Author Interviews, Critical Care - Intensive Care - ICUs, Heart Disease, JAMA, Kidney Disease, Surgical Research / 29.12.2015

MedicalResearch.com Interview with: Azra Bihorac, MD, MS and Department of Anesthesiology Charles Hobson, MD, MHA Department of Surgery, Malcolm Randall Veterans Affairs Medical Center, Department of Health Services Research, Management, and Policy University of Florida Gainesville Florida  Medical Research: What is the background for this study? What are the main findings? Response:   Background is that as ICU clinicians we see acute kidney injury (AKI) and chronic kidney disease (CKD) frequently and have to deal with the consequences, and as AKI researchers we have shown that even mild and moderate AKI – even if there is complete resolution of the AKI by the time of hospital discharge – result in significantly increased morbidity and mortality for the surgical patient. Furthermore we are aware of the existing relationship between CKD and cardiovascular mortality, and we wanted to explore any relationship between AKI and cardiovascular mortality in the vascular surgery patients that we care for on a daily basis. The most important finding was the strong association between AKI and cardiovascular mortality in these patients – equal to the well-known association between CKD and cardiovascular mortality. (more…)
Author Interviews, Endocrinology, Kidney Disease, Transplantation, Vitamin K / 21.12.2015

MedicalResearch.com Interview with: Josep M Cruzado, MD Head, Nephrology Department Hospital Universitari de Bellvitge  Medical Research: What is the background for this study? What are the main findings? Dr. Cruzado: Tertiary hyperparathyroidism is frequent after renal transplantation. Inappropriately high parathyroid hormone levels are associated with hypercalcemia, hyperphosphatemia, both allograft and vascular calcification and bone mineral density loss. Cinacalcet is highly effective to control hypercalcemia in this setting although there were no studies comparing cinacalcet with subtotal parathyroidectomy. Main findings are that subtotal parathyroidectomy is superior to cinacalcet in normalizing hypercalcemia amb iPTH, increased bone mineral density at femoral neck and is more cost effective (the cost of subtotal parathyroidectomy is equal to 14 months of cinacalcet and this drug should be maintained overtime). (more…)
Author Interviews, Duke, Heart Disease, JACC, Kidney Disease / 08.12.2015

MedicalResearch.com Interview with: Daniel Friedman, MD Cardiology Fellow Duke University Hospital Durham, North Carolina MedicalResearch: What is the background for this study? What are the main findings? Dr. Friedman: Cardiac resynchronization therapy (CRT) has been demonstrated to reduce heart failure hospitalizations, heart failure symptoms, and mortality in randomized clinical trials. However, these well-known trials either formally excluded or did not report enrollment of patients with more advanced chronic kidney disease (CKD), which we defined as a glomerular filtration rate of <45ml/minute. Since advanced CKD has been associated with an increased risk of adverse outcomes among patients with a variety of pacemakers and defibrillators, many have questioned whether the risks of CRT may outweigh the benefits in this population. Furthermore, many have hypothesized that the competing causes of morbidity and mortality among advanced CKD patients who meet criteria for CRT may mitigate clinical response and net benefit. Our study assessed the comparative effectiveness of CRT with defibrillator (CRT-D) versus defibrillator alone in CRT eligible patients with a glomerular filtration rate of <60ml/minute (Stage III-V CKD, including those on dialysis). We demonstrated that CRT-D use was associated with a significant reduction in heart failure hospitalization or death in the overall population and across the spectrum of CKD. The lower rates of heart failure hospitalization or death was apparent in all subgroups we tested except for those without a left bundle branch block. Importantly, we also demonstrated that complication rates did not increase with increasing severity of CKD. (more…)
Author Interviews, Biomarkers, Kidney Disease, University of Michigan / 07.12.2015

MedicalResearch.com Interview with: Wenjun Ju, Ph.D., M.S. Research Assistant Professor, Internal Medicine Matthias Kretzler, M.D. Professor, Internal Medicine, Nephrology Research Professor, Computational Medicine and Biology University of Michigan Health System  Medical Research: What is the background for this study? What are the main findings? Response: Chronic kidney disease (CKD) is a global health issue that affects approximately 15% of the global population.. While not all patients with CKD will progress to end-stage kidney disease (ESKD), those that do tend to advance quickly and require dialysis or kidney transplant. They are also at an increased risk of death from cardiovascular disease. According to the International Society of Nephrology, treatment of CKD, including medical management, dialysis and kidney transplant, is very costly.  In the U.S. alone, therapy for CKD is likely to exceed $48 billion per year, and the ESKD program consumes 6.7 percent of the total Medicare budget to care for less than 1 percent of the covered population. In China, the disease will cost the economy the equivalent of $558 billion in the U.S. over the next decade. Early identification of patients that are more likely to experience end-stage kidney disease is an urgent, unmet clinical need. Currently, kidney biopsy is required to determine diagnosis and prognosis of kidney disease. This procedure is costly, carries a low, but significant health risk, and has limited ability to predict the future course of kidney disease. Together with the European Renal cDNA Bank and the Peking University Institute of Nephrology, the University of Michigan team identified epidermal growth factor (EGF) as a promising candidate for prediction of kidney function loss while analyzing transcriptomic data derived from kidney tissue biopsies of CKD patients across Europe and the U.S. We then validated the findings in urine samples from more than 940 patients in North America, Europe and China, and found that a decrease in urinary EGF protein concentration is an early sign of diminishing kidney function and pinpoints the at-risk patient population. (more…)
Author Interviews, Heart Disease, JAMA, Kidney Disease / 05.12.2015

MedicalResearch.com Interview with: Girish N. Nadkarni, MD, MPH Division of Nephrology, Department of Medicine Icahn School of Medicine at Mount Sinai New York, New York MedicalResearch.com: What is the background for this study? What are the main findings? Dr. Nadkarni: Cardiovascular disease is one of the major causes of morbidity and mortality in patients with kidney disease. Moreover, there is a lack of good quality evidence in kidney disease patients. In addition, previous studies have shown that cardiovascular trials exclude patients with kidney disease. We wanted to analyze all of the clinical trials on acute myocardial infarctions and heart failure in the last decade and see if they continued excluding patients with kidney disease. We discovered that in 371 trials including close to six hundred thousand patients, the majority (57%) excluded patients with kidney disease. A large proportion of the trials excluded patients for non-specific reasons, rather than a prespecified threshold of kidney function and did not report kidney function at baseline. Finally, in trials that did include kidney patients and reported outcomes by kidney function, only 13% showed an interaction or suggestion of harm. (more…)
Author Interviews, Diabetes, Kidney Disease / 12.11.2015

MedicalResearch.com Interview with: Charuhas Thakar, MD Director, Division of Nephrology and Hypertension Professor of Medicine University of Cincinnati Medical Research: What is the background for this study? What are the main findings? "Diabetes is the major contributor to the growing burden of end-stage renal disease,” says Charuhas Thakar, MD, professor and director of the Division of Nephrology and Hypertension at the UC College of Medicine. "Acute kidney injury is a common problem among diabetic patients who require admissions to hospitals. Approximately one-third of patients who develop AKI also have diabetes mellitus.” Dr. Thakar along with a team of researchers have looked at a cohort of about 3,700 patients with Type 2 diabetes longitudinally followed for a five-year period to determine AKI’s impact. AKI is a rapid loss of kidney function, which is common in hospitalized patients. It has many causes that include low blood volume, exposure to substances or interventions harmful to the kidney and obstruction of the urinary tract. (more…)
Author Interviews, Blood Pressure - Hypertension, Kidney Disease / 11.11.2015

MedicalResearch.com Interview with: Dr Will Herrington MD, MRCP and Dr Natalie Staplin PhD Nuffield Department of Population Health, University of Oxford Oxford, UK Medical Research: What is the background for this study? What are the main findings? Response: These analyses use data from SHARP, a trial of 9000 patients with chronic kidney disease which established that lowering LDL-cholesterol with a statin-based regime (simvastatin 20mg/ezetimibe 10mg) safely reduced risk of a heart attack or stroke in kidney patients. We have now used the SHARP dataset to investigate the association between blood pressure and rate of renal progression among those with different levels of albumin in the urine. These observations show that higher systolic blood pressure is associated with faster rate of renal progression irrespective of the presence or absence of albumin in the urine. (more…)
Author Interviews, Depression, Diabetes, Kidney Disease / 10.11.2015

MedicalResearch.com Interview with: Miklos Z Molnar, MD, PhD, FEBTM, FERA, FASN Associate Professor of Medicine Division of Nephrology, Department of Medicine University of Tennessee Health Science Center Memphis, TN, 38163  Medical Research: What is the background for this study? What are the main findings? Dr. Molnar: We examine the association between presence of depression and all-cause mortality; incident Coronary Heart Disease (CHD) (new onset AMI, CABG or PCI), incident ischemic stroke, slopes of eGFR (OLS, <-5 vs ≥-5 ml/min/1.73m2/yr) in 933,211 diabetic (based on ICD9, medication and HbA1c ≥ 6.5%) US Veterans with eGFR ≥ 60 ml/min/1.73m2 at baseline. We adjusted for independent covariates, collected from VA databases, such as age, gender, race, BMI, marital status, income, service connection, comorbid conditions (ICD9), baseline eGFR, serum albumin. Mean age was 64±11 years, 97% were male and 18% African-American. Depression was present in 340,806 (37%) patients at enrollment. During a median follow-up of 7.3 years, 180,343 patients (19%) developed Chronic Kidney Disease (CKD).AS (adjusted hazard ratio [aHR] and 95% confidence interval [CI]: 1.20 (1.19-1.21)). Similarly, depression was associated with 35% higher risk of incident stroke (aHR and 95% CI: 1.35 (1.32-1.39), 24% higher risk of incident CHD (aHR and 95% CI: 1.24 (1.22-1.27) and 25% higher risk of all cause mortality (aHR and 95% CI: 1.25 (1.24-1.26) during the follow-up. (more…)
Author Interviews, Kidney Disease, Social Issues / 10.11.2015

MedicalResearch.com Interview with: Dr. Rachael Morton, PhD Associate Professor Director of Health Economics, NHMRC Clinical Trials Centre The University of Sydney, Sydney Australia Medical Research: What is the background for this study? Dr. Morton: Household income was measured at baseline and study end among participants with moderate to severe chronic kidney disease (CKD), randomized into the Study of Heart and Renal Protection (SHARP).Household poverty was defined as <50% of the median household income for the participating country. (more…)
Author Interviews, Kidney Disease, Transplantation / 10.11.2015

MedicalResearch.com Interview with: Sumit Mohan, MD, MPH Assistant Professor of Medicine & Epidemiology Director, Transplant Outcomes Research at CUMC Division of Nephrology, Department of Medicine Columbia University Medical Center   Medical Research: What is the background for this study? What are the main findings? Dr. Mohan: Kidney transplantation is the preferred treatment for End Stage Renal Disease but transplantation access is limited in part to the scarcity of organs in the United States. Despite this, currently 17% of all kidneys that are procured in the United States for transplant are discarded - a number that has been steadily increasing. The reasons for the discard of these kidneys is poorly understood and urgently needs to be studied. (more…)
Author Interviews, Heart Disease, Kidney Disease, Pharmacology / 08.11.2015

MedicalResearch.com Interview with: Frederic T. (Josh) Billings IV, MD, Msc Assistant Professor of Anesthesiology and Critical Care Medicine Vanderbilt University Medical Center  Medical Research: What is the background for this study? What are the main findings? Dr. Billings: Acute kidney injury (AKI) following cardiac surgery is common (affects 20-30% of patients), and even mild forms of AKI are independently associated with a five-fold increase in death. Statins, commonly prescribed to reduce cholesterol concentrations and cardiovascular disease, affect several mechanisms underlying surgical AKI. Observational studies comparing rates of AKI between statin users and non-users have yielded inconsistent results and don’t assess the effect of statin use during the surgical period. In a double blind, placebo-controlled, randomized clinical trial of 653 cardiac surgery patients, we found that high-dose atorvastatin given prior to surgery, the day of surgery and daily postoperatively did not affect AKI. In fact, among statin-naïve patients with pre-existing kidney disease, rates of AKI were higher in those randomized to atorvastatin compared to those randomized to placebo. In patients who were using statins prior to the study, rates of AKI were similar between those randomized to atorvastatin and those randomized to placebo (short-term withdrawal), regardless of baseline kidney function. Safety markers of muscle and liver toxicity were not affected by statin treatment. (more…)
Author Interviews, Kidney Disease, Nature / 27.10.2015

MedicalResearch.com Interview with: Daniele Zink PhD Institute of Bioengineering and Nanotechnology Singapore  Medical Research: What is the background for this study? Dr. Zink: The kidney is one of the main target organs for toxic effects of drugs, environmental toxicants and other compounds. Renal proximal tubular cells (PTCs) are frequently affected due to their roles in compound transport and metabolism. Validated and accepted assays for the prediction of PTC toxicity in humans currently do not exist. Recently, we have developed the first and only pre-validated assays for the accurate prediction of PTC toxicity in humans 1, 2. This previous work was performed with human primary renal proximal tubular cells (HPTCs) or embryonic stem cell-derived HPTC-like cells. HPTCs are associated with a variety of issues that apply to all kinds of primary cells, such as cell sourcing problems, inter-donor variability and limited proliferative capacity. Embryonic stem cell-derived cells are associated with ethical and legal issues. These are the main reasons why induced pluripotent stem cell (iPSC)-derived cells are currently a favored cell source for in vitro toxicology and other applications. The problem was that stem cell-based approaches were not well-established with respect to the kidney. Recently, the group of IBN Executive Director Prof. Jackie Y. Ying developed the first protocol for differentiating embryonic stem cells into HPTC-like cells, and my group has contributed to characterizing these cells and publishing the results 3.  In the work published in Scientific Reports ,4we have applied a modified version of this protocol to iPSCs. In this way, we have established the simplest and fastest protocol ever for differentiating iPSCs into HPTC-like cells. The cells can be used for downstream applications after just 8 days of differentiation. These cells can also be applied directly without further purification due to their high purity of > 90%. By using these cells, we have developed the first and only iPSC-based model for the prediction of PTC toxicity in humans. This was achieved by combining our iPSC-based differentiation protocol with our previously developed assay based on interleukin (IL)6/IL8 induction 1, 2 and machine learning methods 5. Machine learning methods were used for data analysis and for determining the predictive performance of the assay. The test accuracy of the predictive iPSC-based model is 87%, and the assay is suitable for correctly identifying injury mechanisms and compound-induced cellular pathways. (more…)
Author Interviews, Genetic Research, Kidney Disease, Nature, Stem Cells / 24.10.2015

MedicalResearch.com Interview with: Benjamin Freedman, Ph.D. Assistant Professor | University of Washington Department of Medicine | Division of Nephrology Member, Kidney Research Institute Member, Institute for Stem Cell and Regenerative Medicine Seattle WA 98109  Medical Research: What is the background for this study? What are the main findings? Dr. Freedman: We are born with a limited number of kidney tubular subunits called nephrons. There are many different types of kidney disease that affect different parts of the nephron. The common denominator between all of these diseases is the irreversible loss of nephrons, which causes chronic kidney disease in 730 million patients worldwide, and end stage renal disease in 2.5 million. Few treatments have been discovered that specifically treat kidney disease, and the therapeutic gold standards, dialysis and transplant, are of limited availability and efficacy. Pluripotent stem cells are a renewable source of patient-specific human tissues for regeneration and disease analysis. In our study, we investigated the potential of pluripotent cells to re-create functional kidney tissue and disease in the lab. Pluripotent cells treated with a simple chemical cocktail matured into mini-kidney 'organoids' that closely resembled nephrons. Using an advanced gene editing technique called CRISPR, we created stem cells with genetic mutations linked to two common kidney diseases, polycystic kidney disease (PKD) and glomerulonephritis. Mini-kidneys derived from these genetically engineered cells showed specific 'symptoms' of these two different diseases in the petri dish. (more…)
Author Interviews, Bipolar Disorder, Kidney Disease, Lancet, Mental Health Research, Pharmacology / 24.10.2015

MedicalResearch.com Interview with: Dr. Stefan Clos MSc Applied Health Statistics Psychiatrist Murray Royal Hospital Scotland UK Medical Research: What is the background for this study? Dr. Clos: For more than 40 years there has been a debate about the long-term effect of lithium maintenance therapy on renal function. There is a lack of good quality data from randomized clinical trials and two previous meta-analyses from 2010 and 2012 suggest that little evidence exists for a clinically significant reduction in renal function in most patients who are on lithium therapy. However, the two publications point out the poor quality of available study data, emphasising the need for large scale epidemiological studies that control for confounders. Several population-based studies have since attempted to address this problem, but had insufficient ability to adjust for confounders or had limitations because of inappropriate cross-sectional study design or did not include an appropriate comparator group.  (more…)
Anemia, Author Interviews, Infections, Kidney Disease, UCSF / 21.10.2015

Dr. Julie H. Ishida MD San Francisco Veterans Affairs Medical Center Nephrology Section San Francisco, CAMedicalResearch.com Interview with: Dr. Julie H. Ishida MD San Francisco Veterans Affairs Medical Center Nephrology Section San Francisco, CA Medical Research: What is the background for this study? What are the main findings? Dr. Ishida: Intravenous iron is important in the treatment of anemia of end-stage renal disease, but it is biologically plausible that iron may increase infection risk. While results from epidemiologic studies evaluating the association between intravenous iron and infection in hemodialysis patients have been conflicting, guidelines for the treatment of anemia of chronic kidney disease have recommended caution in prescribing, avoidance and withholding of intravenous iron in the setting of active infection. However, no data specifically support the recommendation to withhold intravenous iron during active infection. Our study observed that among hemodialysis patients hospitalized for bacterial infection who had been receiving intravenous iron as an outpatient, continued receipt of intravenous iron was not associated with higher all-cause mortality, readmission for infection, or longer hospital stay. (more…)
Author Interviews, Calcium, Kidney Disease, Kidney Stones, Supplements, Vitamin D / 20.10.2015

MedicalResearch.com Interview with: Christopher Loftus M.D. candidate Cleveland Clinic Lerner College of Medicine Medical Research: What is the background for this study? What are the main findings? Response: Most kidney stones are made, at least partially, of calcium composite. In a prospective study of nurses in the post-menopausal age, it was found that diets that contained high amounts of calcium were beneficial in preventing kidney stones in this population. In the gut, calcium can bind to oxalate which prevents it from being absorbed into the body and decreases the concentration of calcium in the urine. However there has been debate as to whether supplemental calcium (calcium pills) has the same beneficial effects as calcium in the diet. Supplemental calcium enters the gut in large quantities all at once so it may enter the blood stream in higher concentrations over smaller amounts of time. By the same token, vitamin D plays a role in the management and balance of calcium in the body and could potentially have an effect on stone formation as well.  It has also been debated whether vitamin D supplementation has major effect on patients who are known to be stone formers.  So we reviewed CT scans of patients and 24 hour urine collections (both male and female of adult age) who were known to have kidney stones and measured the growth of stones over a period of time. Our main findings were that supplementary calcium increased the rate of stone formation in these patients. We also found that vitamin D had a protective effect and patients taking only vitamin D had a slower rate of stone progression. (more…)
Author Interviews, Cleveland Clinic, Heart Disease, JACC, Kidney Disease, Transplantation / 13.10.2015

W.H. Wilson Tang, MD, FACC Assistant Professor in Medicine, Cleveland Clinic Lerner College of Medicine Staff, Section of Heart Failure & Cardiac Transplant Medicine Assistant Program Director, General Clinical Research Center (GCRC) The Cleveland Clinic Cleveland, OHMedicalResearch.com Interview with: W.H. Wilson Tang, MD, FACC  Assistant Professor in Medicine, Cleveland Clinic Lerner College of Medicine Staff, Section of Heart Failure & Cardiac Transplant Medicine Assistant Program Director, General Clinical Research Center The Cleveland Clinic  Cleveland, OH Medical Research: What is the background for this study? What are the main findings? Dr. Tang: Cardiac function is a key determinant of outcomes after surgery, especially transplantation. End-stage renal disease (ESRD) poses a unique scenario, as the metabolic and uremic derangements that result from this condition lead to adverse cardiac remodeling, and kidney transplantation offers a potential for reverse remodeling. We studied patients who underwent kidney transplantation and found that echocardiogram following transplantation demonstrated consistent and significant improvement in cardiac structure and function. Post-transplant improvement in anemia was a vital factor that independently predicted such positive changes, whereas post-transplant changes in blood pressure, renal function at 12 months, and dialysis duration duration did not. Moreover, patients that demonstrated reverse remodeling had outcomes comparable to those with normal baseline cardiac function. (more…)
Author Interviews, Biomarkers, Cleveland Clinic, Heart Disease, JACC, Kidney Disease / 12.10.2015

Dr. Wilson Tang MD Professor of Medicine Cleveland Clinic Lerner College of Medicine Case Western Reserve University Director of the Center for Clinical Genomics Cleveland ClinicMedicalResearch.com Interview with: Dr. Wilson Tang MD Professor of Medicine Cleveland Clinic Lerner College of Medicine Case Western Reserve University Director of the Center for Clinical Genomics Cleveland Clinic  Medical Research: What is the background for this study? What are the main findings? Dr. Tang: Renal impairment has long been associated with worse outcomes in acute heart failure. Administration of diuretic therapy often obscures accurate assessment of renal function by urine output.  Despite extensive literature suggesting the poor outcomes in those with a rise in creatinine following treatment, recent data has suggested that in the presence of effective diuresis, this phenomenon likely represents hemoconcentration and azotemia rather than acute kidney injury.  We observed that using a novel and sensitive biomarker that identified acute kidney injury, specific to tubular injury, we can identify those at higher risk of adverse outcomes in patents admitted for acute heart failure.   However, after adjusting for standard risk factors, the prognostic value was clearly attenuated. (more…)
Author Interviews, Kidney Disease / 03.10.2015

Austin G. Stack MD., MSc., FRCPI. Professor and Foundation Chair of Medicine, Graduate Entry Medical School (GEMS),Consultant Nephrologist, University Hospital LimerickMedicalResearch.com Interview with: Austin G. Stack MD., MSc., FRCPI. Professor and Foundation Chair of Medicine, Graduate Entry Medical School (GEMS),Consultant Nephrologist, University Hospital Limerick Medical Research: What is the background for this study? Dr. Stack: Height is an important proxy for nutritional health and published studies in the general population have generally shown that taller individuals liver longer. Dialysis patients have life spans that may be 1/5th that of the general population, and it is important to identify those characteristics that are associated with greatest survival. Few studies have described the relationship between adult height and survival in patients undergoing dialysis in the Unites States. Our study, using data from the US Renal Registry, is the largest study ever conducted that has investigated the relationship with height and mortality risk in patients undergoing dialysis. (more…)
Author Interviews, Kidney Disease, Mayo Clinic, Sugar / 30.09.2015

Wisit Cheungpasitporn, MD Nephrology Fellow Departments of Nephrology and Hypertension Mayo Clinic, Rochester, MNMedicalResearch.com Interview with: Wisit Cheungpasitporn, MD Nephrology Fellow Departments of Nephrology and Hypertension Program director: Suzanne Norby, MD Co-authors: Charat Thongprayoon, MD, Oisin A O'Corragain, MD, Peter J Edmonds, BS, Wonngarm Kittanamongkolchai, MD, Stephen B Erickson, MD Project mentor: Stephen B. Erickson, MD Departments of Nephrology and Hypertension Mayo Clinic, Rochester, MN Medical Research: What is the background for this study? Dr. Cheungpasitporn: High-fructose corn syrup consumption in the form of sugar-sweetened soda has dramatically increased worldwide and associated with risk factors for chronic kidney disease (CKD) including diabetes mellitus (DM) and metabolic syndrome. Recently, artificial sweeteners have become commonly used in soda marketed as ‘diet’ alternatives. Recent studies have demonstrated that diet soda consumption may also be associated with weight gain, metabolic syndrome and cardiovascular disease. The risks of CKD in individuals with sugar-sweetened or diet soda consumption, however, were conflicting. We therefore conducted a meta-analysis to assess the associations between CKD and the consumption of sugar sweetened and diet soda. The findings of our study were recently published in Nephrology (Carlton). 2014; 19(12):791-7. Medical Research: What are the main findings? Dr. Cheungpasitporn: Five studies (2 prospective cohort studies, 2 cross-sectional studies and a case-control study) were included in our analysis of the association between consumption of sugar-sweetened soda (≥1-2 drinks of sugary soda/day) and CKD. We found an overall 1.58-fold increase CKD risk in individuals who regularly consumed sugar-sweetened soda with the pooled risk ratio (RR) of 1.58 (95% CI 1.00–2.49). Four studies (2 prospective cohort studies, a cross-sectional studies and a case-control study) were included to assess the association between CKD and diet soda consumption (≥1-2 drinks of diet soda/day). Despite a trend of chronic kidney disease risk in individuals with diet soda consumption with the pooled RR of 1.33 (95% CI 0.82–2.15), this association was not statistically significant. (more…)
Author Interviews, Gout, Heart Disease, Kidney Disease, Mayo Clinic / 14.09.2015

Wisit Cheungpasitporn, MD Nephrology Fellow Departments of Nephrology and Hypertension Mayo Clinic, Rochester, MMedicalResearch.com Interview with: Wisit Cheungpasitporn, MD Nephrology Fellow Departments of Nephrology and Hypertension Mayo Clinic, Rochester, MN Program director: Suzanne Norby, MD Co-authors: Charat Thongprayoon, MD, Andrew M. Harrison, BS and Stephen B. Erickson, MD Project mentors: Stephen B. Erickson, MD Departments of Nephrology and Hypertension Mayo Clinic, Rochester, MN   Medical Research: What is the background for this study? Dr. Cheungpasitporn: Uric acid has been linked to acute kidney injury (AKI) through crystal-dependent pathways and crystal-independent mechanisms, including reduced renal blood flow and glomerular filtration rate. Serum uric acid measurement has recently been examined as a marker for early AKI detection, especially in the setting of postoperative AKI following cardiovascular surgery. The effect of admission serum uric acid levels on the risk of in-hospital AKI in the general hospitalized patients, however, was unclear. Thus, we conducted a study to assess the risk of AKI in all hospitalized patients across different serum uric acid levels. The findings of our study data were recently published in Clinical Kidney Journal. (more…)
Author Interviews, Diabetes, Heart Disease, Karolinski Institute, Kidney Disease / 12.09.2015

MedicalResearch.com Interview with: Dr. Daniel Hertzberg M.D., Ph.D. Student Department of Medicine, Solna Karolinska University Hospital Medical Research: What is the background for this study? Dr. Hertzberg: Acute Kidney Injury (AKI) is a common complication in patients undergoing cardiac surgery. It is associated with increased short and long-term mortality, myocardial infarction, heart failure and chronic kidney disease. Diabetes is often considered as a risk factor for AKI. However, when we searched the literature we did not find any studies which specifically studied diabetes as a risk factor for AKI. In addition, in observational studies, it is uncommon that diabetes is subtyped into type 1 or type 2 even though they have different etiologies and thus may have different impact on risk of adverse outcomes. Thus, we designed this study in order to study the association between the two subtypes of diabetes and risk of AKI. (more…)
Author Interviews, Diabetes, JAMA, Kidney Disease / 01.09.2015

George L. Bakris MD Professor of Medicine Director, Comprehensive Hypertension Center University of Chicago MedicineMedicalResearch.com Interview with: George L. Bakris MD Professor of Medicine Director, Comprehensive Hypertension Center University of Chicago Medicine Medical Research: What is the background for this study? What are the main findings? Dr. Bakris: Aldosterone receptor antagonists such as spironolactone are known to reduce mortality from heart failure and reduce albuminuria, a well-known marker of diabetic kidney disease progression. Finerenone is a novel nonsteroidal aldosterone receptor antagonist and is associated with less hyperkalemia (high blood potassium levels) compared to traditional aldosterone receptor blockers like spironolactone. The current study was a dose finding study to ascertain the optimal dose of finerenone for reducing urine albumin (a key risk marker in people with diabetic kidney disease) that is also associated with the smallest rise in serum potassium. The main findings are that in a dose dependent manner finerenone reduced albuminuria and at the highest dose a modest rise in serum potassium. Finerenone was also very well tolerated.  (more…)
Author Interviews, Heart Disease, Kidney Disease / 22.08.2015

Tae-Hyun Yoo MD PhD Department of Internal Medicine, College of Medicine Severance Biomedical Science Institute, Brain Korea 21 PLUS Yonsei University, Seoul, KoreaMedicalResearch.com Interview with: Tae-Hyun Yoo MD PhD Department of Internal Medicine, College of Medicine Severance Biomedical Science Institute, Brain Korea 21 PLUS Yonsei University, Seoul, Korea Medical Research: What is the background for this study? What are the main findings? Dr. Tae-Hyun Yoo: Sarcopenia, reduction in muscle mass, is frequently observed in PEW and is prevalent in chronic kidney disease (CKD) patients. In ESRD patients, sarcopenia is significantly associated with greater mortality. Skeletal muscles produce and release myokines, which  suggested to mediate their protective effects. Irisin, a novel myokine, has been introduced to drive brown-fat-like conversion of white adipose tissue and has beneficial effects of skeletal muscle on energy homeostasis and glucose metabolisms. Therefore, we hypothesized that irisin had significant association with sarcopenia and cardiovascular disease in dialysis patients. In peritoneal dialysis patients, serum irisin was positively correlated with mid-arm muscle circumference and thigh circumference. In addition, serum irisin was a significant independent predictor for carotid atherosclerosis even after adjustment for high-sensitivity C-reactive protein in these patients. This study demonstrated that serum irisin was significantly associated with sarcopenia and carotid atherosclerosis in peritoneal dialysis patients. (more…)
Author Interviews, Kidney Disease, Lancet, Weight Research / 21.08.2015

Dr. Csaba P. Kovesdy MedicalResearch.com Interview with: Dr. Csaba P. Kovesdy, MD Professor of Medicine University of Tennessee Health Science Center Chief of Nephrology Memphis Veterans Affairs Medical Center Medical Research: What is the background for this study? What are the main findings? Dr. Kovesdy: Obesity has reached epidemic proportions in modern societies, and has been linked to adverse outcomes such as diabetes mellitus, hypertension, cardiovascular disease and mortality. In addition, obesity is also associated with chronic kidney disease through a variety of mechanisms. Our population is ageing, and previous studies have suggested that the effect of obesity on certain outcomes like mortality may be different in older vs. younger individuals, but this has not been previously examined for chronic kidney disease. We have this examined the association of granular BMI categories with progressive loss of kidney function in a very large cohort of patients with normal estimated GFR in patients of different ages. We found that the association of a BMI of >30 kg/m2 with progressive loss of kidney function was not present in younger individuals (< 40 years of age), and increased as people aged, with >80 years old displaying the strongest associations between obesity and loss of kidney function. In addition to this we also examined the association of BMI with mortality in different age groups, and found uniform U-shaped associations that did not vary by age. (more…)
Author Interviews, Diabetes, Kidney Disease, Lancet / 12.08.2015

MedicalResearch.com Interview with: Prof. Der-Cherng Tarng, MD, PhD Division of Nephrology Taipei Veterans General Hospital, and National Yang-Ming University, Taiwan MedicalResearch: What is the background for this study? What are the main findings? Prof. Tarng: Metformin is generally recommended as a first-line therapy for type 2 diabetes mellitus, but the use of metformin has been limited in patients with impaired kidney function because of the perceived risk of lactic acidosis. More recently, available evidence supports the cautious expansion of metformin use in patients with mild to moderate chronic kidney disease (CKD). However, no studies have yet examined whether metformin can be prescribed more widely to patients with advanced CKD. We conducted a propensity score-matched cohort study using Taiwan’s National Health Insurance Research Database to assess the safety of metformin in patients with type 2 diabetes and serum creatinine levels >6 mg/dL, enrolled between January 1, 2000 and June 30, 2009 and followed-up until December 31, 2009, before Taiwan’s prescribing guidelines for metformin contraindicated its use in patients with CKD. From a consecutive sample of 12350 patients, 1005 (8.1%) were metformin users. Of these, 813 were successfully matched 1:3 to 2439 metformin nonusers. After multivariate adjustment, metformin use remained was an independent risk factor for mortality (hazard ratio 1.35, 95% confidence interval 1.20–1.45; p<0.0001). The increased risk was dose-dependent and was consistent across all subgroup analyses. However, metformin users compared with non-users were associated with a higher but insignificant risk of metabolic acidosis (hazard ratio 1.30, 95% confidence interval 0.88–1.93; p=0.188). (more…)
Author Interviews, Kidney Disease, Mayo Clinic, Radiology / 11.08.2015

MedicalResearJennifer S. McDonald Ph.D Assistant Professor Department of Radiology Mayo Clinicch.com Interview with: Jennifer S. McDonald Ph.D Assistant Professor Department of Radiology Mayo Clinic Medical Research: What is the background for this study? What are the main findings? Dr. McDonald: Our research group is interested in studying contrast-induced nephropathy (CIN), which is the development of acute kidney injury following administration of iodinated contrast material. Iodinated contrast material is frequently administered during CT examinations. Recent publications, including those by our group, suggest that the incidence of contrast-induced nephropathy has been overestimated by prior, uncontrolled studies. The purpose of our study was to better evaluate the incidence and severity of CIN in patients with diminished renal function (eGFR < 60 ml/min/1.73m2). In the current article, we performed a controlled retrospective study comparing patients who received a contrast-enhanced CT scan at our institution to patients who received an unenhanced CT scan. We used propensity score analysis that incorporated numerous variables to match contrast recipients and control patients with similar clinical characteristics. After performing this analysis, we found that the rate of AKI, emergent dialysis, and short-term mortality was similar between contrast recipients and control patients. (more…)
Author Interviews, Emory, JAMA, Kidney Disease / 11.08.2015

Rachel Patzer, PhD, MPH Director of Health Services Research, Emory Transplant Center Assistant Professor Department of Surgery Division of Transplantation Emory University School of MedicineMedicalResearch.com Interview with: Rachel Patzer, PhD, MPH Director of Health Services Research, Emory Transplant Center Assistant Professor Department of Surgery Division of Transplantation Emory University School of Medicine Medical Research: What is the background for this study? What are the main findings? Dr. Patzer: There are two main treatments for patients with end stage kidney disease: dialysis or kidney transplantation.  Kidney transplantation offers the best survival and quality of life compared to dialysis.  However, there is a limited supply of organs in the U.S., so not all patients with end stage organ failure get a kidney transplant. Certain regions of the country have lower access to kidney transplantation than other regions.  The Southeastern United States (GA, NC, and SC) has the lowest rates of kidney transplantation in the nation, and Georgia (GA) is the state that ranks at the very bottom. Our research team and collaborators from the Southeastern Kidney Transplant Coalition sought to examine some of the reasons for why Georgia had the lowest rates of kidney transplantation in the nation.  The transplant centers in our Coalition collaborated to share data on patient referrals from dialysis facilities, where the majority of end stage renal disease patients receive treatment, to transplant centers in Georgia. Referral from a dialysis facility to a transplant center is required for patients to undergo the extensive medical evaluation that is required for a patient to either be placed on the national deceased donor waiting list, or to receive a living donor kidney transplant (e.g. from a friend or family member). There were several major findings: 1)    That overall, referral of patients from a dialysis facility to a kidney transplant center is low (only about 28% of patients with kidney failure are referred to a transplant center within a year of starting dialysis). 2)    There was much variation in referral for transplantation across dialysis facilities in GA, where some facilities referred no patients within a year, and others referred up to 75% of their patient population. (more…)