Trend of dioxin exposure and health effects

The author reviewed recent reports about the blood levels and dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs)/furans (PCDFs)/dioxin-like polychlorinated biphenyls (DL-PCBs) to investigate the trends of dioxin exposure, and epidemiologic studies on the associations of blood levels of dioxins with metabolic diseases. In recent years, dietary intake of dioxins has been decreasing, and the means are equal to or less than 1.0 pg Toxic Equivalents (TEQ)/kg/day in the general populations of several countries. The blood levels of dioxins are also decreasing, probably because of reduced dietary intake. Many cross-sectional studies reported positive associations between blood levels of some isomers or TEQ-based concentrations of PCDDs/PCDFs/DL-PCBs and diabetes in general populations. Three cohort studies on populations with heavy exposure and two nested case-control studies on general populations have also been published, but the results are inconsistent. Three large-scale cross-sectional studies and two cohort studies reported an association between blood levels of some isomers or TEQ-based concentrations of PCDDs/PCDFs/DL-PCBs and metabolic syndrome. In addition, three cross-sectional studies reported significant positive associations with gout/hyperuricemia. Further prospective studies and experimental studies are needed to establish cause-effect relationships, and to clarify the biological mechanisms for the association between background exposure to dioxins and potential health effects

Relationship between the type of urinary incontinence and falls among frail elderly women in Japan

Urinary incontinence and falls are serious problem among elderly people, because of restriction of the Activities of Daily Living (ADL) and Quality of Life. Previous studies have examined the association between urinary incontinence and falls. However, results have been inconsistent. In Japan, with the rapid aging of the society, the number of elderly women who have urinary incontinence and are at risk of falling is increasing. We investigated the relationship between type of urinary incontinence and risk of falls among elderly users of day-care services in a long-term care system. Our study population comprised 118 ambulatory women. At baseline, we evaluated incontinent status, lower extremity muscle strength, balance ability, ADL, and Instrumental ADL. We asked subjects about number of falls every 4 months during a year. In univariate analysis, lower extremity muscle strength (p=0.001) and mixed incontinence (p=0.050) differed significantly according to the fall status. Stress and urge incontinence were not significantly associated with falls. In logistic regression analysis, subjects who had mixed incontinence were 3.05 (95% confidence interval 1.01-10.2) times more likely to fall than those without. These results suggest that mixed incontinence have independent associations with falls. Incontinent status should be considered to prevent falls among elderly persons who are partially dependent and need support

Background exposure to PCDDs/PCDFs/PCBs and its potential health effects : a review of epidemiologic studies

Here we review epidemiologic studies dealing with the dietary intake and the body burden of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzo-furans (PCDFs)/ polychlorinated biphenyls (PCBs) in the general population, and potential adverse health effects of these substances, especially on the risk of diabetes mellitus and endometriosis, and on thyroid function and the neurodevelopment of infants. The mean or median intake of dioxin-related compounds among the general populations of various countries is lower than the maximum tolerable daily intake (TDI) set by the WHO in 1998 (4pg TEQ/kg/day). However, there have been few reports on the distribution of intake and the proportion of subjects whose exposure levels exceed the maximum TDI. At present, it remains unclear whether background exposure to dioxin-related compounds is associated with increased risk of diabetes (because of lack of longitudinal studies), endometriosis (because of lack of studies with sufficient statistical power), or altered thyroid function (because of inconsistent results on humans). Consistent results have been reported for the association between exposure to background levels of PCBs/dioxins, especially trans-placental PCBs, and defective neurodevelopment of infants in the U.S. and Europe. Thus, efforts should be made to further decrease the body burden among women of reproductive age by reducing the release of PCDDs/PCDFs/PCBs into the environment

カンキョウ ヨウイン ノ ケンコウ リスク ヒョウカ ト シッペイ ヨボウ エノ コウケン

The research interest of authors has focused on the risk assessment of environmental pollutants such as cadmium and dioxin-related compounds, and epidemiology of human T-cell lymphotropic virus type-I （HTLV-I） infection. The authors （１） showed that low-molecular weight proteinuria and reduced glomerular filtration rate caused by environmental cadmium were strongly associated with shortened survival， （２） clarified serological risk factors for development of adult T-cell leukemia/lymphoma among asymptomatic HTLV-I carriers （plasma levels of soluble interleukin２-receptor＞＝５００U/ml and HTLV-I antibody titer＞＝１，０２４）， （３） conducted the first prospective study of HTLV-I infection and development of malignances other than ATL, and found a significantly reduced risk of gastric cancer among HTLV-I carriers, and （４） by a cooperative study, clarified a new pathogenicity of HTLV-I （association with Sjögren’s syndrome）

Nutrient Patterns and Fatty Liver Index

Backgrounds: The fatty liver index (FLI) is a good non-invasive approach for fatty liver disease diagnosis. The objective of this study was to examine the associations of nutrient patterns with non-alcoholic fatty liver disease (NAFLD) in a Japanese population. Methods: A total of 1,588 subjects (789 men and 799 women) aged 35–69 years were recruited in the baseline survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima Prefecture. Factor analysis was applied to energy-adjusted intake of 21 nutrients, and nutrient patterns were extracted. Multiple logistic regression analysis was used to analyze the relationships between nutrient patterns and the high FLI category (≥60). Results: Four nutrient patterns were extracted: Factor 1, vitamins, dietary fiber, iron and potassium pattern; Factor 2, fats and fat-soluble vitamins pattern; Factor 3, saturated fat, calcium, vitamin B2 and low carbohydrate pattern; and Factor 4, sodium, protein and vitamin D pattern. After adjustment for sex, age, and other potential confounding variables, higher Factor 1 scores were significantly associated with lower odds ratios of NAFLD (P for trend <0.05). Analysis of each component of FLI showed that there were significant inverse associations between Factor 1 scores and high body mass index and large waist circumference. Conclusion: The present findings suggest that a nutrient pattern rich in vitamins, fiber, iron, and potassium was associated with lower prevalence of NAFLD in a Japanese population. Obesity and abdominal obesity may be intermediate variables for the association between this nutrient pattern and NAFLD

Risk factors for shoulder and elbow pain in youth baseball players

Objectives: This study sought to quantify the 1-year cumulative incidence of shoulder and elbow pain among youth baseball players and identify risk factors associated with the occurrence of shoulder and elbow pain. Methods: In total, 900 youth baseball players (aged 7–11 years) were enrolled in a 1-year prospective follow-up study. One year later, subjects were asked whether they had experienced episodes of shoulder or elbow pain and the following risk factors for such pain were investigated: age, position, length of baseball experience, training hours per week, and history of shoulder or elbow pain. Data for the groups with and without shoulder or elbow pain were analyzed using multivariate logistic regression models. Results: Episodes of shoulder pain were reported by 18.3% of players and episodes of elbow pain were reported by 35.2% of players. Multivariate analysis showed that shoulder pain was associated with playing pitcher, catcher, increasing training hours per week, and history of shoulder and elbow pain, and that elbow pain was associated with increasing age, playing pitcher, catcher, increasing training hours per week, and history of elbow pain. Length of baseball experience was not associated with shoulder or elbow pain. Conclusion: History of elbow pain, playing pitcher, catcher and increasing training hours per week were associated with both types of pain. History of shoulder pain was associated with shoulder pain but not elbow pain. Increasing age was associated with elbow pain but not shoulder pain

トクシマケン ニオケル ヒョウジュンカ シボウヒ : 20 ネンカン ノ ネンジ スイイ オヨビ ホケンジョ カンナイベツ ノ ブンセキ

To elucidate the mortality characteristics of Tokushima Prefecture, the authors analyzed the time-related change in the standardized mortality ratio （SMR） of cause-specific death and organ-specific cancer death during 1983-2002, and administrative area-specific SMR during 1993-1998 and 1999-2002. The gender-and 5-year-age-specific and cause-specific death rates in the entire Japanese population were used as the reference mortality, and the population of sex-and-5-year-agespecific category in the census year （1985, 1990, 1995 and 2000） was used as the population of Tokushima Prefecture. Interval estimation of SMR was performed by the exact method, assuming that the number of deaths followed the Poisson distribution. In the analysis of each year from 1983 to 2002, the SMR of diabetes mellitus markedly increased from the mid 1990’s, suggesting the changes in the environmental factors. The SMR of bronchitis, emphysema and asthma was constantly high during the 20 years. In the administrative area-specific analysis, the SMR of diabetes was high in Tokushima and Naruto for both men and women. With regard to malignant neoplasms, the SMR of esophageal cancer was constantly low, while that of liver cancer was constantly high over the 20 years. The SMR of esophageal cancer was low among men in Tokushima and Anan, and among women in Kamojima, while that of liver cancer was high among men and women in Tokushima and among men in Anan. These characteristics were consistent over the recent 10 years, suggesting the involvement of area-specific factors

トクシマケン ニオケル シインベツ オヨビ アクセイ シュヨウ ゾウキベツ ノ ヒョウジュンカ シボウヒ ノ ブンセキ1993 2002ネン

To clarify the characteristics of mortality in Tokushima Prefecture, the authors analyzed the standardized mortality ratio（SMR）from 1993 to 1998 and 1999 to 2002. The sex-and 5-year-agespecific and cause-specific morality rates in Japan were used as the standard mortality, and the population of sex-and 5-year-age-specific category in the census year（1995 and 2000）was used as the population of Tokushima Prefecture. The 95 % confidence interval（CI）of SMR was estimated using the exact method, on the assumption that the number of deaths followed the Poisson distribution. The mortality from all-cause in Tokushima Prefecture was significantly lower than that of the entire Japanese population among women during 1993-1998, while it was significantly higher among men and women during 1999-2002. The SMRs of diabetes mellitus, bronchitis, emphysema and asthma, and chronic hepatitis and liver cirrhosis were significantly higher than 100, with the SMR of diabetes being as high as 130-140. On the other hand, mortality rate from suicide was significantly lower than that of all of Japan. Regarding malignant neoplasms, morality rates from cancers of all sites, esophagus, stomach, and colon and rectum were significantly lower than 100. However, the SMR of liver cancer was significantly high, suggesting that hepatitis C virus infection was endemic. The reason for the high mortality from diabetes should be clarified with regard to environmental and genetic factors, and the way of reporting diabetes as a cause of death in death certificates. In addition, the reason for the low mortality from cancers of the gastrointestinal tract remains unknown, and further investigations on life style factors are required