Reduced number and impaired function of circulating endothelial progenitor cells in patients with abdominal aortic aneurysm

AIM

Circulating endothelial progenitor cells (EPCs) are associated with coronary artery disease (CAD) and predict its outcome. Although the pathophysiology of abdominal aortic aneurysm (AAA) is different, it shares some risk factors with CAD. Therefore, the correlation between EPCs and AAA was investigated.

METHODS AND RESULTS

Seventy-eight subjects (age 77.2 ± 7.8 years) with suspected AAA were prospectively enrolled. Cut-off values (men, 3.5-5.5 cm; women, 3-5 cm) were used to define normal aorta, small AAA, and large AAA on thoraco-abdominal computer tomography. Endothelial function was measured by flow-mediated vasodilation (FMD). Flow cytometry and colony-forming units (CFUs) were used to evaluate circulating EPC numbers. Circulating EPCs were defined as mononuclear cells with low CD45 staining and double-positive staining for KDR, CD34, or CD133. Late out-growth EPCs were cultured from six patients with large AAAs and six age- and sex-matched controls to evaluate proliferation, adhesion, migration, tube formation, and senescence. FMD was significantly lower with large (5.26% ± 3.11%) and small AAAs (6.31% ± 3.66%) than in controls (8.88% ± 4.83%, P=0.008). Both CFUs (normal 38.39 ± 12.99, small AAA 21.22 ± 7.14, large AAA 6.98 ± 1.97; P=0.026) and circulating EPCs (CD34(+)/KDR(+) and CD133(+)/KDR(+)) were significantly fewer in AAA patients than in controls. On multivariate analysis, CFUs and circulating EPCs (CD34(+)/KDR(+)) were independently, inversely correlated to AAA diameter. Proliferation, adhesion, migration, tube formation, and senescence of late EPCs were significantly impaired in AAA patients.

CONCLUSION

The number and function of EPCs were impaired in AAA patients, suggesting their potential role in AAA.

Evaluation of factors influencing grip strength in elderly koreans

Objectives

Grip strength has been used as a measure of function in various health-related conditions. Although grip strength is known to be affected by both physical and psychological factors, few studies have looked at those factors comprehensively in a population-based cohort regarding elderly Koreans. The aim of this study was to evaluate potential factors influencing grip strength in elderly Koreans.

Methods

We evaluated dominant hand grip strengths in 143 men and 123 women older than 65 years who participated in a population-based cohort study, the Korean Longitudinal Study on Health and Aging (KLoSHA). Individuals who had a history of surgery for musculoskeletal disease or trauma in the upper extremity were excluded. Factors assessed for potential association with grip strength were; 1) demographics such as age and gender, 2) body constructs such as height, body mass index (BMI), and bone mineral density (BMD), 3) upper extremity functional status using disabilities of the arm, shoulder and hand (DASH) scores, and 4) mental health status using a depression scale and the short form-36 (SF36) mental health score. Multivariate analyses were performed in order to identify factors independently associated with grip strength.

Results

Grip strengths of dominant hands in elderly Koreans were found to generally decrease with aging, and were significantly different between men and women, as expected. Multivariate analyses indicated that grip strength was independently associated with age, height and BMI in men (R² = 21.3%), and age and height (R² = 19.7%) in women. BMD, upper extremity functional status, or mental health status were not found to be associated with grip strength.

Conclusions

This study demonstrates that in elderly Koreans, grip strength is mainly influenced by age and height in both men and women, and additionally by BMI in men. BMD or self-reported physical or mental health status was not found to influence grip strength in elderly Koreans. This information may be helpful in future studies using grip strength as a measure of function in elderly Koreans.

Association between depression, nutritional status, and inflammatory markers in peritoneal dialysis patients

BACKGROUND

To investigate the relationship between depression, nutritional status, and inflammatory markers in patients on peritoneal dialysis (PD).

PATIENTS AND METHODS

This prospective study included 40 PD patients and 20 healthy people. The severity of depressive symptoms was assessed using the Beck depression inventory, the Hamilton depression rating scale, and the Hamilton anxiety rating scale. The depressive patients received antidepressant drug for 8 weeks. Blood samples were taken before and after antidepressant treatment for the high-sensitive C-reactive protein (hs-CRP), interleukin (IL)-1, IL-6, and tumor necrosis factor-α (TNF-α) levels.

RESULTS

Ten (25%) of the 40 PD patients had depression. No significant difference was determined between depressive patients and nondepressive patients. The mean erythrocyte sedimentation rate was higher in depressive patients. There was no significant difference for other inflammation parameters, including hs-CRP, TNF-α, IL-1, and IL-6, between depressive patients and nondepressive patients. In the depressive patients, we did not observe any significant change in nutritional parameters after antidepressant treatment. When we evaluated inflammation parameters of the depressive patients before and after antidepressant treatment, only IL-1 and IL-6 levels were significantly increased after antidepressant treatment.

CONCLUSION

The depressive disorder in PD patients is a common psychopathology and has no significant effects on nutritional status and inflammation.

Metabolic syndrome and other cardiovascular risk factors associated with the progression of IgA nephropathy

Background

The metabolic syndrome is associated with modest but independent and additive risk of new onset chronic kidney disease (CKD) in several studies. The purpose of our study was to determine whether metabolic syndrome and other cardiovascular risk factors (hyperuricaemia and smoking) are associated with the progression of IgA nephropathy (IgAN).

Methods

Two hundred and twenty three IgAN patients (107 with and 116 without metabolic syndrome) were examined. The primary renal end point was doubling of serum creatinine; secondary end points were reaching eGFR of ≤ 60 ml/min/1,73m² or eGFR of ≤30 ml/min/1.73 m², and end-stage renal disease, ESRD (the composite of serum creatinine ≥500 μmol/l, initiation of dialysis treatment or transplantation). The association of metabolic syndrome with renal end points was examined using the Kaplan-Meier method and Cox models.

Results

Metabolic syndrome established at the diagnosis or during follow-up of IgAN patients was significantly associated with the primary renal end point (unadjusted hazard ratio of doubling of serum creatinine, 95% confidence interval: 1.96 (1.17–1.33, p = 0.011). The association remained significant after adjustment for confounders: 1.70 (1.02–3.83, p = 0.040). Results were similar for secondary end points except ESRD which was not associated with the presence of metabolic syndrome. Hyperuricaemia and smoking were independent risk factors of progression. Survival curves stratified on metabolic syndrome status showed significant differences for the end points (p = 0.017–0.001) except for ESRD.

Conclusions

Early diagnosis and treatment of metabolic syndrome, hyperuricaemia and smoking may be an additional cost-effective strategy for preventing the progression of IgAN.

Is vitamin C intake too low in dialysis patients?

Vitamin C has several well-established roles in physiology including synthesis of collagen, carnitine and epinephrine, absorption of dietary iron, and mobilization of storage iron for erythropoeisis. Loss of several of these functions explains the pathology of scurvy, where defective collagen synthesis and anemia are major symptoms. Vitamin C deficiency is very common in dialysis patients and may arise from dialytic vitamin C clearance, restricted intake of vitamin C-rich foods, and increased vitamin C catabolism in vivo from inflammation. In the dialysis population, greater vitamin C intake may be needed for optimal health. Relationships between intake, body distribution, inflammation, and dialytic losses are complex and need further study. Concern about vitamin C metabolism leading to accumulation of tissue oxalate has led to the recommendation that vitamin C intake equals, but not exceeds, the intake recommended for the general population. Vitamin C deficiency in dialysis patients may have clinical consequences; a study in Renal Research Institute clinics found an association with periodontal disease. Data also support a role for vitamin C in prevention of dialysis-related anemia. New research questions are proposed in this editorial, with a discussion of strategies to determine the optimal provision of vitamin C for CKD patients.

Factors associated with CKD in the elderly and nonelderly population

BACKGROUND AND OBJECTIVES

The risk factors for CKD in different age groups remain unknown. This community-based study aimed to identify the risk factors for CKD in elderly and nonelderly patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A multistage sampling survey for CKD was conducted in 2007 in Kaohsiung County, an area with the highest prevalence of dialysis in the world. CKD was defined as proteinuria in at least the microalbuminuric stage or an estimated GFR (eGFR) of <60 ml/min per 1.73 m(2). The factors for CKD in elderly and nonelderly patient groups were identified (with age 60 years as a cutoff value).

RESULTS

The analyses included 3352 participants, of whom 687 had CKD. The weighted prevalence of CKD was 19.4% (95% confidence interval [CI], 18.0%-20.7%). Elderly patients typically presented with low eGFR and nonelderly patients, with proteinuria. Age, annual income, use of oral analgesics, metabolic syndrome, hyperuricemia, and hemoglobin were risk factors for CKD in both age groups. In elderly patients, risk factors were medical history of diabetes mellitus, CKD, stroke, and not using analgesic injection (odds ratios [95% CIs], 3.58 [2.06-6.22], 3.66 [1.58-8.43], 3.89 [1.09-13.87], 2.27 [1.21-4.17], respectively). In nonelderly patients, associated risk factors for CKD were gout, hepatitis B virus infection, and use of the Chinese herbal medicine Long Dan Xie Gan Tang (odds ratios [95% CIs], 3.15 [1.96-5.07], 1.66 [1.09-2.53], and 8.86 [1.73-45.45], respectively).

CONCLUSIONS

The risk factors for CKD vary by age.

Demystifying ethnic/sex differences in kidney function: is the difference in (estimating) glomerular filtration rate or in serum creatinine concentration?

BACKGROUND

The recent evaluation of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for estimating the glomerular filtration rate (GFR) in multiple ethnicities has raised the question on how well this equation performs for African-American and Asian subjects. There is no doubt that serum creatinine (Scr) concentration differs between ethnicities and sexes. We show that creatinine-based equations for white populations may be inaccurate for estimating GFR in other ethnic/gender groups, especially in populations from Asia.

METHODS

This study presents a mathematical analysis of the CKD-EPI-equation complemented with a literature review of median and reference values for IDMS-standardized Scr-concentrations for multiple ethnicities.

RESULTS

The study shows that at equal eGFR-CKD-EPI-values, the ratio of Scr between females and males equals 0.79 and between other ethnicities/sexes and white males is constant too. From this information, it is possible to calculate mean Scr-values that correspond very well with literature values directly obtained from Scr-distributions in healthy white males and females and in black males, but the discrepancy is larger for other populations.

CONCLUSIONS

Our results confirm the criticism that has been raised for using the CKD-EPI-equation for these ethnicities. An alternative eGFR-model is proposed based on a population-normalized Scr that needs further validation.

High prevalence and associated risk factors for impaired renal function and urinary abnormalities in a rural adult population from southern China

Background

The prevalence of chronic kidney disease (CKD) has increased and will continue to rise worldwide. However, data regarding the prevalence of CKD in a rural area of China are limited. We therefore investigated the prevalence and associated risk factors of impaired renal function and urinary abnormalities in an adult rural population in southern China.

Methods

Between December 2006 and January 2007, residents older than 20 years from four villages in Zhuhai city were randomly selected using a stratified, multistage sampling technique. All participants were interviewed and tested for hematuria, albuminuria and estimated glomerular filtration rate (eGFR). The associations between age, gender, diabetes mellitus, hypertension, hyperuricemia, education level and indicators of renal damage were examined.

Results

Overall, 1,214 subjects were enrolled in this study. After adjustment for age and gender, the prevalence of albuminuria was 7.1% (95% CI: 4.5, 8.1), reduced eGFR was 2.6% (95% CI: 1.7%, 3.3%), and hematuria was 4.6% (95% CI: 3.3%, 6.0%). Approximately 13.6% (95% CI: 12.0%, 15.1%) of the patients had at least one indicator of renal damage, but only 8.3% were previously aware. Age, diabetes, hyperlipidemia, hypertension, hyperuricemia, use of nephrotoxic medications, coronary heart disease and history of CKD were independently associated with impaired renal function and urinary abnormalities. Additionally, age, diabetes, and hypertension were independently associated with albuminuria. Age, hypertension, hyperuricemia, central obesity, and coronary heart disease were independently associated with reduced renal function.

Conclusions

The high prevalence and low awareness of impaired renal function and urinary abnormalities in this population illustrates the urgent need to implement a CKD prevention program in the rural areas of southern China.

Determining cut-off values for neck circumference as a measure of the metabolic syndrome amongst a South African cohort: the SABPA study

The aim was to determine receiver operating characteristic (ROC) neck circumference (NC) cut offs best associated with the metabolic syndrome (MetS) in a South African cohort. We included 409 urban Africans and Caucasians and stratified them into gender and age groups (25-45 years; 45-65 years). Measurements included anthropometric, fasting overnight urine and biological markers for the MetS (systolic and diastolic blood pressure, glucose, triglycerides, and high density lipoprotein). ROC analysis determined pathological (NC) cut-points of 39 and 35 cm for young and older African men; 32 and 35 cm for young and old African women; 40 and 41 cm for Caucasian men; 34 and 33 cm for Caucasian women. Pathological NC cut-points significantly predicted MetS in all ethnic-gender-age groups except in African women (ORs 2.3-5.4; 95% CI 1.36-16.5). Multiple regression analyses revealed that MetS prevalence and ROC cut-points were not associated with renal impairment in any groups. ROC NC cut-points demonstrated that NC may be used as an additional anthropometric marker to predict the MetS in a South African cohort but not in African women.

Outcome of Lamivudine-Resistant Chronic Hepatitis B after up to 5 Years of Combination Therapy with Adefovir

Background

There is a paucity of data on the long-term efficacy of combination lamivudine and adefovir therapy in patients with lamivudine-resistant chronic hepatitis B.

Methods

We determined the cumulative virological, serological and biochemical outcomes of 165 lamivudine-resistant chronic hepatitis B patients on lamivudine and adefovir for up to 5 years. Resistance profiles using a line probe assay were determined among patients with detectable viraemia. The significance of different baseline and on-treatment virological parameters was analysed.

Results

The median age and duration of follow-up were 45.1 years and 37.1 months, respectively. The cumulative rates of HBV DNA undetectability (<20 IU/ml), alanine aminotransferase normalization and hepatitis B e antigen seroconversion up to 5 years were 74.0%, 95.1% and 44.4%, respectively. One patient achieved hepatitis B surface antigen seroclearance. The 5-year cumulative resistance rate to adefovir was 10.2%. Among different baseline and on-treatment virological parameters, week 24 HBV DNA<200 IU/ml was associated with an increased chance of long-term virological suppression ( P<0.001, OR 13.89, 95% CI 3.90, 49.46). Primary non-response and high baseline viral titres were not useful in predicting long-term virological outcomes. The 5-year cumulative rate of serum creatinine elevation >0.5 mg/dl was 4.1%.

Conclusions

Combination lamivudine and adefovir therapy for up to 5 years achieved modest rates of virological suppression, but resistance developed in only 10.2% of patients. Week 24 HBV DNA<200 IU/ml was predictive of favourable long-term virological outcomes and could be used to assist treatment decisions on continuing lamivudine and adefovir or switching to more potent therapy.

Are cystatin C-based equations superior to creatinine-based equations for estimating GFR in Chinese elderly population?

PURPOSE

Cystatin C has been proposed as a surrogate marker of kidney function. The elderly population accounts for the largest proportion of chronic kidney disease (CKD) patients. The aim of this study was to assess the diagnostic value of serum cystatin C and compare the applicability of cystatin C-based equations with serum creatinine (Scr)-based equations for estimating glomerular filtration rate (GFR).

METHODS

The estimated GFR (eGFR) values from six cystatin C-based equations (Tan, MacIsaac, Ma, Stevens1-3) and three Scr-based equations (CG, MDRD, CKD-EPI) were compared with the reference GFR (rGFR) values from 99mTc-DTPA renal dynamic imaging method.

RESULTS

A total of 110 elderly Chinese (60-92 year, 71.05±7.62 year) were enrolled. Cystatin C had better diagnostic value than Scr (relationship coefficient with rGFR: cystatin C -0.847 vs. Scr -0.729, P<0.01; sensitivity: cystatin C 0.90 vs. Scr 0.55, P<0.01; AUCROC: cystatin C 0.857 vs. Scr 0.757, P<0.01). All the equations predicted GFR more accurately for rGFR≥60 ml/min/1.73 m2 than for rGFR<60 ml/min/1.73 m2. Most equations had acceptable accuracy. The cystatin C-based equations deviated from rGFR by -12.78 ml/min/1.73 m2 to -2.12 ml/min/1.73 m2, with accuracy varying from 64.6 to 82.7%. The Scr-based equations deviated from rGFR by -5.37 ml/min/1.73 m2 to -0.68 ml/min/1.73 m2, with accuracy varying from 77.3 to 79.1%. The CKD-EPI, MacIsaac and Ma equations predicted no bias with rGFR (P>0.05), with higher accuracy and lower deviation in the total group. The MacIsaac, CKD-EPI and Stevens3 equations could be optimal for those with normal and mildly impaired kidney function, whereas the Ma equation for those with CKD.

CONCLUSION

Cystatin C is a promising kidney function marker. However, not all cystatin C-based equations could be superior to the Scr-equations.

A randomized controlled trial of long term effect of BCM guided fluid management in MHD patients (BOCOMO study): rationales and study design

BACKGROUND

Bioimpedance analysis (BIA) has been reported as helpful in identifying hypervolemia. Observation data showed that hypervolemic maintenance hemodialysis (MHD) patients identified using BIA methods have higher mortality risk. However, it is not known if BIA-guided fluid management can improve MHD patients' survival. The objectives of the BOCOMO study are to evaluate the outcome of BIA guided fluid management compared with standard care.

METHODS

This is a multicenter, prospective, randomized, controlled trial. More than 1300 participants from 16 clinical sites will be included in the study. The enrolment period will last 6 months, and minimum length of follow-up will be 36 months. MHD patients aged between 18 years and 80 years who have been on MHD for at least 3 months and meet eligibility criteria will be invited to participate in the study. Participants will be randomized to BIA arm or control arm in a 1:1 ratio. A portable whole body bioimpedance spectroscopy device (BCM-Fresenius Medical Care D GmbH) will be used for BIA measurement at baseline for both arms of the study. In the BIA arm, additional BCM measurements will be performed every 2 months. The primary intent-to-treat analysis will compare outcomes for a composite endpoint of death, acute myocardial infarction, stroke or incident peripheral arterial occlusive disease between groups. Secondary endpoints will include left ventricular wall thickness, blood pressure, medications, and incidence and length of hospitalization.

DISCUSSIONS

Previous results regarding the benefit of strict fluid control are conflicting due to small sample sizes and unstable dry weight estimating methods. To our knowledge this is the first large-scale, multicentre, prospective, randomized controlled trial to assess whether BIS-guided volume management improves outcomes of MHD patients. The endpoints of the BOCOMO study are of utmost importance to health care providers. In order to obtain that aim, the study was designed with very careful important considerations related to the endpoints, sample size, inclusion criteria, exclusion criteria and so on. For example, annual mortality of Beijing MHD patients was around 10%. To reach statistical significance, the sample size will be very large. By using composite endpoint, the sample size becomes reasonable and feasible. Limiting inclusion to patients with urine volume less than 800 ml/day the day before dialysis session will limit confounding due to residual renal function effects on the measured parameters. Patients who had received BIS measurement within 3 months prior to enrolment are excluded as data from such measurements might lead to protocol violation. Although not all patients enrolled will be incident patients, we will record the vintage of dialysis in the multivariable analysis.

Prevalence of anemia in Chinese nursing home older adults: implication of age and renal impairment

AIM

There is little data regarding the prevalence and associated comorbidities of anemia in Chinese nursing home older adults. The objective of this study was to investigate the prevalence and associated comorbidities of anemia in Chinese nursing home older adults.

METHODS

We carried out a retrospective cross-sectional study in nine nursing homes in Hong Kong. The hemoglobin (Hb) level, mean corpuscular volume (MCV), serum creatinine and comorbidities data of residents were examined. Older adults were regarded as anemic according to the World Health Organization criteria (Hb <13 g/dL for men and <12 g/dL for women). The glomerular filtration rate (eGFR) was estimated by the Modification of Diet in Renal Disease Study (MDRD [Chinese-adjusted]) equation. Patients with chronic renal impairment were defined as having eGFR <60 mL/min/1.73 m(2) .

RESULTS

A total of 812 residents were included (mean age 86.0 ± 7.6 years). The mean hemoglobin was 12.0 ± 1.8 g/dL in men and 11.4 ± 1.6g/dL in women. The mean eGFR was 75.1 ± 31.7 mL/min/1.73 m(2) . A total of 67.0% of residents had anemia (70.5% in men and 65.2% in women). Anemic older adults were older and had a higher prevalence of renal impairment than non-anemic older adults (P<0.001). There was no significant difference between the two groups regarding the prevalence of other comorbidities. When stratified into different age groups, there were significant correlations between anemia and renal impairment in all subgroups (age ≤ 80 years, P<0.05; age 81-90 years, P<0.01; age >90 years, P<0.05). The same correlation was found between normocytic anemia and renal impairment. Conversely, when stratified according to eGFR (≥ 60 mL/min/1.73 m(2) vs <60 mL/min/1.73 m(2) ), we did not observe a significant correlation between anemia and age group.

CONCLUSION

In conclusion, anemia is prevalent in Chinese nursing home residents and is strongly associated with renal impairment. Further studies of early identification and management of anemia with renal impairment are recommended in this population.

Simple cystatin C formula for estimation of glomerular filtration rate in overweight patients with diabetes mellitus type 2 and chronic kidney disease

In clinical practice the glomerular filtration rate (GFR) is estimated from serum creatinine-based equations like the Cockcroft-Gault formula (C&G) and Modification of Diet in Renal Disease formula (MDRD). Recently, serum cystatin C-based equations, the newer creatinine formula (The Chronic Kidney Disease Epidemiology Collaboration formula (CKD-EPI)), and equation that use both serum creatinine and cystatin C (CKD-EPI creatinine & cystatin formula) were proposed as new GFR markers. Present study compares serum creatinine-based equations, combined (including both serum creatinine and cystatin C) equation, and serum simple cystatin C formula (100/serum cystatin C) against 51CrEDTA clearance in 113 adult overweight Caucasians with diabetes mellitus type 2 (DM2) and chronic kidney disease (CKD). The results of present study demonstrated that the simple cystatin C formula could be a useful tool for the evaluation of renal function in overweight patients with DM2 and impaired kidney function in daily clinical practice in hospital and especially in outpatients. Despite the advantages of the simple cystatin C formula, cystatin C-based equations cannot completely replace the "gold standard" for estimation of the GFR in a population of DM2 patients with CKD, but may contribute to a more accurate selection of patients requiring such invasive and costly procedures.

Comparisons between validated estimated glomerular filtration rate equations and isotopic glomerular filtration rate in HIV patients

OBJECTIVE

Understanding how best to measure renal function in HIV-infected patients is critical because estimated glomerular filtration rate (eGFR) in HIV-infected patients can be affected by ethnicity and body composition. We validated the available eGFR equations and compared them to the plasma Tc-diethylenetriaminepentaacetic acid (Tc-DTPA) clearance in HIV-infected patients.

DESIGN

Test of diagnostic accuracy.

METHODS

One hundred and ninety-six HIV-infected patients underwent measuring of Tc-DTPA plasma clearance, five creatinine-based eGFR equations, cystatin-C GFR, and 24-h urine creatinine clearance (CrCl).

RESULTS

Mean (SD) Tc-DTPA GFR was 117.7 ± 29.2 ml/min per 1.73 m. The re-expressed Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), re-expressed MDRD formula with Thai racial correction factor, Thai eGFR equation, Cockcroft-Gault equation, cystatin-C GFR, and 24-h urine CrCl underestimated the reference GFR. The bias estimated by the mean of differences (SD) for the re-expressed MDRD equation, CKD-EPI, re-expressed MDRD formula with Thai racial correction factor, Thai eGFR, Cockcroft-Gault equation, cystatin-C, and 24-h urine CrCl can be expressed as 18.9 ± 27.3, 11.1 ± 25.5, 6.2 ± 28.8, 15.4 ± 27.0, 30.4 ± 28.0, 3.2 + 36.1, and 5.0 ± 12.1 ml/min per 1.73 m, respectively.

CONCLUSION

The available eGFR equations underestimated GFR in HIV-infected adults. However, the eGFR by cystatin-C GFR was the most precise and accurate. Among creatinine-based eGFR equations, re-expressed MDRD formula with Thai racial correction factor was the most precise and accurate. The racial factor for each ethnicity is important and the existing eGFR equation should be validated before using it in the HIV population.

Gender difference in the association of hyperuricemia with chronic kidney disease in southern China

BACKGROUND

The effect of hyperuricemia on chronic kidney disease (CKD) is controversial, and little is known about gender as it relates to hyperuricemia and CKD.

METHODS

This was a cross-sectional study of 7,053 adults in the general Chinese population in Southern China using a multi-stage stratified sampling method. In which associations between hyperuricemia and indicators of CKD (defined by albuminuria (urinary albumin-to -creatinine ratio ≥ 30 mg/g) or decreased modified MDRD equation estimated GFR (<60 ml/min per 1.73 m2) were tested using multivariate logistic regression.

RESULTS

After adjustment for potential confounders, hyperuricemia was associated with increased risk of reduced renal function and CKD but not albuminuria, with odds ratios (ORs) (95% CI) of 4.39 (3.38-5.70, P < 0.001), 1.54 (1.31-1.82, P <0.001) and 0.96 (0.78-1.17, P =0.671), respectively. The interaction between gender and hyperuricemia with CKD was significant (P =0.010); and stratified analysis showed a stronger association of hyperuricemia with CKD in males (OR (95% CI): 2.04 (1.56-2.67), P < 0.001) than in females (1.45 (1.17-1.80), P = 0.001).

CONCLUSIONS

We observed an independent association of hyperuricemia with CKD that was stronger in males, and this independent association in male might imply some gender specific mechanisms. These results should be confirmed in future prospective studies.

Variation in APOL1 Contributes to Ancestry-Level Differences in HDLc-Kidney Function Association

Low levels of high-density cholesterol (HDLc) accompany chronic kidney disease, but the association between HDLc and the estimated glomerular filtration rate (eGFR) in the general population is unclear. We investigated the HDLc-eGFR association in nondiabetic Han Chinese (HC, n = 1100), West Africans (WA, n = 1497), and African Americans (AA, n = 1539). There were significant differences by ancestry: HDLc was positively associated with eGFR in HC (β = 0.13, P < 0.0001), but negatively associated among African ancestry populations (WA: -0.19, P < 0.0001; AA: -0.09, P = 0.02). These differences were also seen in nationally-representative NHANES data (among European Americans: 0.09, P = 0.005; among African Americans -0.14, P = 0.03). To further explore the findings in African ancestry populations, we investigated the role of an African ancestry-specific nephropathy risk variant, rs73885319, in the gene encoding HDL-associated APOL1. Among AA, an inverse HDLc-eGFR association was observed only with the risk genotype (-0.38 versus 0.001; P = 0.03). This interaction was not seen in WA. In summary, counter to expectation, an inverse HDLc-eGFR association was observed among those of African ancestry. Given the APOL1 × HDLc interaction among AA, genetic factors may contribute to this paradoxical association. Notably, these findings suggest that the unexplained mechanism by which APOL1 affects kidney-disease risk may involve HDLc.

Association of the PPARG Pro12Ala polymorphism with type 2 diabetes and incident coronary heart disease in a Hong Kong Chinese population

AIMS

We examined the risk association between single nucleotide polymorphisms (SNPs) in eleven candidate genes with type 2 diabetes (T2D). T2D-associated polymorphisms were also examined for prediction of incident CHD.

METHODS

113 tagging SNPs were genotyped in stage 1 (467 T2D cases, 290 controls), and 15 SNPs were analyzed in the final cohort (1462 T2D cases, 600 controls). Three T2D-associated SNPs were further tested for prediction of CHD within a subset of 1417 T2D cases free of CHD at enrolment.

RESULTS

In the case-control analysis, PPARG rs1801282 (Pro12Ala) (OR=1.48 (1.02-2.16)), ADIPOQ rs1063539 (OR=1.17 (1.01-1.35)), and HNF4A rs1884614 (OR=1.16 (1.00-1.32) were associated with T2D (P(allelic)<0.05). Joint analysis of rs1801282-C, rs1063539-G, and rs1884614-T risk alleles showed an additive dosage effect (P for trend=0.001). Moreover, carriers with two PPARG rs1801282-C risk alleles were associated with an increased risk of incident CHD (HR=4.38 (1.03-18.57), P=0.045) in T2D patients in the prospective analysis.

CONCLUSIONS

Genetic variants of PPARG, ADIPOQ and HNF4A were individually and jointly associated with T2D in Hong Kong Chinese. The PPARG Pro12 risk allele contributed to increased risk for both T2D and CHD.

Impact of acute kidney injury on one-year survival after surgery for aortic dissection

BACKGROUND

Surgical treatment is an option for both type A aortic dissection and complicated type B aortic dissection. Acute kidney injury (AKI) influences the disease course after surgery. Our hypothesis was that AKI should be an important prognostic factor for aortic dissection after surgical treatment.

METHODS

Between July 2005 and October 2010, 268 patients (mean age 53 ± 14 years; range, 16 to 88) underwent open surgery for aortic dissection. We reviewed the clinical presentations, surgical variables, and postoperative outcomes to identify the risk factors of death. The 256 patients were divided into groups, with and without AKI, within 24 hours after operation according to the RIFLE (acronym for risk, injury, failure, loss, end stage) criteria.

RESULTS

The in-hospital mortality rate was 17.9%, the 1-year mortality rate was 18.7%, and the major adverse cardiac events rate within 1 year was 29.9%. In multivariate analysis, patients more than 70 years of age (hazard ratio [HR] 2.390, p = 0.029), cardiogenic shock (HR 2.895, p = 0.005), preoperative ventilator use (HR 4.137, p = 0.018), operation at midnight (HR 2.295, p = 0.028), longer bypass time (HR 1.007, p < 0.001), and AKI (HR 2.552, p = 0.041) were clinical predictors of mortality. Kaplan-Meier analysis showed that the survival rate was strongly correlated with the severity of AKI by the RIFLE criteria. The independent predictors of AKI included hypertension (odds ratio 2.340, p = 0.027), sepsis (odds ratio 2.594, p = 0.043), and lower limb malperfusion (odds ratio 4.558, p = 0.022).

CONCLUSIONS

Our study provides outcomes of postoperative aortic dissection. We found that AKI was a predictor of 1-year mortality by using the RIFLE criteria. Factors associated with increased 1-year mortality and AKI should be taken into consideration for surgery and postoperative care.

U-curve association between timing of renal replacement therapy initiation and in-hospital mortality in postoperative acute kidney injury

Background

Postoperative acute kidney injury (AKI) is associated with poor outcomes in surgical patients. This study aims to evaluate whether the timing of renal replacement therapy (RRT) initiation affects the in-hospital mortality of patients with postoperative AKI.

Methodology

This multicenter retrospective observational study, which was conducted in the intensive care units (ICUs) in a tertiary hospital (National Taiwan University Hospital) and its branch hospitals in Taiwan between January, 2002, and April, 2009, included adult patients with postoperative AKI who underwent RRT for predefined indications. The demographic data, comorbid diseases, types of surgery and RRT, and the indications for RRT were documented. Patients were categorized according to the period of time between the ICU admission and RRT initiation as the early (EG, ≦1 day), intermediate (IG, 2–3 days), and late (LG, ≧4 days) groups. The in-hospital mortality rate censored at 180 day was defined as the endpoint.

Results

Six hundred forty-eight patients (418 men, mean age 63.0±15.9 years) were enrolled, and 379 patients (58.5%) died during the hospitalization. Both the estimated probability of death and the in-hospital mortality rates of the three groups represented U-curves. According to the Cox proportional hazard method, LG (hazard ratio, 1.527; 95% confidence interval, 1.152–2.024; P = 0.003, compared with IG group), age (1.014; 1.006–1.021), diabetes (1.279; 1.022–1.601; P = 0.031), cirrhosis (2.147; 1.421–3.242), extracorporeal membrane oxygenation support (1.811; 1.391–2.359), initial neurological dysfunction (1.448; 1.107–1.894; P = 0.007), pre-RRT mean arterial pressure (0.988; 0.981–0.995), inotropic equivalent (1.006; 1.001–1.012; P = 0.013), APACHE II scores (1.055; 1.037–1.073), and sepsis (1.939; 1.536–2.449) were independent predictors of the in-hospital mortality (All P<0.001 except otherwise stated).

Conclusions

The current study found a U-curve association between the timing of the RRT initiation after the ICU admission and patients’ in-hospital mortalities, and alerts physicians of certain factors affecting the outcome after the RRT initiation.

Age-related change in kidney function, its influencing factors, and association with asymptomatic carotid atherosclerosis in healthy individuals--a 5-year follow-up study

OBJECTIVES

To better define the longitudinal changes in renal function, to examine the associated risk factors, and to investigate whether there is an independent association of decline in renal function with presence of carotid plaque in a middle-aged and elderly healthy population.

METHODS

245 healthy individuals (98 males, 147 females) evaluated at baseline and 5 years later.

RESULTS

Over five years, estimated glomerular filtration rate (eGFR) decreased from 98.1±15.6 to 90.4±17.3mL/min/1.73m(2). There are three kinds of change in eGFR (elevated, stable and decreased) during follow-up, accounting for 14%, 29% and 57%, respectively. Multivariate analysis of cross-sectional data showed that gender, age, and serum uric acid (UA) were major factors which consistently affected eGFR at both baseline and follow-up, and that higher systolic blood pressure (SBP) and presence of plaque were involved in lower eGFR at the follow-up point. In longitudinal analysis, five baseline factors - age, SBP, low-density lipoprotein cholesterol (LDL-C), serum transferrin (TRF) and eGFR - independently predicted a greater variability in renal function. In addition, presence of plaque was an independent risk factor for a faster decline of eGFR.

CONCLUSIONS

Cross-sectional analysis demonstrates that renal function declines with increasing age. However, 43% of participants did not experience a decline in eGFR during follow-up. Besides older age and higher initial eGFR, presence of atherosclerotic carotid plaque, higher SBP, higher LDL-C and lower TRF are independent risk factors to predict a rapid decline of renal function in the healthy Chinese population.

Association of glomerular filtration rate with arterial stiffness in Chinese women with normal to mildly impaired renal function

Objective

Both decreased glomerular filtration rate (GFR) and arterial stiffness were considered as risk factors for atherosclerosis. Previous studies have suggested the association between central arterial stiffness and the degree of GFR loss. Whether decreased GFR contributes to peripheral artery stiffness remains controversial. Moreover, data analyzed from a cohort of Chinese women are rare. Our aim was to explore the relationship between GFR and regional arterial stiffness in Chinese women.

Methods

In this cross-sectional study, we randomly recruited 1131 adult women residents with GFR ≥ 60 mL/min per 1.73 m² estimated by the Chinese Modification of Diet in Renal Disease equation from three large communities. Central and peripheral arterial stiffness were estimated simultaneously by measuring carotid-femoral pulse wave velocity (PWVcf) and carotid-radial PWV (PWVcr) using a validated automatic device. Augmentation Index at heart rate 75 beats/minutes (AIx-75) was measured by pulse wave analysis as a composite parameter reflecting both large and distal arterial properties.

Results

The mean estimated GFR (eGFR) of the study group was 100.05 ± 23.26 mL/minute per 1.73 m². Subjects were grouped by tertiles of eGFR level. PWVcf and AIx-75 increased ongoing from the top to the bottom eGFR tertile, while the values of PWVcr were comparable. Both univariate Pearson correlations and multiple stepwise regression analyses showed that eGFR significantly correlated to PWVcf, but not to PWVcr and AIx-75.

Conclusions

In Chinese women with normal to mildly impaired renal function, decreased eGFR affected carotid-to-femoral rather than carotid-to-radial stiffening. This provides rational to conduct future prospective studies to investigate predictors of atherosclerosis in this population.

Circulating adiponectin is associated with renal function independent of age and serum lipids in west africans

Adiponectin, a protein secreted by adipose tissue, has been associated with renal dysfunction. However, these observations have not been adequately investigated in large epidemiological studies of healthy individuals in general and in African populations in particular. Hence, we designed this study to evaluate the relationship between adiponectin and renal function in a large group of nondiabetic West Africans. Total adiponectin was measured in 792 participants. MDRD and Cockroft-Gault (CG-) estimated GFR were used as indices of renal function. Linear and logistic regression models were used to determine the relationship between adiponectin and renal function. Adiponectin showed an inverse relationship with eGFR in univariate (Beta_MDRD = −0.18, Beta_CG = −0.26) and multivariate (Beta_MDRD = −0.10, Beta_CG = −0.09) regression analyses. The multivariate models that included age, sex, BMI, hypertension, smoking, HDL-C, LDL-C, triglycerides, and adiponectin explained 30% and 55.6% of the variance in GFR estimated by MDRD and CG methods, respectively. Adiponectin was also a strong predictor of moderate chronic kidney disease (defined as eGFR < 60 mL/min/1.73 m²). We demonstrate that adiponectin is associated with renal function in nondiabetic West Africans. The observed relationship is independent of age and serum lipids. Our findings suggest that adiponectin may have clinical utility as a biomarker of renal function.

Chronic kidney disease and automatic reporting of estimated glomerular filtration rate: new developments and revised recommendations

The publication of the Australasian Creatinine Consensus Working Group's position statements in 2005 and 2007 resulted in automatic reporting of estimated glomerular filtration rate (eGFR) with requests for serum creatinine concentration in adults, facilitated the unification of units of measurement for creatinine and eGFR, and promoted the standardisation of assays. New advancements and continuing debate led the Australasian Creatinine Consensus Working Group to reconvene in 2010. The working group recommends that the method of calculating eGFR should be changed to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula, and that all laboratories should report eGFR values as a precise figure to at least 90 mL/min/1.73 m(2). Age-related decision points for eGFR in adults are not recommended, as although an eGFR < 60 mL/min/1.73 m(2) is very common in older people, it is nevertheless predictive of significantly increased risks of adverse clinical outcomes, and should not be considered a normal part of ageing.If using eGFR for drug dosing, body size should be considered, in addition to referring to the approved product information. For drugs with a narrow therapeutic index, therapeutic drug monitoring or a valid marker of drug effect should be used to individualise dosing. The CKD-EPI formula has been validated as a tool to estimate GFR in some populations of non-European ancestry living in Western countries. Pending publication of validation studies, the working group also recommends that Australasian laboratories continue to automatically report eGFR in Aboriginal and Torres Strait Islander peoples. The working group concluded that routine calculation of eGFR is not recommended in children and youth, or in pregnant women. Serum creatinine concentration (preferably using an enzymatic assay for paediatric patients) should remain as the standard test for kidney function in these populations.

National Health Survey on the Prevalence of Urinary Abnormalities in the Population: then and now (1975 to 2012)

Introduction: This paper presents the results of a community survey on urinary abnormalities which covered 1/80th of the population of Singapore in 1975. These findings were compared with the data from the Singapore National Service Registrants in 1974 as well as data from a recent survey in Singapore and that of other Asian and Western countries. Materials and Methods: The study covered 18,000 persons aged 15 years and above, representing a sampling fraction of 1/80th of the population. A total of 16,808 respondents attended the fi eld examination centres, of whom 16,497 had their urine sample tested representing 92.7% of the sample population. Results: In the dipstick urine testing at the fi eld examination centres, 769 subjects (4.6%) were found to have urinary abnormalities. Two hundred and eighty-two (36.7%) of these 769 subjects were found to have urinary abnormalities based on urine microscopy constituting a prevalence of 1.71%. The prevalence of proteinuria was 0.63% and for both haematuria and proteinuria was 0.73%. The prevalence for hypertension was 0.43% and renal insufficiency was 0.1%. Discussion: The consensus is that routine screening for chronic kidney disease (CKD) in the general population is not cost effective as the yield is too low. Whilst, most studies showed that screening of the general population was not cost effective, it has been suggested that screening for targeted groups of subjects could help to identify certain risk groups who may benefit from early intervention to prevent or retard the progression of CKD. Conclusion: The prevalence of urinary abnormalities in Singapore has remained the same, now and three decades ago. Key words: Chronic kidney disease, Proteinuria, Screening

Clinical features of Chinese coronary heart disease patients with chronic kidney disease

OBJECTIVES

To investigate the prevalence of chronic kidney disease (CKD) by stage in Chinese patients with coronary heart disease (CHD) and to identify the clinical features and examine control of cardiovascular risk factors.

METHODS AND RESULTS

Clinical data of hospitalized patients were collected by investigators in China. CKD stages were classified according to estimated glomerular filtration rate (eGFR). A total of 2509 participants with CHD were included in the final statistical analysis. The overall prevalence of CKD stage 3 and greater (eGFR of less than 60 mL/min/1.73 m(2)) in the CHD patients was 32.5%. As the CKD stage increased, fasting blood glucose (FBG), systolic blood pressure (SBP), diastolic blood pressure (DBP), and high-sensitivity C-reactive protein (HS-CRP) levels all worsened. As the CKD stage became more severe, CHD patients had comorbidities such as diabetes mellitus, periphery arterial disease, and ischemic stroke, and more CHD patients had triple vessel disease increased. Even when patients received treatment of CHD and risk factors, control of cardiovascular risk factors such as SBP, DBP, FBG, and low-density lipoprotein was worsened as CKD stage became more severe over a 6-week follow-up.

CONCLUSIONS

The data suggested a high prevalence of CKD in Chinese patients with CHD. Many conventional risk factors and comorbidities were correlated with high prevalence of CKD in CHD patients. Control of cardiovascular risk factors in those patients was poor.

Is the Chronic Kidney Disease Epidemiology Collaboration four-level race equation better than the cystatin C equation?

AIM

To evaluate the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) four-level race equation in the assessment of glomerular filtration rate (GFR) in Chinese people with chronic kidney disease (CKD), which was published in 2011, compared with the cystatin C-based GFR estimation equation (CysC GFR) and the combination of CysC and serum creatinine equation (CysC-Scr GFR).

METHODS

The CKD-EPI four-level race equation estimated GFR (CKD-EPI GFR) was compared with the CysC GFR and CysC-Scr GFR. Three equations were compared with body surface area (BSA) standardized GFR (sGFR), which was measured by (99m) Tc-DTPA renal dynamic imaging method in 111 CKD cases.

RESULTS

A statistically significant correlation was found between sGFR and CKD-EPI GFR, CysC GFR and CysC-Scr GFR. Three estimated GFR (eGFR) equations of 30% accuracy were 58.6%, 56.8% and 63.5%, respectively. Average deviations of eGFR from sGFR were 2.34, 1.19, and 1.32 (mL/min per 1.73 m(2)) (P > 0.05), respectively. There was no significant deviation in the CKD from stages 1 to 5 in CKD-EPI GFR and CysC-Scr GFR. However, when estimated by CysC GFR, the deviation was increased, with the value of 12.41 mL/min per 1.73 m(2) (P= 0.002) in CKD stage 5.

CONCLUSION

Our results showed that in a Chinese population with CKD, CKD-EPI GFR, CysC GFR and CysC-Scr GFR of bias and overall accuracy of 30% were very similar. There was little advantage in adding Asian coefficient to modifying the CKD-EPI equation. CysC GFR overestimated GFR in patients with CKD stages 4 and 5.

Predicting outcomes after myocardial infarction by using the Chronic Kidney Disease Epidemiology Collaboration equation in comparison with the Modification of Diet in Renal Disease study equation: results from the Korea Acute Myocardial Infarction Registry

BACKGROUND

The presence of chronic kidney disease is an independent prognostic factor in patients with myocardial infarction (MI). We compared the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation and the Modification of Diet in Renal Disease (MDRD) study equation with regard to prognostic value in patients with MI.

METHODS

This study analyzed a retrospective cohort of 11 050 consecutive patients who had MI and were enrolled in the Korea Acute Myocardial Infarction Registry from November 2005 to August 2008. We applied the CKD-EPI equation and the MDRD study equation to determine the estimated glomerular filtration rate (eGFR) in a cohort of patients with MI.

RESULTS

The mean eGFR(CKD-EPI) was slightly higher than that of eGFR(MDRD) (73.16 versus 72.23 mL/min/1.73 m(2); P < 0.001). The prevalence of eGFR(CKD-EPI) <60 mL/min/1.73 m(2) was 26.9%, whereas that of eGFR(MDRD) was 28.5%. The area under the receiver operating characteristic curve was significantly larger for predicting the 1-year major adverse cardiovascular event (MACE) and 1-year all-cause mortality with CKD-EPI equation (0.648 versus 0.641, 0.768 versus 0.753, respectively; P < 0.001). The net reclassification index for improvement in risk of 1-year MACE and 1-year all-cause mortality were 4.09% (P< 0.001) and 9.25% (P< 0.001), respectively.

CONCLUSIONS

The application of the eGFR(CKD-EPI) demonstrated better predictive values for clinical outcomes than eGFR(MDRD) in a cohort of patients with MI.

Association of reduced renal function with hepatitis B virus infection and elevated alanine aminotransferase

BACKGROUND AND OBJECTIVES

Clinically, hepatitis B virus (HBV) infection is observed to be associated with nephropathy. However, previous population-based studies failed to show an association between HBV infection and CKD. Therefore, this cross-sectional study was designed to further explore this association.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A representative sample of 6854 Chinese adults aged 30-75 years was tested for levels of serum hepatitis B surface antigen, alanine aminotransferase (ALT), creatinine, urinary albumin/creatinine ratio, and potential CKD risk factors.

RESULTS

Neither HBV infection nor elevated ALT (ALT+; ≥ sex-specific 90th percentile of ALT levels of noninfected persons) was significantly associated with reduced estimated GFR (eGFR < 60 ml/min per 1.73 m(2)). Compared with noninfected persons, HBV-infected persons with ALT+, but not those with ALT- (P=0.26), were more likely to have reduced eGFR (odds ratio, 4.07; 95% confidence interval, 1.18-14.0; P=0.03). Further analysis with a general linear model revealed a significant difference in eGFR (mean ± SEM) between HBV-infected and noninfected persons (87.8±0.8 versus 90.2±0.4 ml/min per 1.73 m(2); P=0.002). This difference was mainly derived from that between HBV-infected persons with ALT+ and noninfected persons, with an average difference in eGFR of -4.5 (95% confidence interval, -0.9 to -8.1; P=0.01). HBV infection and ALT+, alone or in combination, were not significantly associated with albuminuria or CKD.

CONCLUSIONS

HBV infection with elevated ALT, rather than HBV infection alone, was associated with reduced renal function.

Clinical characteristics and outcomes of "silent" and "non-silent" peritonitis in patients on peritoneal dialysis

OBJECTIVES

We compared the clinical characteristics and outcomes of "silent" peritonitis (meaning episodes without fever and abdominal pain) and "non-silent" peritonitis in patients on peritoneal dialysis (PD).

METHODS

Our cohort study collected data about all peritonitis episodes occurring between January 2008 and April 2010. Disease severity score, demographics, and biochemistry and nutrition data were recorded at baseline. Effluent cell counts were examined at regular intervals, and the organisms cultured were examined. Treatment failure was defined as peritonitis-associated death or transfer to hemodialysis.

RESULTS

Of 248 episodes of peritonitis occurring in 161 PD patients, 20.9% led to treatment failure. Of the 248 episodes, 51 (20.6%) were not accompanied by fever and abdominal pain. Patients with these silent peritonitis episodes tended to be older (p = 0.003). The baseline values for body mass index, triglycerides, and daily energy intake were significantly lower before silent peritonitis episodes than before non-silent episodes (p = 0.01, 0.003, and 0.001 respectively). Although silent peritonitis episodes were more often culture-negative and less often caused by gram-negative organisms, and although they presented with low effluent white cell counts on days 1 and 3, the risk for treatment failure in those episodes was not lower (adjusted odds ratio: 1.33; 95% confidence interval: 0.75 to 2.36; p = 0.33).

CONCLUSIONS

Silent peritonitis is not a rare phenomenon, especially in older patients on PD. Although these episodes were more often culture-negative, silent presentation was not associated with a better outcome.

Comparison of clinicopathological features between children and adults with IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is prevalent among both children and adults. Illumination of the differences between them is important for clinical doctors.

METHODS

We retrospectively compared clinicopathological features in 110 children and 908 adults with IgAN.

RESULTS

The male to female ratio was 1.62:1 in children and 0.85:1 in adults. Most patients lacked triggers, but IgAN was preceded by upper respiratory infection (URI) in 45.5% of children and 20.2% of adults. Gross hematuria was the most common initial symptom in children (53.6%), especially in those associated with URI (82.0%), while other symptoms and abnormal laboratory parameters were more common in adults. Estimated glomerular filtration rate (eGFR) was higher in children than in adults. Co-deposition of IgA and C3 were found in 50.9% of children, while IgA deposit was often accompanied by two or more immune complexes in adults. The frequency of subclass I was significantly higher in children than in adults. Mild histological lesions were more common in pediatric IgAN patients associated with URI than other patients.

CONCLUSIONS

Pediatric patients showed relatively mild clinical manifestations and histological lesions compared with adult patients. URI was the most important trigger for IgAN, particularly in children. IgAN associated with URI was relatively mild.

Exploring the association between macroeconomic indicators and dialysis mortality

BACKGROUND AND OBJECTIVES

Mortality on dialysis varies greatly worldwide, with patient-level factors explaining only a small part of this variation. The aim of this study was to examine the association of national-level macroeconomic indicators with the mortality of incident dialysis populations and explore potential explanations through renal service indicators, incidence of dialysis, and characteristics of the dialysis population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Aggregated unadjusted survival probabilities were obtained from 22 renal registries worldwide for patients starting dialysis in 2003-2005. General population age and health, macroeconomic indices, and renal service organization data were collected from secondary sources and questionnaires. Linear modeling with log-log transformation of the outcome variable was applied to establish factors associated with survival on dialysis.

RESULTS

Two-year survival on dialysis ranged from 62.3% in Iceland to 89.8% in Romania. A higher gross domestic product per capita (hazard ratio=1.02 per 1000 US dollar increase), a higher percentage of gross domestic product spent on healthcare (1.10 per percent increase), and a higher intrinsic mortality of the dialysis population (i.e., general population-derived mortality risk of the dialysis population in that country standardized for age and sex; hazard ratio=1.04 per death per 10,000 person years) were associated with a higher mortality of the dialysis population. The incidence of dialysis and renal service indicators were not associated with mortality on dialysis.

CONCLUSIONS

Macroeconomic factors and the intrinsic mortality of the dialysis population are associated with international differences in the mortality on dialysis. Renal service organizational factors and incidence of dialysis seem less important.

Acute kidney injury and bilateral symmetrical enlargement of the kidneys as first presentation of B-cell lymphoblastic lymphoma

Lymphoblastic lymphoma is an uncommon subtype of lymphoid neoplasm in adults. Acute kidney injury at initial presentation due to lymphoblastic lymphoma infiltration of the kidneys has rarely been described. We report a 19-year-old woman who presented with acute kidney injury due to massive lymphomatous infiltration of the kidneys. The diagnosis of B-cell lymphoblastic lymphoma was established by immunohistochemical study of the biopsied kidney. The patient had an excellent response to the VDCLP protocol (vincristine, daunomycin, cyclophosphamide, asparaginase, and dexamethasone) with sustained remission. We recommend that lymphomatous infiltration be considered in patients presenting with unexplained acute kidney injury and enlarged kidneys.

Analysis of urinary microRNAs in chronic kidney disease

Kidney biopsy is the gold-standard diagnostic test for intrinsic renal disease, but requires hospital admission and carries a 3% risk of major complications. Current non-invasive prognostic indicators such as urine protein quantification have limited predictive value. Better diagnostic and prognostic tests for chronic kidney disease patients are a major focus for industry and academia, with efforts to date directed largely at urinary proteomic approaches. microRNAs constitute a recently identified class of endogenous short non-coding single-stranded RNA oligonucleotides that regulate gene expression post-transcriptionally. Quantification of urinary microRNAs offers an alternative approach to the identification of chronic kidney disease biomarkers.

Hepatitis B and C co-infection are independent predictors of progressive kidney disease in HIV-positive, antiretroviral-treated adults

Chronic kidney disease (CKD) is an important cause of morbidity and mortality in HIV-positive individuals. Hepatitis C (HCV) co-infection has been associated with increased risk of CKD, but prior studies lack information on potential mechanisms. We evaluated the association between HCV or hepatitis B (HBV) co-infection and progressive CKD among 3,441 antiretroviral-treated clinical trial participants. Progressive CKD was defined as the composite of end-stage renal disease, renal death, or significant glomerular filtration rate (eGFR) decline (25% decline to eGFR <60 mL/min/1.73 m(2) or 25% decline with a baseline <60). Generalized Estimating Equations were used to model the odds of progressive CKD. At baseline, 13.8% and 3.3% of participants were co-infected with HCV and HBV, respectively. Median eGFR was 111, and 3.7% developed progressive CKD. After adjustment, the odds of progressive CKD were increased in participants with HCV (OR 1.72, 95% CI 1.07-2.76) or HBV (OR 2.26, 95% CI 1.15-4.44). Participants with undetectable or low HCV-RNA had similar odds of progressive CKD as HCV seronegative participants, while participants with HCV-RNA >800,000 IU/ml had increased odds (OR 3.07; 95% CI 1.60-5.90). Interleukin-6, hyaluronic acid, and the FIB-4 hepatic fibrosis index were higher among participants who developed progressive CKD, but were no longer associated with progressive CKD after adjustment. Future studies should validate the relationship between HCV viremia and CKD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00027352; NCT00004978.

Periodontitis associated with chronic kidney disease among Mexican Americans

OBJECTIVE

In comparison to non-Hispanic whites, a number of health-care disparities, including poor oral health, have been identified among Hispanics in general and Mexican Americans in particular. We hypothesized that Mexican Americans with chronic kidney disease (CKD) would have higher prevalence of chronic periodontitis compared with Mexican Americans with normal kidney function, and that the level of kidney function would be inversely related to the prevalence of periodontal disease.

METHODS

We examined this hypothesis using the National Health and Nutrition Examination Survey 1988-1994 (NHANES III) data set. We followed the American Academy of Periodontology/Center for Disease Control and Prevention case definition for periodontitis. Glomerular filtration rate was estimated using the CKD-Epidemiology equation for Hispanic populations. The classification to CKD stages was based on the National Kidney Foundation Kidney Disease Outcomes Quality Initiative.

RESULTS

Periodontitis prevalence increased across the kidney function groups showing a statistically significant dose-response association (P<0.001). Mexican Americans with reduced kidney function were twofold more likely to have periodontitis compared with Mexican Americans with normal kidney function after adjusting for potential confounders such as smoking, diabetes, and socioeconomic status. Multivariate adjusted odds ratio for periodontitis significantly increased with 1, 5, and 10 mL/minute estimated glomerular filtration rate reduction from the mean.

CONCLUSION

This is the first report, to the best our knowledge, that showed an increase of periodontitis prevalence with decreased kidney function in this population.

Association between vitamin C deficiency and dialysis modalities

AIM

  We designed a cross-sectional study to investigate plasma vitamin C level in patients who underwent maintenance haemodialysis (MHD) and continuous ambulatory peritoneal dialysis (CAPD) to explore whether there is a difference in vitamin C deficiency between MHD patients and CAPD patients.

METHODS

  This investigation included 382 dialysis patients without vitamin C supplement before the study. Demographic characteristics, laboratory tests, ascorbic acid and total plasma vitamin C level were measured. A linear regression model was built to explore the association between vitamin C deficiency and dialysis modalities after adjusting for age, dialysis vintage, gender, Charlson index, modality of dialysis and hsCRP.

RESULTS

  The range of plasma vitamin C level was from 0.48 µg/mL to 31.16 µg/mL. 35.9% (n = 137) patients had severe vitamin C deficiency (<2 µg/mL). Plasma vitamin C level was inversely associated with age and dialysis vintage. After age and dialysis vintage were adjusted, vitamin C deficiency was associated with MHD. R square for model fitting was relatively low, which implied that there were other vitamin C influencing factors not included in the model.

CONCLUSIONS

  Vitamin C deficiency is common in dialysis patients, especially in patients treated with MHD.

Association between blood glucose levels and high-sensitivity cardiac troponin T in an overt cardiovascular disease-free community-based study

AIM

To investigate the relationship between blood glucose levels and high-sensitivity cardiac troponin T (hs-cTnT) in an overt cardiovascular disease-free community-based study.

METHODS

Cardiac troponin T levels were measured using a highly sensitive assay in 1365 individuals, aged 45 years or older, without overt cardiovascular disease in a community-based, cross-sectional study, in Beijing, China. All participants underwent anthropometric measurements, biochemical analysis and an oral glucose tolerance test.

RESULTS

Both the prevalence of detectable hs-cTnT (≥3.0 pg/mL) and elevated hs-cTnT (≥13.3 pg/mL) were significantly higher in patients with diabetes mellitus (DM) than in patients with normal glucose tolerance (NGT), and those with impaired glucose regulation (IGR). After adjustment for multiple factors, the prevalence of detectable hs-cTnT (adjusted OR=1.22) and elevated hs-cTnT (adjusted OR=1.29) in the DM group were still significantly higher than in the NGT group. hs-cTnT was related to multiple risk factors for cardiovascular events, and fasting blood glucose level was an independent predictor of hs-cTnT.

CONCLUSIONS

hs-cTnT showed a varied distribution in a community-based population with different blood glucose levels. Both the prevalence of detectable hs-cTnT and elevated hs-cTnT were increased significantly in the diabetic population. hs-cTnT was related to multiple risk factors for cardiovascular events, and fasting blood glucose level was an independent predictor of hs-cTnT.