferritin; 123.5 ± 121.0 (ng/ml), hs-CRP; 0.89 ± 2.53 (mg/l), 8-OHdG; 10.2 ± 4.4 [ng/mg creatinine (Cre)] and H2O2; 6.5 ± 10.9 (µM/g Cre), (All data mentioned above were expressed as mean ± SD). CP was significantly and positively correlated with hs-CRP and inversely correlated with ferritin, Fe and 8-OHdG. By a multiple logistic regression analysis, odds ratio of CP according to quartiles of hs-CRP was 4.86, and according to quartiles of 8-OHdG was 0.39 after adjusting for age and other confounding factors. In conclusion, our findings suggest that CP was an antioxidative biomarker which controls oxidative stress, whereas ferritin was a marker which may participate in the generation of oxidative stress.

Evaluation of urinary hydrogen peroxide as an oxidative stress biomarker in a healthy Japanese population

Abstract The usefulness of urinary hydrogen peroxide (H2O2) as an oxidative stress biomarker was evaluated in 766 healthy Japanese. The mean level of urinary concentrations of H2O2 was 5.66 ± 8.27 μmol/g creatinine, and was significantly higher in females than in males. Significant correlations of H2O2 were observed with age, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), insulin, 8-hydroxy-2’-deoxyguanosine (8-OHdG), and exercise habit in females. In both sexes, H2O2 showed a significant correlation with 8-OHdG. By a multiple logistic regression analysis, urinary H2O2 was positively associated with urinary 8-OHdG and TC and was inversely associated with insulin. By stratification of sex and age, the association of urinary H2O2 with TC was positive in both sexes under 50 years old and was inverse in males over 50 years old, and that with insulin was inverse in males over 50 years old and in females under 50 years old. Moreover, by stratification of sex and age, a positive association of H2O2 with exercise and an inverse association of H2O2 with alcohol consumption became clear in males under 50 years old, although there were no significant odds for H2O2 after adjustment for covariates. In conclusion, the present results suggest that urinary H2O2 is a useful biomarker for oxidative stress, showing an association with 8-OHdG, TC, and insulin independently.

Possible Health-protecting Effects of Feeling Useful to Others on Symptoms of Depression and Sleep Disturbance in the Workplace

Possible Health‐protecting Effects of Feeling Useful to Others on Symptoms of Depression and Sleep Disturbance in the Workplace: Jiro Takaki, et al. Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences

Uncovering Adiponectin Replenishing Property of Sujiaonori Algal Biomaterial in Humans

The replenishment of adiponectin—an adipocyte-derived hormone with salutary health effects—has recently been proposed as a new approach to treat hypertension, also ameliorate cardiovascular and metabolic risks. We conducted a prospective placebo-controlled, non-randomized and investigator-blinded dietary intervention study to evaluate the health effects of dietary intake of Sujiaonori (Ulva/Enteromorpha prolifera Müller) algal biomaterial (SBM), especially on adiponectin production, blood pressure (BP), and body mass index (BMI) in human subjects. Participants (N = 32) were divided into two equally sized groups (n = 16 for each group): SBM group (subjects supplemented with 3 g SBM powder twice a day during meal) and the control group (subjects who took 3 g of a supplement made of 70% corn starch powder and 30% spinach twice a day) for four weeks. Two health survey questionnaires (dietary and current health questionnaires) were completed anonymously, saliva sampling was done for adiponectin measurement by ELISA, and blood pressure (BP) and anthropometric parameters were measured at baseline and four weeks later. Student paired t-test was performed to compare baseline and post-intervention data on outcome variables between the two study groups. Results showed a 2.24-fold increase in adiponectin level in SBM group (2.81 and 6.26 ng/mL at baseline and at the end of study, respectively) (p < 0.01); whereas no significant change was observed in controls (3.58 and 3.51 ng/mL, respectively) (p > 0.05). In SBM subjects, an improvement of BP profile was noted with a significant decrease in systolic BP (p < 0.01). A positive correlation was found between SBM supplementation and adiponectin level, whereas an inverse correlation was noted between SBM supplementation and blood pressure, and also BMI. These findings suggest that SBM-increased adiponectin level and improved BP in a sample of Japanese young adults, and has the potential to improve blood pressure in humans.

Sujiaonori-Derived Algal Biomaterials Inhibit Allergic Reaction in Allergen-Sensitized RBL-2H3 Cell Line and Improve Skin Health in Humans

Sujiaonori, a river alga growing in the Kochi prefecture, Japan, contains several bioactive compounds such as sulfated polysaccharides (ulvans), ω-3 fatty acids, and vitamins. Dietary intake of this alga-based supplement has been reported to increase circulatory adiponectin, a salutary hormone that is reported to be associated with healthy longevity and prevents a number of cardiovascular and metabolic disorders. This report highlights the anti-allergic and skin health enhancing effects of Sujiaonori-derived ulvan (Tosalvan) and supplement, respectively. RBL-2H3 cell line was used to investigate the anti-allergic effect of algal SP through the evaluation of β-hexosaminidase activity. Algal sulfated polysaccharides or SP (Tosalvan, Yoshino SP) were extracted from powders of dried alga samples provided by local food manufacturers. Report on the effect of daily dietary intake of Sujiaonori-based supplement on skin health is part of a four-week clinical investigation that, in comparison with a supplement made of 70% corn starch powder and 30% spinach powder mixture (twice 3 g daily), explore the beneficial effects of Sujiaonori algal biomaterial (SBM; 3 g taken twice daily) on cardiovascular, gastrointestinal and skin health in a sample of Japanese women. Transepidermal water loss (TEWL) was the skin health marker used in this study and was measured with the use of a corneometer. Significant reduction of β-hexosaminidase activity was observed in Tosalvan and Yoshino SP-treated cells (vs. control; p < 0.05), whereas dietary intake of SBM markedly reduced TEWL level after four weeks of supplementation, as compared to baseline TEWL (p < 0.001). Additionally, SBM improved TEWL better than the control product (p < 0.001). Findings contained in this report suggest that Sujiaonori-derived Tosalvan and Yoshino SP have anti-allergic potential and that the dietary intake of SBM has a beneficial effect on skin health.