Association between exposure to cadmium and blood pressure in Japanese peoples

The authors studied the effects of environmental cadmium exposure on blood pressure (BP). Subjects 1140 men and 1713 women, aged > or =50 yr lived in three areas of Japan considered "unpolluted" by cadmium. Multiple logistic regression analysis was used to evaluate relationships between hypertension/nonhypertension and cadmium concentrations in blood (B-Cd) or urine (U-Cd). Age, body mass index, drinking and smoking habits, and blood and urine chemistry data were incorporated into the model. Odds ratios for hypertension were significantly less than 1 in either gender when U-Cd was the indicator of cadmium exposure and hypertension was defined as systolic BP > or =140 mmHg and/or diastolic BP > or =90 mmHg. The results suggest a significant negative association between cadmium exposure and BP in inhabitants in Japan.     

Cadmium exposure and hypertension in the 1999-2004 National Health and Nutrition Examination Survey (NHANES)

INTRODUCTION: Cadmium induces hypertension in animal models. Epidemiologic studies of cadmium exposure and hypertension, however, have been inconsistent. OBJECTIVE: We aimed to investigate the association of blood and urine cadmium with blood pressure levels and with the prevalence of hypertension in U.S. adults who participated in the 1999-2004 National Health and Nutrition Examination Survey (NHANES). METHODS: We studied participants > or = 20 years of age with determinations of cadmium in blood (n = 10,991) and urine (n = 3,496). Blood and urine cadmium were measured by atomic absorption spectrometry and inductively coupled plasma-mass spectrometry, respectively. Systolic and diastolic blood pressure levels were measured using a standardized protocol. RESULTS: The geometric means of blood and urine cadmium were 3.77 nmol/L and 2.46 nmol/L, respectively. After multivariable adjustment, the average differences in systolic and diastolic blood pressure comparing participants in the 90th vs. 10th percentile of the blood cadmium distribution were 1.36 mmHg [95% confidence interval (CI), -0.28 to 3.00] and 1.68 mmHg (95% CI, 0.57-2.78), respectively. The corresponding differences were 2.35 mmHg and 3.27 mmHg among never smokers, 1.69 mmHg and 1.55 mmHg among former smokers, and 0.02 mmHg and 0.69 mmHg among current smokers. No association was observed for urine cadmium with blood pressure levels, or for blood and urine cadmium with the prevalence of hypertension. CONCLUSIONS: Cadmium levels in blood, but not in urine, were associated with a modest elevation in blood pressure levels. The association was stronger among never smokers, intermediate among former smokers, and small or null among current smokers. Our findings add to the concern of renal and cardiovascular cadmium toxicity at chronic low levels of exposure in the general population.     

Kidney cadmium as compared to other markers of cadmium exposure in workers at a secondary metal smelter

BACKGROUND: The aim of the study was to evaluate whether cadmium concentrations in kidney (K-Cd), blood (B-Cd) or urine (U-Cd) could reveal previous occupational cadmium exposure at a metal smelter. METHODS: The study included 90 smelters and 35 controls (B-Cd and U-Cd determination). In a subgroup (N = 33), K-Cd was also determined. RESULTS: B-Cd (median 4.6; range 0.5-53 nmol/L), U-Cd (0. 29; 0.04-1.9 micromol/mol creatinine) and K-Cd (14; 3-61 microg/g wet weight) were similar to reported concentrations in the general Swedish population. In the subgroup, significant associations (P<0. 001) were obtained between B-Cd and K-Cd (r = 0.70), U-Cd and K-Cd (r = 0.60) and between U-Cd and B-Cd (r = 0.62). Multiple regression analyses revealed smoking as the major predictor of K-Cd, B-Cd, and U-Cd. B-Cd and U-Cd were both associated with the duration of employment at the smelter. CONCLUSIONS: There was no statistically significant evidence of previous occupational exposure at the smelter from measurement of K-Cd.     

Determinants and Within-Person Variability of Urinary Cadmium Concentrations among Women in Northern California

Background: Cadmium (Cd) is a toxic metal associated with increased morbidity and mortality. Urinary Cd (U-Cd) concentration is considered a biomarker of long-term exposure.Objectives: Our objectives were to evaluate the within-person correlation among repeat samples and to identify predictors of U-Cd concentrations.Methods: U-Cd concentrations (micrograms per liter) were measured in 24-hr urine samples collected from 296 women enrolled in the California Teachers Study in 2000 and a second 24-hr sample collected 3–9 months later from 141 of the participants. Lifestyle and sociodemographic characteristics were obtained via questionnaires. The Total Diet Study database was used to quantify dietary cadmium intake based on a food frequency questionnaire. We estimated environmental cadmium emissions near participants’ residences using a geographic information system.Results: The geometric mean U-Cd concentration was 0.27 µg/L and the range was 0.1–3.6 µg/L. The intraclass correlation among repeat samples from an individual was 0.50. The use of a single 24-hr urine specimen to characterize Cd exposure in a case–control study would result in an observed odds ratio of 1.4 for a true odds ratio of 2.0. U-Cd concentration increased with creatinine, age, and lifetime pack-years of smoking among ever smokers or lifetime intensity-years of passive smoking among nonsmokers, whereas it decreased with greater alcohol consumption and number of previous pregnancies. These factors explained 42–44% of the variability in U-Cd concentrations.Conclusion: U-Cd levels varied with several individual characteristics, and a single measurement of U-Cd in a 24-hr sample did not accurately reflect medium- to long-term body burden.     

Blood and Urine Cadmium,Blood Pressure,and Hypertension: A Systematic Review and Meta-analysis

Background

Cadmium exposure has been inconsistently related to blood pressure.

Objectives

We updated and reevaluated the evidence regarding the relationships of blood cadmium (BCd) and urine cadmium (UCd) with blood pressure (BP) and hypertension (HTN) in nonoccupationally exposed populations.

Data sources and extraction

We searched PubMed and Web of Science for articles on BCd or UCd and BP or HTN in nonoccupationally exposed populations and extracted information from studies that provided sufficient data on population, smoking status, exposure, outcomes, and design.

Data synthesis

Twelve articles met inclusion criteria: eight provided data adequate for comparison, and five reported enough data for meta-analysis. Individual studies reported significant positive associations between BCd and systolic BP (SBP) among nonsmoking women [β = 3.14 mmHg per 1 μg/L untransformed BCd; 95% confidence interval (CI), 0.14–6.14] and among premenopausal women (β = 4.83 mmHg per 1 nmol/L log-transformed BCd; 95% CI, 0.17–9.49), and between BCd and diastolic BP (DBP) among women (β = 1.78 mmHg comparing BCd in the 90th and 10th percentiles; 95% CI, 0.64–2.92) and among premenopausal women (β = 3.84 mmHg per 1 nmol/L log-transformed BCd; 95% CI, 0.86–6.82). Three meta-analyses, each of three studies, showed positive associations between BCd and SBP (p = 0.006) and DBP (p < 0.001) among women, with minimal heterogeneity (I² = 3%), and a significant inverse association between UCd and HTN among men and women, with substantial heterogeneity (I² = 80%).

Conclusion

Our results suggest a positive association between BCd and BP among women; the results, however, are inconclusive because of the limited number of representative population-based studies of never-smokers. Associations between UCd and HTN suggest inverse relationships, but inconsistent outcome definitions limit interpretation. We believe a longitudinal study is merited.     

Associations of toenail arsenic, cadmium, mercury, manganese, and lead with blood pressure in the normative aging study

Background: Arsenic, cadmium, mercury, and lead are associated with cardiovascular disease in epidemiologic research. These associations may be mediated by direct effects of the metals on blood pressure (BP) elevation. Manganese is associated with cardiovascular dysfunction and hypotension in occupational cohorts.Objectives: We hypothesized that chronic arsenic, cadmium, mercury, and lead exposures elevate BP and that manganese lowers BP.Methods: We conducted a cross-sectional analysis of associations between toenail metals and BP among older men from the Normative Aging Study (n = 639), using linear regression and adjusting for potential confounders.Results: An interquartile range increase in toenail arsenic was associated with higher systolic BP [0.93 mmHg; 95% confidence interval (CI): 0.25, 1.62] and pulse pressure (0.76 mmHg; 95% CI: 0.22, 1.30). Positive associations between arsenic and BP and negative associations between manganese and BP were strengthened in models adjusted for other toenail metals.Conclusions: Our findings suggest associations between BP and arsenic and manganese. This may be of public health importance because of prevalence of both metal exposure and cardiovascular disease. Results should be interpreted cautiously given potential limitations of toenails as biomarkers of metal exposure.     

Early-Life Cadmium Exposure and Child Development in 5-Year-Old Girls and Boys: A Cohort Study in Rural Bangladesh

Background: Cadmium is a commonly occurring toxic food contaminant, but health consequences of early-life exposure are poorly understood.Objectives: We evaluated the associations between cadmium exposure and neurobehavioral development in preschool children.Methods: In our population-based mother–child cohort study in rural Bangladesh, we assessed cadmium exposure in 1,305 women in early pregnancy and their children at 5 years of age by measuring concentrations in urine (U-Cd), using inductively coupled plasma mass spectrometry. Children’s IQ at 5 years of age, including Verbal (VIQ), Performance (PIQ), and Full-Scale IQ (FSIQ), were measured by Wechsler Preschool and Primary Scale of Intelligence. Behavior was assessed by the Strengths and Difficulties Questionnaire (SDQ).Results: In multiple linear regression models, adjusted for sex, home stimulation, socioeconomic status (SES), and maternal and child characteristics, a doubling of maternal U-Cd was inversely associated with VIQ (–0.84 points; 95% confidence interval: –1.3, –0.40), PIQ (–0.64 points; –1.1, –0.18), and FSIQ (–0.80 points; –1.2, –0.39). Concurrent child U-Cd showed somewhat weaker association with VIQ and FSIQ, but not PIQ. Stratification by sex and SES indicated slightly stronger associations with PIQ and FSIQ in girls than in boys and in higher-income compared with lower-income families. Concurrent U-Cd was inversely associated with SDQ-prosocial behavior and positively associated with SDQ-difficult behavior, but associations were close to the null after adjustment. Quantile regression analysis showed similar associations across the whole range of each developmental outcome.Conclusion: Early-life low-level cadmium exposure was associated with lower child intelligence scores in our study cohort. Further research in this area is warranted.     

In vivo analysis of cadmium in battery workers versus measurements of blood, urine, and workplace air.

OBJECTIVES: To measure in vivo the cadmium concentrations in kidney cortex (kidney-Cd) and in superficial liver tissue (liver-Cd) of nickel cadmium battery workers, and to compare the results with other commonly used estimates of cadmium exposure (current concentrations of cadmium in blood (B-Cd) and urine (U-Cd)) or repeated measurements of cadmium in workplace air (CumAir-Cd). METHODS: The study comprised 30 workers with a range of duration of exposure of 11-51 years. 13 subjects were currently employed, whereas the other 17 had a median period without occupational exposure of eight years before the measurements. The in vivo measurements were made with an x ray fluorescence technique permitting average detection limits of 30 and 3 micrograms cadmium per g tissue in kidney and liver, respectively. RESULTS: 19 of 30 (63%) people had kidney-Cd and 13 of 27 (48%) had liver-Cd above the detection limits. Kidney-Cd ranged from non-detectable to 350 micrograms/g and liver-Cd from non-detectable to 80 micrograms/g. The median kidney-Cd and liver-Cd were 55 micrograms/g and 3 micrograms/g, respectively. Kidney-Cd correlated significantly with B-Cd (r, 0.49) and U-Cd (r, 0.70), whereas liver-Cd correlated significantly with U-Cd (r, 0.58). Neither kidney-Cd nor liver-Cd correlated with the CumAir-Cd. The prevalence of beta 2-microglobulinurea increased with increased liver-Cd. CONCLUSIONS: Current U-Cd can be used to predict the kidney-Cd and liver-Cd measured in vivo. In vivo measurements of kidney-Cd and liver-Cd were not shown to correlate with the individual cadmium exposure estimates, obtained by integration of the cadmium concentration in workplace air. There may be several reasons for this, including uncertainties in the estimate of the individual cumulative exposures as well as in the in vivo measurements. There was a suggestion of a relation between liver-Cd and tubular proteinuria.     

Application of the hybrid approach to the benchmark dose of urinary cadmium as the reference level for renal effects in cadmium polluted and non-polluted areas in Japan

Objectives

The aim of this study was to evaluate the reference level of urinary cadmium (Cd) that caused renal effects. An updated hybrid approach was used to estimate the benchmark doses (BMDs) and their 95% lower confidence limits (BMDL) in subjects with a wide range of exposure to Cd.

Methods

The total number of subjects was 1509 (650 men and 859 women) in non-polluted areas and 3103 (1397 men and 1706 women) in the environmentally exposed Kakehashi river basin. We measured urinary cadmium (U-Cd) as a marker of long-term exposure, and β2-microglobulin (β2-MG) as a marker of renal effects. The BMD and BMDL that corresponded to an additional risk (BMR) of 5% were calculated with background risk at zero exposure set at 5%.

Results

The U-Cd BMDL for β2-MG was 3.5 μg/g creatinine in men and 3.7 μg/g creatinine in women.

Conclusions

The BMDL values for a wide range of U-Cd were generally within the range of values measured in non-polluted areas in Japan. This indicated that the hybrid approach is a robust method for different ranges of cadmium exposure. The present results may contribute further to recent discussions on health risk assessment of Cd exposure.     

Heavy drinking is associated with poor blood pressure control in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study

Alcohol intake has been shown to have a J-shaped association with blood pressure (BP). However, this association has not been examined in mixed race populations or in people with diabetes where tighter blood pressure control is recommended. Participants in the REGARDS study who were 45 years or older (n = 30,239) were included. Medical history (including self-reported alcohol intake) was collected by telephone while blood collection and clinical measurements were done during an in-home visit. We defined diabetes as use of medications and/or fasting glucose ≥ 126 mg/dL and hypertension as use of blood pressure lowering medications and/or BP ≥ 140/90 mmHg or BP ≥ 130/80 mmHg in people with diabetes. After adjustment for confounders, heavy drinking was associated with an increased odds of hypertension (OR = 1.59; 95% CI = 1.37, 1.87). Diabetes and gender significantly modified (interaction P < 0.05 for both) the association between alcohol use and hypertension, although heavy drinking remained associated with increased odds of hypertension in sub-group analyses. We did not observe the previously described J-shaped relationship in any sub-group except white females. These data suggest heavy alcohol consumption is associated with poor BP control and that heavy drinkers may want to consider limiting alcohol intake in order to manage hypertension.     

Impact of urinary cadmium on mortality in the Japanese general population in cadmium non-polluted areas

PurposeThe aim of the present study was to evaluate the dose–effect relationship between urinary cadmium (U-Cd as an index of internal Cd exposure) and mortality in a cohort of the Japanese general population.MethodsA 19-year cohort study was conducted in 897 men and 1307 women who lived in two non-polluted areas in Japan. The subjects were categorized into four quartiles based on creatinine adjusted U-Cd (μg/g cre). Hazard ratio (HR) and 95% confidence interval (95%CI) of the quartiles of U-Cd for mortality was calculated using a proportional hazards regression. Forward stepwise model selection was applied to the potential covariates such as age, body mass index, mean arterial pressure, various lifestyle factors and present illness.ResultsThe mortality rates per 1000 person years were 27.8 and 12.5 in men and women, respectively. In men, the fourth quartile of U-Cd (≥2.919 μg/g cre) showed a significant, positive HR (1.50, 95%CI: 1.11–2.02) for mortality compared to the first quartile (<1.014). In women, the fourth quartile of U-Cd (≥3.943 μg/g cre) also showed a significant HR (1.50, 95%CI: 1.08–2.09) for mortality compared to the first quartile (<1.140).ConclusionThe present study clarified that U-Cd was significantly associated with increased mortality, indicating the worsened life prognosis of the general population in Cd non-polluted areas in Japan. These results highlight the importance of further discussion of the health risk assessment of Cd exposure in the general population.     

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.     

动态血压监测指导腹膜透析患者高血压治疗的临床观察

目的　探讨动态血压监测指导腹膜透析患者高血压治疗的意义。方法　使用非侵入性的动态血压监测仪监测 34例腹膜透析 (CAPD)合并有高血压的患者 ,通常从早上 9:0 0开始每 30分钟记录 1次血压 ,共监测 2 4小时。结果　所有病人 2 4小时的平均血压是 14 5 6 / 91 3mmHg ,39 6 %收缩压记录超过 15 0mmHg ,4 8 7%的舒张压记录超过 90mmHg。糖尿病肾病患者 (12例 )平均血压是 15 7 3/ 88 8mmHg ,5 8 5 %的收缩压记录和 4 4 6 %的舒张压记录超过 15 0 / 90mmHg。平均血压、心率和血压负荷白天和夜间没有显著性差异。结论　大多数的CAPD患者伴有高血压的病人其血压控制不佳 ,糖尿病患者血压控制情况更差。大多数CAPD患者血压 2 4小时节律性消失 ,白天和夜间高血压控制不佳并没有区别 ,使用动态血压监测仪评估血压可以指导降压治疗和增加降压达标。     

镉暴露人群早期肾损伤指标敏感性比较

目的 通过对湖北省黄石市某有色金属冶炼厂周边地区镉污染暴露人群血、尿等生物样品的检测,在血镉、尿镉中筛选出能敏感反映镉性肾早期损伤的暴露指标.方法 现场采集污染区389人和对照区居民260人的血液和尿液,检测血镉、尿镉、尿肌酐、尿β2-微球蛋白(β2-MG)及尿N-乙酰-B-D-氨基葡萄糖苷酶(NAG)等5项生物指标,以尿β2-MG及尿NAG酶二者之一超标为肾早期损伤阳性判断标准,通过接受者工作特征曲线(ROC)曲线下面积和Logistic回归模型的标准化偏回归系数来判断暴露指标血镉、尿镉的敏感性.结果 649份样本中,血镉ROC曲线下面积(0.569,P<0.05)小于尿镉的ROC曲线下面积(0.725,P<0.05);相对肾早期损伤,尿镉的标准化偏回归系数(0.5036)大于血镉(-0.0212).结论 对于肾早期损伤的判断,暴露指标尿镉优于血镉.     

Occupational exposure to lead and blood pressure: a study in 105 workers

A group of workers, occupationally exposed to lead and cadmium compounds (n = 53), was compared to a group of workers not exposed to these metals (n = 52). The average values of systolic, diastolic, and mean blood pressure were found to be higher in the exposed group (p less than 0.05). In contrast with the correlation between CdU and blood pressure, the correlation between PbB and systolic and mean blood pressure remained statistically significant after controlling for age and pulse rate (r = 0.22, p less than 0.05). The prevalence of potential hypertension (defined as systolic blood pressure greater than or equal to 160 mm Hg and/or diastolic blood pressure greater than or equal to 95 mm Hg and/or under treatment for hypertension) was higher in the exposed group, but the observed relative risk was not statistically significant: relative risk = 1.91 (95% confidence limits, 0.90-4.05). Furthermore, a significant correlation between PbB and Hgb (r = -0.28, p = 0.004) was observed. Differences in kidney function, as assessed in this study, were not detected.     

镉接触工人尿镉血镉与尿β_2MG RPB含量的跟踪研究

目的:跟踪调查镉接触工人停止接触镉后尿镉、血镉的变化及肾功能损害情况,寻找镉接触指标与肾功能损害指标的关系,初步探讨职业性镉引起的肾功能特点及规律。方法:选择深圳某镍镉电池厂29名镉中毒观察对象(尿镉连续2次超过5μmol/mol肌酐)为研究对象,分析尿镉、血镉含量与尿β2-微球蛋白(β2MG)、尿视黄醇结合蛋白(RPB)排出量的关系;并通过跟踪研究他们在停止接触镉1年后,接触指标(尿镉、血镉)及肾功能损害指标的变化的规律。结果:镉中毒观察对象在停止接触1年后,尿镉由(7.16±2.81)μmol/mol肌酐下降至(7.03±2.84)μmol/mol肌酐,尿镉含量下降没有显著性差异(P>0.05);血镉明显下降,由(5.8±1.81)μg/L下降至(3.5±1.24)μg/L,有显著性差异(P<0.01);尿β2-微球蛋白含量(中位数)由1.19μmol/mol肌酐上升至1.21μmol/mol肌酐,尿视黄醇结合蛋白含量(中位数)由0.39μmol/mol肌酐上升至0.42μmol/mol肌酐,统计学秩和检验结果显示均没有显著性差异(P>0.05)。尿镉与血镉存在明显的线性正相关,相关系数(r)为0.721,(P<0.01),回归分析得出的方程为:y=1.132x+3.656,(y代表尿镉,x代表血镉)。尿镉、血镉与尿β2-微球蛋白含量的相关系数分别为0.321,0.346,统计学上均没有显著性相关(P>0.05)。结论:职业性镉中毒观察对象停止接触镉1年后,血镉明显下降,尿镉含量下降不明显,尿镉与血镉存在线性正相关,尿β2-微球蛋白、尿视黄醇结合蛋白含量总体水平变化不显著,但有个别仍可以出现肾功能异常,镉对肾功能损害存在明显个体差异性。     

Benchmark dose for cadmium-induced renal effects in humans

OBJECTIVES: Our goal in this study was to explore the use of a hybrid approach to calculate benchmark doses (BMDs) and their 95% lower confidence bounds (BMDLs) for renal effects of cadmium in a population with low environmental exposure. METHODS: Morning urine and blood samples were collected from 820 Swedish women 53-64 years of age. We measured urinary cadmium (U-Cd) and tubular effect markers [N-acetyl-beta-d-glucosaminidase (NAG) and human complex-forming protein (protein HC) ] in 790 women and estimated glomerular filtration rate (GFR; based on serum cystatin C) in 700 women. Age, body mass index, use of nonsteroidal anti-inflammatory drugs, and blood lead levels were used as covariates for estimated GFR. BMDs/BMDLs corresponding to an additional risk (benchmark response) of 5 or 10% were calculated (the background risk at zero exposure was set to 5%) . The results were compared with the estimated critical concentrations obtained by applying logistic models used in previous studies on the present data. RESULTS: For both NAG and protein HC, the BMDs (BMDLs) of U-Cd were 0.5-1.1 (0.4-0.8) microg/L (adjusted for specific gravity of 1.015 g/mL) and 0.6-1.1 (0.5-0.8) microg/g creatinine. For estimated GFR, the BMDs (BMDLs) were 0.8-1.3 (0.5-0.9) microg/L adjusted for specific gravity and 1.1-1.8 (0.7-1.2) microg/g creatinine. CONCLUSION: The obtained benchmark doses of U-Cd were lower than the critical concentrations previously reported. The critical dose level for glomerular effects was only slightly higher than that for tubular effects. We suggest that the hybrid approach is more appropriate for estimation of the critical U-Cd concentration, because the choice of cutoff values in logistic models largely influenced the obtained critical U-Cd.     

Biologic markers of oxidative stress and nephrotoxicity as studied in biomonitoring of adverse effects of occupational exposure to lead and cadmium

OBJECTIVES: In this work, we studied impregnation levels of workers occupationally exposed to lead (Pb) and cadmium (Cd), usefulness of early urinary markers of nephrotoxicity, and occurrence of oxidative stress as the underlying mechanism involved in Pb- or Cd-induced adverse effects. Thirty-five men were recruited from a nonferrous metal smelter. Pb and Cd in blood (B-Pb, B-Cd) and urine (U-Pb, U-Cd) were measured. Relations between oxidative stress markers (malondialdehyde, superoxide dismutase, glutathione peroxidase, selenium, glutathione reductase, glutathione status, 8-hydroxy-2'-deoxyguanosine) and exposure levels, on the one hand, and early urinary markers (alpha-1-microprotein, beta-2-microglobulin, retinol binding protein, alpha and pi-glutathione S-transferases) and exposure levels, on the other hand, were evaluated. RESULTS: Mean exposure levels were moderate (B-Pb = 395.71 microg Pb/L; U-Pb = 95.19 microg Pb/g creatinine; B-Cd = 5.83 microg Cd/L; U-Cd = 4.67 microg Cd/g creatinine). Changes in malondialdehyde, glutathione status, 8-hydroxy-2'-deoxyguanosine, and alpha-glutathione S-transferases were closely correlated with exposure levels and did not depend on tobacco consumption. We showed that these workers showed moderate Pb and Cd exposure levels. CONCLUSIONS: Taken together, the data suggests the use of alpha-glutathione S-transferases excretion in urine as a hallmark of early changes in the proximal tubular integrity that could later lead to clinical disease if exposure is not reduced.     

重度子痫前期孕产妇产前血压与妊娠结局的关系

目的探讨重度子痫前期孕产妇不同程度的产前血压与妊娠结局的相关性。方法选取广州医科大学附属第三医院2016年7月1日至2018年6月30日收治的177例重度子痫前期孕产妇作为研究对象,按照产前血压分为高血压1组和高血压2组(高血压1组:收缩压为160~179mm Hg和/或舒张压为100~109mm Hg;高血压2组:收缩压≥180mm Hg和/或舒张压≥110mmHg),回顾性分析两组患者一般临床资料。结果①高血压2组的发病孕周、分娩孕周早于高血压1组(t值分别为2.14、3.06,均P <0.05)。②高血压2组的HELLP综合征发生率高于高血压1组(χ~2=4.66,P <0.05)。③高血压2组患者的胎儿早产、胎儿生长受限、出生并发症发生率及围产儿结局、低体重儿及新生儿转新生儿重症监护室(NICU)发生率均显著高于高血压1组(χ~2值分别为6.64、8.85、11.07、7.06,均P <0.05)。结论重度子痫前期患者不良妊娠结局的发生率随着产前血压升高而增加。     

儿童期血压偏高对成年期高血压的影响研究

目的 本研究旨在探讨儿童期血压偏高对成年期高血压的影响,为成人高血压的早期防控提供科学依据。方法 基于“中国居民健康与营养调查”资料(1991-2011年),纳入儿童期(6~17岁)和成年期(18~38岁)均进行至少1次随访的研究对象。儿童期血压偏高前期定义采用中国儿童青少年血压参考值性别和年龄的第90百分位(P₉₀)至第95百分位(P₉₅),儿童期血压偏高采用≥P₉₅。成年期高血压前期为收缩压/舒张压≥120/80 mmHg且<140/90 mmHg;成年期高血压为收缩压/舒张压≥140/90 mmHg,或有高血压史,或目前正服用降压药物。采用协方差分析和Cox比例风险回归模型分析儿童期血压偏高对成年期高血压前期和高血压的影响,控制混杂因素包括儿童期性别和年龄,成年期的体重指数(BMI)、吸烟和饮酒。结果 本研究共纳入1 984名数据完整的研究对象,中位随访时间为11.7年。基线儿童期共有108人(5.4%)为血压偏高前期,199人(10.0%)为血压偏高。随访成年期共有697人(35.1%)为高血压前期,104人(5.2%)为高血压。协方差分析表明,成年期收缩压和舒张压水平均随着儿童期血压百分位的增加而增加(P_趋势<0.001)。多因素Cox回归分析显示,儿童期血压偏高者成年后为高血压前期的风险增加(HR=1.41,95%CI:1.12~1.77)。儿童期血压偏高者成年后为高血压的风险显著增加(HR=1.73,95%CI:1.01~2.98)。结论 儿童期血压偏高会增加成年期罹患高血压的风险。应该重视儿童青少年血压监测,对血压偏高的高危儿童应及时采取干预措施。