Blood cadmium level's association with 18-month mortality in diabetic patients with maintenance haemodialysis

Prognostic Value of Systemic Inflammatory Response Index for the Prognosis of Diabetic Maintenance Hemodialysis Patients: A Retrospective Observational Study

Background

The systemic inflammatory response index (SIRI) had been identified as an inflammatory marker and has been linked to determining clinical outcomes in several diseases. We advocated the relationship between the initial SIRI and the prognosis of diabetic maintenance hemodialysis (MHD) patients.

Methods

A total of 153 diabetic MHD patients who accepted regular HD treatment at our hospital were enrolled in this study. SIRI was calculated as neutrophil × monocyte/lymphocyte. All patients were separated into two groups based on the levels of SIRI. LASSO regression and Cox regression analyses were then made to determine the prognostic value of SIRI for diabetic MHD patients.

Results

During a median 33-month follow-up period, 50 (32.7%) patients died. The higher SIRI value (≥ 2.5) had a higher risk of death (adjusted HR=4.00, 95% CI 1.77-9.07, P=0.001) after adjusting for other confounding clinical features. The devised nomogram ground on SIRI value and clinical features had great predictive value for overall survival in diabetic MHD patients. The nomogram proved both prominent calibration competence and therapeutic subservience.

Conclusion

SIRI is a relatively excellent predictor for OS, and the suggested nomogram ground on SIRI leads to an accurate prediction value for diabetic MHD patients.

Do trace elements play a role in coronary artery calcification in hemodialysis patients?

PURPOSE

Abnormalities of trace elements have previously been linked to inflammatory processes in hemodialysis (HD) patients. We aimed to establish the trace element status of maintenance HD patients, to investigate the relationship between coronary artery calcification scores (CACs) and whole blood levels of trace elements.

METHODS

Patients undergoing HD in three times a week for > 6 months and age-and sex-matched controls were included from October 2015 to June 2016. Data were collected from patient files. All subjects' whole blood levels of trace elements were measured by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). CACs for patients were assessed by multi-detector computed tomography.

RESULTS

The 35 patients (male, 60%) with a mean age of 45.7 ± 10.4 years and 35 controls were included. HD patients showed significantly lower levels of selenium and uranium and higher cadmium (Cd), cobalt, lithium, manganese, nickel, lead, platinum, tin, strontium, and thallium levels compared to controls. Coronary artery calcification (CAC) was present in 21 patients (60%), and median CACs were 14.2 (IQR 0-149). Patients with CACs > median were significantly older, had a higher prevalence of hypertension and lower ALP levels than patients with CACs ≤ median. No significant differences in whole blood levels of trace elements were found between patients with CACs > median and patients with CACs ≤ median. A near significance was noted in median whole blood levels of Cd between these groups (P = 0.096). According to multivariate analysis, age was the only independent determinant for CAC development.

CONCLUSION

Age is independently associated with coronary vascular calcification. High Cd levels might play a role in CAC development in HD patients.

Associations of exposure to lead and cadmium with risk of all-cause and cardiovascular disease mortality among patients with type 2 diabetes

The aim of this paper is to investigate the associations of lead and cadmium exposure with all-cause and cardiovascular disease (CVD) mortality among adults with type 2 diabetes (T2D). The prospective cohort study included participants with T2D (n = 7420 for blood lead; n = 5113 for blood cadmium) from the National Health and Nutrition Examination Survey (NHANES) III and NHANES 1999-2014. Death outcomes were ascertained through linkage with the National Death Index records. The geometric mean (interquartile range) concentrations of blood lead and cadmium were 19.6 (11.8, 35.0) μg/L and 0.39 (0.21, 0.60) μg/L, respectively. During 72,279 and 37,017 person-years of followup, 2818 all-cause deaths (including 832 CVD deaths) for blood lead and 1237 all-cause deaths (including 319 CVD deaths) for blood cadmium were documented, respectively. Comparing extreme quartiles, the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause mortality were 1.51 (1.25, 1.82) for blood lead (P_trend < 0.001) and 1.58 (1.22, 2.03) for blood cadmium (P_trend < 0.001); and the HRs (95% CIs) of CVD mortality were 2.27 (1.54, 3.34) for blood lead (P_trend < 0.001) and 1.78 (1.04, 3.03) for blood cadmium (P_trend = 0.07). In the joint analysis, compared with participants in the lowest tertiles of blood lead and cadmium, participants in the highest tertiles had a HR (95% CI) of 2.09 (1.35, 3.24) for all-cause mortality. Exposure to lead and cadmium alone or in combination was significantly associated with higher risk of mortality among patients with T2D. These findings imply that minimizing exposure to lead and cadmium may aid in the prevention of premature death among individuals with diabetes.

The Risk Factors of Blood Cadmium Elevation in Chronic Kidney Disease

Low-level cadmium exposure has adverse effects on chronic kidney disease (CKD); however, the risk factors for elevated blood cadmium levels (BCLs) have not been studied in CKD. We conducted a cross-sectional investigation in 200 CKD patients and stratified them by the tertiles of BCL to compare their demographic, environmental, and biochemical data. The factors associated with BCL were identified, and their effects were examined in subgroups. In the analyses, female sex, smoking, and CKD stage 5D were associated with high BCL, and statin was inversely correlated with BCL (odds ratio [95% confidence interval, CI], 6.858 [2.381–19.746], p < 0.001, 11.719 [2.843–48.296], p = 0.001, 30.333 [2.252–408.520], p = 0.010, and 0.326 [0.122–0.873], p = 0.026; deviations of BCL [nmol/L, 95% CI], 2.66 [1.33–4.00], p < 0.001, 3.68 [1.81–5.56], p < 0.001, 3.38 [0.95–5.82], p = 0.007, and −2.07 [−3.35–−0.78], p = 0.002). These factors were also independently correlated with BCL in subgroups, including non-dialysis CKD, hypertensive patients, non-smokers, and male patients. In conclusion, female sex, smoking, and CKD stage 5D were the major risk factors for elevated BCL; additionally, statins were negatively associated with BCL in CKD.

Environmental Cadmium Exposure and Dental Indices in Orthodontic Patients

BACKGROUND

Previous studies have shown that environmental cadmium exposure could disrupt salivary gland function and is associated with dental caries and reduced bone density. Therefore, this cross-sectional study attempted to determine whether tooth decay with tooth loss following cadmium exposure is associated with some dental or skeletal traits such as malocclusions, sagittal skeletal pattern, and tooth decay.

METHODS

Between August 2019 and June 2020, 60 orthodontic patients with no history of previous orthodontics, functional appliances, or surgical treatment were examined. The patients were stratified into two groups according to their urine cadmium concentrations: high (>1.06 µg/g creatinine, n = 28) or low (<1.06 µg/g creatinine, n = 32).

RESULTS

The patients were 25.07 ± 4.33 years old, and most were female (female/male: 51/9 or 85%). The skeletal relationship was mainly Class I (48.3%), followed by Class II (35.0%) and Class III (16.7%). Class I molar relationships were found in 46.7% of these patients, Class II molar relationships were found in 15%, and Class III molar relationships were found in 38.3%. The mean decayed, missing, and filled surface (DMFS) score was 8.05 ± 5.54, including 2.03 ± 3.11 for the decayed index, 0.58 ± 1.17 for the missing index, and 5.52 ± 3.92 for the filled index. The mean index of complexity outcome and need (ICON) score was 53.35 ± 9.01. The facial patterns of these patients were within the average low margin (26.65 ± 5.53 for Frankfort-mandibular plane angle (FMA)). There were no significant differences in the above-mentioned dental indices between patients with high urine cadmium concentrations and those with low urine cadmium concentrations. Patients were further stratified into low (<27, n = 34), average (27-34, n = 23), and high (>34, n = 3) FMA groups. There were no statistically significant differences in the urine cadmium concentration among the three groups. Nevertheless, a marginally significant p-value of 0.05 for urine cadmium concentration was noted between patients with low FMA and patients with high FMA.

CONCLUSION

This analysis found no association between environmental cadmium exposure and dental indices in our orthodontic patients.

Lifestyle-Related Exposure to Cadmium and Lead is Associated with Diabetic Kidney Disease

BACKGROUND

Environmental factors contributing to diabetic kidney disease are incompletely understood. We investigated whether blood cadmium and lead concentrations were associated with the prevalence of diabetic kidney disease, and to what extent lifestyle-related exposures (diet and smoking) contribute to blood cadmium and lead concentrations.

MATERIAL AND METHODS

In a cross-sectional analysis in 231 patients with type 2 diabetes included in the DIAbetes and LifEstyle Cohort Twente (DIALECT-1), blood cadmium and lead concentrations were determined using inductively coupled plasma mass spectrometry. The associations between diet (derived from food frequency questionnaire), smoking and cadmium and lead were determined using multivariate linear regression. The associations between cadmium and lead and diabetic kidney disease (albumin excretion >30 mg/24 h and/or creatinine clearance <60 mL/min/1.73 m²) were determined using multivariate logistic regression.

RESULTS

Median blood concentrations were 2.94 nmol/L (interquartile range (IQR): 1.78-4.98 nmol/L) for cadmium and 0.07 µmol/L (IQR: 0.04-0.09 µmol/L) for lead, i.e., below acute toxicity values. Every doubling of lead concentration was associated with a 1.75 (95% confidence interval (CI): 1.11-2.74) times higher risk for albuminuria. In addition, both cadmium (odds ratio (OR) 1.50 95% CI: 1.02-2.21) and lead (OR 1.83 95% CI: 1.07-3.15) were associated with an increased risk for reduced creatinine clearance. Both passive smoking and active smoking were positively associated with cadmium concentration. Alcohol intake was positively associated with lead concentration. No positive associations were found between dietary intake and cadmium or lead.

CONCLUSIONS

The association between cadmium and lead and the prevalence of diabetic kidney disease suggests cadmium and lead might contribute to the development of diabetic kidney disease. Exposure to cadmium and lead could be a so far underappreciated nephrotoxic mechanism of smoking and alcohol consumption.

The role of cadmium in obesity and diabetes

Multiple studies have shown an association between environmental exposure to hazardous chemicals including toxic metals and obesity, diabetes, and metabolic syndrome. At the same time, the existing data on the impact of cadmium exposure on obesity and diabetes are contradictory. Therefore, the aim of the present work was to review the impact of cadmium exposure and status on the risk and potential etiologic mechanisms of obesity and diabetes. In addition, since an effect of cadmium exposure on incidence of diabetes mellitus and insulin resistance was suggested by several epidemiologic studies, we carried out a meta-analysis of all studies assessing risk of prevalence and incidence of diabetes. By comparing the highest versus the lowest cadmium exposure category, we found a high risk of diabetes incidence (odds ratio=1.38, 95% confidence interval 1.12-1.71), which was higher for studies using urine as exposure assessment. On the converse, results of epidemiologic studies linking cadmium exposure and overweight or obesity are far less consistent and even conflicting, also depending on differences in exposure levels and the specific marker of exposure (blood, urine, hair, nails). In turn, laboratory studies demonstrated that cadmium adversely affects adipose tissue physiopathology through several mechanisms, thus contributing to increased insulin resistance and enhancing diabetes. However, intimate biological mechanisms linking Cd exposure with obesity and diabetes are still to be adequately investigated.

Association Between Hemodiafiltration and Hypoalbuminemia in Middle-Age Hemodialysis Patients

The advantage of hemodiafiltration (HDF) is well known. One of the disadvantages of HDF is loss of serum albumin, but this issue is still obscure. Some risk factors associated with mortality were age dependent. Studies on serum albumin/hypoalbuminemia and HDF in different age stratification were limited. The aim of this cross-sectional study was to assess the role of HDF and other clinical variables on serum albumin values in maintenance hemodialysis (MHD) patients of different age groups. We recruited a total of 1216 patients on MHD. Patients were divided into 4 groups by age stratification of youth (<30 years old), young-middle age (30-44 years old), middle age (45-64 years old), and old age (≥65  years old). Biochemical, hematological, nutritional, inflammatory parameters, and receiving HDF or not were recorded. The associations between age groups, HDF, and variables mentioned above were analyzed. Only in middle-age group, patients with HDF was significantly (P = 0.013) associated with serum albumin <4 g/dL. In middle-age group, a multivariate-forward logistic regression analysis showed that male sex (2.169 [1.029, 4.574], P = 0.042), inflammation (4.167 [2.043, 8.498], P < 0.001), cardiovascular disease (2.92 [1.019, 8.402], P = 0.046), serum creatinine level (0.639 [0.538, 0.758], P < 0.001), and cholesterol level (0.984 [0.975, 0.993], P = 0.001) were associated with serum albumin level <3.6 g/dL. Hepatitis C virus infection (1.911 [1.186, 3.077], P = 0.008), HDF (2.143 [1.298, 3.540], P = 0.003), inflammation (2.309 [1.549, 3.440], P < 0.001), use of arterio-venous fistula (0.518 [0.327, 0.820], P = 0.005), Kt/V (0.395 [0.193, 0.809], P = 0.011), nonanuria (0.542 [0.337, 0.870], P = 0.011), serum creatinine level (0.744 [0.669, 0.828], P < 0.001), and cholesterol level (0.993 [0.987, 0.998], P = 0.013) were associated with serum albumin level <4 g/dL. HDF can predict serum albumin level <4 g/dL in middle-age HD patients. The effect of age needs to be taken into consideration when interpreting the correlation between hypoalbuminemia and HDF.

Effect of Blood Cadmium Level on Mortality in Patients Undergoing Maintenance Hemodialysis

Previous studies of general populations indicated environmental exposure to low-level cadmium increases mortality. However, the effect of cadmium exposure on maintenance hemodialysis (MHD) patients is unclear.A total of 937 MHD patients from 3 centers in Taiwan were enrolled in this 36-month observational study. Patients were stratified by baseline blood cadmium level (BCL) into 3 groups: high BCL (>0.521 μg/L; n = 312), intermediate BCL (0.286-0.521 μg/L; n = 313), and low BCL (<0.286 μg/L; n = 312). The mortality rates and causes of death were analyzed.The analytic results demonstrated patients in the high BCL group had a significantly higher prevalence of malnutrition and inflammation than patients in the low and intermediate BCL groups. After 3 years of follow-up, 164 (17.5%) patients died and the major cause of death was cardiovascular disease. A Cox multivariate analysis indicated the high BCL group had increased hazard ratios (HRs) for all-cause mortality (HR = 1.72; 95% confidence interval [CI]: 1.14-2.63; P = 0.018), cardiovascular-related mortality (HR = 1.85; 95% CI: 1.09-3.23; P = 0.032), and infection-related mortality (HR = 2.27; 95% CI: 1.12-4.55; P = 0.035). A Cox multivariate analysis of MHD patients who never smoked (n = 767) indicated the high BCL group had increased HRs for all-cause mortality (HR = 1.67; 95% CI: 1.04-2.63; P = 0.048) and cardiovascular-related mortality (HR = 2.08; 95% CI: 1.08-4.00; P = 0.044).In conclusion, BCL is an important determinant of mortality in MHD patients. Therefore, MHD patients should avoid cadmium exposure as much as possible, such as tobacco smoking and eating cadmium-containing foods.

Oral tori in chronic hemodialysis patients

BACKGROUND

This study investigated the epidemiology of torus palatinus (TP) and torus mandibularis (TM) in hemodialysis patients and analyzed the influences of hyperparathyroidism on the formation of oral tori.

METHOD

During 2013, 119 hemodialysis patients were recruited for dental examinations for this study.

RESULTS

The prevalence of oral tori in our sample group was high at 33.6% (40 of 119). The most common location of tori was TP (70.0%), followed by TM (20.0%), and then both TP and TM (10.0%). Of the 40 tori cases, most (67.5%) were <2 cm in size; moreover, the majority (52.5%) were flat in shape. In symmetry, most (70.0%) occurred in the midline, followed by bilateral sides (20.0%). Notably, the levels of intact parathyroid hormone did not differ in patients with or without tori (P = 0.611). Furthermore, patients with tori did not differ from patients without tori in inflammatory variables such as log high-sensitivity C-reactive protein (P = 1.000) or nutritional variables such as albumin (P = 0.247). Finally, there were no differences between patients with and without tori in adequacy of dialysis (P = 0.577).

CONCLUSIONS

Neither hyperparathyroidism nor inflammation malnutrition syndrome was found to contribute to the formation of oral tori in chronic hemodialysis patients. Further studies are warranted.

Association between blood cadmium levels and malnutrition in peritoneal dialysis

Background

Malnutrition is associated with an increased risk of cardiovascular death and may cause protein-energy wasting in individuals with chronic kidney disease. A previous study demonstrated that blood cadmium levels (BCLs) were associated with malnutrition in maintenance hemodialysis (MHD) patients. However, the correlation between cadmium exposure and malnutrition remains unclear in chronic peritoneal dialysis (CPD) patients. This study examined the possible adverse effects of environmental cadmium exposure in CPD patients.

Methods

A total of 301 CPD patients were enrolled and divided into 3 study groups based on the following BCL tertiles: low (<0.19 μg/L), middle (0.19–0.39 μg/L), and high (>0.39 μg/L). Demographic, hematological, biochemical, and dialysis-related data were obtained for analysis. The analysis also included values of nutritional and inflammatory markers.

Results

The BCLs of CPD patients were lower than those of MHD patients. At baseline, patients in the high BCL group were older and had a higher prevalence of diabetes mellitus but lower serum albumin, creatinine, and phosphate levels than the patients in the other 2 groups. After adjusting for potential variables, stepwise backward multiple linear regression analysis revealed that age and alanine aminotransferase levels were positively associated with logarithmic transformation of BCLs (log BCLs), while serum albumin levels were negatively associated with log BCLs in CPD patients. The log BCLs were a significant determinant (beta coefficient ± standard error = -0.185 ± 0.074; P = 0.013) of nutritional status and significantly associated with the presence of malnutrition (odds ratio = 2.64; 95% confidence interval: 1.07–6.48; P = 0.035) in CPD patients after adjustment for related variables.

Conclusions

BCL is significantly associated with nutritional status and malnutrition in CPD patients. Therefore, it is important for CPD patients to avoid environmental exposure to cadmium such as through smoking and consumption of cadmium-rich foods.

Education level is associated with mortality in male patients undergoing maintenance hemodialysis

BACKGROUND

Studies of the correlation between education levels and mortality in hemodialysis (HD) patients are rare. The aim of this multi-center study was to investigate the relationship between education levels and 3-year mortality rates in HD patients.

METHODS

A total of 935 HD patients from 3 HD centers participated in this 3-year prospective observational study. Education levels were categorized as either less than senior high school and above or equal to senior high school. The causes of death and mortality rates were also analyzed for each subgroup.

RESULTS

At the end of the 3-year follow-up period, 164 patients had died. In the male group, forward stepwise Cox regression analysis revealed that age, HD duration, hypertension, creatinine level, serum albumin level ≥3.6 g/dl, anuria, Kt/Vurea, and high education level were significant predictive factors for 3-year mortality rates.

CONCLUSION

This prospective observational study demonstrated that education level was associated with mortality in men undergoing HD.

Association of blood cadmium level with cardiometabolic risk factors and liver enzymes in a nationally representative sample of adolescents: the CASPIAN-III study

Introduction. This study aimed to determine the association of blood cadmium level with cardiometabolic risk factors and liver enzymes in adolescents. Methods. This case control study comprised 320 Iranian adolescents, 160 with metabolic syndrome and an equal number of controls. They were selected from participants of a nationwide survey entitled the CASPIAN-III study. Cadmium was measured by atomic absorption method. Results. The mean age of the case and control groups was not significantly different (15.3 ± 2.6 versus 14.63 ± 2.5 years, resp., P > 0.05). The mean cadmium level was near double-fold higher than the standards of the World Health Organization, without significant difference between the MetS and control groups (10.09 ± 2.21, 9.97 ± 2.38 μg/L, resp., P > 0.05). Cadmium level had positive but nonsignificant correlations with diastolic blood pressure, serum triglycerides, fasting blood glucose, LDL-C, and liver enzymes. Conclusion. Cadmium level had positive but nonsignificant association with some cardiometabolic risk factors and liver enzymes. The associations did not reach statistical significant level, and this may be because of the high levels of cadmium in both groups studied or because of the young age group of participants. Controlling environmental pollutants shall be a priority for the prevention of chronic diseases.

Hepatocellular carcinoma in patients with chronic kidney disease

AIM: To investigate outcomes of hepatocellular carcinomas (HCCs) in patients with chronic kidney disease (CKD).

METHODS: Four hundred and forty patients referred between 2000 and 2002 for management of HCCs were categorized according to their CKD stage, i.e., estimated glomerular filtration rate (eGFR) > 90 (stage 1), 60-90 (stage 2), 30-60 (stage 3), 15-30 (stage 4), and < 15 (stage 5) mL/min per 1.73 m², respectively. Demographic, clinical and laboratory data were collected and mortality rates and cause of mortality were analyzed. The mortality data were examined with Kaplan-meier method and the significance was tested using a log-rank test. An initial univariate Cox regression analysis was performed to compare the frequency of possible risk factors associated with mortality. To control for possible confounding factors, a multivariate Cox regression analysis (stepwise backward approach) was performed to analyze those factors that were significant in univariate models (P < 0.05) and met the assumptions of a proportional hazard model.

RESULTS: Most HCC patients with CKD were elderly, with mean age of diagnosis of 60.6 ± 11.9 years, and mostly male (74.8%). Hepatitis B, C and B and C co-infection virus were positive in 61.6%, 45.7% and 14.1% of the patients, respectively. It was found that patients with stages 4 and 5 CKD were not only older (P = 0.001), but also had higher hepatitis C virus carrier rate (P = 0.001), lower serum albumin level (P = 0.001), lower platelet count (P = 0.037), longer prothrombin time (P = 0.001) as well as higher proportions of advanced cirrhosis (P = 0.002) and HCCs (P = 0.001) than patients with stages 1 and 2 CKD. At the end of analysis, 162 (36.9%) patients had died. Kaplan-Meier analysis revealed that patients with stages 4 and 5 CKD suffered lower cumulative survival than stages 1 and 2 CKD (log-rank test, χ² = 11.764, P = 0.003). In a multivariate Cox-regression model, it was confirmed that CKD stage [odds ratio (OR) = 1.988, 95%CI: 1.012-3.906, P = 0.046)], liver cirrhosis stage (OR = 3.571, 95%CI: 1.590-8.000, P = 0.002) and serum albumin level (OR = 0.657, 95%CI: 0.491-0.878, P = 0.005) were significant predictors for mortality in this population.

CONCLUSION: HCC patients with stages 4 and 5 CKD had inferior survival than stages 1 and 2 CKD. This warrants further studies.

Antihyperglycemic, antihyperlipidemic, and renoprotective effects of Chlorella pyrenoidosa in diabetic rats exposed to cadmium

OBJECTIVE

The objective of the present study is to evaluate the antihyperlipidemic effect of Chlorella pyrenoidosa in diabetic rats exposed to cadmium (Cd).

MATERIALS AND METHODS

Group 1 and 2 rats were treated as control and C. pyrenoidosa control. Group 3 and 4 rats were given single injection of streptozotocin (40 mg/kg b.w; i.p) followed by Cd (0.6 mg/kg b.w; s.c) for 5 days per week for a total period of 90 days. In addition, group 4 rats alone were treated with C. pyrenoidosa throughout the study period of 90 days. Assessments of plasma glucose, insulin, lipid profile and renal function markers were performed in control and experimental rats along with histological examination of kidney tissues.

RESULTS

Diabetic rats exposed to Cd showed increased levels of plasma glucose and decreased levels of plasma insulin accompanied by the significantly elevated levels of tissue lipids viz., total cholesterol, triglyceride, free fatty acid, and phospholipids compared with control rats. Alterations in lipoproteins (low density lipoprotein-C, very low density lipoprotein-C, and high density lipoprotein-C) levels were also observed.

DISCUSSION

Elevated levels of urinary albumin, creatinine, and blood urea nitrogen confirmed the onset of renal dysfunction in unsupplemented diabetic rats exposed to Cd.

CONCLUSION

C. pyrenoidosa (100 mg/kg body weight) supplemented diabetic nephropathic rats showed near normal biochemical profile and well preserved renal histology that substantiate the antihyperglycemic, antihyperlipidemic, and renoprotective effects of C. pyrenoidosa in diabetic rats exposed to Cd.

Temporal trend of cadmium exposure in the United States population suggests gender specificities

BACKGROUND

Over the years, environmental cadmium exposure has been linked to increased mortality. Over the years, the use of cadmium has generally decreased.

AIMS

Although even relatively low levels of cadmium have been associated with increased mortality in the general population, whether this applies to blood cadmium is not well understood.

METHODS

The authors analysed data of the National Health and Nutrition Examination Survey to study the temporal trend of cadmium exposure in the period 1988-2006 and the risk of all-cause, cancer and cardiovascular mortality associated with blood cadmium levels.

RESULTS

Urinary cadmium decreased significantly over time in males (0.58 (0.01) mcg/g to 0.41 (0.01) mcg/g; P < 0.001) but not in females (0.71 (0.09) mcg/g to 0.63 (0.08) mcg/g; P= 0.66). All-cause mortality was significantly higher in the highest quartiles compared with the lowest quartile of blood cadmium in both males (hazard ratio 1.89, 95% confidence interval 1.22, 2.89; P= 0.005) and females (hazard ratio 2.03, 95% confidence interval 1.06, 3.89; P= 0.035) after adjustment for age, race/ethnicity, smoke status, alcohol intake, annual household income and body mass index. There was also a significant association with cardiovascular mortality in females (P= 0.025).

CONCLUSIONS

Our data show that elevated blood cadmium levels are associated with elevated mortality, that there seem to be gender differences in temporal trends of cadmium exposure and that blood cadmium is a proxy of chronic cadmium exposure.