Renal dysfunctions of inhabitants in a cadmium-polluted area

Renal functions of all cadmium-exposed inhabitants of a village over the age of 40 and of a control group were examined. Creatinine clearance and percentage renal phosphorus reabsorption (%TRP) were used as the renal function tests. Creatinine clearance and %TRP fell significantly in the cadmium-exposed inhabitants. At the early stage of renal dysfunction, the fall of creatinine clearance was much greater than that of %TRP. Creatinine clearance may be a rather sensitive indicator of renal dysfunction caused by cadmium exposure.     

Urinary cadmium and mortality among inhabitants of a cadmium-polluted area in Japan

The influence of cadmium (Cd) body burden on mortality remains controversial. Excess mortality and the dose-response relationship between mortality and urinary cadmium excretion were investigated in this study among environmentally exposed subjects. A 15-year follow-up study was carried out on 3119 inhabitants (1403 men and 1716 women) of the Cd-polluted Kakehashi River basin, whose urinary Cd concentration was examined in a 1981-1982 health impact survey. The mortality risk of high urinary Cd (> or = 10 microg/g Cr) subjects after adjustment for age using Cox's proportional hazard model was higher than that of moderate urinary Cd (< 10 microg/g Cr) subjects in both sexes. When the subjects were divided into five groups according to the amount of urinary Cd (<3, 3-5, 5-10, 10-20, > or = 20 microg/g Cr), the mortality risk was significantly increased among the subjects with urinary Cd > or = 3 microg/g Cr in proportion to the increases in the amount of urinary Cd concentration after adjustment for age, especially in women. Furthermore, special causes of death among high and moderate urinary Cd were investigated, and mortality risk ratio for heart failure, which is a cause of death often diagnosed in cases with a gradual deterioration culminating in death, was significantly increased in both sexes, compared with the moderate urinary Cd subjects. Also, in women the mortality risk for renal diseases in the high urinary Cd subjects was significantly higher than that in the moderate urinary Cd subjects. These results suggest that a causal association between Cd body burden and mortality exists among inhabitants environmentally exposed to Cd but that no special disease may be induced except renal diseases.     

Latest status of cadmium accumulation and its effects on kidneys, bone, and erythropoiesis in inhabitants of the formerly cadmium-polluted Jinzu River Basin in Toyama, Japan, after restoration of rice paddies

Purpose  

The cadmium-polluted Jinzu River Basin in Toyama, Japan, where nephropathy and itai-itai disease were endemic among resident farmers decades ago, has been almost completely restored. The aim of this study is to investigate whether inhabitants there would still exhibit cadmium accumulation and its effects on kidneys, bones, and erythropoiesis.     

Relative weight and mortality during a five-year follow-up study in an aged population--a study of aged inhabitants of a rural area in Japan

The present study, a follow-up study for 669 aged examinees of a health check performed in July 1983 in a rural area in Fukushima Prefecture, was conducted to clarify the relationship between relative weight and mortality among aged individuals living in a Japanese rural area. Using the standard body weights calculated from Japanese mean body weights by sex, age class (60-69 and 70 or more) and height cited from the data of the Ministry of Health and Welfare from 1966, mortalities during the five year follow-up were compared among four groups different in relative weight at baseline. The results are as follows. 1) The mortalities in the group of 'Relative weight less than or equal to -10% the leanest group among the four groups, were highest in both sexes, 52.8 per 1000 person-years for males and 33.2 per 1000 person-years for females. On the other hand, those in the group of '+10% less than or equal to Relative weight less than +20%' were lowest in both sexes, 23. 1 per 1000 person-years for males and 7.0 per 1000 person-years for females. In females, the difference in the mortality between these two groups was statistically significant at the 0.05 level, provided age structures in both groups were taken into consideration. 2) In both sexes, the mortalities of cancer and cerebrovascular disease in the group of 'Relative weight less than or equal to -10%' were highest among the four groups, whereas such mortalities in the group of '+10% less than or equal to Relative weight less than +20%' were lowest.(ABSTRACT TRUNCATED AT 250 WORDS)     

Renal function after reduction in cadmium exposure: an 8-year follow-up of residents in cadmium-polluted areas

Background and objective: Long-term exposure to cadmium (Cd) causes renal dysfunction, but the change in renal function with exposure is unknown. We assessed the evolution of Cd-induced renal effects after a reduction in dietary exposure to Cd in rice.Methods: Four hundred twelve residents in previously Cd-polluted and nonpolluted areas were examined twice, in 1998 and in 2006. Changes in blood Cd, urinary Cd, and kidney function [N-acetyl-β-d-glucosaminidase (NAG), β₂-microglobulin, and albumin in urine] were measured.Results: In the most polluted area, mean blood Cd was 8.9 μg/L and 3.3 μg/L in 1998 and in 2006, respectively, and urinary Cd was 11.6 and 9.0 μg/g creatinine. Urinary albumin in 1998 increased with urinary Cd, but no such exposure–response relation appeared for 2006 albumin versus urinary Cd 1998, indicating recovery. Other biomarkers of kidney function were also elevated in 1998. Partial recovery was observed for NAG among women and was suggested for β₂-microglobulin among young individuals. The probability of having β₂-microglobulin levels above the 95th percentile in 2006 was high in those with elevated β₂-microglobulin in 1998 [odds ratio (OR) = 24.8; 95% confidence interval (CI): 11.2, 55.3] compared with albumin (OR = 3.0; 95% CI: 1.2, 7.5) and NAG (OR = 2.6; 95% CI: 1.6, 4.4).Conclusions: Results suggest that a Cd-mediated increase in urinary albumin excretion is reversible upon substantial reduction of exposure. For markers of tubular effects, we observed a tendency toward improvement but not complete recovery. Data from repeated observations suggest that β₂-microglobulin may be more informative than NAG as an indicator for an individual’s future tubular function.     

Cadmium concentrations in hair, urine and blood among residents in a cadmium-polluted area, Nagasaki, Japan: a 18-year follow-up after soil replacement]

In 1981, the soil of cadmium (Cd)-polluted rice fields was replaced with new soil in Kashine, a Cd-polluted district located on Tsushima Island, Nagasaki Prefecture, Japan. Consequently, the average dietary Cd intake among the inhabitants decreased from 215 micrograms/day in 1969 to 106 micrograms/day in 1983. The authors investigated the health status of Kashine inhabitants before and after the reduction of Cd intake. Concentrations of beta 2-microglobulin in urine (U-beta 2-mg) and Cd in urine (U-Cd), hair (H-Cd) and blood (B-Cd) were measured on 35 inhabitants in 1979 and 1996. The geometric mean of U-beta 2-mg concentration for 9 subjects with U-beta 2-mg levels > or = 1,000 micrograms/g creatinine (microgram/g cr) in 1979 increased by approximately 2.5-fold in 1996. Meanwhile there was little change in the geometric mean for 26 subjects with U-beta 2-mg levels < 1,000 micrograms/g cr in 1996. It was concluded that renal tubular dysfunction among Cd-exposed inhabitants was irreversible and progressive, even after dietary Cd intake decreased. The geometric mean of U-Cd concentration decreased significantly from 11.0 micrograms/g cr in 1979 to 6.3 micrograms/g cr in 1996. The decrease in U-Cd concentrations was significantly greater among inhabitants with U-beta 2-mg levels > or = 1,000 micrograms/g cr than among those with U-beta 2-mg levels < 1,000 micrograms/g cr (p = 0.03). From these results, it was considered that the level of U-Cd was more decreased by the presence of renal tubular dysfunction. The geometric mean of H-Cd concentration decreased significantly from 109.1 micrograms/kg in 1979 to 55.1 micrograms/kg in 1996. However, it was unclear whether the decrease of H-Cd depended on the decrease of dietary Cd intake, decrease of body burden or both, because U-Cd concentrations also decreased by approximately 43% during this period. H-Cd concentration was weakly and positively correlated with U-Cd (r = 0.38-0.44), an indicator of body burden of Cd. These results suggested that H-Cd concentration was influenced by the body burden of this metal. The geometric mean of B-Cd concentration in 33 inhabitants was 5.7 micrograms/l in 1996. The geometric mean was significantly greater in subjects with initial U-beta 2-mg levels > or = 1,000 micrograms/g cr than in those with U-beta 2-mg levels < 1,000 micrograms/g cr. A close positive correlation was found between B-Cd concentrations and U-Cd (r = 0.70, p < 0.01). It was suggested that the body burden influenced the levels of B-Cd as well as U-Cd, many years after Cd exposure had decreased.     

Severity of tubular brush border damage in cadmium-polluted area (Jinzu river basin): clinical role of urinary trehalase

Urinary trehalase activity and leucine aminopeptidase activity were parabolically correlated with urinary beta 2-microglobulin, and these enzymes were observed to be biphasic in relation to urinary beta 2-microglobulin when the study populations included patients of Itai-itai disease and inhabitants of a cadmium-polluted area. Furthermore, urinary trehalase activity was parabolically correlated with urinary total protein and urinary glucose. From these results, it is inferred that by measuring both urinary trehalase and urinary beta 2-microglobulin, one can elucidate the degree of tubular damage.     

Follow up study of renal tubular dysfunction and mortality in residents of an area polluted with cadmium.

A retrospective cohort study was conducted to investigate the association between cadmium induced renal tubular dysfunction and mortality. A total of 230 subjects aged 40 or older and living in a cadmium polluted area in Kosaka Town, Akita Prefecture, Japan, were studied at least once between 1975 and 1977 and again in 1990. Urinary beta 2-microglobulin and total amino nitrogen concentrations were significantly related to mortality from all causes in women. The finding supports the idea that cadmium induced kidney damage is a factor associated with mortality in a general population exposed to environmental cadmium.     

Follow up study of renal tubular dysfunction and mortality in residents of an area polluted with cadmium.

A retrospective cohort study was conducted to investigate the association between cadmium induced renal tubular dysfunction and mortality. A total of 230 subjects aged 40 or older and living in a cadmium polluted area in Kosaka Town, Akita Prefecture, Japan, were studied at least once between 1975 and 1977 and again in 1990. Urinary beta 2-microglobulin and total amino nitrogen concentrations were significantly related to mortality from all causes in women. The finding supports the idea that cadmium induced kidney damage is a factor associated with mortality in a general population exposed to environmental cadmium.     

镉污染区居民疾病死亡谱分析

目的 研究长期镉污染对居民健康状况的影响。方法 对镉污染地区的6个自然村作了5年死亡情况的回顾调查。结果 镉污染区婴儿死亡率和早产发生率偏高；污染区居民疾病死亡谱与福建省山区不同，也与同县的非污染区不同；恶性肿瘤、呼吸系统病、消化系统病及新生儿病的标化死亡率均高于非污染区。结论 污染区居民的健康已经受到镉污染的影响。     

上海市社区居民糖尿病知识知晓情况分析

目的 了解上海市居民糖尿病知识知晓状况的变化规律.方法 2002年采用抽样分层横断面现场调查方法,对上海市浦东新区4个社区≥18岁居民1 869人进行糖尿病知识问卷调查.随访5年,于2007年再进行问卷调查.2次均接受问卷调查的660人.结果 上海市社区人群糖尿病知识知晓率仍低于50%,糖代谢正常人群糖尿病知识知晓率有明显提高(t=2.634,P=0.009).调查的9项糖尿病知识中有4项的普及率明显提高.糖尿病知识知晓程度与年龄呈负相关(r=-0.189,P<0.01),与受教育程度呈正相关(r=0.347,P<0.01),与空腹血糖和餐后2h血糖均无明显相关性.结论 上海市社区居民对糖尿病知识的知晓状况虽有所提高但仍需改善.糖代谢异常人群、老年和高龄人群是值得关注和重点实施教育的对象.     

Parental infertility and semen quality in male offspring: a follow-up study

Jensen et al. (Am J Epidemiol 2007;165:583-90) reported for the first time that men whose mothers had received fertility treatment had poor semen quality. This result could be confounded by the mothers' body mass index. Obesity is a strong predictor of fecundity and could have a programming effect on semen quality through hormonal factors or links to fetal growth. The authors of the current study tried to replicate the finding of Jensen et al. after controlling for maternal body mass index and other covariates using data from a recently conducted, population-based, Danish follow-up study on the association between maternal smoking during pregnancy in 1984-1987 and sons' semen quality, in which the participants were sampled according to levels of maternal smoking during pregnancy. After adjustment, sons of mothers who reported that they had been examined or treated for childlessness (n = 30) had a lower sperm concentration and total sperm count and fewer motile and morphologically normal spermatozoa in comparison with sons of mothers who had not been examined or treated for childlessness (n = 295). None of the differences (except for semen concentration) between the groups reached statistical significance, but the study has limited power. The findings were in the same direction as those reported by Jensen et al. and do not indicate that their results are confounded by maternal body mass index.