Blood lead levels, malnutrition, inflammation, and mortality in patients with diabetes treated by long-term hemodialysis

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.

Simultaneous multielement analysis by ICP-MS with simple whole blood sample dilution and its application to uremic patients undergoing long-term hemodialysis

Few studies were reported on trace elements' alterations in uremic patients undergoing long-term (>24 months) hemodialysis (HD), especially by using the whole blood as the biological fluid for the measuring purpose. Our objective was to develop an improved micro-sampling inductively coupled plasma-mass spectrometry (ICP-MS) method to determine the levels of Ca, Mg, Cu, Zn, Fe, Mn, Se and Pb in uremic patients receiving long-term HD. A ICP-MS method with a modified whole blood sample preparation procedure with small volumes was established and applied for the simultaneous quantification of the various elements in uremic patients undergoing long-term HD. 124 eligible uremic patients receiving long-term HD (75 males and 49 females) and 77 healthy subjects (54 males and 23 females) were recruited and Ca, Mg, Cu, Zn, Fe, Mn, Se and Pb levels were further determined. Our results revealed that uremic patients with HD had significantly higher blood levels of Ca, Mg, Zn and Pb and lower Cu, Fe, Se and Mn concentrations than healthy controls. In conclusion, a reproducible and reliable ICP-MS method using minimal whole blood sample volume (50 μL) with a simple dilution-based preparation procedure was successfully improved, validated and applied. Uremic patients undergoing long-term HD might be at increased risk of some essential trace elements deficiency (especially for Cu, Fe and Se) or toxic trace element excess (Pb) in respect to healthy subjects. Monitoring of blood levels and supplementation of some trace elements may be indicated in uremic patients undergoing long-term HD.

Blood lead level: an overlooked risk of carpal tunnel syndrome in hemodialysis patients

Introduction: Carpal tunnel syndrome (CTS) is a severe complication observed in long-term maintenance hemodialysis (MHD) patients. The most common cause of CTS is dialysis-related β2-microglobulin amyloidosis, which is associated with inflammation and oxidative stress in dialysis patients. Patients on MHD have higher blood lead levels (BLLs) than the general population. Lead (Pb) exposure in chronic dialysis patients has been noted to induce oxidative stress and inflammation. Therefore, lead-related inflammation and oxidative stress might contribute to CTS. Methods: The medical records of 866 MHD patients were reviewed. Two hundred and thirty-four patients with symptoms of CTS were surveyed by senior neurologists via physical examinations and nerve conduction studies. Patients in this study were stratified into groups with low-normal (<10 μg/dL), high-normal (10 to 20 μg/dL), and abnormal (>20 μg/dL) BLLs. The associations between CTS and BLLs and the clinical data were analyzed. Results: Multivariate logistic regression analyses showed that Log BLL (OR: 54.810, 95% CI: 13.622-220.54, p < .001), high-normal BLLs (OR: 4.839, 95% CI: 2.262-10.351, p < .001) with low-normal BLL as a reference, high BLLs (OR: 12.952, 95% CI: 5.391-31.119, p < .001) with low-normal BLL as a reference, and a BLL >12.3 μg/dL (OR: 6.827, 95% CI: 3.737-12.472, p < .001) were positively associated with CTS according to three different analyses. Discussion: In conclusion, blood lead levels were positively associated with CTS in patients on MHD. Dialysis patients should pay more attention to their environmental exposure to Pb. Avoidance of environmental Pb may reduce the incidence of CTS in MHD patients. Future studies will address the role of Pb in the pathophysiology of CTS in this patient population.

Association of serum chromium levels with malnutrition in hemodialysis patients

BACKGROUND

Chromium is an essential trace metal that reduces oxidative stress and inflammation. In patients undergoing maintenance hemodialysis (MHD), a correlation among chromium exposure, inflammation, and malnutrition remains unclear. This study examined the possible effects of serum chromium levels (SCLs) in MHD patients.

METHODS

Initially, 732 MHD patients in dialysis centers were recruited. A total of 647 patients met the inclusion criteria and were stratified by SCL into four equal-sized groups: first quartile (< 0.29 μg/L), second quartile (0.29-0.56 μg/L), third quartile (0.57-1.06 μg/L), and fourth quartile (> 1.06 μg/L). Demographic, biochemical, and dialysis-related data were obtained for analyses. The analysis included nutritional and inflammatory markers.

RESULTS

As compared with the highest quartile group, more subjects in the lowest quartile group were of an older age; had lower hemoglobin and creatinine levels; had a higher prevalence of DM and malnutrition (serum albumin level < 3.6 g/dL); and higher serum transferrin saturation and ferritin levels. A stepwise multiple linear regression analysis revealed a significant negative correlation between malnutrition and SCL (β coefficient = - 0.129, p = 0.012) and negative associations among body mass index (β coefficient = - 0.010, p = 0.041), ferritin (β coefficient = - 0.107, p = 0.001) and SCL. A multivariate logistic regression analysis also demonstrated a negative correlation between malnutrition and SCL. With a 10-fold increase in SCL, the risk ratio of malnutrition was 0.49 (95% confidence interval: 0.25-0.96; p = 0.039).

CONCLUSIONS

SCL is significantly associated with malnutrition in MHD patients. Further evaluation of the relationship between clinical outcomes (morbidity/mortality) and SCL is necessitated.

Blood lead level is a positive predictor of uremic pruritus in patients undergoing hemodialysis

Although uremic pruritus (UP) is a common and annoying symptom for end-stage renal disease patients on hemodialysis (HD) and peritoneal dialysis, its pathogenesis is poorly understood. However, systemic inflammation is one of the possible pathogenesis of UP, and blood lead level (BLL) has been noted to be associated with inflammation and nutritional status in long-term HD patients. There might be an interaction or association, therefore, between BLL and UP through systemic inflammation. We analyzed cross-sectional data among 866 participants. All of the 866 patients in this study were stratified into groups with low-normal (<10 μg/dL), high-normal (10-20 μg/dL), and abnormal BLLs (>20 μg/dL). The associations between UP and BLL and the clinical data were analyzed. Multivariate logistic regression demonstrated that HD duration, non-anuria, log ferritin, serum low-density lipoprotein, log BLL, high-normal BLL, and high BLL were associated with UP. In conclusion, BLL was positively associated with UP.

Positive correlation between environmental PM2.5 and blood lead levels in patients undergoing maintenance hemodialysis

Patients undergoing hemodialysis (HD) have significantly higher mean blood lead levels (BLLs) than those in healthy individuals. Because elementary lead can be found in particulate matter with a diameter of <2.5 μm (PM_2.5), this cross-sectional study was conducted to assess the effect of environmental PM_2.5 exposure and other clinical variables on BLLs in patients receiving HD. We recruited 921 patients on maintenance HD (MHD) who had undergone HD for at least 6 months and who had previously participated in a BLL study. Mean PM_2.5 concentrations in living environments in the previous 12 and 24 months were analyzed using a blood lead test. From a multivariate analysis, after adjustment for related factors, the mean PM_2.5 concentrations in the previous 12 and 24 months were positively associated with log BLLs. In addition, days with PM_2.5 levels exceeding the standard level during the previous 12 and 24 months were positively associated with log BLLs. Patients exposed to higher PM_2.5 concentrations and more days with PM_2.5 levels exceeding the standard level exhibited a higher prevalence of high and high-normal BLLs and a lower prevalence of low-normal BLLs. After adjustment for related variables, the BLLs exhibited a significantly positive association with environmental PM_2.5 in patients undergoing MHD.

Negative Relationship between Erythropoietin Dose and Blood Lead Level in Patients Undergoing Maintenance Hemodialysis

The adverse effects of increased blood lead levels have been well discussed. Several antioxidant agents have been reported to offer protection from lead toxicity and to reduce blood lead levels (BLL). Given that erythropoietin (EPO) also has antioxidant properties, the aim of this cross-sectional study was to assess the role of EPO and other clinical variables on BLL in hemodialysis (HD) patients. We recruited 931 maintenance hemodialysis (MHD) patients who had undergone HD for at least 6 months and who had ever received blood lead level (BLL) study. Use of erythropoiesis-stimulating agents followed the The National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF KDOQI) Clinical Practice Guideline. We estimated demographic, hematological, nutritional, inflammatory, biochemical, and dialysis-related data based on this study. In the group with EPO, 7% had high BLL. In the group without EPO, 22% had high BLL. From the stepwise liner regression, urban areas, hemodialysis duration, and clearance of urea (KT/V_urea) were positively associated with log BLL. In contrast, diabetes (DM), and monthly EPO dose were negatively associated with log BLL. This study showed that EPO dose might be negatively associated with blood lead levels in patients on maintenance hemodialysis.

Variation of trace element concentrations in patients undergoing hemodialysis in the north of Spain

BACKGROUND

Trace elements are essential substances for the proper physiological and biochemical functioning of the organism. Hemodialysis patients are potentially at risk of deficiency or excess of these elements. The application of inductively coupled plasma mass spectrometry (ICP-MS) allows the simultaneous quantification of very small amounts of multiple trace elements. The aim was to measure the serum concentration of copper (Cu), zinc (Zn), selenium (Se), and nickel (Ni), and the whole blood concentration of arsenic (As), lead (Pb), and manganese (Mn), in patients undergoing hemodialysis as well as in controls.

METHODS

The study was carried out in 57 hemodialysis patients compared with 57 controls with normal renal function. Serum and whole blood samples from the dialysis group were collected before and after hemodialysis sessions and Cu, Zn, Se, Ni, As, Pb and Mn levels were determined using ICP-MS.

RESULTS

Hemodialysis patients showed significantly lower blood levels of Cu, Zn and Se than controls (p < 0.001) and higher concentrations of Ni, As and Pb (p < 0.0001). The levels of Mn were similar in both groups. After performing hemodialysis, Cu, Zn, Se and Ni concentrations were significantly higher than the pre-hemodialysis levels (p < 0.0001). However, the concentration of As decreased (p < 0.0001) and Pb and Mn levels were not significantly altered after the dialysis session.

CONCLUSION

Hemodialysis patients are at increased risk of trace elements deficiency (especially for Zn and Se) or excess (Ni) in respect to healthy subjects. Monitoring of blood levels and supplementation of some trace elements may be indicated in patients undergoing hemodialysis.

Association of a high normalized protein catabolic rate and low serum albumin level with carpal tunnel syndrome in hemodialysis patients

Carpal tunnel syndrome (CTS) is the most common mononeuropathy in patients with end-stage renal disease (ESRD). The association between chronic inflammation and CTS in hemodialysis (HD) patients has rarely been investigated. HD patients with a high normalized protein catabolic rate (nPCR) and low serum albumin level likely have adequate nutrition and inflammation. In this study, we assume that a low serum albumin level and high nPCR is associated with CTS in HD patients. We recruited 866 maintenance hemodialysis (MHD) patients and divided them into 4 groups according to their nPCR and serum albumin levels: (1) nPCR <1.2 g/kg/d and serum albumin level <4 g/dL; (2) nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL; (3) nPCR <1.2 g/kg/d and serum albumin level ≥4 g/dL; and (4) nPCR ≥1.2 g/kg/d and serum albumin level ≥4 g/dL. After adjustment for related variables, HD duration and nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL were positively correlated with CTS. By calculating the area under the receiver-operating characteristic curve, we calculated that the nPCR and HD duration cut-off points for obtaining the most favorable Youden index were 1.29 g/kg/d and 7.5 years, respectively. Advance multivariate logistic regression analysis revealed that in MHD patients, nPCR ≥1.29 g/kg/d and serum albumin <4 g/dL, and also HD duration >7.5 years were associated with CTS. A high nPCR and low serum albumin level, which likely reflect adequate nutrition and inflammation, were associated with CTS in MHD patients.

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.

Associations of cadmium and lead exposure with leukocyte telomere length: findings from National Health and Nutrition Examination Survey, 1999-2002

Cadmium and lead are ubiquitous environmental contaminants that might increase risks of cardiovascular disease and other aging-related diseases, but their relationships with leukocyte telomere length (LTL), a marker of cellular aging, are poorly understood. In experimental studies, they have been shown to induce telomere shortening, but no epidemiologic study to date has examined their associations with LTL in the general population. We examined associations of blood lead and cadmium (n = 6,796) and urine cadmium (n = 2,093) levels with LTL among a nationally representative sample of US adults from the National Health and Nutrition Examination Survey (1999-2002). The study population geometric mean concentrations were 1.67 µg/dL (95% confidence interval (CI): 1.63, 1.70) for blood lead, 0.44 µg/L (95% CI: 0.42, 0.47) for blood cadmium, and 0.28 µg/L (95% CI: 0.27, 0.30) for urine cadmium. After adjustment for potential confounders, the highest (versus lowest) quartiles of blood and urine cadmium were associated with -5.54% (95% CI: -8.70, -2.37) and -4.50% (95% CI: -8.79, -0.20) shorter LTLs, respectively, with evidence of dose-response relationship (P for trend < 0.05). There was no association between blood lead concentration and LTL. These findings provide further evidence of physiological impacts of cadmium at environmental levels and might provide insight into biological pathways underlying cadmium toxicity and chronic disease risks.

Water quality in conventional and home haemodialysis

Dialysis water can be contaminated by chemical and microbiological factors, all of which are potentially hazardous to patients on haemodialysis. The quality of dialysis water has seen incremental improvements over the years, with advances in water preparation, monitoring and disinfection methods, and high standards are now readily achievable in clinical practice. Advances in dialysis membrane technology have refocused attention on water quality and its potential role in the bioincompatibility of haemodialysis circuits and adverse patient outcomes. The role of ultrapure dialysate is increasingly being advocated, given its proposed clinical benefits and relative ease of production as a result of the widespread use of reverse osmosis and ultrafiltration. Many of the issues pertaining to water quality in hospital-based dialysis units are also pertinent to haemodialysis in the home. Furthermore, an increased awareness of the environmental and financial consequences of home haemodialysis has resulted in the development of automated and more efficient dialysis machines. These new machines have an increased emphasis on water conservation and recycling along with a decreased need for a complex infrastructure for water purification and maintenance.

Correlation of serum lead levels with inflammation, nutritional status, and clinical complications in hemodialysis patients

The aim of this study was to determine blood lead level (BLL) in hemodialysis (HD) patients and their relation with high-sensitivity C-reactive protein (hsCRP) and albumin which are inflammatory and nutritional biomarkers, respectively, and clinical complications. A total of 93 patients, who were dialyzed at least for 3 months, were included in the study. Blood samples were collected before HD and BLL was measured and categorized as three equal groups: low normal (BLL < 8 μg/dL), middle normal (BLL = 8-10.6 μg/dL), and high normal (BLL > 10.6 μg/dL). All patients had normal BLL, 9.7 ± 3.4 g/dL. Patients with abnormal hsCRP level (>3 mg/L) had higher BLL than other patients (16.4 ± 0.8 vs. 11.5 ± 2.7 mg/L, p = 0.003). Patients with BLL > 10.6 μg/dL had significantly lower hemoglobin, ferritin, iron, and albumin levels and higher hsCRP and intact parathyroid hormone (iPTH) levels than the patients with BLL < 8 μg/dL. In addition, BLL revealed a significant positive correlation with duration of dialysis. We concluded that BLL associated to inflammation, malnutritional status, iron-deficiency condition, and high iPTH level in HD patients.

Relationships and Inflammation across the Lifespan: Social Developmental Pathways to Disease

There are well documented links between close relationships and physical health, such that those who have supportive close relationships have lower rates of morbidity and mortality compared to those who do not. Inflammation is one mechanism that may help to explain this link. Chronically high levels of inflammation predict disease. Across the lifespan, people who have supportive close relationships have lower levels of systemic inflammation compared to people who have cold, unsupportive, conflict-ridden relationships. Not only are current relationships associated with inflammation, but past relationships are as well. In this article, we will first review the literature linking current close relationships across the lifespan to inflammation. We will then explore recent work showing troubled past relationships also have lasting consequence on people's inflammatory levels. Finally, we will explore developmental pathways that may explain these findings.

High incidence and recurrence of transitional cell carcinoma in Taiwanese patients with end-stage renal disease

AIM

This study examines the epidemiology of transitional cell carcinoma (TCC) in end-stage renal disease (ESRD) population from Taiwan, the area with the highest incidence and prevalence of ESRD.

METHODS

A total of 98 out of 10,890 ESRD patients were referred for management of TCC between 2000 and 2008. Demographic, clinical and laboratory data were collected and patient mortality and tumour recurrence rates were analyzed.

RESULTS

TCC patients were aged 61.4 ± 10.2 years and 66.3% were female. The average time from initiation of dialysis to tumour detection was 51.2 ± 36.4 months. Hypertensive nephrosclerosis, diabetes mellitus, chronic glomerulonephritis and unknown aetiology accounted for 25.5%, 20.4%, 22.4% and 31.6% of the causes of renal failure, respectively. The aetiology of renal failure for the 31.6% of patients was unclear, but chronic tubulointerstitial nephritis following long-term consumption of Chinese herbs (19.4%) or analgesic compounds (3.1%) was considered in some patients. Almost all (98.0%) patients presented with gross haematuria. Most TCC were in early stage (stage 0, 3.1%; stage I, 56.1%) during diagnosis. At the end of this study, 17 of 98 (17.3%) patients died. Multivariate Cox regression analysis found that age (odds ratio =1.140, 95% confidence interval = 1.049-1.239, P = 0.002) and tumour pain (odds ratio = 0.234, 95% confidence interval = 0.057-0.961, P = 0.044) were significant risk factors for all-cause mortality. Furthermore, 35.7% of TCC recurred during follow up. The 5 year patient and tumour-free survival rates were 72.4% and 14.4%, respectively.

CONCLUSION

The data shows that Taiwanese patients with ESRD had high incidence (0.9%) and recurrence (35.7%) of TCC.

Association of blood lead levels with mortality in patients on maintenance hemodialysis

BACKGROUND

The association between blood lead levels and mortality in patients on maintenance hemodialysis remains unclear.

METHODS

A cross-sectional and 18-month prospective study included 927 patients on maintenance hemodialysis. Baseline variables and blood lead levels were measured before hemodialysis and categorized as 3 equal groups: high (>12.64 μg/dL), middle (8.51-12.64 μg/dL), and low (<8.51 μg/dL). Mortality and cause of death were recoded for longitudinal analyses.

RESULTS

At baseline, after related variables were adjusted, logarithmic transformation of blood lead level was negatively related to log ferritin and positively related to the vintage of hemodialysis and the percentage of urban area patients. By the end of the follow-up, 59 patients had died. Kaplan-Meier survival analysis showed that the high blood lead level group had greater mortality than the low blood lead level group (log-rank test, P<.001). After adjustment for potential variables, Cox multivariate analysis demonstrated that by using the low blood lead level as the reference, high blood lead levels were associated with increased hazard ratios (HRs) for all-cause (HR 4.70; 95% confidence interval [CI], 1.92-11.49; P=.003), cardiovascular-cause (HR 9.71; 95% CI, 2.11-23.26; P=.005), and infection-cause (HR 5.35; 95% CI, 1.38-20.83; P=.046) 18-month mortality in patients on maintenance hemodialysis. Moreover, there was a significant trend (P=.032) of HRs for all-cause mortality among the 3 study groups.

CONCLUSION

High blood lead level is associated with increased HRs for all-cause, cardiovascular-cause, and infection-cause 18-month mortality in patients on maintenance hemodialysis.

Association between body mass and mortality in maintenance hemodialysis patients

A total of 959 Taiwanese patients undergoing maintenance hemodialysis-102 underweight (BMI < 18.5 kg/m(2)), 492 normal weight (BMI 18.5-22.9 kg/m(2)), 187 overweight (BMI 23.0-24.9 kg/m(2)), and 178 obese (BMI >or= 25 kg/m(2)) were recruited into this three-year, multicenter longitudinal study. It was found initially that the underweight group had more females, longer hemodialysis durations, less use of a biocompatible membrane (BCM) dialyzer, higher erythropoietin doses and Kt/V(urea), and lower white blood cell counts, hemoglobin, serum creatinine and phosphate, and high sensitivity C-reactive protein (hsCRP) than other groups (P < 0.001). Furthermore, a chi(2)-test demonstrated that underweight patients had poorer nutrition (P = 0.023), but less systemic inflammation (P < 0.001) than other groups. A stepwise multiple linear regression analysis established that age, sex, diabetes mellitus, hemodialysis duration, use of BCM dialyzer, Kt/V(urea), creatinine, high-density lipoprotein cholesterol, and hsCRP were significant risk factors associated with BMI (P < 0.001-0.002). After three years, 149 (15.5%) patients had died, including 22 of 102 (21.6%) underweight patients, 64 of 492 (13.0%) normal weight patients, 38 of 187 (20.3%) overweight patients, and 25 of 178 (15.5%) obese patients. The primary causes of mortality were cardiovascular (52.3%) and infection (39.6%). A multivariate Cox regression analysis revealed that age, diabetes mellitus, BMI, albumin, hsCRP, and cardiothoracic ratio were significant risk factors associated with all-cause mortality over three years (P < 0.001-0.022). Finally, Kaplan-Meier analysis confirmed that underweight patients suffer higher mortality than other groups (Log rank, P = 0.0392); therefore, the data have demonstrated a survival disadvantage of low BMI in Taiwanese patients undergoing maintenance hemodialysis.

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

BACKGROUND

Cadmium exposure is related to severity of diabetes and diabetes-related organ damage in diabetic patients. Elevated blood cadmium levels (BCLs) are well known in maintenance haemodialysis (MHD) patients but the clinical significance in diabetic MHD patients remains unknown.

METHODS

A total of 212 diabetic MHD patients were enrolled in this 18-month prospective study and were categorized into three equal groups according to the basal BCL: high (> 0.889 μg/L; n = 71), middle (0.373-0.889 μg/L; n = 70) and low (< 0.373 μg/L; n = 71) BCL groups. The mortality and cause of death were recorded and analysed longitudinally.

RESULTS

Patients with high BCL had trends of higher white blood cell counts, glycosylated haemoglobin, phosphate and blood lead levels than other group patients. At the end of the follow-up, 31 patients had died. Kaplan-Meier analysis showed that the high BCL group patients had a higher mortality than other group patients (log-rank test, P = 0.036). Cox multivariate analysis demonstrated that logarithmic BCL was associated with increased hazard ratios (HR) for the all-cause mortality (HR = 2.336, 95% confidence intervals [CI] = 1.099-4.964, P = 0.027) in diabetic MHD patients. Similarly, if the low BCL group was the reference, the high BCL was associated with increased HR for all-cause mortality (HR = 2.865, 95% CI = 1.117-7.353, P = 0.043) in these patients.

CONCLUSIONS

The study results first demonstrated that BCL is associated with increased HR for 18-month all-cause mortality in diabetic MHD patients. Avoiding smoking and high cadmium-containing food may be important in these patients.

Blood lead levels association with 18-month all-cause mortality in patients with chronic peritoneal dialysis

BACKGROUND

The clinical significance of blood lead levels (BLLs) in chronic peritoneal dialysis (CPD) patients was undetermined prior to this study.

METHODS

A total of 315 patients on CPD were included in this 18-month prospective study. BLLs measured at baseline were categorized according to a BLL tertile of high (>8.66 microg/dL), middle (5.62-8.66 microg/dL) and low (<5.62 microg/dL) for cross-sectional analyses. Mortality and cause of death were recorded for longitudinal analyses.

RESULTS

At baseline, patients with high BLLs had a trend of higher parathyroid hormone and lower residual renal function than patients in other groups. Stepwise multiple regression analysis found that parathyroid hormone positively correlated and residual renal function negatively correlated with logarithmic-transformed BLLs in CPD patients after other confounders were adjusted. At the end of follow-up, 37 (11.7%) patients had died. Kaplan-Meier analysis showed that patients with high BLLs had greater mortality than those with middle and low BLLs (P = 0.008). Cox multivariate analysis showed that, using the low BLL group as the reference, basal high BLLs (hazard ratio [HR] = 3.745, 95% confidence interval [95% CI] = 1.218-11.494, P = 0.001) and middle BLLs (HR = 1.867, 95% CI = 1.618-2.567, P = 0.001) were associated with increased HR for all-cause mortality for CPD patients. There is a significant trend (P < 0.001) of HR for mortality trend tests among the three study groups.

CONCLUSIONS

BLLs are associated with residual renal function and hyperparathyroidism and are related to increased HR for all-cause 18-month mortality in CPD patients.

Protective effect of N-acetylcysteine on experimental chronic lead nephrotoxicity in immature female rats

Oxidative stress plays a key role in lead (Pb)-induced nephrotoxicity. N-acetylcysteine (NAC) is a potent oxygen free radicals scavenger and a metal chelator. In the present study, female Sprague-Dawley rats received PbAc2 (300 mg/L, via drinking water) and/or NAC (100 mg/kg/day, by intraperitoneal injection) to investigate the protective effect of NAC on Pb-induced renal damage and oxidative stress as well as its mechanism of action. Renal toxicity was evaluated by measuring urinary excretion of total protein, β2-microglobulin, albumin and urinary enzyme markers of tubular necrosis, as well as serum urea nitrogen level. Activities of antioxidant enzymes, contents of glutathione and malondialdehyde in kidney were also measured. Renal cell damage was assessed by electron microscopy. Animals that received both Pb and NAC showed a better renal function than those receiving Pb alone. Lead-induced tubular lesions and mitochondrial damage were markedly reduced in rats that also received NAC. Also, NAC significantly reduced the levels of lipid peroxidation and markedly restored the enzymic and non-enzymatic antioxidants levels in kidney of Pb-treated rats. Moreover, NAC administration significantly increased urinary Pb excretion and decreased its level in the serum and kidney. In conclusion, NAC treatment prevents renal tubular damage induced by chronic Pb administration, most probably through its antioxidant properties and chelating ability.

Type 2 diabetes in Belgians of Turkish and Moroccan origin

Objectives

To compare the prevalence of type 2 diabetes in adults aged 35 to 74 years of the Turkish and Moroccan communities in Belgium with the prevalence in native Belgians. To examine the determinants and specific mechanisms responsible for differences in diabetes between these communities.

Method

Both objectives were examined using the Health Interview Surveys of 1997, 2001 and 2004. Stepwise logistic regression analyses were performed with diabetes as the outcome variable. The variables 'age', 'sex', 'ethnic origin', 'body mass index', 'lack of physical activity', 'educational attainment' and 'income' were introduced in the model in consecutive steps.

Results

In 35- to 74-year-olds, the prevalence of type 2 diabetes is higher in Belgians of Tur-kish and Moroccan origin than in native Belgians. In native Belgian men, the prevalence amounts to 5.0%. In 35- to 74-year-old men of Turkish and Moroccan origin, the diabetes prevalence is 5.8% and 6.5% respectively. 4.3%, 18.7% and 11.9% of the women of Belgian, Turkish and Moroccan origin respectively suffer from diabetes. In men, differences in the prevalence of diabetes are strongly reduced after controlling for lack of physical activity and educational attainment. In women, differences remain high, although they become smaller after accounting for BMI and educational attainment.

Conclusions

In men, the differences in diabetes prevalence are explained by lifestyle factors and educational attainment. In women, the community differences in diabetes prevalence persist, although lifestyle factors and educational attainment play an important part in understanding these differences.

Cross-sectional audit of blood lead levels in regular outpatient haemodialysis patients dialysing in north London

AIM

Blood lead was measured and found to be high in one haemodialysis patient with atypical abdominal pain and peripheral neuropathy. This prompted an audit of blood lead concentrations in prevalent haemodialysis patients under the care of a University Teaching hospital.

METHODS

Blood lead was determined in 271 prevalent adult haemodialysis patients regularly dialysing three times a week, in five dialysis centres and/or on the home dialysis programme. All samples were carefully collected into lead-free plastic containers, and measured by graphite furnace atomic absorption spectrometry.

RESULTS

25.5% of haemodialysis patients had abnormal blood lead concentrations (>200 microg/L), compared with 59% with high-normal values of 100-200 microg/L, and only 15.5% with normal values (<100 microg/L). Blood lead increased with haemodialysis vintage (r = 0.38, P < 0.001), the use of a single carbon filter and reverse osmosis water purification device unit (r = 0.29, P < 0.001), but reduced by urine output (r = -0.44, P < 0.001).

CONCLUSION

Despite UK government legislation to reduce permissible lead contamination of drinking water, blood lead was increased in 84.5% of prevalent haemodialysis patients. Single reverse osmosis machines and carbon filters may not be as effective at filtering out possible lead contamination compared with large industrial reverse osmosis devices and carbon filters, and thus blood lead testing should be considered for home haemodialysis patients, particularly in those areas where monochloramines are used to sterilize domestic water supplies.

Selenium, lead, and cadmium levels in renal failure patients in China

Whole blood and serum samples of Chinese stable chronic renal failure (CRF) patients (n = 81), hemodialysis patients (n = 135), posttransplant patients (n = 60), and subjects with normal renal function (NRF; N = 42) were collected, as well as water and dialysate samples from five dialysis centers. The concentration of selenium (Se), lead (Pb), and cadmium (Cd) was measured by atomic absorption spectrometry. The mean serum Se levels in patients with different degrees of renal failure were significantly lower than those of subjects with NRF (p < 0.01). Pb levels were not increased in renal failure patients, while the Cd levels in patients with various degrees of renal failure were higher than in subjects with NRF (p < 0.05). After correcting the results of Pb and Cd for hematocrit (Hct) however, Pb levels of dialysis patients were also increased. In the dialysis population under study, blood Pb and Cd levels were closely related to the time on dialysis, while contamination of the final dialysate may also contribute to the increased blood Cd and to a less extent Pb levels. Correction for Hct may be recommended to accurately compare blood Pb and Cd levels in dialysis patients and CRF patients with varying degrees of anemia to those of subjects with NRF.

Association of blood lead concentrations with mortality in older women: a prospective cohort study

BACKGROUND

Blood lead concentrations have been associated with increased risk of cardiovascular, cancer, and all-cause mortality in adults in general population and occupational cohorts. We aimed to determine the association between blood lead, all cause and cause specific mortality in elderly, community residing women.

METHODS

Prospective cohort study of 533 women aged 65-87 years enrolled in the Study of Osteoporotic Fractures at 2 US research centers (Baltimore, MD; Monongahela Valley, PA) from 1986-1988. Blood lead concentrations were determined by atomic absorption spectrometry. Using blood lead concentration categorized as < 8 microg/dL (0.384 micromol/L), and > or = 8 microg/dL (0.384 micromol/L), we determined the relative risk of mortality from all cause, and cause-specific mortality, through Cox proportional hazards regression analysis.

RESULTS

Mean blood lead concentration was 5.3 +/- 2.3 microg/dL (range 1-21) [0.25 +/- 0.11 micromol/L (range 0.05-1.008)]. After 12.0 +/- 3 years of > 95% complete follow-up, 123 (23%) women who died had slightly higher mean (+/- SD) blood lead 5.56 (+/- 3) microg/dL [0.27(+/- 0.14) micromol/L] than survivors: 5.17(+/- 2.0) [0.25(+/- 0.1) micromol/L] (p = 0.09). Women with blood lead concentrations > or = 8 microg/dL (0.384 micromol/L), had 59% increased risk of multivariate adjusted all cause mortality (Hazard Ratio [HR], 1.59; 95% confidence interval [CI], 1.02-2.49) (p = 0.041) especially coronary heart disease (CHD) mortality (HR = 3.08 [CI], (1.23-7.70)(p = 0.016), compared to women with blood lead concentrations < 8 microg/dL(< 0.384 mumol/L). There was no association of blood lead with stroke, cancer, or non cardiovascular deaths.

CONCLUSION

Women with blood lead concentrations of > or = 8 microg/dL (0.384 micromol/L), experienced increased mortality, in particular from CHD as compared to those with lower blood lead concentrations.