291 results match your criteria: "Harold Simmons Center for Kidney Disease Research and Epidemiology[Affiliation]"
J Am Soc Nephrol
December 2016
Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California, Irvine School of Medicine, Orange, California;
In patients with ESRD, residual kidney function (RKF) contributes to achievement of adequate solute clearance. However, few studies have examined RKF in patients on hemodialysis. In a longitudinal cohort of 6538 patients who started maintenance hemodialysis over a 4-year period (January 2007 through December 2010) and had available renal urea clearance (CL) data at baseline and 1 year after hemodialysis initiation, we examined the association of annual change in renal CL rate with subsequent survival.
View Article and Find Full Text PDFAm J Kidney Dis
August 2016
Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine Health, Orange, CA; Department of Medicine, Long Beach Veteran Affairs Health System, Long Beach, CA. Electronic address:
Background: Chronic pain is a common condition in the general population. However, large epidemiologic studies examining the role of pain in the deterioration of kidney function, development of chronic kidney disease, and risk for death are lacking.
Study Design: Retrospective cohort study.
Am J Nephrol
July 2018
Division of Nephrology and Hypertension, Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine, Orange, Calif., USA.
J Clin Endocrinol Metab
June 2016
Division of Nephrology and Hypertension (Y.O., E.S., C.M.R., W.L.L., K.K.-Z.), Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine, School of Medicine, Orange, California 92868; Division of Nephrology (R.M., M.B.R.), Kidney Research Institute and Harborview Medical Center, University of Washington, Seattle, Washington 98104; Division of Nephrology (C.P.K.), University of Tennessee Health Science Center, Memphis, Tennessee 38103; Nephrology Section (C.P.K.), Memphis VA Medical Center, Memphis, Tennessee 38104; Fielding School of Public Health at University of California at Los Angeles (K.K.-Z.), Los Angeles, California 90024; and Los Angeles Biomedical Research Institute at Harbor-University of California at Los Angeles (K.K.-Z.), Torrance, California 90502.
Context: Neither uncorrected- nor albumin-corrected total calcium reliably predict ionized calcium in patients with end-stage renal disease. However, little is known about the consequences of inaccurate assessment of calcium concentration using total calcium.
Objective: We hypothesized that hidden hypercalcemia (ie, elevated ionized calcium with normal total calcium) and apparent hypercalcemia (ie, elevated ionized calcium with elevated total calcium) are both associated with increased mortality risk.
Curr Opin Nephrol Hypertens
May 2016
Division of Nephrology and Hypertension, Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine School of Medicine, Orange, California, USA.
Purpose Of Review: Obesity is a major risk factor for the development of de novo chronic kidney disease (CKD). However, once kidney disease is acquired, obesity is paradoxically linked with greater survival, especially in those with advanced CKD. This review examines current evidence for obesity as a risk factor for incident CKD, studies of obesity and mortality across various CKD populations, and potential mechanisms underlying the 'obesity paradox' in kidney disease.
View Article and Find Full Text PDFCardiorenal Med
February 2016
Division of Nephrology and Hypertension, Orange, Calif., USA; Harold Simmons Center for Kidney Disease Research and Epidemiology, Orange, Calif., USA; Department of Medicine, VA Long Beach Health Care System, Long Beach, Calif., USA.
Background: Cardiorenal syndrome (CRS) encompasses conditions in which cardiac and renal disorders co-exist and are pathophysiologically related. The newest classification of CRS into seven etiologically and clinically distinct types for direct patient management purposes includes hemodynamic, uremic, vascular, neurohumoral, anemia- and/or iron metabolism-related, mineral metabolism-related and protein-energy wasting-related CRS. This classification also emphasizes the pathophysiologic pathways.
View Article and Find Full Text PDFAm J Nephrol
January 2017
Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine, School of Medicine, Orange, Calif., USA.
Background: Abnormalities in mineral and bone disorder (MBD) markers are common in patients with chronic kidney disease. However, previous studies have not accounted for their changes over time, and it is unclear whether these changes are associated with survival.
Methods: We examined the association of change in MBD markers (serum phosphorus (Phos), albumin-corrected calcium (Ca(Alb)), intact parathyroid hormone (iPTH) and alkaline phosphatase (ALP)) during the first 6 months of hemodialysis (HD) with all-cause mortality across baseline MBD strata using survival models adjusted for clinical characteristics and laboratory measurements in 102,754 incident HD patients treated in a large dialysis organization between 2007 and 2011.
Int Urol Nephrol
May 2016
Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine Medical Center, Orange, CA, USA.
Lowering dietary protein intake (DPI) to approximately 0.6-0.8 g/kgBW/day may be renoprotective through various mechanisms, and it has been recommended in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) as a means to also control various metabolic consequences of advanced CKD, such as uremic symptoms, hyperparathyroidism, hypertension, hyperkalemia, and hyperphosphatemia.
View Article and Find Full Text PDFAm J Kidney Dis
August 2016
Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, CA; Fielding School of Public Health at UCLA, Los Angeles, CA; Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA. Electronic address:
Background: Maintenance hemodialysis is typically prescribed thrice weekly irrespective of a patient's residual kidney function (RKF). We hypothesized that a less frequent schedule at hemodialysis therapy initiation is associated with greater preservation of RKF without compromising survival among patients with substantial RKF.
Study Design: A longitudinal cohort.
Am J Kidney Dis
July 2016
Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine, School of Medicine, Orange, CA. Electronic address:
Background: Red cell distribution width (RDW) is an index of red blood cell volume variability that has historically been used as a marker of iron deficiency anemia. More recently, studies have shown that elevated RDW is associated with higher mortality risk in the general population. However, there is lack of data demonstrating the association between RDW and mortality risk in hemodialysis (HD) patients.
View Article and Find Full Text PDFNephrol Dial Transplant
July 2016
David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
Conclusion: the van den Beukel study adds new knowledge to a growing body of evidence demonstrating a lower mortality risk among immigrant dialysis patients versus native residents in European-based countries, and provides greater insight into potential explanatory factors specific to the Danish population.
View Article and Find Full Text PDFClin J Am Soc Nephrol
February 2016
Department of Medicine, Division of Nephrology, Kidney Research Institute, University of Washington, Seattle, Washington;
Background And Objectives: In individuals undergoing in-center hemodialysis (HD), use of central venous catheters (CVCs) is associated with worse clinical outcomes compared with use of arteriovenous access. However, it is unclear whether a similar difference in risk by vascular access type is present in patients undergoing home HD.
Design, Setting, Participants, & Measurements: Our study examined the associations of vascular access type with all-cause mortality, hospitalization, and transfer to in-center HD in patients who initiated home HD from 2007 to 2011 in 464 facilities in 43 states in the United States.
Nephrol Dial Transplant
August 2016
Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine, School of Medicine, Orange, CA, USA Department of Medicine, Long Beach Veteran Affairs Health System, Long Beach, CA, USA.
Background: The inverse association between body mass index (BMI) and mortality observed in patients treated with maintenance hemodialysis (MHD), also known as the obesity paradox, may be a result of residual confounding. Marginal structural model (MSM) analysis, a technique that accounts for time-varying confounders, may be more appropriate to investigate this association. We hypothesize that after applying MSM, the inverse association between BMI and mortality in MHD patients is attenuated.
View Article and Find Full Text PDFJ Ren Nutr
January 2016
School of Medicine, Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine, Orange, California; Department of Medicine, Long Beach Veteran Affairs Health System, Long Beach, California. Electronic address:
Background: Lean body mass (LBM) represents the "fat-free" muscle mass in hemodialysis (HD) patients and is an important nutritional measure. Previous studies have found that both higher LBM and body mass index (BMI) were related to greater survival in HD patients. Additional studies have shown differences in survival across racial-ethnic groups of HD patients.
View Article and Find Full Text PDFPerit Dial Int
March 2017
Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine Medical Center, Orange, California, USA Department of Population Health and Disease Prevention, Program in Public Health, University of California Irvine, Irvine, California, USA Veterans Affairs Long Beach Healthcare System, Long Beach, California, USA Department of Epidemiology, UCLA School of Public Health, Los Angeles, California, USA
Unlabelled: ♦
Background: Although higher body mass index (BMI) is associated with better outcomes in hemodialysis patients, the relationship in peritoneal dialysis (PD) patients is less clear. We aimed to synthesize the results from all large and high-quality studies to examine whether underweight, overweight, or obesity is associated with any significantly different risk of death in peritoneal dialysis patients. ♦
Methods: We searched MEDLINE, EMBASE, Web of Science, CINAHL, and Cochrane CENTRAL, and screened 7,123 retrieved studies for inclusion.
J Am Med Dir Assoc
November 2015
Division of Nephrology and Hypertension, Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine Medical Center, Orange, CA; Department of Population Health and Disease Prevention, Program in Public Health, University of California Irvine, Irvine, CA; Nephrology Section, Department of Medicine, Veterans Affairs Long Beach Healthcare System, Long Beach, CA; Department of Epidemiology, UCLA School of Public Health, Los Angeles, CA. Electronic address:
Traditional risk factors of cardiovascular death in the general population, including body mass index (BMI), serum cholesterol, and blood pressure (BP), are also found to relate to outcomes in the geriatric population, but in an opposite direction. Some degrees of elevated BMI, serum cholesterols, and BP are reportedly associated with lower, instead of higher, risk of death among the elderly. This phenomenon is termed "reverse epidemiology" or "risk factor paradox" (such as obesity paradox) and is also observed in a variety of chronic disease states such as end-stage renal disease requiring dialysis, chronic heart failure, rheumatoid arthritis, and AIDS.
View Article and Find Full Text PDFNephrol Dial Transplant
May 2016
Division of Nephrology and Hypertension, Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine Medical Center, Orange, CA, USA Nephrology Section, Long Beach VA Healthcare System, Long Beach, CA, USA.
Background: Liver disease is a common comorbid condition in maintenance hemodialysis (MHD) patients and may be associated with poor survival. The relationship between aspartate aminotransferase (AST) and survival has not yet been addressed in these patients. We hypothesized that higher AST level is associated with higher death risk in MHD patients.
View Article and Find Full Text PDFAm J Kidney Dis
December 2015
Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine, School of Medicine, Orange, CA. Electronic address:
Background: In the general population, low serum magnesium levels are associated with poor outcomes and death. While limited data suggest that low baseline magnesium levels may be associated with higher mortality in hemodialysis (HD) patients, the impact of changes in magnesium levels over time is unknown.
Study Design: We examined the association of time-varying serum magnesium levels with all-cause mortality using multivariable time-varying survival models adjusted for clinical characteristics and other time-varying laboratory measures.
Clin J Am Soc Nephrol
July 2015
Harold Simmons Center for Kidney Disease Research and Epidemiology, Orange, California; School of Medicine, University of California, Irvine, Orange, California;
Background And Objectives: Pulse pressure has been shown as a risk factor for mortality in patients on maintenance hemodialysis (MHD). However, the effect of change in pulse pressure during hemodialysis on survival in a large cohort of patients on MHD has not been sufficiently investigated.
Design, Setting, Participants, & Measurements: This study examined the association between time-varying Δ pulse pressure (postdialysis minus predialysis pulse pressure) and mortality in a cohort of 98,577 patients on MHD (July 2001-June 2006) using Cox proportional hazard models with restricted cubic splines.
Clin J Am Soc Nephrol
June 2015
Division of Nephrology and Hypertension, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California; UCLA Fielding School of Public Health, Los Angeles, California; David Geffen School of Medicine at UCLA, Los Angeles, California
Background And Objectives: Body mass index (BMI), determined as kilograms in body weight divided by the square of the height in meters (m(2)), is inversely associated with mortality in patients undergoing maintenance hemodialysis (MHD). It is commonly inferred that differences in the weight component of the BMI equation are responsible for this negative correlation. However, there are almost no data on the relationship between height and mortality in these patients.
View Article and Find Full Text PDFAm J Kidney Dis
May 2015
Department of Medicine, UC Irvine School of Medicine, Irvine, CA; Atherosclerosis Research Center, Long Beach Veteran Affairs Healthcare System, Long Beach, CA. Electronic address:
Niacin is the oldest drug available for the treatment of dyslipidemia. It has been studied extensively and tested in clinical trials of atherosclerotic cardiovascular disease prevention and regression in the general population, but not specifically in patients with chronic kidney disease (CKD), who are at extremely high residual risk despite current therapy. Despite the current controversy about recent trials with niacin, including their limitations, there may be a place for this agent in select patients with CKD with dyslipidemia.
View Article and Find Full Text PDFJ Ren Nutr
March 2015
UCLA Fielding School of Public Health, Los Angeles, California; Division of Nephrology and Hypertension, University of California at Irvine, Irvine, California; Harold Simmons Center for Kidney Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California.
Maintenance hemodialysis (MHD) patients display reduced daily physical activity (DPA) and physical performance (PP). Previous studies did not differentiate the effects of kidney failure and MHD treatments from comorbidities as causes for reduced DPA and PP. In relatively healthy MHD patients and normal adults, we evaluated DPA and PP and examined relationships between DPA and PP and possible associations between anxiety or depression and DPA and PP.
View Article and Find Full Text PDFJ Ren Nutr
July 2015
Division of Nephrology and Hypertension, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California; UCLA Fielding School of Public Health, Los Angeles, California; David Geffen School of Medicine at UCLA, Los Angeles, California. Electronic address:
Objectives: Studies suggest that maintenance hemodialysis (MHD) patients report dietary energy intakes (EIs) that are lower than what is actually ingested. Data supporting this conclusion have several important limitations. The present study introduces a novel approach of assessing underreporting of EI in MHD patients.
View Article and Find Full Text PDFSemin Dial
December 2015
Division of Nephrology and Hypertension, Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine, Orange, California; Long Beach Veterans Affairs Healthcare System, Long Beach, California; Department of Epidemiology, UCLA Fielding School of Public Health, University of California Los Angeles, Los Angeles, California; Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, California.
A significant number of dietary restrictions are imposed traditionally and uniformly on maintenance dialysis patients, whereas there is very little data to support their benefits. Recent studies indicate that dietary restrictions of phosphorus may lead to worse survival and poorer nutritional status. Restricting dietary potassium may deprive dialysis patients of heart-healthy diets and lead to intake of more atherogenic diets.
View Article and Find Full Text PDFAm J Nephrol
August 2015
Harold Simmons Center for Kidney Disease Research and Epidemiology; Division of Nephrology and Hypertension, University of California Irvine Medical Center, Orange, Calif., USA.
Background: A higher body mass index (BMI) seems to be linked to survival advantage in maintenance hemodialysis patients. However, it is uncertain if this 'obesity survival paradox' is also observed in kidney transplant recipients. Hence, we systematically reviewed the literature on the impact of pre-transplantation BMI on all-cause mortality in this population.
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