Transplant Clinician Opinions on Use of Race in the Estimation of Glomerular Filtration Rate.

BACKGROUND AND OBJECTIVES: Current race-based eGFR calculators assign a higher eGFR value to Black patients, which could affect the care of kidney transplant candidates and potential living donors. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted a survey of staff at adult kidney transplant centers in the United States (December 17, 2020 to February 28, 2021) to assess opinions on use of race-based eGFR equations for waitlisting and living donor candidate evaluation, availability of serum cystatin C testing and measured GFR, and related practices. RESULTS: Respondents represented 57% (124 of 218) of adult kidney transplant programs, and the responding centers conducted 70% of recent kidney transplant volume. Most (93%) programs use serum creatinine-based eGFR for listing candidates. However, only 6% of respondents felt that current race-based eGFR calculators are appropriate, with desire for change grounded in concerns for promotion of health care disparities by current equations and inaccuracies in reporting of race. Most respondents (70%) believed that elimination of race would allow more preemptive waitlisting for Black patients, but a majority (79%) also raised concerns that such an approach could incur harms. More than one third of the responding programs lacked or were unsure of availability of testing for cystatin C or measured GFR. At this time, 40% of represented centers did not plan to remove race from eGFR calculators, 46% were planning to remove, and 15% had already done so. There was substantial variability in eGFR reporting and listing of multiracial patients with some Black ancestry. There was no difference in GFR acceptance thresholds for Black versus non-Black living donors. CONCLUSIONS: This national survey highlights a broad consensus that extant approaches to GFR estimation are unsatisfactory, but it also identified a range of current opinions.

Reassessing the Inclusion of Race in Diagnosing Kidney Diseases: An Interim Report from the NKF-ASN Task Force.

For almost two decades, equations that use serum creatinine, age, sex, and race to eGFR have included "race" as Black or non-Black. Given considerable evidence of disparities in health and healthcare delivery in African American communities, some regard keeping a race term in GFR equations as a practice that differentially influences access to care and kidney transplantation. Others assert that race captures important non GFR determinants of serum creatinine and its removal from the calculation may perpetuate other disparities. The National Kidney Foundation (NKF) and American Society of Nephrology (ASN) established a task force in 2020 to reassess the inclusion of race in the estimation of GFR in the United States and its implications for diagnosis and subsequent management of patients with, or at risk for, kidney diseases. This interim report details the process, initial assessment of evidence, and values defined regarding the use of race to estimate GFR. We organized activities in phases: (1) clarify the problem and examine evidence, (2) evaluate different approaches to address use of race in GFR estimation, and (3) make recommendations. In phase one, we constructed statements about the evidence and defined values regarding equity and disparities; race and racism; GFR measurement, estimation, and equation performance; laboratory standardization; and patient perspectives. We also identified several approaches to estimate GFR and a set of attributes to evaluate these approaches. Building on evidence and values, the attributes of alternative approaches to estimate GFR will be evaluated in the next phases and recommendations will be made.

Association of APOL1 Genotypes With Measures of Microvascular and Endothelial Function, and Blood Pressure in MESA.

Background APOL1 high-risk genotypes are associated with increased risk for hypertension-attributed kidney disease among Black adults in the United States. Biopsy studies show differences in kidney vasculature by APOL1 status; less is known about the variants' associations with systemic vascular and endothelial function. Whether APOL1 risk variants are associated with blood pressure (BP) is also uncertain. Methods and Results Using linear regression, we examined cross-sectional associations of APOL1 risk genotypes (high=2 risk alleles, low=0 or 1 risk allele) with subclinical measures of vascular function (small arterial elasticity, n=1586; large arterial elasticity, n=1586; ascending aortic distensibility, n=985) and endothelial function (flow-mediated dilation, n=777). Using linear mixed-effects models, we studied longitudinal associations of APOL1 risk genotypes with BP (n=1619), adjusting for age, sex, and African ancestry. Among 1619 (12% APOL1 high-risk) Black participants in MESA (Multi-Ethnic Study of Atherosclerosis), mean age was 62 years old, 58% had hypertension, and mean systolic BP was 131 mm Hg at baseline. At examination 1 (2000-2002), there was no significant difference in small arterial elasticity, large arterial elasticity, ascending aortic distensibility, or flow-mediated dilation in participants with APOL1 high- versus low-risk genotypes (P>0.05 for all). Over a mean follow-up of 7.8 years, relative annual changes in systolic and diastolic BP and pulse pressure did not differ significantly by APOL1 risk status (between-group differences of -0.20, -0.14, and -0.25, respectively; P>0.05 for all). Conclusions Among Black participants in MESA, APOL1 high-risk genotypes were not associated with subclinical vascular and endothelial function or BP trajectories. The relationship of APOL1 with kidney disease may be intrinsic to the kidney rather than through peripheral effects on systemic vasculature or BP.

Kidney Disease, Race, and GFR Estimation.

Assessment of GFR is central to clinical practice, research, and public health. Current Kidney Disease Improving Global Outcomes guidelines recommend measurement of serum creatinine to estimate GFR as the initial step in GFR evaluation. Serum creatinine is influenced by creatinine metabolism as well as GFR; hence, all equations to estimate GFR from serum creatinine include surrogates for muscle mass, such as age, sex, race, height, or weight. The guideline-recommended equation in adults (the 2009 Chronic Kidney Disease Epidemiology Collaboration creatinine equation) includes a term for race (specified as black versus nonblack), which improves the accuracy of GFR estimation by accounting for differences in non-GFR determinants of serum creatinine by race in the study populations used to develop the equation. In that study, blacks had a 16% higher average measured GFR compared with nonblacks with the same age, sex, and serum creatinine. The reasons for this difference are only partly understood, and the use of race in GFR estimation has limitations. Some have proposed eliminating the race coefficient, but this would induce a systematic underestimation of measured GFR in blacks, with potential unintended consequences at the individual and population levels. We propose a more cautious approach that maintains and improves accuracy of GFR estimates and avoids disadvantaging any racial group. We suggest full disclosure of use of race in GFR estimation, accommodation of those who decline to identify their race, and shared decision making between health care providers and patients. We also suggest mindful use of cystatin C as a confirmatory test as well as clearance measurements. It would be preferable to avoid specification of race in GFR estimation if there was a superior, evidence-based substitute. The goal of future research should be to develop more accurate methods for GFR estimation that do not require use of race or other demographic characteristics.

Spectrum of glomerular diseases in Arab countries: A systematic review.

According to the best of our knowledge, there is no review compiling incidence of glomerular disease in all Arab countries. Most of the Arab countries do not have a national renal biopsy registry. In addition, there is scanty data available on the epidemiology of glomerular diseases in Arab countries. In this review, we performed a systematic review analyzing the incidence of glomerular disease in all Arab countries. Relevant manuscripts in all 22 Arab countries found through searches of Medline, Science Direct, Embase, and Google Scholar were evaluated. The time was from January 1990 to March 2018. A total of 36 manuscripts containing 10,727 biopsies from 11 countries were analyzed. The male-to-female ratio was 1.2:1. Saudi Arabia had the largest number of published studies with 14 papers followed equally by Iraq, Jordan, and Sudan with three papers each. The average period of study was 8.17 years. Retrospective studies represented 86.11%. Focal and segmental glomerulosclerosis (FSGS) (27%), minimal change disease (14%), membranoproliferative glomerulonephritis (13%), mesangioproliferative glomerulonephritis (13%), and membranous glomerulopathy (11%) were the main types of primary glomerular diseases. The most common types of secondary glomerular diseases were lupus nephritis (LN) (58%), amyloidosis (10.19%), diabetic nephropathy (9.89%), hypertension (4.84%) and poststreptococcal glomerulonephritis (2.72%). In conclusion, FSGS and LN are the most common types of primary and secondary glomerular diseases, respectively, in all evaluated Arab countries. The trend of all types of glomerular diseases has not changed in the last three decades. We strongly recommend that each Arab country should have its own renal biopsy registry.

Chronic Environmental and Occupational Lead Exposure and Kidney Function among African Americans: Dallas Lead Project II.

Background: We examined the effects of lead on kidney function in occupationally and environmentally exposed adults from a Dallas lead smelter community that was the site of an Environmental Protection Agency (EPA) Superfund clean-up. All subjects were African Americans-a racial group that bears a disproportionate burden of kidney disease. Methods: A two-phase health screening was conducted. Phase II included a physical examination and laboratory tests. Study subjects were African Americans residents, aged ≥19 years to ≤89 years. Of 778 subjects, 726 were environmentally exposed and 52 were both occupationally and environmentally exposed. The effects of lead exposure on estimated glomerular filtration rate (eGFR) were examined in three groups: male and female smelter-community residents, as well as males with both occupational and environmental exposure. Multiple linear regression was used to analyze the dependence of eGFR on log (blood lead level), duration of residence in the community, type 2 diabetes, and hypertension. Results: There was a statistically significant negative effect on kidney function for all three groups. Comparison of female and male residents showed a slightly larger negative effect of blood lead level on eGFR in females versus males, with the largest effect seen in male smelter-working residents. For each unit increase (log10 10µg/dL = 1) in blood lead level, age-adjusted eGFR was reduced 21.2 mL/min/1.73 m² in male residents, 25.3 mL/min/1.73 m² in female residents and 59.2 mL/min/1.73 m² in male smelter-working residents. Conclusions: Chronic lead exposure is associated with worsening kidney function in both African American male and female residents, as well as male workers in Dallas smelter communities. This effect is slightly, but not statistically significantly, worse in female residents than male residents, and significantly worse in males that both worked and resided in the smelter community.

Racial Differences in Cause-Specific Mortality Between Community-Dwelling Older Black and White Adults.

OBJECTIVES: To understand which causes of death are higher in black than white community-dwelling older adults and determine whether differences in baseline risk factors explain racial differences in mortality. DESIGN: Longitudinal cohort study (Health, Aging, and Body Composition Study). SETTING: Pittsburgh, Pennsylvania; and Memphis, Tennessee. PARTICIPANTS: Black and white men and women aged 70 to 79 during recruitment (N=3,075; 48% men, 42% black) followed for a median of 13 years. MEASUREMENTS: A committee of physicians adjudicated cause of death, which was categorized as cardiovascular disease (CVD), stroke, cancer, dementia, pulmonary, infection, kidney, or other causes. Using competing risks regression, we examined whether known risk factors at baseline (demographic characteristics, smoking, body mass index, chronic diseases, physical function, cognition) could explain racial differences in cause-specific mortality risk. RESULTS: During follow-up, 1,991 (65%) participants died. Black participants died at higher rates from cancer (hazard ratio (HR)=1.36, 95% confidence interval (CI)=1.14-1.63), kidney disease (HR=2.09, 95% CI=1.16-3.74), stroke (HR=1.31, 95% CI=0.98-1.76); and CVD (HR=1.16, 95% CI=0.98-1.37). Poorer physical and cognitive performance at baseline among black participants explained most of the racial difference in risks of dying from kidney disease, stroke, and CVD but not cancer. When examining types of cancer deaths, black participants died at higher rates from multiple myeloma, pancreatic cancer, and prostate cancer, which baseline risk factors did not explain either. CONCLUSION: Factors contributing to poorer physical and cognitive performance in similarly aged black men and women could be targets to reduce excess mortality from CVD, stroke, and kidney disease. More work is needed to identify factors contributing to cancer mortality disparities.

Black-White Difference in the Impact of Long-Term Blood Pressure From Childhood on Adult Renal Function: The Bogalusa Heart Study.

BACKGROUND: To examine racial difference in the impact of long-term burden of blood pressure (BP) from childhood on adult renal function between middle-aged blacks and whites. METHODS: The study cohort consisted of 1,646 whites and 866 blacks aged 20-51 years at follow-up who had BP measured at least 4 times since childhood, with a mean follow-up period of 25.3 years. The area under the curve (AUC) was calculated as a measure of long-term burden of BP from childhood to adulthood. Estimated glomerular filtration rate (eGFR) was calculated based on serum creatinine to assess renal function in adulthood. RESULTS: Black vs. white adults had significantly higher values of eGFR and long-term burden of systolic BP for both males and females. In multivariable linear regression analyses, adjusting for sex, adult age, body mass index, smoking, and alcohol use, adult eGFR was significantly and negatively associated with adult systolic BP (standardized regression coefficient [ß] = -0.10, P = 0.005) and diastolic BP (ß = -0.11, P = 0.003) in blacks, but not in whites. The total BP AUC values were also significantly and negatively associated with adult eGFR (ß = -0.10, P = 0.005 for systolic BP and ß = -0.09, P = 0.013 for diastolic BP) in blacks only. Childhood BP was not significantly associated with adult eGFR in blacks and whites. CONCLUSIONS: These findings suggest that black-white disparities in the influence of elevated BP on the development of renal dysfunction occur in middle adulthood, which underscores the importance of BP control in the black population.

Race, contrast-induced nephropathy and long-term outcomes after coronary and peripheral angiography and intervention.

BACKGROUND: Contrast-induced nephropathy (CIN) is a complication of diagnostic angiography and percutaneous coronary and endovascular intervention. We investigated the effect of race on the development of CIN. METHODS: We studied 4070 predominantly male patients undergoing peripheral and coronary angiography and percutaneous coronary and endovascular intervention. We analyzed the incidence of CIN at 72 h, of renal dysfunction at 3 months as well as the long-term incidence of hemodialysis and of death. RESULTS: The mean age was 67.2 years. CIN occurred in 92 (7.1%) Caucasian patients and in 42 (6.6%) non-Caucasians at 72 h after the procedure (odds ratio [OR] 1.08, 95% confidence interval [CI] 0.74-1.57; P = 0.69). At 3 months, renal dysfunction was seen in 231 (11.24%) Caucasian patients versus 121 (11.52%) of the non-Caucasian group (OR 0.97, CI 0.77-1.23; P = 0.81). After a follow-up of 5 years, of the 4070 patients, 17 patients (0.64%) of the Caucasian group were placed on dialysis versus 27 (1.88%) of the non-Caucasian group (OR 0.34, 0.18-0.62; P = 0.0004) and 535 (20.28%) of the Caucasian patients had died compared to 293 (20.44%) of the non-Caucasian group (OR = 0.99, 95% CI 0.85-1.17; P = 0.94). CONCLUSIONS: In this cohort of patients, race was not associated with the development of CIN at 72 h, or the development of renal dysfunction at 3 months post angiography or intervention. In the long-term, the rate of initiation of dialysis was significantly lower in the Caucasian patients but mortality was not.

The references level of cadmium intake for renal dysfunction in a Chinese population.

Recent several studies indicated that a more restrictive dietary intake guideline for cadmium should be made for sufficient health protection. In the present study, we showed the references level of food cadmium intake (FCd) and total cadmium intake (TCd) for renal dysfunction by using benchmark dose (BMD) approach. 342 subjects living in a control and a cadmium polluted area were included in this study. The FCd, TCd and cadmium in urine (UCd) and blood (BCd) were calculated or determined. Urinary ß2Microglobulin (UBMG) was determined as indicator of renal function. The median FCd, TCd, UCd and BCd were 1.4 g, 1.4 g, 3.1 µg/g creatinine(cr) and 1.3 µg/L in control and 3.3 g, 3.6 g, 13.5 µg/g cr and 12.1 µg/L in polluted area. The 95% lower confidence bounds of BMD (BMDLs) of FCd for renal dysfunction were 1.36-1.55 g (BMR = 10%) and 0.88-1.11 g (BMR = 5%). The BMDLs of TCd were 1.29-1.46 g (BMR = 10%) and 0.73-0.95 g (BMR = 5%). FCd and TCd are valuable markers for the predication of renal dysfunction induced by cadmium. The BMDLs of FCd were close to previous report in Japan and the BMDLs of TCd were lower than the critical standard previously reported, in particular at BMR of 5% which can be interpreted as representing the influence of smoking.

Tailored Predictive Formulas for Glomerular Filtration Rate for Early Detection of Deteriorating Renal Function After Pediatric Living-Donor Liver Transplant.

OBJECTIVES: In pediatric patients, renal dysfunction after living-donor liver transplant is a major issue that is difficult to evaluate. Recently, predictive equations for Japanese children have been introduced. MATERIALS AND METHODS: We conducted a retrospective study by prospectively collecting data on 26 patients under 16 years old who underwent living-donor liver transplant between June 2004 and March 2015. Serum creatinine and cystatin C levels were measured. Paired t tests and Bland-Altman plots were used to compare the following formulas for estimated glomerular filtration rate: the Schwartz formula and 3 formulas that were matched with Japanese children (polynomial, simple, and cystatin C formulas). RESULTS: Average estimated glomerular filtrations rates (in mL/min/1.73 m2) were 143.46, 122.90, 121.58, and 123.31 using the Schwartz, polynomial, simple, and cystatin C formulas, respectively. The estimated glomerular filtrations rate for biliary atresia was 141.53 ± 31.37 versus 109.95 ± 19.52 for other diseases, with significant differences only noted with the cystatin C formula. The formulas tailored for Japanese children showed significantly lower estimated glomerular filtrations rates than those obtained using the Schwartz formula (P < .01). CONCLUSIONS: The use of formulas for measuring estimated glomerular filtrations rates that are based on race may allow early detection of deteriorating renal function.

High Baseline Levels of Tumor Necrosis Factor Receptor 1 Are Associated With Progression of Kidney Disease in Indigenous Australians With Diabetes: The eGFR Follow-up Study.

OBJECTIVE: To examine the association between soluble tumor necrosis factor receptor 1 (sTNFR1) levels and kidney disease progression in Indigenous Australians at high risk of kidney disease. RESEARCH DESIGN AND METHODS: This longitudinal observational study examined participants aged ≥18 years recruited from >20 sites across diabetes and/or kidney function strata. Baseline measures included sTNFR1, serum creatinine, urine albumin-to-creatinine ratio (uACR), HbA1c, C-reactive protein (CRP), waist-to-hip ratio, systolic blood pressure, and medical history. Linear regression was used to estimate annual change in estimated glomerular filtration rate (eGFR) for increasing sTNFR1, and Cox proportional hazards were used to estimate the hazard ratio (HR) and 95% CI for developing a combined renal outcome (first of a ≥30% decline in eGFR with a follow-up eGFR <60 mL/min/1.73 m2, progression to renal replacement therapy, or renal death) for increasing sTNFR1. RESULTS: Over a median of 3 years, participants with diabetes (n = 194) in the highest compared with the lowest quartile of sTNFR1 experienced significantly greater eGFR decline (-4.22 mL/min/1.73 m2/year [95% CI -7.06 to -1.38]; P = 0.004), independent of baseline age, sex, eGFR, and uACR. The adjusted HR (95% CI) for participants with diabetes per doubling of sTNFR1 for the combined renal outcome (n = 32) was 3.8 (1.1-12.8; P = 0.03). No association between sTNFR1 and either renal outcome was observed for those without diabetes (n = 259). CONCLUSIONS: sTNFR1 is associated with greater kidney disease progression independent of albuminuria and eGFR in Indigenous Australians with diabetes. Further research is required to assess whether TNFR1 operates independently of other metabolic factors associated with kidney disease progression.

A comparison of TAFRO syndrome between Japanese and non-Japanese cases: a case report and literature review.

TAFRO syndrome was first described as a variant of multicentric Castleman's disease with thrombocytopenia, anasarca, fever, renal dysfunction, and organomegaly. We report the case of a 25-year-old Caucasian male with diagnosis of TAFRO syndrome and present a literature review. The objective of the study was to compare TAFRO syndrome between Japanese and non-Japanese patients. Cases were included by searching the term "TAFRO" in the Medline database using PubMed between 2010 and 2016. The Student t test and Mann-Whitney U test were used to compare continuous variables. Fisher's exact test was used for categorical variables. Statistical significance was set at p < 0.05. Forty-four cases were included. Thirty-two patients (73%) were of Japanese origin. Japanese patients were significantly older than non-Japanese ones (52.0 ± 13.6 years versus 36.9 ± 19.8 years, p = 0.0064) but there was no difference in gender. Creatinine level on admission was significantly higher in the non-Japanese group (1.87 ± 0.84 mg/dL versus 1.32 ± 0.57 mg/dL, p = 0.0347). There were no significant differences concerning lymphadenopathy, elevated number of megakaryocytes on bone marrow aspiration, autoimmune abnormalities, and the following parameters on admission: platelet count, hemoglobin, albumin, alkaline phosphatase (ALP). Corticotherapy was always used on induction for Japanese patients while it was only used in 75% of the cases on induction in non-Japanese patients (p = 0.0166). Our study was the first to compare TAFRO syndrome according to ethnicity. Japanese patients were significantly older and had a significantly lower creatinine level on admission than non-Japanese patients.

Racial disparities after infrainguinal bypass surgery in hemodialysis patients.

BACKGROUND: Peripheral arterial disease poses a significant burden in the hemodialysis (HD)-dependent population. Race is a known modifier of outcomes after surgical treatment of peripheral arterial disease. A comprehensive evaluation of the effect of race on infrainguinal bypass surgery (IBS) outcomes in HD patients is lacking. In this study, we evaluated the effects of race on long-term IBS outcomes in a large, nationally representative cohort of HD patients. METHODS: We studied all HD patients who underwent IBS between January 2007 and December 2011 in the United States Renal Disease System-Medicare matched database. Univariate methods were used to compare patients' demographic and medical characteristics. Kaplan-Meier, univariate and multivariable logistic, and Cox regression analyses were used to evaluate long-term graft patency, limb salvage, and mortality. RESULTS: There were 9305 IBSs performed in 5188 white (56%), 3354 black (36%), and 763 Hispanic (8%) patients. Of these, 4531 (49%) were femoral-popliteal, 3173 (34%) were femoral-tibial, and 1601 (17%) were popliteal-tibial bypasses. Comparing whites vs blacks vs Hispanics, acute graft failure was 14% vs 16% vs 15% (P = .03), with no statistical difference on multivariate analyses. Primary patency was 52% vs 45% vs 48% at 1 year and 24% vs 21% vs 26% at 4 years (P < .001). Primary assisted patency was 56% vs 48% vs 53% at 1 year and 29% vs 25% vs 32% at 4 years (P < .001); secondary patency was 65% vs 56% vs 60% at 1 year and 40% vs 33% vs 40% at 4 years (P < .001). Limb salvage was 68% vs 60% vs 62% at 1 year and 45% vs 42% vs 40% at 4 years (P < .001). Black patients had higher long-term graft failure (adjusted hazard ratio [aHR], 1.14; 95% confidence interval [CI], 1.05-1.24; P = .001) and limb loss (aHR, 1.27; 95% CI, 1.15-1.40; P < .001) compared with white patients. No differences in graft failure (aHR, 0.99; 95% CI, 0.89-1.11; P = .89) and limb loss (aHR, 1.08; 95% CI, 0.94-1.23; P = .28) were found in Hispanics vs whites. All-cause mortality was lower among blacks (aHR, 0.65; 95% CI, 0.60-0.71; P < .001) and Hispanics (aHR, 0.67; 95% CI, 0.59-0.75; P < .001) compared with whites. CONCLUSIONS: This large study confirms the presence of multidirectional racial disparities in graft durability, limb salvage, and mortality after IBS in HD patients. Black patients had lower graft patency and higher limb loss than white and Hispanic patients, whereas perioperative and long-term mortality was higher in white patients. These results should inform further granular root cause analyses and subsequent action to eliminate these disparities.

The pathological spectrum associated with the ultrastructural finding of thin glomerular basement membrane: A tertiary medical city experience and review of the literature.

BACKGROUND: Thin glomerular basement membrane (GBM) has been noted in several glomerular diseases including IgA nephropathy, focal segmental glomerulosclerosis (FSGS), Fabry's disease, and Alport's syndrome. We conducted this study to investigate the pathological ultrastructural spectrum of thin GBMs, to identify associated diseases, and to measure the GBM thickness in thin GBMs in our adult population. MATERIALS AND METHODS: All renal biopsies with thin GBM, diagnosed between 2010 and 2016, were retrieved and reviewed. RESULTS: Of 24 cases, 50.0% were diagnosed with FSGS, 12.5% with IgA nephropathy, 8.3% with tubulointerstitial nephritis, 4.2% with acute thrombotic microangiopathy, 4.2% with focal global sclerosis, 4.2% with lupus nephritis, and 16.7% with only thin GBM disease. Mean GBM thickness was 213.4 ± 24.7 nm. Mean interstitial fibrosis/tubular atrophy percentage (IF/TA) was 27.9 ± 22.2%. There was no significant correlation between GBM thickness and patients' age or IF/TA percentage. CONCLUSION: The association of thin GBM with FSGS and IgA nephropathy is high. Morphometric analysis of the GBM thickness should be made routine, noting that ethnic variations in the GBM thickness are reported. Cases of thin GBM should be reported to facilitate proper diagnosis and institute the most appropriate treatment.

[Long-term effect of environmental cadmium exposure on human body's mineral metabolic balance].

OBJECTIVE: To investigate the effect of long-term exposure to environmental cadmium on eight mineral element's metabolic balance of human body. METHODS: To choose a high cadmium area polluted by smelting and mining north of Guangdong province and a cadmium-free area with a similar economic level, and living and eating habit of residents as a contrast from April 2011 to August 2012. Stratified random sampling and clustered sampling method were adopted to choose the non-occupationally cadmium-exposed respondents who have lived in local area for more than 15 years, older than 40 years, having local rice and vegetable as the main dietary source, with simple and relatively stable diet, and without diabetes, kidney disease, thyroid disease, liver disease or other history of chronic disease. This study included 298 respondents, of whom 155 were in cadmium exposure group and 143 in control group. Questionnaires was used to acquire their health status and their morning urine samples were collected. Electrolytically coupled plasma mass spectrometry (ICP-MS) was used to test the concentrations of sodium(Na), magnesium (Mg), phosphorus (P), potassium (K), calcium (Ca), copper (Cu), zinc (Zn) and iodine (I). The Mann-Whitney U test method was used to compare the differences of concentrations of urinary cadmium, Na, Mg, P, K, Ca, Cu, Zn, I, and the ratio of Na to K (Na/K), Ca to P (Ca/P) between exposed group and control group.χ(2) test was used to compare the abnormal rate of urinary cadmium between exposed group and control group. Pearson correlation and multiple regression method were used to investigate the relationship between urinary cadmium levels, gender, age, smoking, passive smoking, and minerals. RESULTS: The urinary cadmium level P50 (P25-P75) in exposed group was 5.45 (2.62-10.68) µg/g·cr, which was higher than that of the control group, which was 1.69 (1.22-2.36) µg/g·cr (Z=-10.49,P<0.001). The abnormal rate of urinary cadmium was 51.6% (80/155), which was higher than that of the control group (2.8 %(4/143)) (χ(2)= 87.56, P<0.001). The urinary Ca, Cu, Zn, and I level P50 (P25-P75) of exposed group were 173.80 (114.40-251.70), 20.55 (14.95-28.44), 520.23 (390.25-647.15), and 246.94 (203.65-342.97) µg/g·cr, which were higher than those in control group (142.42 (96.87-179.11), 15.44 (12.26-20.98), 430.09 (309.85-568.78) and 213.85 (156.70-281.63) µg/g·cr, respectively) (Z values were-4.33,-5.04,-3.47 and-4.24, all P values <0.001). The urinary P, K level P50 (P25-P75) of exposed group were 582.50 (463.20-742.8), 890.10(666.00-1 305.40) µg/g·cr, which were lower than control group (694.50 (546.20-851.17), 1 098.58(904.53-1 479.18) µg/g·cr) (Z values were-3.36,-4.02, all P values <0.001). on Based the results of Pearson correlation analysis, urinary cadmium was positively correlated with urinary Ca, Cu, Zn, and I, and the correlation coefficients were 0.31, 0.61, 0.38, and 0.25, respectively (all P values <0.05). Based on the results of multiple regression analysis, urinary cadmium levels contributed most to the metabolic balance of urinary Ca, Cu, Zn and I. The standardized regression coefficients were 0.31, 0.59, 0.39, and 0.24, respectively (all P values<0.001). CONCLUSION: Long-term environmental exposure to cadmium affected the metabolic balance of Ca, Cu, Zn and I in human body.

Estimating glomerular filtration rate by serum creatinine or/and cystatin C equations: An analysis of multi-centre Chinese subjects.

AIM: Various equations based on serum creatinine or/and cystatin C, required further validation in a Chinese population. We compared the performance of six Chinese equations (Mascr, Peiscr, Macys, Fengcys, Mascr-cys and Fengscr-cys) with the CKD-EPI equations in multi-centre Chinese subjects and evaluated their applicability in clinical practice. METHODS: A total of 1522 adult patients from four different hospitals of China were enrolled in the study. (99m) Tc-DTPA renal dynamic imaging was used as the reference GFR (rGFR), and serum creatinine and cystatin C were measured by standardized assays. An optimal score system was implemented in the study. RESULTS: The average rGFR of recruited subjects was 67.30±28.89 mL/min per 1.73m(2) . All estimated GFR (eGFR) correlated well with rGFR. In accordance with Bland-Altman analysis, the Fengscr-cys equations achieved optimal overall performance (score 14 vs 0-6), with least bias (median difference, -0.57 mL/min per 1.73m(2) ; median absolute difference, 8.83 mL/min per 1.73m(2) ), best precision (17.99 mL/min per 1.73m(2) ), highest accuracy (percentage of eGFR within 15%, 30% and 50% of the rGFR (P15 , P30 and P50 ; 49.7%, 78.7% and 91.8%, respectively); root-mean-square-error (RMSE, 16.28)). The Fengcys equation, a typical cystatin C based equation, was another well-behaved formula with an impressive performance. The Ma equations performed much poorer than the CKD-EPI equations. Consistent results can be observed in the GFR- /age- and sex-specific subgroups, while none equation yielded ideal accuracy in GFR<60 mL/min per 1.73 m(2) subgroup. CONCLUSION: The Fengscr-cys equation appeared to achieve the best performance for GFR estimation in overall Chinese adult patients. However, further research is warranted to improve the accuracy of available equations in GFR less than 60 mL/min per 1.73 m(2) individuals.

Factors influencing maturation time of native arteriovenous fistulas.

BACKGROUND: To determine the factors influencing the maturation time of native arteriovenous fistulas. METHODS: A retrospective review was performed of hemodialysis patients from a single university-associated dialysis center from 2004 to 2009. Demographics, comorbidities, and insurance status were recorded. Maturation time was defined as the time from access creation until the access was able to be used regularly for hemodialysis for a period of 2 weeks. RESULTS: A total of 249 patients were identified during the study period who had an arteriovenous fistula created that successfully matured; 104 (42%) patients were women and 145 (58%) were men. Most of the patients were Hispanic (82%). Ninety-seven (39%) of the patients had Medicaid-type insurance and 133 (53%) had Medicare. The mean age was 51 years, and 190 (76%) of the patients had diabetes. The overall mean maturation time was 79 days. Women had a significantly longer time to fistula maturation than males (91.9 days vs. 70.5 days, P = 0.0028). Diabetics also had a significantly longer maturation time than nondiabetics (92.5 days vs. 75.4 days, P = 0.0004). Age did not have an effect on maturation time. On multivariable analysis, sex remained significant (P = 0.007), however, diabetes lost its significance. CONCLUSIONS: In this predominantly Hispanic hemodialysis population, women require longer fistula maturation times than men. The exact reasons for this are unknown based on this data. More study is required to determine the etiology of this gender discrepancy.

Renal involvement in Chinese patients with Behcet's disease: a report of 16 cases.

AIM: To investigate the clinical and pathological characteristics of renal involvement in Behcet's disease (BD). METHODS: A retrospective analysis was carried out in BD patients complicated with renal damage who were hospitalized in Peking Union Medical College Hospital from June 1998 to July 2012. RESULTS: There were 16 BD patients with renal involvement, accounted for 2.6% of all the 618 hospitalized BD patients. The presentation of renal disease was chronic glomerulonephritis in six patients (including one with nephritic syndrome), renal tubular acidosis in one patient, renal artery stenosis in eight patients and renal vein thrombosis in one patient. Renal biopsy was performed in five patients, three of whom revealed to have minor glomerular lesions, mild mesangial proliferative glomerulonephritis and chronic tubular-interstitial nephropathy, respectively. The other two patients underwent a second biopsy, the one with minor glomerular lesion in the first biopsy was transformed into grade III immunoglobulin A (IgA) nephropathy on Lee's glomerular grading system 6 years later, and the other one who had IgA nephropathy of grade II in the first biopsy was progressed to grade IV 2 years later. Among the nine patients with renal vascular involvement, two underwent surgery, and several received anticoagulant therapy. During the follow-up of 13 patients, the urine protein quantifications were reduced, and renal function remained relatively stable. CONCLUSIONS: Renal damage is relatively uncommon in BD patients. There are various clinical presentations of renal involvement in BD. Routine screening with urinalysis, serum creatinine and imaging studies should be carried out for the early diagnosis of renal involvement in BD.