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BACKGROUND AND OBJECTIVES - Diabetes is the leading cause of ESRD. Glucose control improves kidney outcomes. Most patients eventually require treatment intensification with second-line medications; however, the differential effects of those therapies on kidney function are unknown.
DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS - We studied a retrospective cohort of veterans on metformin monotherapy from 2001 to 2008 who added either insulin or sulfonylurea and were followed through September of 2011. We used propensity score matching 1:4 for those who intensified with insulin versus sulfonylurea, respectively. The primary composite outcome was persistent decline in eGFR≥35% from baseline (GFR event) or a diagnosis of ESRD. The secondary outcome was a GFR event, ESRD, or death. Outcome risks were compared using marginal structural models to account for time-varying covariates. The primary analysis required persistence with the intensified regimen. An effect modification of baseline eGFR and the intervention on both outcomes was evaluated.
RESULTS - There were 1989 patients on metformin and insulin and 7956 patients on metformin and sulfonylurea. Median patient age was 60 years old (interquartile range, 54-67), median hemoglobin A1c was 8.1% (interquartile range, 7.1%-9.9%), and median creatinine was 1.0 mg/dl (interquartile range, 0.9-1.1). The rate of GFR event or ESRD (primary outcome) was 31 versus 26 per 1000 person-years for those who added insulin versus sulfonylureas, respectively (adjusted hazard ratio, 1.27; 95% confidence interval, 0.99 to 1.63). The rate of GFR event, ESRD, or death was 64 versus 49 per 1000 person-years, respectively (adjusted hazard ratio, 1.33; 95% confidence interval, 1.11 to 1.59). Tests for a therapy by baseline eGFR interaction for both the primary and secondary outcomes were not significant (P=0.39 and P=0.12, respectively).
CONCLUSIONS - Among patients who intensified metformin monotherapy, the addition of insulin compared with a sulfonylurea was not associated with a higher rate of kidney outcomes but was associated with a higher rate of the composite outcome that included death. These risks were not modified by baseline eGFR.
Copyright © 2016 by the American Society of Nephrology.
BACKGROUND - Whether polyunsaturated fatty acids (PUFA) are associated with end-stage renal disease (ESRD) in populations with a high burden of risk factors for kidney disease is unknown. We sought to determine whether PUFA intake is associated with ESRD.
METHODS - We conducted a nested case-control study of ESRD within the Southern Community Cohort Study (SCCS), a prospective cohort of low-income blacks and whites in the southeastern US (2002-2009). Through 2012, 1,074 incident ESRD cases were identified by linkage with the United States Renal Data System and matched to 3,230 controls by age, sex and race. Dietary intake of total, n-3 or n-6 PUFA was assessed from a validated food frequency questionnaire administered at baseline. Odds ratios (ORs) and 95 % confidence intervals (CIs) were computed from logistic regression models that included matching variables, body mass index, smoking, diabetes, hypertension, education, income, total energy intake and percent energy from protein and saturated fat.
RESULTS - The mean (SD) age of participants was 55 (9) years. Most participants were women (55 %), black (87 %), with hypertension (67 %) and on average obtained 8 % of their energy from PUFA. Higher PUFA intake was marginally associated with a lower risk of ESRD in adjusted analyses. The adjusted odds ratios (95 % confidence intervals) for ESRD for the 5 vs. 1 quintile of PUFA were 0.79 (0.60-1.05; P = 0.06) for total PUFA, 0.81 (0.61-1.06; P = 0.04) for n-6 PUFA and 0.93 (0.71-1.21; P = 0.45) for n-3 PUFA.
CONCLUSIONS - We observed a marginally significant inverse trend between dietary PUFA intake and ESRD incidence, mainly driven by n-6 fatty acid intake. Our findings require replication but suggest that a diet rich in n-6 PUFA may prevent ESRD development in a population with a high burden of kidney disease risk factors.
BACKGROUND AND AIMS - Diabetes, a risk factor for end-stage renal disease (ESRD), is associated with impaired protein metabolism. We investigated whether protein intake is associated with ESRD and whether the risk is higher among blacks with diabetes.
METHODS AND RESULTS - We conducted a nested case-control study of ESRD within the Southern Community Cohort Study, a prospective study of low-income blacks and whites in the southeastern US (2002-2009). Through 2012, 1057 incident ESRD cases were identified by linkage with the United States Renal Data System and matched to 3198 controls by age, sex, and race. Dietary intakes were assessed from a validated food frequency questionnaire at baseline. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed from logistic regression models that included matching variables, BMI, education, income, hypertension, total energy intake, and percent energy from saturated and polyunsaturated fatty acids. Mean (±SD) daily energy intake from protein was higher among ESRD cases than controls (15.7 ± 3.3 vs. 15.1 ± 3.1%, P < 0.0001). For a 1% increase in percent energy intake from protein, the adjusted ORs (95% CIs) for ESRD were 1.06 (1.02-1.10) for blacks with diabetes, 1.02 (0.98-1.06) for blacks without diabetes, 0.99 (0.90-1.09) for whites with diabetes and 0.94 (0.84-1.06) for whites without diabetes. Protein intake in g/kg/day was also associated with ESRD (4th vs. 1st quartile OR = 1.76; 95% CI: 1.17-2.65).
CONCLUSION - Our results raise the possibility that among blacks with diabetes, increased dietary protein is associated with increased incidence of ESRD. Studies on how protein intake and metabolism affect ESRD are needed.
Copyright Â© 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.
BACKGROUND AND OBJECTIVES - Despite the potential benefits of conservative management, providers rarely discuss it as a viable treatment option for patients with advanced CKD. This survey was to describe the knowledge, attitudes, and practices of nephrologists and primary care providers regarding conservative management for patients with advanced CKD in the United States.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS - We developed a questionnaire on the basis of a literature review to include items assessing knowledge, attitudes, and self-reported practices of conservative management for patients with advanced CKD. Potential participants were identified using the American Medical Association Physician Masterfile. We then conducted a web-based survey between April and May of 2015.
RESULTS - In total, 431 (67.6% nephrologists and 32.4% primary care providers) providers completed the survey for a crude response rate of 2.7%. The respondents were generally white, men, and in their 30s and 40s. Most primary care provider (83.5%) and nephrology (78.2%) respondents reported that they were likely to discuss conservative management with their older patients with advanced CKD. Self-reported number of patients managed conservatively was >11 patients for 30.6% of nephrologists and 49.2% of primary care providers. Nephrologists were more likely to endorse difficulty determining whether a patient with CKD would benefit from conservative management (52.8% versus 36.2% of primary care providers), whereas primary care providers were more likely to endorse limited information on effectiveness (49.6% versus 24.5% of nephrologists) and difficulty determining eligibility for conservative management (42.5% versus 14.3% of nephrologists). There were also significant differences in knowledge between the groups, with primary care providers reporting more uncertainty about relative survival rates with conservative management compared with different patient groups.
CONCLUSIONS - Both nephrologists and primary care providers reported being comfortable with discussing conservative management with their patients. However, both provider groups identified lack of United States data on outcomes of conservative management and characteristics of patients who would benefit from conservative management as barriers to recommending conservative management in practice.
Copyright © 2016 by the American Society of Nephrology.
BACKGROUND - Coenzyme Q10 (CoQ10) supplementation improves mitochondrial coupling of respiration to oxidative phosphorylation, decreases superoxide production in endothelial cells, and may improve functional cardiac capacity in patients with congestive heart failure. There are no studies evaluating the safety, tolerability and efficacy of varying doses of CoQ10 in chronic hemodialysis patients, a population subject to increased oxidative stress.
METHODS - We performed a dose escalation study to test the hypothesis that CoQ10 therapy is safe, well-tolerated, and improves biomarkers of oxidative stress in patients receiving hemodialysis therapy. Plasma concentrations of F2-isoprostanes and isofurans were measured to assess systemic oxidative stress and plasma CoQ10 concentrations were measured to determine dose, concentration and response relationships.
RESULTS - Fifteen of the 20 subjects completed the entire dose escalation sequence. Mean CoQ10 levels increased in a linear fashion from 704 ± 286 ng/mL at baseline to 4033 ± 1637 ng/mL, and plasma isofuran concentrations decreased from 141 ± 67.5 pg/mL at baseline to 72.2 ± 37.5 pg/mL at the completion of the study (P = 0.003 vs. baseline and P < 0.001 for the effect of dose escalation on isofurans). Plasma F2-isoprostane concentrations did not change during the study.
CONCLUSIONS - CoQ10 supplementation at doses as high as 1800 mg per day was safe in all subjects and well-tolerated in most. Short-term daily CoQ10 supplementation decreased plasma isofuran concentrations in a dose dependent manner. CoQ10 supplementation may improve mitochondrial function and decrease oxidative stress in patients receiving hemodialysis.
TRIAL REGISTRATION - This clinical trial was registered on clinicaltrials.gov [NCT00908297] on May 21, 2009.
UNLABELLED - ♦
BACKGROUND - Insulin resistance (IR) is common in maintenance dialysis patients and is associated with excess mortality. Hyperinsulinemic euglycemic glucose clamp (HEGC) is the gold standard for measuring IR. There are limited studies using HEGC for comparison to other indirect indices of IR in peritoneal dialysis (PD) patients, nor have there been direct comparisons between patients receiving PD and those on maintenance hemodialysis (MHD) with regard to severity of IR, methods of measurement, or factors associated with the development of IR. ♦
METHODS - This is a cross-sectional, single-center study performed in 10 prevalent PD patients of median age 48 years (range 41 - 54); 50% were female and 60% were African American. Insulin resistance was assessed by HEGC (glucose disposal rate [GDR]), homeostatic model assessment of IR (HOMA-IR), HOMA-IR corrected by adiponectin (HOMA-AD), leptin adiponectin ratio (LAR), quantitative insulin sensitivity check index (QUICKI), McAuley's index, and oral glucose tolerance test (OGTT) at each time point for a total of 18 studies. Retrospective analysis compared this cohort to 12 hemodialysis patients who had previously undergone similar testing. ♦
RESULTS - The median GDR was 6.4 mg/kg/min (interquartile range [IQR] 6.0, 7.8) in the PD cohort compared with the MHD group, which was 5.7 mg/kg/min (IQR 4.3, 6.6). For both the PD and MHD cohorts, the best predictors of GDR by HEGC after adjusting for age, gender, and body mass index (BMI), were HOMA-AD (PD: r = -0.69, p = 0.01; MHD: r = -0.78, p = 0.03) and LAR (PD: r = -0.68, p < 0.001; MHD: r = -0.65, p = 0.04). In both groups, HOMA-IR and QUICKI failed to have strong predictive value. Eight of 10 PD patients had at least 1 abnormal OGTT, demonstrating impaired glucose tolerance. ♦
CONCLUSIONS - Insulin resistance is highly prevalent in PD patients. The adipokine based formulas, HOMA-AD and LAR, correlated well in both the PD and MHD populations in predicting GDR by HEGC, outperforming HOMA-IR. The use of these novel markers could be considered for large-scale, epidemiological outcome studies.
Copyright © 2016 International Society for Peritoneal Dialysis.
BACKGROUND - Endothelial dysfunction occurs in patients with end-stage renal disease (ESRD) and is associated with increased cardiovascular morbidity and mortality. Asymmetric dimethylarginine (ADMA) contributes to endothelial dysfunction in ESRD. In the general population, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) decrease ADMA levels, but no study has compared the effect of these drugs in patients with ESRD on maintenance hemodialysis (MHD).
METHODS - We evaluated the effect of 1-week treatment with ramipril (5 mg/d), valsartan (160 mg/d), and placebo on ADMA levels in 15 patients on MHD in a double-blind, placebo-controlled, three x three cross-over study.
RESULTS - We found that ADMA levels were increased at baseline and throughout the dialysis session during ramipril treatment (p < 0.001 compared to both, placebo and valsartan). Ramipril did not increase ADMA levels in a study of patients without ESRD, suggesting that factors related to ESRD or hemodialysis contribute to the ACE inhibitor-induced increase in ADMA. We have previously shown that ACE inhibition increases bradykinin (BK) levels during hemodialysis. We therefore evaluated the effect of bradykinin on ADMA production in A549 cells; a cell line that expresses BK receptors. Incubation with BK increased intracellular ADMA concentration through BK B2-receptor stimulation.
CONCLUSION - These data indicate that short-term ACE inhibition increases ADMA in patients on MHD whereas ARBs do not. In vitro studies further suggest that this may occur through BK-mediated increase in ADMA production during ACE inhibition.
TRIAL REGISTRATION - Clinicaltrials.gov NCT00732069 August 6 2008 and NCT00607672 February 4 2008.
UNLABELLED - ♦
BACKGROUND - In general, efforts to standardize care based on group consensus practice guidelines have resulted in lower morbidity and mortality. Although there are published guidelines regarding insertion and perioperative management of peritoneal dialysis (PD) catheters, variation in practice patterns between centers may exist. The objective of this study is to understand variation in PD catheter insertion practices in preparation for conducting future studies. ♦
METHODS - An electronic survey was developed by the research committee of the International Society for Peritoneal Dialysis - North American Research Consortium (ISPD-NARC) to be completed by physicians and nurses involved in PD programs across North America. It consisted of 45 questions related to 1) organizational characteristics; 2) PD catheter insertion practices; 3) current quality-improvement initiatives; and 4) interest in participation in PD studies. Invitation to participate in the survey was given to nephrologists and nurses in centers across Canada and the United States (US) identified by participation in the inaugural meeting of the ISPD-NARC. Descriptive statistics were applied to analyze the data. ♦
RESULTS - Fifty-one ISPD-NARC sites were identified (45% in Canada and 55% in the US) of which 42 responded (82%). Center size varied significantly, with prevalent PD population ranging from 6 - 300 (median: 60) and incident PD patients in the year prior to survey administration ranging from 3 - 180 (median: 20). The majority of centers placed fewer than 19 PD catheters/year, with a range of 0 - 50. Availability of insertion techniques varied significantly, with 83% of centers employing more than 1 insertion technique. Seventy-one percent performed laparoscopic insertion with advanced techniques (omentectomy, omentopexy, and lysis of adhesions), 62% of sites performed open surgical dissection, 10% performed blind insertion via trocar, and 29% performed blind placement with the Seldinger technique. Use of double-cuff catheters was nearly universal, with a near even distribution of catheters with pre-formed bend versus straight inter-cuff segments. There was also variation in the choice of perioperative antibiotics and perioperative flushing practices. Although 86% of centers had quality-improvement initiatives, there was little consensus as to appropriate targets. ♦
CONCLUSIONS - There is marked variability in PD catheter insertion techniques and perioperative management. Large multicenter studies are needed to determine associations between these practices and catheter and patient outcomes. This research could inform future trials and guidelines and improve practice. The ISPD-NARC is a network of PD units that has been formed to conduct multicenter studies in PD.
Copyright © 2016 International Society for Peritoneal Dialysis.
Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health approach to the management of LTBI in high risk individuals in countries with high or middle upper income and TB incidence of <100 per 100 000 per year. The guidelines strongly recommend systematic testing and treatment of LTBI in people living with HIV, adult and child contacts of pulmonary TB cases, patients initiating anti-tumour necrosis factor treatment, patients receiving dialysis, patients preparing for organ or haematological transplantation, and patients with silicosis. In prisoners, healthcare workers, immigrants from high TB burden countries, homeless persons and illicit drug users, systematic testing and treatment of LTBI is conditionally recommended, according to TB epidemiology and resource availability. Either commercial interferon-gamma release assays or Mantoux tuberculin skin testing could be used to test for LTBI. Chest radiography should be performed before LTBI treatment to rule out active TB disease. Recommended treatment regimens for LTBI include: 6 or 9 month isoniazid; 12 week rifapentine plus isoniazid; 3-4 month isoniazid plus rifampicin; or 3-4 month rifampicin alone.
Copyright ©ERS 2015.
UNLABELLED - ♦
BACKGROUND - A low protein diet supplemented with ketoacids has been shown to improve the metabolic profile, including insulin resistance, in patients with chronic kidney disease (CKD), but whether ketoacids alone exert similar effects is unknown. In this prospective randomized controlled trial, we aimed to evaluate the effects of ketoacid supplementation on insulin resistance, systemic inflammation, oxidative stress and endothelial dysfunction among 100 CKD patients undergoing peritoneal dialysis (PD). ♦
METHODS - Patients from one Chinese PD center were randomly assigned to take ketoacids (12 tablets per day) (n = 50) versus a control group (n = 50) for 6 months in an open-label parallelarm design. Daily protein intake of 0.8 - 1.2 g/kg/d and daily energy intake of 25 - 35 kcal/kg/d was prescribed to both groups. Insulin resistance was evaluated using homeostatic model assessment (HOMA-IR) index as the primary outcome. We assessed systemic inflammation using high-sensitive C-reactive protein (hs-CRP) and interleukin-6 (IL-6), oxidative stress using plasma oxidized low density lipoprotein (oxLDL), adipokines using leptin and adiponectin and endothelial dysfunction using serum soluble intercellular adhesion molecule-1 (sICAM) and soluble vascular adhesion molecule-1 (sVCAM) as secondary outcomes. ♦
RESULTS - There were no significant differences in baseline characteristics between the 2 groups except a slightly higher age in patients assigned to the intervention. A total of 89% of participants completed the 6-month intervention. There was no significant difference in the change of HOMA-IR values from baseline between groups after adjusting for baseline age, gender, body mass index and HOMA-IR. For secondary outcomes, hs-CRP varied significantly between groups (p = 0.02), increasing over time for the control group while remaining stable for the ketoacid group. Similarly, the leptin/adiponectin ratio (LAR) differed between groups (p < 0.001), remaining stable in the ketoacid group but increasing in the control group. ♦
CONCLUSION - Ketoacid therapy administered for 6 months had no effect on HOMA-IR but resulted in improvements in hs-CRP and LAR, suggesting metabolic benefit. Future studies are needed to confirm these results and any potential benefit in vascular health of PD patients.
Copyright © 2015 International Society for Peritoneal Dialysis.