Hidenobu Takami

Prevalence of Metabolic Syndrome Associated with Body Burden Levels of Dioxin and Related Compounds among Japan’s General Population

Background Environmental exposure to some persistent organic pollutants has been reported to be associated with a metabolic syndrome in the U.S. population. Objectives We evaluated the associations of body burden levels of dioxins and related compounds with the prevalence of metabolic syndrome among the general population in Japan. Methods We conducted a cross-sectional study with 1,374 participants not occupationally exposed to these pollutants, living throughout Japan during 2002–2006. In fasting blood samples, we measured biochemical factors and determined lipid-adjusted concentrations of 10 polychlorinated dibenzo-p-dioxins (PCDDs), 7 polychlorinated dibenzofurans (PCDFs), and 12 dioxin-like poly-chlorinated biphenyls (DL-PCBs) all of which have toxic equivalency factors. We also performed a questionnaire survey. Results The toxic equivalents (TEQs) of PCDDs, PCDFs, and DL-PCBs and total TEQs had significant adjusted associations with metabolic syndrome, whether or not we excluded diabetic subjects. By analyzing each component of metabolic syndrome separately, the DL-PCB TEQs and total TEQs were associated with all components, and the odds ratios (ORs) in the highest quartile of DL-PCB TEQs in four of the five components were higher than those for PCDDs or PCDFs. We also found congener-specific associations with metabolic syndrome; in particular, the highest quartiles of PCB-126 and PCB-105 had adjusted ORs of 9.1 and 7.3, respectively. Conclusions These results suggest that body burden levels of dioxins and related compounds, particularly those of DL-PCBs, are associated with metabolic syndrome. Of the components, high blood pressure, elevated triglycerides, and glucose intolerance were most closely associated with these pollutants.

Inverse Correlation Between Coffee Consumption and Prevalence of Metabolic Syndrome: Baseline Survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima, Japan

Background It is unclear whether consumption of coffee and green tea is associated with metabolic syndrome. Methods This cross-sectional study enrolled 554 adults who had participated in the baseline survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima Prefecture, Japan. Consumption of coffee and green tea was assessed using a questionnaire. Metabolic syndrome was diagnosed using the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) and the Japan Society for the Study of Obesity (JASSO). Logistic regression analysis was used to examine the association between consumption of coffee and green tea and prevalence of metabolic syndrome and its components. Results After adjustment for sex, age, and other potential confounders, greater coffee consumption was associated with a significantly lower prevalence of metabolic syndrome, as defined by NCEP ATP III criteria (P for trend = 0.03). Participants who drank more coffee had a lower odds ratio (OR) for high serum triglycerides (P for trend = 0.02), but not for increased waist circumference or high blood pressure. Using JASSO criteria, moderate coffee consumption (1.5 to <3 cups/day) was associated with a significantly lower OR for high plasma glucose (OR = 0.51, 95% CI 0.28-0.93). Green tea consumption was not associated with the prevalence of metabolic syndrome or any of its components. Conclusions Coffee consumption was inversely correlated with metabolic syndrome diagnosed using NCEP ATP III criteria, mainly because it was associated with lower serum triglyceride levels. This association highlights the need for further prospective studies of the causality of these relationships.

Dietary patterns and blood levels of PCDDs, PCDFs, and dioxin-like PCBs in 1656 Japanese individuals

The association between dietary patterns and blood dioxin levels has not been fully investigated. The present study population consisted of 755 men and 901 women (aged 15-73years) living in 90 different areas of 30 prefectures of Japan. Dietary habits were assessed by inquiring about the consumption frequency of 28 foods, food groups and beverages. In addition, the blood levels of 29 polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzo-furans (PCDFs), and dioxin-like polychlorinated biphenyl (DL-PCBs) congeners were determined by high-resolution gas chromatography/mass spectrometry. The median total toxicity equivalent (TEQ) in the blood, which was calculated on the basis of the toxicity equivalency factors of WHO (2005), was 16 pg TEQg(-1) lipid. Principal component analysis identified five dietary patterns: Healthy diet (high intake of vegetables and fruits); Meat/High fat intake (high intake of meat, meat products, and eggs); Seafood and Alcohol (high intake of fish, shellfish, and alcoholic beverages); Miscellaneous; and Milk products and Alcohol intake (high intake of milk, Milk products, and alcoholic beverages). After adjusting for sex, age, body mass index, and smoking habits, the Seafood and Alcohol pattern scores were significantly related to higher blood levels of total TEQ and PCDDs/PCDFs/DL-PCBs, and the Milk products and Alcohol pattern scores were correlated with higher blood levels of DL-PCBs. More detailed analysis showed that the intake frequencies for alcoholic beverages and seafood were independently and positively associated with total TEQ and the TEQ of PCDFs and DL-PCBs. The association between alcoholic beverage intake and PCDDs was also significant. Analysis of dietary patterns may be useful for identifying the dietary characteristics of individuals with a high dioxin body burden.

Consumption of Seafood, Serum Liver Enzymes, and Blood Levels of PFOS and PFOA in the Japanese Population

Consumption of Seafood, Serum Liver Enzymes, and Blood Levels of PFOS and PFOA in the Japanese Population: Miwa YAMAGUCHI, et al. Department of Preventive Medicine, Institute of Health Biosciences, the University of Tokushima Graduate School, Japan—

d-Dopachrome tautomerase is a candidate for key proteins to protect the rat liver damaged by carbon tetrachloride

Carbon tetrachloride (CCl4) is known to induce liver damage. Animal experiments with CCl4 injections have revealed many findings, especially mechanisms of liver damage and liver regeneration. Recently, proteomic approaches have been introduced in various studies to evaluate the quantitative and qualitative changes in the comprehensive proteome level. The aim of this research is to elucidate the key protein for liver damage, liver protection and liver regeneration by using proteomic techniques. 50 % (v/v) CCl4 in corn oil was administered intraperitoneally to adult male rats at a dose of 4ml/kg body weight. Approximately 24h after the injection, the liver was removed and extracted proteins were analyzed with cleavable isotope coded affinity tag (cICAT) reagents, two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). A twelvefold increase in D-dopachrome tautomerase (DDT) was indicated. This enzyme has been reported to be involved in the biosynthesis of melanin, an antioxidant. According to the histological analysis, melanin levels were increased in un-damaged hepatocytes of CCl4-treated rats. These results suggest that the increase in DDT is a response to liver damage, accelerates melanin biosynthesis and protects the liver from oxidative stress induced by CCl4.

Congener-specific body burden levels and possible determinants of polybrominated diphenyl ethers in the general Japanese population

OBJECTIVE Our objective was to investigate congener-specific body burden levels and possible determinants of polybrominated diphenyl ethers (PBDEs) in the Japanese human population. METHODS We conducted a cross-sectional study on 72 participants aged 15-74 years; subjects were not occupationally exposed to PBDEs or dioxin-like polychlorinated biphenyls (DL-PCBs). Participants lived in two urban areas and two fishing villages. Twenty-seven PBDE congeners, PCB-126, PCB-118, PCB-156, and biochemical factors were determined in fasting blood. A questionnaire survey on life-style was also conducted. RESULTS More than half of the PBDE values for 14 congeners were below the levels of detection (LODs). The median concentration of total PBDEs was 3.6 ng g(-1) lipid. The most abundant congener was BDE-209 (median concentration, 0.90 ng g(-1) lipid), followed by BDE-153, BDE-207, and BDE-47 in the given order. Most PBDE congeners with < or = 6 bromine atoms had significant positive associations with the concentrations of the three DL-PCBs (suggesting common routes of exposure) and with plasma concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), biological markers of fish intake. These associations did not change substantially after adjustment for age, sex, and log(body mass index). These positive associations with the concentrations of DL-PCBs or EPA/DHA were not found in analyses of high-brominated PBDE congeners with > or = 8 bromine atoms. CONCLUSIONS Fish consumption may be a major contributor to the accumulation of PBDE congeners with 6 bromine atoms among the general Japanese population. In contrast, the main exposure routes to high-brominated PBDEs in humans are probably not associated with fish consumption.

Relationship of Dietary Factors and Habits with-Sleep-wake Regularity

The purpose of this study was to evaluate the associations between dietary factors and sleep-wake regularity in the Japanese population. We analyzed 1368 eligible subjects (931 men and 437 women) aged 35-69 years who had participated in the baseline survey of a cohort study in Tokushima Prefecture, Japan. Information on individual lifestyle characteristics, including dietary habits and sleep-wake regularity, was obtained by a self administrated questionnaire. Logistic regression analyses were performed to evaluate adjusted associations of the intake energy ratios of macronutrients, as well as intake frequency, and the amount of staple foods with sleep wake regularity. The lowest quartile of protein intake as well as the highest quartile of carbohydrates showed significantly higher multivariable-adjusted odds ratios of 2.1 (95% confidence interval, 1.3-3.3) and 2.1 (1.3-3.5), respectively, for poor sleep-wake regularity compared with the respective second quartile that is thought to be moderate intake. Regarding intake of staple foods, low weekly intake frequency at breakfast (<5 times/week), the lowest intake amount (<1 bowl or slice/roll) at breakfast, and the highest intake amount (>=2 bowls or slices/ rolls) at lunch and dinner exhibited significantly high adjusted odds ratios for poor sleep-wake regularity. Additionally adjusting for sleep duration, these results did not substantially alter. Our results suggested that low intake energy ratio of proteins and high intake energy ratio of carbohydrates, skipping intake of the staple foods at breakfast, and excessive intake amount of the staple foods at lunch and dinner may be associated with poor sleep-wake regularity.