Kuninori Shiwaku

The New BMI Criteria for Asians by the Regional Office for the Western Pacific Region of WHO are Suitable for Screening of Overweight to Prevent Metabolic Syndrome in Elder Japanese Workers

The New BMI Criteria for Asians by the Regional Office for the Western Pacific Region of WHO are Suitable for Screening of Overweight to Prevent Metabolic Syndrome in Elder Japanese Workers: Erdembileg Anuurad, et al. Department of Environmental and Preventive Medicine, Shimane University School of Medicine—Obesity occurs less frequently in Japanese than in various other ethnic populations. A person with abnormal glucose tolerance is often found to have one or more of the other cardiovascular disease risk factors, such as obesity, hypertension and hyperlipidemia. This clustering has been labeled as metabolic syndrome (WHO, 1998). It was suggested that Japanese, categorized as having normal weight (BMI of less than 25.0), as defined by the WHO (2000), have an increasing tendency toward metabolic syndrome. Our objective was to analyze metabolic syndrome in “Overweight” with BMI of 23.0–24.9 in Japanese workers, and to assess the suitability for Asians of the Regional Office for the Western Pacific Region of WHO criteria pertaining to obesity (WPRO criteria, 2000). We conducted a cross‐sectional study in the workplace setting and investigated the relationship between BMI classification based on WPRO criteria and metabolic syndrome by gender and age group (18–44 yr vs. 45–60 yr). Three hundred seventy‐nine men and 432 women Japanese workers participated in this study. BMI were categorized as 20% “Overweight” (23.0–24.9 BMI), 20% “Obese I” (25.0–29.9 BMI) and 2% “Obese II” (over 30.0 BMI), based on WPRO criteria. Graded increases in BMI were positively associated with body fat percentage, waist circumference, hip circumference and waist/hip ratio in both genders and age groups. A progressively increasing BMI category in the elder group aged 45– 60 yr in both genders was positively related with parameters constituting metabolic syndrome. Graded increases in BMI classes in elder workers based on WPRO criteria were positively associated with prevalence of metabolic syndrome, and “Overweight” elder women had significantly higher prevalence of metabolic syndrome. The present investigation, based on the increasing risks of “Overweight” with a BMI of 23.0–24.9, suggests that WPRO criteria are suitable for Japanese workers aged over 45 yr.

Overweight Japanese with body mass indexes of 23.0-24.9 have higher risks for obesity-associated disorders: a comparison of Japanese and Mongolians.

OBJECTIVE: The degree of obesity of Asians is less than that of Caucasians. It has been suggested that Japanese, categorized as having normal weight (BMI<25.0), as defined by WHO (2000), have a tendency toward increased incidences of dyslipidemia and diabetes. Our objective was to analyze parameters constituting obesity-associated disorders in overweight Japanese and Mongolians with a body mass index (BMI) of 23.0–24.9, and to assess the suitability for Asians of the Regional Office for Western Pacific Region of WHO criteria pertaining to obesity (WPRO criteria, 2000).DESIGN: Cross-sectional study in a workplace setting.SUBJECTS: A total of 386 Japanese men and 363 Japanese women, and 102 Mongolian men and 155 Mongolian women.MEASUREMENTS: Anthropometric measurements (weight, height, waist circumference, hip circumference and blood pressure) and metabolic measurements (plasma levels of total cholesterol, HDL cholesterol, triglyceride, glucose and insulin).RESULTS: Graded increases in BMI of Japanese and Mongolians were positively associated with body fat percent, waist circumference, hip circumference and waist/hip ratio. The Japanese were categorized as 22% overweight, 22% obese I, 3% obese II; the Mongolians rated as 18% overweight, 34% obese I, 19% obese II, based on the WPRO BMI criteria. The Mongolians had a higher prevalence of obesity and a higher body fat percent, but a lesser gradation of dyslipidemia, than did the BMI-matched Japanese groups. Overweight Japanese (BMI 23.0–24.9), in comparison to normal Japanese (BMI 18.5–22.9), had significant differences in systolic blood pressure, HDL-choresterol and triglyceride in men, and in systolic and diastolic blood pressure, HDL-choresterol, triglyceride, insulin and Homoeostasis model assessment-insulin resistance in women. In contrast, the Mongolians showed no significant differences in metabolic parameters between overweight and normal subjects, except for diastolic blood pressure.CONCLUSION: Since the relationship between abdominal fat mass and BMI is ethnic-specific, a universal BMI cutoff point is inappropriate for Asian populations such as the Japanese and Mongolians. The present investigation suggests that, while the WPRO criteria are suitable for Japanese, the WHO criteria are more appropriate for Mongolians.

Prevalence of the metabolic syndrome using the modified ATP III definitions for workers in Japan, Korea and Mongolia.

Prevalence of the Metabolic Syndrome using the Modified ATP III Definitions for Workers in Japan, Korea and Mongolia: Kuninori Shiwaku, et al. Department of Environmental and Preventive Medicine, Shimane University School of Medicine— A clustering of insulin resistance, hypertension and dyslipidemia has been labeled as the metabolic syndrome. Asians have a lower frequency of obesity than do Caucasians, but have an increasing tendency toward metabolic syndrome. Most data on metabolic syndrome are based on studies from Western countries with only limited information derived from Asian populations. We conducted a cross‐sectional study of individuals aged 30–60 yr in workplace settings. We examined and analyzed the health data of 1,384 Japanese, Koreans and Mongolians for metabolic syndrome based on the modified definitions of the working definition proposed by the Third Report of the National Cholesterol Educational Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III definition). The prevalence of metabolic syndrome using the ATP III‐BMI30 and ATP III‐BMI25 definitions was 7% and 12% for Japanese, 7% and 13% for Koreans, and 12% and 16% for Mongolians, respectively. With the exception of obesity, the prevalences of individual metabolic abnormalities within each of the three Asian groups were similar to each other and to reported rates of prevalence in the U.S.A. Nevertheless, the values of sensitivity and specificity by the metabolic syndrome definitions are remarkably different relative to ethnicity. A universal metabolic syndrome definition is inappropriate for comparisons of metabolic syndrome among Asian ethnic groups. We believe that the ATP III‐BMI25 definition is suitable for the determination of metabolic syndrome among Japanese and Koreans, and that the ATP III‐BMI30 is more appropriate for Mongolians.

Difficulty in losing weight by behavioral intervention for women with Trp64Arg polymorphism of the β3-adrenergic receptor gene

OBJECTIVE: Trp64Arg mutation in the β 3-adrenergic receptor (β 3AR) gene is relatively common in Japanese people. However, it has not been clear whether persons with Trp64Arg mutation in the β 3AR gene tend to have obesity and difficulty in losing weight even with a restricted diet and exercise. We investigated the response of body weight and metabolic factors to behavioral intervention in Japanese women with Trp64Arg mutation in the β 3AR gene.DESIGN: A 3-month behavioral intervention study using a combination of diet and exercise programs.SUBJECTS: A total of 76 perimenopausal women with no clinical symptoms (age: 54.7±7.7 y, body mass index (BMI): 21.0–33.0 kg/m2).MEASUREMENTS: Anthropometric measurements (weight, height, body fat, waist circumference, hip circumference, skin fold, resting energy expenditure and blood pressure) and metabolic measurements (serum levels of cholesterol, triglyceride, phospholipid, nonesterified fatty acid, glucose, insulin and leptin) and determination of the β 3AR genotype by polymerase chain reaction followed by BstNI digestion.RESULTS: At the baseline of BMI, body weight, body fat, waist circumference, hip circumference, the arm skin fold, resting energy expenditure, or blood lipid and glucose profiles, there was no significant difference in participants with/without mutation of the β 3AR gene. The intervention yielded a body weight reduction in 69 and 48%, and induced a significant difference in weight loss (−0.74 and −0.01 kg) for women with wild-type and Trp64Arg mutation, respectively. Significant differences of anthropometric parameters were found in body weight, BMI, waist and hip circumferences and blood pressure of wild type by the intervention. However, women with Trp64Arg mutation did not show significant changes in these anthropometric parameters, except for hip circumference. A significant difference was found in high-density lipoprotein cholesterol (HDL-C) and in the low-density lipoprotein cholesterol/HDL-C ratio in both genotypes.CONCLUSION: The results of the present study suggest that the Trp64Arg mutation of the β 3AR gene is associated with difficulty in losing weight through behavioral intervention, although it is not related to obesity-related phenotypes and resting energy expenditure before the intervention.

Social capital and mental health in Japan: a multilevel analysis.

Background A national cross-sectional survey was conducted in Japan. This is because the growing recognition of the social determinants of health has stimulated research on social capital and mental health. In recent years, systematic reviews have found that social capital may be a useful factor in the prevention of mental illness. Despite these studies, evidence on the association between social capital and mental health is limited as there have been few empirical discussions that adopt a multilevel framework to assess whether social capital at the ecological level is associated with individual mental health. The aim of this study was to use the multilevel approach to investigate the association between neighborhood social capital and mental health after taking into account potential individual confounders. Methodology/Principal Findings We conducted a multilevel analysis on 5,956 individuals nested within 199 neighborhoods. The outcome variable of self-reported mental health was measured by the one dimension of SF-36 and was summed to calculate a score ranging from 0 to 100. This study showed that high levels of cognitive social capital, measured by trust (regression coefficient = 9.56), and high levels of structural social capital, measured by membership in sports, recreation, hobby, or cultural groups (regression coefficient = 8.72), were associated with better mental health after adjusting for age, sex, household income, and educational attainment. Furthermore, after adjusting for social capital perceptions at the individual level, we found that the association between social capital and mental health also remained. Conclusions/Significance Our findings suggest that both cognitive and structural social capital at the ecological level may influence mental health, even after adjusting for individual potential confounders including social capital perceptions. Promoting social capital may contribute to enhancing the mental health of the Japanese.

Effects of paraquat on mitochondrial electron transport system and catecholamine contents in rat brain

The effects of paraquat on rat brain were studied. Activities of complex I (NADH: ubiquinone oxidoreductase) in mitochondrial electron transport system, lipid peroxidation and the amount of catecholamines in rat brain were measured after acute paraquat exposure. Complex I activities were significantly lower and lipid peroxides were higher in the brains of a paraquat-treated group than in those of a control group. Lipid peroxide in rat serum, however, did not increase after paraquat exposure. A study of the time dependency of paraquat effects disclosed that mitochondrial complex I activities in rat brain as well as those in rat lung and liver gradually decreased prior to the appearance of respiratory dysfunction. As compared to controls, the dopamine in rat striatum was significantly lower in the paraquat-treated group. These results suggest that paraquat after crossing the blood-brain barrier might be reduced to the radical in rat brain, which may damage the brain tissue, especially dopaminergic neurons in striatum. We therefore propose that cerebral damage should be taken into consideration on paraquat exposure. Patients may therefore need to be followed up after exposure to high doses of paraquat.

Mechanism of cytotoxicity of paraquat: I.NADH oxidation and paraquat radical formation via complex I

The mechanism of cytotoxicity by paraquat was studied focusing attention on its effect on the mitochondrial electron transport system. Paraquat inhibited both mitochondrial and cytoplasmic malate dehydrogenase activities. NADH oxidation was verified in NADH: ubiquinone oxidoreductase (complex I) reaction mixture in which paraquat was an only electron acceptor, and paraquat radical formation was observed as turning blue of the reaction mixture. A kinetic characteristic of this enzyme reaction was that Km was so high as 4.1 mM. The maximum reaction velocity was defined in the range over pH 9. NADH autoxidation with complex I, but without paraquat, was not observed in any pH range. The maximum reaction velocity of the NADH autoxidation by paraquat without complex I was observed in pH 8.5, but the figure was so small as to be negligible. With these results, we propose the hypothesis that paraquat does not promote the autoxidation with complex I, but accepts electrons via complex I to induce paraquat radical formation.

Mechanism of cytotoxicity of paraquat: III. The effects of acute paraquat exposure on the electron transport system in rat mitochondria

The effects of acute paraquat exposure on mitochondrial function in rat lung were studied. The paraquat dose-response study and time-effective study were performed to prove our hypothesis, enzyme toxicity especially in electron transport system following lipid peroxidation of mitochondrial inner membrane. In dose-response study, lipid peroxidation was increased by high dose paraquat exposure (40 mg/kg body weight) in rat lung, but not by low dose exposure (10 mg/kg body weight). But paraquat inhibited NADH:ubiquinone oxidoreductase (complex I) activities, especially NADH:ubiquinone reaction (NQR), even in low dose exposure. The lipid peroxide concentration did not correspond to the damage of complex I activity. In paraquat time-effective study, both lung and blood lipid peroxides increased after 6 h of paraquat exposure, decreased after 12 and 24 h and increased again after 48 h. After first peak of lipid peroxidation, NQR velocity decreased earlier than NADH:ferricyanide reaction (NFR) velocity. From these results, the cytotoxicity via mitochondrial dysfunction by acute paraquat exposure might be caused by complex I toxicity following lipid peroxidation of mitochondrial inner membrane.

Effect of flavonol glycoside in mulberry (Morus alba L.) leaf on glucose metabolism and oxidative stress in liver in diet-induced obese mice.

BACKGROUND Mulberry therapies on type 2 diabetic patients or streptozotocin-induced diabetic rats have been reported to improve fasting blood glucose levels. We investigated the effects of dietary consumption of mulberry-leaf powder and purified quercetin 3-(6-malonylglucoside), the quantitatively major flavonol glycoside in mulberry leaves, on glucose and lipid metabolism in high-fat diet-induced obese mice. Male C57BL/6J mice aged 8 weeks were assigned to three groups (control, mulberry leaf powder (MLP), and quercetin 3-(6-malonylglucoside) (Q3MG)) and treated with their respective diets for 8 weeks. RESULTS We found that dietary supplementation of 10 g MLP kg(-1) or 1 g Q3MG kg(-1) in high-fat diet effectively suppressed blood glucose levels. We also noted increased expression of glycolysis-related genes and suppression of thiobarbituric acid reactive substances concentrations in the liver of Q3MG group compared to control mice. CONCLUSION Dietary consumption of Q3MG, the quantitatively major flavonol glycoside in mulberry leaves, improved hyperglycemia in obese mice and reduced oxidative stress in the liver.

Validation of a new mass screening tool for cognitive impairment: Cognitive Assessment for Dementia, iPad version

Background We have developed a new screening test for dementia that runs on an iPad and can be used for mass screening, known as the Cognitive Assessment for Dementia, iPad version (CADi). The CADi consists of items involving immediate recognition memory for three words, semantic memory, categorization of six objects, subtraction, backward repetition of digits, cube rotation, pyramid rotation, trail making A, trail making B, and delayed recognition memory for three words. The present study examined the reliability and validity of the CADi. Methods CADi evaluations were conducted for patients with dementia, healthy subjects selected from a brain checkup system, and community-dwelling elderly people participating in health checkups. Results CADi scores were lower for dementia patients than for healthy elderly individuals and correlated significantly with Mini-Mental State Examination scores. Cronbach’s alpha values for the CADi were acceptable (over 0.7), and test–retest reliability was confirmed via a significant correlation between scores separated by a one-year interval. Conclusion These results suggest that the CADi is a useful tool for mass screening of dementia in Japanese populations.