Effect of renal tubular damage on non-cancer mortality in the general Japanese population living in cadmium non-polluted areas.

This study aimed to clarify the cause-effect relationship between renal tubular damage and non-cancer mortality in the general Japanese population. We conducted a 19-year cohort study including 1110 men and 1,03 women who lived in three cadmium-non-polluted areas in 1993 or 1994. Mortality risk ratios based on urinary ß2-microglobulin (ß2MG) and N-acetyl-ß-glucosaminidase (NAG) concentrations were estimated for specific non-cancer diseases using the Fine and Gray competing risks regression model. In men, continuous urinary NAG (+1 µg/g cre) concentrations were significantly correlated with increased mortality caused by diseases of the respiratory system (hazard ratio (HR): 1.09, 95% confidence interval (CI): 1.03-1.15). Urinary ß2MG (+100 µg/g cre) concentrations were significantly correlated with increased mortalities caused by kidney and urinary tract diseases (HR: 1.01, 95% CI: 1.00-1.03), renal diseases (HR: 1.01, 95% CI: 1.00-1.03), renal failure (HR: 1.02, 95% CI: 1.00-1.03), and external causes of mortality (HR: 1.01, 95% CI: 1.00-1.02). In women, urinary NAG (+1 µg/g cre) concentrations were significantly associated with increased mortality caused by ischemic heart diseases (HR: 1.02, 95% CI: 1.00-1.04) and kidney and urinary tract diseases (HR: 1.01, 95% CI: 1.00-1.04). Urinary ß2MG (+100 µg/g cre) concentrations were significantly correlated with increased mortality caused by cardiovascular diseases (HR: 1.01, 95%CI: 1.00-1.02), ischemic heart diseases (HR: 1.01, 95%CI: 1.00-1.02), and kidney and urinary tract diseases (HR: 1.02, 95% CI: 1.01-1.03). The present study indicates that renal tubular damage was significantly related to several non-cancer disease causes of mortality in Japan's general population living in cadmium-non-polluted areas.

Cadmium body burden and health effects after restoration of cadmium-polluted soils in cadmium-polluted areas in the Jinzu River basin.

BACKGROUND: Itai-itai disease is caused by environmental cadmium (Cd) pollution in the Jinzu River basin in Japan. To reduce the Cd contamination of rice, soil restoration of paddy fields was carried out. We evaluated the effect of soil restoration on the health status of residents of the former Cd-polluted area. METHODS: Participants were 1,030 men and 944 women who lived in the area of restoration of Cd-polluted rice paddies. First morning urine was collected and urinary Cd, ß2-microglobulin (ß2MG), and N-acetyl-ß-D-glucosaminidase (NAG) levels were measured. Associations among age, years of residence before and after soil restoration, and urinary Cd, ß2MG, and NAG levels were evaluated by multiple regression analysis. RESULTS: The geometric mean (interquartile range) of urinary Cd (µg/g Cr) was 1.00 (0.58-1.68) in men and 1.67 (1.02-2.91) in women. The geometric means of urinary ß2MG (µg/g Cr) and NAG (U/g Cr) were 174.6 (92.6-234.2) and 1.47 (0.72-3.14) in men, and 217.6 (115.3-28.7) and 1.48 (0.73-2.96) in women, respectively. Urinary Cd, ß2MG, and NAG were significantly positively correlated (p < 0.01 all). Age and duration of residence in the Cd-polluted area before soil restoration were independently associated with urinary Cd, ß2MG, and NAG. Among the 916 participants who had resided in the area before the soil restoration, urinary Cd concentrations were significantly higher, thus by 1.03-fold (95% CI, 1.01-1.04) in men and 1.03-fold (95% CI, 1.01-1.05) in women, when the years of residence before soil restoration by each 5-years increment. By contrast, urinary Cd concentrations were significantly lower, thus 0.97-fold (95% CI, 0.96-0.99) lower in men and 0.97-fold (95% CI, 0.95-0.99) lower in women, by each 5-year increment of residence after soil restoration. A similar association was observed for urinary ß2MG concentration, and no significant association was observed for urinary NAG levels in men or women. CONCLUSIONS: Cd exposure and associated renal tubular dysfunction in residents of a former Cd-polluted area were influenced by Cd exposure from the environment prior to soil restoration. Soil restoration in Cd-polluted areas reduced the Cd exposure of local residents.

Renal tubular dysfunction and cancer mortality in the Japanese general population living in cadmium-non-contaminated areas.

The relationship between cadmium exposure, exposure-related renal tubular dysfunction, and mortality have been reported, mainly in the residents of Cd-contaminated areas in Japan. The aim of this study was to establish the cause-effect relationship between renal tubular dysfunction and cancer mortality in the general population in non-contaminated areas. A 19-year cohort study was conducted in 1110 men and 1703 women in 1993 or 1994, who lived in three cadmium-non-contaminated areas. Mortality risk ratios of urinary ß2-microglobulin (ß2MG) and N-acetyl-ß-glucosaminidase (NAG) for all malignant neoplasms and specific cancers were estimated using the Fine and Gray competing risks regression model. Significant hazard ratios (HRs) for liver and pancreas cancer were observed for NAG (liver: HR corresponding to an increase of 1 IU/g cr, 1.10, 95%CI, 1.02-1.19, pancreas: HR, 1.10, 95%CI, 1.02-1.19) in men. In women, a negative HR was observed for NAG (lung cancer: HR 0.80, 95% CI, 0.67-0.96) and for ß2MG (all malignant neoplasms: HR, 0.97, 95% CI, 0.93-1.00). The present study indicated that renal tubular dysfunction was significantly related to mortality in the general population of cadmium-non-contaminated areas in Japan.

Relationship between urinary ß2 -microglobulin concentration and mortality in a cadmium-polluted area in Japan: A 35-year follow-up study.

The relationship between urinary ß2 -microglobulin (ß2 -MG) and the risk of all-cause mortality and cause-specific mortality in a cadmium (Cd)-polluted area was investigated in 3139 inhabitants (1404 men and 1735 women) of the Kakehashi River basin in Japan at 35-year follow-up. The subjects had been participants in the 1981-1982 health impact survey that assessed Cd-induced renal dysfunction, as measured by the urinary ß2 -MG concentration. Hazard ratios were calculated to assess the risk of all-cause and cause-specific mortality according to the urinary ß2 -MG concentrations. Risk ratios (RRs) were assessed using the Fine and Gray regression model to account for competing risks of cause-specific mortality. The mortality rate was significantly higher in participants with urinary ß2 -MG concentrations >1000 µg/g creatinine (Cr) for men and >300 µg/g Cr for women. In the proportional hazard model, higher urinary ß2 -MG concentrations were associated with higher risks of circulatory disease, digestive system diseases, and kidney and urinary tract diseases in men and women, and with senility for women. However, when competing risk was accounted for, the RRs were significantly higher only for kidney and urinary tract diseases in men and women (RR for each increment of 1000 µg/g Cr [95% confidence interval]: 1.02 [1.00-1.04] for men, and 1.01 [1.00-1.02] for women). The long-term prognosis of participants with renal tubular dysfunction was poor, most likely due to kidney and renal tract diseases.

Environmental cadmium exposure and noncancer mortality in a general Japanese population in cadmium nonpolluted regions.

The objective of this study was to assess the effect of environmental cadmium exposure according to urinary cadmium concentration (U-Cd) on noncancer mortality in a general Japanese population. We conducted a longitudinal study for 19 years in 2804 inhabitants (1107 men and 1697 women) in some cadmium nonpolluted regions in Japan. The participants were classified into quartiles based on U-Cd (µg/g cre) adjusted for urinary creatinine. Hazard ratio (HR) and 95% confidence interval (95% CI) for continuous U-Cd or the quartiles of U-Cd were calculated for noncancer mortality. By applying a Fine and Gray competing risk model, continuous U-Cd (+1 µg/g cre) showed significant HR for cardiocerebrovascular diseases (HR 1.05, 95% CI: 1.00-1.11), cerebrovascular diseases (HR 1.08, 95% CI: 1.01-1.16), and cerebral infarction (HR 1.11, 95% CI: 1.04-1.20) in men. However, notable significant HR for continuous and quartered U-Cd were not observed in women. In this study, U-Cd was associated with increased cardiocerebrovascular mortality in a general Japanese population, suggesting that environmental cadmium exposure is detrimental to the life prognosis in cadmium nonpolluted regions in Japan.

Associations of Overweight, Obesity, and Underweight With High Serum Total Cholesterol Level Over 30 Years Among the Japanese Elderly: NIPPON DATA 80, 90, and 2010.

BACKGROUND: The trend of association between overweight and high serum total cholesterol (TC) among the elderly is unclear. In addition, there is little evidence of risk of underweight for high TC. Therefore, we examined the trend of association of overweight or underweight with high TC among Japanese elderly people using nationwide population-based data. METHODS: Data of the National Survey on Circulatory Disorders and National Health and Nutrition Survey for 1980, 1990, 2000, and 2010 were used in the analysis. High TC was defined as 220 mg/dL and above. For participants aged ≥50 years, sex-specific odds ratios (ORs) of overweight or underweight compared with normal body mass index participants for high TC were calculated using a logistic regression model adjusted for age, smoking, drinking, exercise, food, and treatment of hyperlipidemia. RESULTS: A total of 5,734, 4,673, 5,059, and 2,105 participants enrolled in these surveys in 1980, 1990, 2000, and 2010, respectively. Although overweight was positively and significantly associated with high TC in 1980, the association has gradually weakened since (ORs in 1980 and 2010 were 2.44; 95% confidence interval [CI], 1.83-3.24 and 0.92; 95% CI, 0.66-1.27 among men and 1.43; 95% CI, 1.18-1.72 and 1.08; 95% CI, 0.81-1.44 among women, respectively). While underweight was inversely and significantly associated with high TC in 1980, the association also gradually weakened among women (ORs in 1980 and 2010 were 0.28; 95% CI, 0.12-0.60 and 0.37; 95% CI, 0.10-1.28 among men and 0.39; 95% CI, 0.26-0.57 and 0.96; 95% CI, 0.58-1.57 among women, respectively). CONCLUSIONS: These findings provide evidence that high TC prevention efforts must expand the target to not only overweight but also to normal and underweight people.

Associations of High-Density Lipoprotein Particle and High-Density Lipoprotein Cholesterol With Alcohol Intake, Smoking, and Body Mass Index　- The INTERLIPID Study.

BACKGROUND: Recently, high-density lipoprotein particles (HDL-P) have been found to be more strongly inversely associated with coronary artery disease (CAD) risk than their counterpart, HDL cholesterol (HDL-C). Given that lifestyle is among the first targets in CAD prevention, we compared the associations of HDL-P and HDL-C with selected lifestyle factors. Methods and Results: We examined 789 Japanese participants of the INTERLIPID Study: men (n=386) and women (n=403) aged 40-59 years in 1996-1998. Participants treated for dyslipidemias were excluded. Lifestyle factors included alcohol intake, smoking amount, and body mass index (BMI). Multivariable linear regression was used for cross-sectional analyses of these factors with HDL-P, HDL-C, HDL-P size subclasses (small, medium and large) and mean HDL-P size. In men, higher alcohol intake was associated with higher HDL-P and higher HDL-C. The associations of alcohol, however, were strongest with HDL-P. A higher smoking amount tended to be associated with lower HDL-P and HDL-C. In contrast, BMI was not associated with HDL-P, but was strongly inversely associated with HDL-C. While alcohol intake favored larger mean HDL-P size, smoking and BMI favored a lipid profile with smaller HDL-P subclasses and overall smaller mean HDL-P size. Similar, but generally weaker results were observed in women. CONCLUSIONS: Although both HDL-P and HDL-C are parameters of HDL, they have different associations with alcohol, smoking and BMI.

Increase of lifetime cadmium intake dose-dependently increased all cause of mortality in female inhabitants of the cadmium-polluted Jinzu River basin, Toyama, Japan.

BACKGROUND: Exposure to cadmium (Cd) via food is supposed to affect life prognosis of inhabitants of Cd-polluted area in Japan. However, there have been few reports demonstrating a significant relationship between the amount of Cd intake and mortality. We aimed to investigate the relationship between mortality and individual lifetime Cd intake (LCd) in inhabitants of the polluted Jinzu River basin, Toyama, Japan. METHODS: We conducted a 26-year follow-up survey in 2407 inhabitants (1208 men and 1199 women) who participated in health examinations for screening of renal dysfunction from 1979 to 1984. The calculation of LCd in each inhabitant was based on the formula of Nogawa (Nogawa et al., 1989): (mean Cd concentration in rice of the present hamlet × 333.5 g/day + 34 µg/day) × 365 days/year × number of years of residence in the present hamlet + 50 µg/day × 365 days/year × number of years living in Cd non-polluted regions. In this formula, 333.5 g/day is the 1970 average daily intake of rice in this area, 34 µg/day is the Cd intake from foods other than rice in this area, and 50 µg/day is the average intake of Cd in non-polluted areas in Japan. Mortality risk ratios of LCd for all and specific causes were estimated after adjustments for age at baseline, smoking status, and history of hypertension using a Cox hazard model or Fine and Gray competing risks regression model. RESULTS: The mortality risk ratios of LCd (+ 1 g) for all causes in women were significantly dose-dependently increased (risk ratio: 1.08). Relative risk of LCd for kidney and urinal tract disease, renal diseases, renal failure and toxic effects of cadmium were significantly higher in women. CONCLUSIONS: The present study documents that individual LCd dose-dependently decreased life prognosis over long-term observation in women. LCd was significantly related to the increased mortality for renal disease and toxic effect of Cd in women. The result provides clear evidence that life prognosis was adversely affected by Cd-exposure, especially in women.

Macronutrient Intake and Socioeconomic Status: NIPPON DATA2010.

BACKGROUND: This study examined the relationships among household income, other SES indicators, and macronutrient intake in a cross-sectional study of a representative Japanese population. METHODS: In 2010, we established a cohort of participants in the National Health and Nutrition Survey (NHNS) from 300 randomly selected areas throughout Japan. A total of 2,637 participants (1,145 men and 1,492 women) were included in the study. Data from NHNS2010 and the Comprehensive Survey of Living Conditions 2010 (CSCL2010) were merged, and relationships among macronutrient intake and SES were evaluated. Additionally, socioeconomic factors associated with a risk of a higher carbohydrate/lower fat intake beyond dietary recommendations were evaluated. RESULTS: Household income was positively associated with fat intake (P = 0.001 for men and <0.001 for women) and inversely associated with carbohydrate intake (P = 0.003 for men and <0.001 for women) after adjustments for age and other SES variables. Similar relationships were observed between equivalent household expenditure (EHE) and macronutrient intake; however, these relationships were weaker than those of household income. Older age was the factor most strongly associated with a high carbohydrate/low fat intake, followed by household income, EHE, education levels, and occupation type. CONCLUSIONS: Older age was the factor most strongly associated with a high carbohydrate/low fat intake, and some aspects of SES, such as household income, EHE, education levels, and occupation type, were independently associated with an imbalanced macronutrient intake. SES may affect the health status of individuals through the intake of macronutrients.

Socioeconomic Status Associated With Urinary Sodium and Potassium Excretion in Japan: NIPPON DATA2010.

BACKGROUND: Although socioeconomic status (SES) may affect food and nutrient intakes, few studies have reported on sodium (Na) and potassium (K) intakes among individuals with various SESs in Japan. We investigated associations of SES with Na and K intake levels using urinary specimens in a representative Japanese population. METHODS: This was a cross-sectional study of 2,560 men and women (the NIPPON DATA2010 cohort) who participated in the National Health and Nutrition Survey Japan in 2010. Casual urine was used to calculate estimated excretion in 24-hour urinary Na (E24hr-Na) and K (E24hr-K). The urinary sodium-to-potassium (Na/K) ratio was calculated from casual urinary electrolyte values. An analysis of covariance was performed to investigate associations of aspects of SES, including equivalent household expenditure (EHE), educational attainment, and job category, with E24hr-Na, E24hr-K, and the Na/K ratio for men and women separately. A stratified analysis was performed on educational attainment and the job category for younger (<65 years) and older (≥65 years) participants. RESULTS: In men and women, average E24hr-Na was 176.2 mmol/day and 172.3, average E24hr-K was 42.5 and 41.3, and the average Na/K ratio was 3.61 and 3.68, respectively. Lower EHE was associated with a higher Na/K ratio in women and lower E24hr-K in men and women. A shorter education was associated with a higher Na/K ratio in women and younger men, and lower E24hr-K in older men and women. CONCLUSION: Lower EHE and a shorter education were associated with a lower K intake and higher Na/K ratio estimated from casual urine specimens in Japanese men and women.

Factors Related to Participation in Health Examinations for Japanese National Health Insurance: NIPPON DATA2010.

BACKGROUND: This study investigated relationships among socioeconomic factors and participation in health examinations for Japanese National Health Insurance (NHI) using a representative Japanese population. METHODS: We used the linkage database of NIPPON DATA2010 and Comprehensive Survey of Living Conditions 2010. Participants with NHI aged 40-74 years were included in the analysis. Prevalence ratios (PRs) for participation in health examinations in the past year were set as an outcome. Participant characteristics, including sex, age, socioeconomic factors (educational attainment, employment, equivalent household expenditure [EHE], house ownership, and marital status), laboratory measures, and lifestyle were included in an age-stratified modified Poisson regression analysis to examine relationships. RESULTS: The number of study participants was 812, and 564 (69.5%) participated in health examinations in the past year. Among those aged 40-64 years, there was no significant PR for socioeconomic factors. Among those aged 65-74 years, high (≥13 years) educational attainment (adjusted PR, 1.22; 95% confidence interval [CI], 1.05-1.41) and house ownership (PR 1.40; 95% CI, 1.11-1.77) were positively associated with participation, while high (4th quartile) EHE (PR 0.84; 95% CI, 0.73-0.97) was negatively associated. CONCLUSION: These results suggest that high educational attainment, house ownership, and low EHE were positive factors for participation in health examinations among those aged 65-74 years.

Relationship between mortality and rice cadmium concentration in inhabitants of the polluted Jinzu River basin, Toyama, Japan: A 26 year follow-up.

The aim of this study was to investigate the relationship between mortality and rice cadmium (Cd) concentration in inhabitants of a polluted area in Japan. The target subjects were inhabitants of the Jinzu River basin who participated in health examinations for screening of renal dysfunction from 1979 to 1984. The mean rice Cd concentration in each hamlet was used as an index of the Cd exposure. We conducted a 26 year follow-up survey in 3281 inhabitants (1544 men and 1737 women) whose data regarding the rice Cd concentration were available. Mortality risk ratios for all and specific causes were estimated after adjustments for age at baseline, smoking status and history of hypertension using a Cox hazard model or Fine and Gray competing risks regression model. The mortality risk ratios of rice Cd concentration (+0.1 ppm) for all causes in women were significantly increased (risk ratio: 1.04). Furthermore, the relative risks of rice Cd concentration for kidney and urinary tract disease, renal diseases, renal failure and toxic effects of cadmium were significantly increased in both sexes. These findings indicated that increased rice Cd concentration decreased the prognosis for life over a long-term observation in women. This result provides important information for determining the worldwide standard for allowable rice Cd concentration.

Food sources of dietary sodium in the Japanese adult population: the international study of macro-/micronutrients and blood pressure (INTERMAP).

PURPOSE: It is often reported that Na intake levels are higher in Japan than in western countries. Detailed analysis of food intake and its association with Na intake are necessary for supporting further decreases in Na consumption in Japan. We investigated the association between Na and food intake by food group using data from the Japanese participants of the INTERMAP Study. METHOD: Results from the Japanese participants of the INTERMAP Study who did not use antihypertensive medication and/or consume a reduced Na diet were used (531 men and 518 women, aged 40-59 years), obtained from four 24-h dietary recalls and two 24-h urine collections from each participant. We developed a classification system with 46 food group classifications; food consumption and Na intake from these groups were compared across quartiles of participants determined by 24-h urinary Na excretion per unit of body weight (UNa/BW). RESULTS: Average daily Na intake from Japanese high-Na foods was 2552 mg/day. Participants with a higher UNa/BW consumed a significantly greater amount of high-Na Japanese foods, such as salted fish (P = 0.001) and miso soup (P < 0.001). They also had greater amount of rice (P = 0.001). Participants with lower UNa/BW consumed a significantly greater amount of western foods, such as bread (P < 0.001) and milk and dairy products (P < 0.001). CONCLUSIONS: Detailed analyses of various Japanese and western food intakes in addition to Na intake were performed. These results can be used to help draw up effective programs for the reduction in Na intake and prevention of prehypertension/hypertension in the Japanese population.

Age-specific impact of diabetes mellitus on the risk of cardiovascular mortality: An overview from the evidence for Cardiovascular Prevention from Observational Cohorts in the Japan Research Group (EPOCH-JAPAN).

BACKGROUND: Diabetes mellitus is a strong risk factor for cardiovascular disease. However, the age-specific association of diabetes with cardiovascular risk, especially in the elderly, remains unclear in non-Western populations. METHODS: A pooled analysis was conducted using 8 cohort studies (mean follow-up period, 10.3 years) in Japan, combining the data from 38,854 individual participants without history of cardiovascular disease. In all, 1867 of the participants had diabetes, defined based on the 1998 World Health Organization criteria. The association between diabetes and the risk of death from cardiovascular disease, coronary heart disease (CHD), and stroke was estimated using a stratified Cox model, accounting for variability of baseline hazard functions among cohorts. RESULTS: During the follow-up, 1376 subjects died of cardiovascular disease (including 268 of coronary heart disease and 621 of stroke). Diabetes was associated with an increased risk of cardiovascular death after multivariable adjustment (hazard ratio [HR] 1.62; 95% confidence interval [CI], 1.35-1.94). Similarly, diabetes was a risk factor for CHD (HR 2.13; 95% CI, 1.47-3.09) and stroke (HR 1.40; 95% CI, 1.05-1.85). In the age-stratified analysis of the risk of cardiovascular death, the relative effects of diabetes were consistent across age groups (p for heterogeneity = 0.18), whereas the excess absolute risks of diabetes were greater in participants in their 70s and 80s than in younger subjects. CONCLUSIONS: The management of diabetes is important to reduce the risk of death from cardiovascular disease, not only in midlife but also in late life, in the Japanese population.

Threshold limit values of the cadmium concentration in rice in the development of itai-itai disease using benchmark dose analysis.

The aim of this study was to estimate the benchmark dose (BMD) as the threshold limit level of the cadmium (Cd) concentration in rice for itai-itai disease and/or suspected disease; it was based on the data that previously evaluated the association for such diseases with the Cd concentration in rice by using a logistic regression model. From 1971 to 1976, a total of 2446 rice samples were analyzed across the 88 hamlets in the Jinzu river basin. The mean Cd concentration in rice in each hamlet was used as the index of external Cd exposure of the entire population of the hamlet. We employed the incidence of itai-itai disease and/or suspected disease obtained from the available 55 hamlets. As the threshold, the lower limit of the BMD (BMDL) of the Cd concentration in rice for itai-itai disease and/or suspected disease was estimated using a logistic model, setting the benchmark response at 1% or 2%. The estimated BMDLs of the Cd concentration in rice for itai-itai disease and/or suspected disease were 0.62-0.76 and 0.27-0.56 mg kg-1 in men and women, respectively. The lowest BMDL was 0.27 mg kg-1 in women. In the present study, the threshold limit level of the Cd concentration in rice for itai-itai disease, which is the most severe form of chronic Cd poisoning, was estimated for the first time. This result provides important information about the worldwide standard for the Cd concentration in rice. Copyright © 2017 John Wiley & Sons, Ltd.

Effects of aging on cadmium concentrations and renal dysfunction in inhabitants in cadmium-polluted regions in Japan.

The absorption of cadmium (Cd) may lead to Cd-related diseases such as renal tubular dysfunction and bone disease, and it is known to take around 10-30 years to reduce Cd concentrations to half their original levels. Urinary ß2 -microglobulin (ß2 -MG), N-acetyl-ß-D-glucosaminidase (NAG), protein, glucose and albumin were used as indicators of renal dysfunction caused by Cd exposure. Our previous study found that urinary Cd concentrations had increased recently and that age was more strongly associated with urinary ß2 -MG concentration than recent Cd body burden. Therefore, the purpose of the present study was to investigate the effect of aging on Cd concentrations and renal dysfunction. The Cd, ß2 -MG, NAG, protein, glucose and albumin concentrations in the urine of 40 Japanese subjects (20 females and 20 males) environmentally exposed to Cd were collected. They lived in the Kakehashi River basin and were divided into three age categories: 50-69, 70-79 and 80-99 years. Significant differences in urinary Cd and ß2 -MG concentrations were found among age groups, with urinary Cd levels tending to increase with age in both sexes. No significant correlations were found between urinary Cd and any indicators of renal dysfunction. The correlation between age, Cd and indicators of renal dysfunction was observed more clearly in females than in males. Age is more strongly correlated with indicators of renal dysfunction than Cd body burden. Copyright © 2017 John Wiley & Sons, Ltd.

Estimation of Benchmark Dose of Lifetime Cadmium Intake for Adverse Renal Effects Using Hybrid Approach in Inhabitants of an Environmentally Exposed River Basin in Japan.

The aim of this study is to estimate the reference level of lifetime cadmium intake (LCd) as the benchmark doses (BMDs) and their 95% lower confidence limits (BMDLs) for various renal effects by applying a hybrid approach. The participants comprised 3,013 (1,362 men and 1,651 women) and 278 (129 men and 149 women) inhabitants of the Cd-polluted and nonpolluted areas, respectively, in the environmentally exposed Kakehashi River basin. Glucose, protein, aminonitrogen, metallothionein, and ß2 -microglobulin in urine were measured as indicators of renal dysfunction. The BMD and BMDL that corresponded to an additional risk of 5% were calculated with background risk at zero exposure set at 5%. The obtained BMDLs of LCd were 3.7 g (glucose), 3.2 g (protein), 3.7 g (aminonitrogen), 1.7 g (metallothionein), and 1.8 g (ß2 -microglobulin) in men and 2.9 g (glucose), 2.5 g (protein), 2.0 g (aminonitrogen), 1.6 g (metallothionein), and 1.3 g (ß2 -microglobulin) in women. The lowest BMDL was 1.7 g (metallothionein) and 1.3 g (ß2 -microglobulin) in men and women, respectively. The lowest BMDL of LCd (1.3 g) was somewhat lower than the representative threshold LCd (2.0 g) calculated in the previous studies. The obtained BMDLs may contribute to further discussion on the health risk assessment of cadmium exposure.

Effects of Perinatal Dioxin Exposure on Development of Children during the First 3 Years of Life.

OBJECTIVE: To investigate the longitudinal effects of perinatal exposure to dioxin on neurodevelopment and physical growth of a birth cohort during the first 3 years of life. STUDY DESIGN: A total of 217 mother-infant pairs living in a dioxin-contaminated area in Vietnam were followed up. Perinatal dioxin exposure of infants was estimated by the measurement of dioxin levels in breast milk of nursing mothers. Neurodevelopment of infants and children, including cognitive, language, and motor development, was determined at 4 months, 1 year, and 3 years of age. Physical growth, including weight, height, and head and abdominal circumferences, was measured at birth, 1 and 4 months, and 1 and 3 years of age. Multivariate mixed models were applied for analyzing repeated measures. RESULTS: In boys, composite motor and gross motor scores were decreased with increasing exposure of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TetraCDD). The high toxic equivalent of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs-TEQ) group showed a significant decrease in expressive communication score. In girls, there was no decreased score in any neurodevelopment aspects in high-exposure groups. All body size measures in boys were decreased in the high-exposure groups of 2,3,7,8-TetraCDD and PCDDs/PCDFs-TEQ. In girls, high 2,3,7,8-TetraCDD and PCDDs/PCDFs-TEQ exposure was associated with increased head and abdominal circumferences. CONCLUSIONS: Perinatal dioxin exposure affects physical growth and neurodevelopment of infants and children in the first 3 years of life in a sex-specific manner.

Relationship of three different types of low-carbohydrate diet to cardiometabolic risk factors in a Japanese population: the INTERMAP/INTERLIPID Study.

PURPOSE: Low-carbohydrate diets (LCD) are a popular dietary strategy for weight reduction. The effects of LCD on long-term outcome vary depending on type of LCD, possibly due to the fact that effects on cardiometabolic risk factors may vary with different types of LCD. Accordingly, we studied these relations. METHODS: We assessed serum concentrations of high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), high-sensitivity C-reactive protein (CRP), total cholesterol, glycated hemoglobin, and uric acid, and nutrient intakes by standardized methods in men and women ages 40-59 years from four population samples of Japanese in Japan (553 men and 544 women, combined). For people consuming usual, animal-based, and plant-based LCDs, we calculated LCD scores, based on relative level of fat, protein, and carbohydrate, by modifying the methods of Halton et al. Instead of calculating scores based on animal or vegetable fat, we used saturated fatty acids (SFA) or monounsaturated fatty acids (MUFA) + polyunsaturated fatty acids (PUFA). RESULTS: In multivariate regression analyses with adjustment for site, age, sex, BMI, smoking, alcohol intake, physical activity, and years of education, all three LCD scores were significantly positively related to HDLc (all P < 0.001), but not to LDLc. The plant-based LCD score was significantly inversely related to log CRP (coefficient = -0.010, P = 0.018). CONCLUSIONS: All three LCD scores were significantly positively related to HDLc. The plant-based LCD score was significantly inversely related to CRP. Carbohydrate intake below 50 % of total energy with higher intakes of vegetable protein and MUFA + PUFA, and lower intakes of SFA may be favorable for reducing cardiometabolic risk factors.

Sex Differences in Associations Among Obesity, Metabolic Abnormalities, and Chronic Kidney Disease in Japanese Men and Women.

AIMS: The present study aimed to investigate relationships among abdominal obesity, metabolic abnormalities, and the prevalence of chronic kidney disease (CKD) in relatively lean Japanese men and women. PARTICIPANTS AND METHODS: The participants included 8133 men and 15 934 women between 40 and 75 years of age recruited from the government health check-up center in Kanazawa City, Japan. The prevalence of abdominal obesity, high blood pressure, dyslipidemia, and high fasting plasma glucose levels were assessed according to the Japanese criteria for metabolic syndrome. The estimated glomerular filtration rate (eGFR) was calculated using the modified Modification of Diet in Renal Disease equation for the Japanese population, and participants with an eGFR <60 mL/min/1.73 m(2) and/or proteinuria were diagnosed with CKD. RESULTS: Overall, 23% of males and 14% of females met criteria for CKD. Having more numerous complicated metabolic abnormalities was significantly associated with a higher odds ratio (OR) of CKD for men and women, irrespective of abdominal obesity. However, there was a sex difference in the OR of CKD for obese participants without metabolic abnormalities, such that abdominal obesity without metabolic abnormalities was significantly associated with a higher OR for men (multivariate-adjusted OR 1.63; 95% confidence interval [CI], 1.16-2.28) but not for women (OR 1.01; 95% CI, 0.71-1.44). CONCLUSIONS: The present findings demonstrated that obesity without metabolic abnormalities was associated with a higher risk of CKD in men but not women in a relatively lean Japanese population.