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1.
BMJ Open ; 14(3): e076729, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38443080

ABSTRACT

OBJECTIVES: This scoping review maps the extant literature on students' and graduates' mental health experiences throughout their university-to-work transitions. The current review investigates the methodological features of the studies, the main findings, and the theories that the studies draw on to conceptualise mental health and transitions. DESIGN: This project used a scoping review methodology created and developed by Peters and colleagues and the Joanna Briggs Institute. The review searched academic databases and screened existing studies that met predetermined inclusion criteria. DATA SOURCES: Seven academic databases and Google Scholar were searched with sets of search terms. ELIGIBILITY: The included studies examined participants who were final-year university students or those who had graduated from university within a 3-year period. Studies published in English since 2000 and from any country were included. The review included studies examining the negative dimensions of mental health. The review excluded studies focusing on medical students and graduates. DATA EXTRACTION: Basic information about the studies and their findings on mental health and university-to-work transitions was retrieved. The findings are presented in tables and in a qualitative thematic summary. RESULTS: The scoping review included 12 studies. Mental health was often not explicitly defined and it's theoretical foundations were not clearly articulated. The review identified factors, including a lack of social support and economic precarity, as sources of adverse mental health. Other protective factors in these studies-variables that guard against mental health problems-were identified, such as career preparedness and having a good job. CONCLUSIONS: Despite the methodological focus on the negative aspects of mental health, people's mental health experiences during university-to-work transitions are not uniformly negative. Clear conceptualisations of mental health in future studies will aid in developing resources to improve well-being. TRIAL REGISTRATION NUMBER: This scoping review adhered to a protocol previously published in this journal and that is registered on the Open Science Framework website (https://osf.io/gw86x).


Subject(s)
Mental Health , Students, Medical , Humans , Universities , Academies and Institutes , Concept Formation
3.
Opt Lett ; 45(18): 5089-5092, 2020 Sep 15.
Article in English | MEDLINE | ID: mdl-32932460

ABSTRACT

A real-time jitter meter is used to measure and digitally sample the pulse-to-pulse timing error in a laser pulse train. The jitter meter is self-referenced using a single-pulse delay line interferometer and measures timing jitter using optical heterodyne detection between two frequency channels of the pulse train. Jitter sensitivity down to 3×10-10fs2/Hz at 500 MHz has been demonstrated with a pulse-to-pulse noise floor of 1.6 fs. As a proof of principle, the digital correction of the output of a high-frequency photonic analog-to-digital converter (PADC) is demonstrated with an emulated jitter signal. Up to 23 dB of jitter correction, down to the noise floor of the PADC, is accomplished with radio-frequency modulation up to 40 GHz.

4.
Semin Nephrol ; 38(6): 570-581, 2018 11.
Article in English | MEDLINE | ID: mdl-30413252

ABSTRACT

In the United States, end-stage renal disease patients receiving hemodialysis have an exceedingly high risk of sudden cardiac death (SCD), accounting for 29% of death events, likely relating to their uremic milieu, recurring exposure to fluid and electrolyte fluxes, and underlying cardiovascular pathology. Furthermore, epidemiologic studies have shown that SCD events, as well as mortality and hospitalizations, occur most frequently on the first dialysis day after the long interdialytic gap, suggesting that abrupt fluctuations in the accumulation and removal of electrolytes, fluid, and uremic toxins over the dialysis cycle may be contributory. Some population-based observational studies have suggested that lower dialysate potassium concentrations appear to be associated with a heightened risk of postdialysis cardiac arrest in hemodialysis patients, although the optimal serum-to-dialysate potassium gradient remains unclear. Some observational studies have suggested that low dialysate calcium concentrations and high serum-to-dialysate calcium gradients may predispose patients to SCD. There is ongoing controversy about an association between higher dialysate bicarbonate concentrations and higher risk of cardiac arrest, likely owing to confounding by indication. Some observational studies also have shown that large interdialytic weight gains, fluid retention, and high ultrafiltration rates are linked with higher risk of SCD and mortality. However, there remains considerable controversy regarding the pros and cons of designating a specific upper ultrafiltration limit with extended treatment times as a clinical practice measure, and further studies are needed to define the optimal tools, metrics, targets, and implementation measures for volume control in the hemodialysis population. In this review, we highlight the epidemiology and pathophysiology of how specific aspects of the hemodialysis procedure may relate to the risk of SCD, as well as preventative strategies and future research directions that can address this risk.


Subject(s)
Death, Sudden, Cardiac/epidemiology , Hemodialysis Solutions/chemistry , Kidney Failure, Chronic/therapy , Potassium/blood , Renal Dialysis/adverse effects , Acid-Base Imbalance/blood , Bicarbonates/administration & dosage , Bicarbonates/analysis , Calcium/administration & dosage , Calcium/analysis , Death, Sudden, Cardiac/prevention & control , Hemodialysis Solutions/administration & dosage , Humans , Magnesium/administration & dosage , Magnesium/analysis , Potassium/administration & dosage , Potassium/analysis , Renal Dialysis/methods , Time Factors , Water-Electrolyte Balance
5.
Semin Dial ; 31(4): 343-352, 2018 07.
Article in English | MEDLINE | ID: mdl-29737013

ABSTRACT

While many patients have substantial residual kidney function (RKF) when initiating hemodialysis (HD), most patients with end stage renal disease in the United States are initiated on 3-times per week conventional HD regimen, with little regard to RKF or patient preference. RKF is associated with many benefits including survival, volume control, solute clearance, and reduced inflammation. Several strategies have been recommended to preserve RKF after HD initiation, including an incremental approach to HD initiation. Incremental HD prescriptions are personalized to achieve adequate volume control and solute clearance with consideration to a patient's endogenous renal function. This allows the initial use of less frequent and/or shorter HD treatment sessions. Regular measurement of RKF is important because HD frequency needs to be increased as RKF inevitably declines. We narratively review the results of 12 observational cohort studies of twice-weekly compared to thrice-weekly HD. Incremental HD is associated with several benefits including preservation of RKF as well as extending the event-free life of arteriovenous fistulas and grafts. Patient survival and quality of life, however, has been variably associated with incremental HD. Serious risks must also be considered, including increased hospitalization and mortality perhaps related to fluid and electrolyte shifts after a long interdialytic interval. On the basis of the above literature review, and our clinical experience, we suggest patient characteristics which may predict favorable outcomes with an incremental approach to HD. These include substantial RKF, adequate volume control, lack of significant anemia/electrolyte imbalance, satisfactory health-related quality of life, low comorbid disease burden, and good nutritional status without evidence of hypercatabolism. Clinicians should engage patients in on-going conversations to prepare for incremental HD initiation and to ensure a smooth transition to thrice-weekly HD when needed.


Subject(s)
Kidney Failure, Chronic/diagnosis , Kidney Failure, Chronic/therapy , Kidney/physiopathology , Patient Selection , Renal Dialysis , Humans , Kidney Failure, Chronic/physiopathology
6.
Nephron ; 139(1): 13-22, 2018.
Article in English | MEDLINE | ID: mdl-29402814

ABSTRACT

BACKGROUND/AIMS: Ultrafiltration rate (UFR) appears to be associated with mortality in prevalent hemodialysis (HD) patients. However, the association of UFR with mortality in incident HD patients remains unknown. METHODS: We examined a US cohort of 110,880 patients who initiated HD from 2007 to 2011. Baseline UFR was divided into 5 groups (<4, 4 to <6, 6 to <8, 8 to <10, and ≥10 mL/h/kg body weight [BW]). We examined predictors of higher baseline UFR using logistic regression and the association of baseline UFR and all-cause and cardiovascular (CV) mortality using Cox proportional hazard models with adjustments for demographics, comorbidities, and markers of malnutrition-inflammation-cachexia syndrome. RESULTS: Patients were 63 ± 15 years, with 43% women, 32% African Americans, and had a mean baseline UFR of 7.5 ± 3.1 mL/h/kg BW. In the fully adjusted logistic regression models, factors associated with higher UFR (≥7.5 mL/h/kg BW) included Hispanic ethnicity, diabetes, and higher dietary protein intake. There was a linear association between UFR and all-cause and CV mortality, where UFR ≥10 mL/h/kg BW (reference UFR 6-<8 mL/h/kg BW) conferred the highest risk in both unadjusted (HR 1.15 [95% CI 1.10-1.19]) and adjusted models (HR 1.23 [95% CI 1.16-1.31]). The linear association with all-cause mortality remained consistent across strata of age, urine volume, and treatment time. CONCLUSIONS: Higher UFR is independently associated with higher all-cause and CV mortality in incident HD patients. Clinical trials are warranted to examine the effects of lowering UFR on outcomes.


Subject(s)
Kidney Failure, Chronic/mortality , Kidney Failure, Chronic/therapy , Renal Dialysis/mortality , Ultrafiltration , Adult , Age Factors , Aged , Body Weight , Cardiovascular Diseases/mortality , Cohort Studies , Diabetic Neuropathies/mortality , Diabetic Neuropathies/therapy , Dietary Proteins , Ethnicity , Female , Hemodiafiltration , Humans , Male , Middle Aged , Proportional Hazards Models , Treatment Outcome , United States/epidemiology , Urodynamics
7.
Nephrol Dial Transplant ; 33(1): 149-159, 2018 01 01.
Article in English | MEDLINE | ID: mdl-28444336

ABSTRACT

Background: Intradialytic hypotension (IDH) occurs frequently in maintenance hemodialysis (HD) patients and may be associated with higher mortality. We hypothesize that nadir intradialytic systolic blood pressure (niSBP) is inversely related to death risk while iSBP change (Δ) and IDH frequency are incrementally associated with all-cause mortality. Methods: In a US-based cohort of 112 013 incident HD patients over a 5-year period (2007-11), using niSBP, ΔiSBP (pre-HD SBP minus niSBP) and IDH frequency (proportion of HD treatments with niSBP <90 mmHg) within the first 91 days of HD, we examined mortality-predictability at 1, 2 and 5 years using Cox models and restricted cubic splines adjusted for case-mix, comorbidities and laboratory covariates. Results: We observed that niSBP of <90 and ≥140 mmHg had a 5-year mortality hazard ratio (HR) (95% confidence interval) of 1.57 (1.47-1.67) and 1.25 (1.18-1.33), respectively, compared with niSBP 110 to <120 mmHg. ΔiSBP of <15 and ≥50 compared with 21-30 mmHg had mortality HR of 1.31 (1.26-1.37) and 1.32 (1.24-1.39), respectively. Among patients with >40% IDH frequency, we observed a mortality HR of 1.49 (1.42-1.57) compared with 0% IDH frequency in fully adjusted models. These associations were robust at 1 and 2 years of follow-up. Conclusion: In conclusion, we observed a U-shaped association between niSBP and ΔiSBP and mortality and a direct linear relationship between IDH frequency and mortality. Our findings lend some prognostic insight of HD blood pressure and hemodynamics, and have the potential to guide blood pressure management strategies among the HD population.


Subject(s)
Hypotension/mortality , Renal Dialysis/adverse effects , Renal Dialysis/mortality , Blood Pressure , Cohort Studies , Female , Humans , Hypotension/etiology , Kidney Failure, Chronic/therapy , Male , Middle Aged , Prognosis , Risk Factors , Survival Rate
8.
Semin Dial ; 31(3): 300-304, 2018 05.
Article in English | MEDLINE | ID: mdl-29265477

ABSTRACT

The vast majority of maintenance dialysis patients suffer from poor long-term survival rates and lower levels of health-related quality of life. However, home hemodialysis is a historically significant dialysis modality that has been associated with favorable outcomes as well as greater patient autonomy and control, yet only represents a small minority of the total dialysis performed in the United States. Some potential disadvantages of home hemodialysis include vascular access complications, infection-related hospitalizations, patient fatigue, and attrition. In addition, current barriers and challenges in expanding the utilization of this modality include limited patient and provider education and technical expertise. Here we report a 65-year old male with end-stage renal disease due to Alport's syndrome who has undergone 35 years of uninterrupted thrice-weekly home hemodialysis (ie, every Sunday, Tuesday, and Thursday evening, each session lasting 3 to 3» hours in length) using a conventional hemodialysis machine who has maintained a high functional status allowing him to work 6-8 hours per day. The patient has been able to liberalize his dietary and fluid intake while only requiring 3-4 liters of ultrafiltration per treatment, despite having absence of residual kidney function. Through this case of extraordinary longevity and outcomes after 35 years of dialysis and a review of the literature, we illustrate the history of home hemodialysis, its significant clinical and psychosocial advantages, as well as the barriers that hinder its widespread adaptation.


Subject(s)
Hemodialysis, Home/methods , Kidney Failure, Chronic/therapy , Nephritis, Hereditary/complications , Quality of Life , Aged , Asian , Disease Progression , Hemodialysis, Home/adverse effects , Hemodialysis, Home/psychology , Humans , Kidney Failure, Chronic/etiology , Kidney Failure, Chronic/physiopathology , Male , Nephritis, Hereditary/diagnosis , Risk Assessment , Survivors , Treatment Outcome
9.
Anticancer Res ; 38(1): 169-178, 2018 01.
Article in English | MEDLINE | ID: mdl-29277770

ABSTRACT

BACKGROUND/AIM: Ouabain, a plant-derived product/substance with Na+/K+-ATPase inhibiting properties, has been shown to exert anti-cancer activity on human cancer cells. This is the first study to investigate the effect of ouabain on apoptotic cell death of human osteosarcoma-derived U-2 OS cells. MATERIALS AND METHODS: Flow cytometry was used to examine cell viability, cell cycle, and reactive oxygen species (ROS), Ca2+, mitochondrial membrane potential (MMP) and caspase activity. Morphological changes were examined by contrast-phase microscopy, while apoptosis-associated protein levels were analyzed by western blot. RESULTS: Ouabain, at concentrations of 5-60 µM, significantly decreased the total viable cells and induced cell morphological changes in a time-dependent manner. It also time-dependently decreased G0/G1 phase and increased S and G2/M phase in U-2 OS cells. The production of ROS and the levels of MMPs (ΔΨm) were inhibited, while Ca2+ production in U-2 OS cells was increased. Regarding cell apoptosis, flow cytometry assay revealed increased caspase-3, -8, and -9 activities in U-2 OS cells. Moreover, western blot results showed that ouabain increased the expression of pro-apoptotic protein Bax and decreased the expression of anti-apoptotic protein Bcl-2 in U-2 OS cells. Furthermore, results also showed that ouabain increased cytochrome c release, apoptosis-inducing factor (AIF) and endonuclease (Endo) G that is associated with apoptosis through caspase-dependent and -independent pathway in U-2 OS cells. CONCLUSION: Our findings provide important insight into the cytotoxic effects of ouabain on U-2 OS cells, in vitro, which are mediated at least partly via cell apoptosis induction.


Subject(s)
Antineoplastic Agents/pharmacology , Bone Neoplasms/metabolism , Osteosarcoma/metabolism , Ouabain/pharmacology , Apoptosis/drug effects , Bone Neoplasms/drug therapy , Calcium/metabolism , Caspases/metabolism , Cell Line, Tumor , Humans , Membrane Potential, Mitochondrial/drug effects , Mitochondria/drug effects , Mitochondria/metabolism , Osteosarcoma/drug therapy , Proto-Oncogene Proteins c-bcl-2/metabolism , Reactive Oxygen Species/metabolism
10.
In Vivo ; 31(5): 877-884, 2017.
Article in English | MEDLINE | ID: mdl-28882954

ABSTRACT

BACKGROUND/AIM: Antrodia cinnamomea is found with polysaccharides, lipids, vitamins, fibers and ash (minerals) and is well known in Taiwan as a traditional Chinese medicine. Its biological activities have been reported to have anti-inflammatory, anti-fatigue, anti-tumor and immunomodulatory effects, but its protective effects on liver function are still unclear. MATERIALS AND METHODS: We determined if Antrodia cinnamomea was hepatoprotective against carbon tetrachloride (CCl4) toxicity in Wistar rats. Six groups were used in the study: 1) control (no induction by CCl4); 2) negative control (CCl4-induction and no treatment); 3) positive control (silymarin treatment); 4) groups 4-6 were treated with CC14 and different concentrations (350 mg/kg, 1,400 mg/kg, 3,150 mg/kg) of Antrodia cinnamomea. Blood and liver samples of rats were harvested and then detected by biochemical and tissue histochemical analysis. Activity of the antioxidative enzymes glutathione peroxidase, superoxide dismutase and catalase in the liver were also monitored. RESULTS: Only the high-dose treatment was able to decrease serum glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) levels and improve liver function. High and medium doses increased total liver protein and reduced hydroxyproline. It was also observed that the high dose treatment reduced lipid peroxidation. Liver sections of CC14 treated animals receiving Antrodia cinnamomea showed less fibrosis compared to the CCl4 control group. CONCLUSION: This finding suggested that Antrodia cinnamomea can either enhance liver recovering from CCl4 damage or attenuate CCl4 toxicity in rats.


Subject(s)
Antioxidants , Antrodia , Carbon Tetrachloride/adverse effects , Chemical and Drug Induced Liver Injury/therapy , Medicine, Chinese Traditional , Protective Agents , Animals , Biomarkers , Biopsy , Catalase/metabolism , Chemical and Drug Induced Liver Injury/complications , Chemical and Drug Induced Liver Injury/metabolism , Chemical and Drug Induced Liver Injury/pathology , Disease Models, Animal , Glutathione/metabolism , Glutathione Peroxidase/metabolism , Histocytochemistry , Lipid Peroxidation , Liver Cirrhosis/etiology , Liver Cirrhosis/pathology , Liver Function Tests , Male , Oxidative Stress , Rats , Superoxide Dismutase/metabolism
11.
Curr Heart Fail Rep ; 14(5): 421-427, 2017 10.
Article in English | MEDLINE | ID: mdl-28803369

ABSTRACT

PURPOSE OF REVIEW: Volume management in hemodialysis patients is often challenging. Assessing volume status and deciding how much fluid to remove during hemodialysis, the so-called ultrafiltration rate (UFR), has remained a conundrum. RECENT FINDINGS: To date there is no objective assessment tool to determine the needed UFR during each hemodialysis session. Higher volume overload or higher UFR is associated with poor outcomes including worse mortality and unfavorable clinical outcomes. We suggest combined use of the following criteria to determine UFR or post-dialysis target dry weight: pre-hemodialysis blood pressure and its intradialytic changes, muscle cramps, dyspnea from pulmonary vascular congestion, peripheral edema, tachycardia or palpitation, headache or lightheadedness, perspiration, and post-dialysis fatigue. Restricting fluid and salt intake-and high-dose loop diuretic use in cases of residual kidney function-can be helpful in controlling fluid gains. More frequent and more severe hypotensive episodes are associated with poor outcomes including higher death risk.


Subject(s)
Heart Failure , Kidney Failure, Chronic/therapy , Renal Dialysis/methods , Ultrafiltration/methods , Heart Failure/complications , Heart Failure/metabolism , Heart Failure/physiopathology , Humans , Kidney Failure, Chronic/complications , Kidney Failure, Chronic/metabolism , Water-Electrolyte Imbalance
12.
Mol Med Rep ; 16(3): 2483-2490, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28677783

ABSTRACT

The aim of the present study was to investigate the effect of chitosan (a naturally derived polymer) on the immune responses and glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and lactate dehydrogenase (LDH) levels in WEHI­3 cell­generated leukemia mice. Mice were divided into control, WEHI­3 control, acetic acid (vehicle)­treated, and 5 and 20 mg/kg chitosan­treated groups. Mice were subsequently weighed, blood was collected, and liver and spleen samples were isolated and weighed. Blood samples were measured for cell markers, the spleen underwent phagocytosis and natural killer (NK) cell activity examination, and cell proliferation was analyzed by flow cytometry. Chitosan did not significantly affect the weights of body, liver and spleen at 5 and 20 mg/kg treatment. Chitosan increased the percentage of CD3 (T cells marker), decreased the levels of CD19 (B­cell marker) and CD11b at 5 mg/kg treatment, and decreased the levels of Mac­3 at 5 and 20 mg/kg treatment. Chitosan significantly increased macrophage phagocytosis of PBMCs, but did not significantly affect macrophage phagocytosis in the peritoneal cavity. Chitosan treatment did not significantly affect the cytotoxic activity of NK cells, and also did not affect T- and B-cell proliferation. Chitosan significantly increased total white blood cell numbers, and GOT and GPT activities were both significantly increased. However, chitosan did not significantly affect LDH activity in leukemia mice. Chitosan may aid in future studies on improving immune responses in the treatment of leukemia.


Subject(s)
Adjuvants, Immunologic/therapeutic use , Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Chitosan/therapeutic use , Immunity, Cellular/drug effects , L-Lactate Dehydrogenase/blood , Leukemia/drug therapy , Adjuvants, Immunologic/pharmacology , Alanine Transaminase/immunology , Animals , Aspartate Aminotransferases/immunology , Cell Line, Tumor , Chitosan/pharmacology , Cytotoxicity, Immunologic/drug effects , Killer Cells, Natural/drug effects , Killer Cells, Natural/immunology , L-Lactate Dehydrogenase/immunology , Leukemia/blood , Leukemia/immunology , Leukocyte Count , Lymphocyte Activation/drug effects , Male , Mice , Mice, Inbred BALB C , Phagocytosis/drug effects
13.
Semin Dial ; 30(6): 473-480, 2017 11.
Article in English | MEDLINE | ID: mdl-28661565

ABSTRACT

Intradialytic hypotension (IDH), a common complication of ultrafiltration during hemodialysis therapy, is associated with high mortality and morbidity. IDH, defined as a nadir systolic blood pressure of less than 90 mm Hg on more than 30% of treatments, is a relevant definition and is correlated with mortality. Risk factors for IDH include patient demographics, anti-hypertensive medication use, larger interdialytic weight gain, and dialysis prescription features as dialysate sodium, high ultrafiltration rate, and dialysate temperature. A high frequency of IDH events carries a substantial death risk. An ultrafiltration rate >10 mL/h/kg, and even more so >13 mL/h/kg, is highly predictive of cardiovascular and all-cause mortality. Evidence suggests that IDH causes acute reversible segmental myocardial hypoperfusion and contractile dysfunction (myocardial stunning), which can result in long-term loss of myocardial contractility, leading to premature death. IDH also has negative end-organ effects on the brain and gut, contributing to mortality through stroke, and endotoxin translocation with associated inflammation and protein-energy wasting. Given strong association of IDH and dialysis mortality, a paradigm shift to its approach is urgently needed. Randomized controlled trials are required to prospectively test drugs and monitoring devices which may reduce IDH.


Subject(s)
Hypotension/etiology , Renal Dialysis/adverse effects , Blood Pressure , Humans , Hypotension/complications , Hypotension/mortality , Kidney Failure, Chronic/therapy , Risk Factors , Survival Rate
14.
Am J Nephrol ; 45(6): 509-521, 2017.
Article in English | MEDLINE | ID: mdl-28528336

ABSTRACT

BACKGROUND: Hyperkalemia is observed in chronic kidney disease patients and may be a risk factor for life-threatening arrhythmias and death. Race/ethnicity may be important modifiers of the potassium-mortality relationship in maintenance hemodialysis (MHD) patients given that potassium intake and excretion vary among minorities. METHODS: We examined racial/ethnic differences in baseline serum potassium levels and all-cause and cardiovascular mortality using Cox proportional hazard models and restricted cubic splines in a cohort of 102,241 incident MHD patients. Serum potassium was categorized into 6 groups: ≤3.6, >3.6 to ≤4.0, >4.0 to ≤4.5 (reference), >4.5 to ≤5.0, >5.0 to ≤5.5, and >5.5 mEq/L. Models were adjusted for case-mix and malnutrition-inflammation cachexia syndrome (MICS) covariates. RESULTS: The cohort was composed of 50% whites, 34% African-Americans, and 16% Hispanics. Hispanics tended to have the highest baseline serum potassium levels (mean ± SD: 4.58 ± 0.55 mEq/L). Patients in our cohort were followed for a median of 1.3 years (interquartile range 0.6-2.5). In our cohort, associations between higher potassium (>5.5 mEq/L) and higher mortality risk were observed in African-American and whites, but not Hispanic patients in models adjusted for case-mix and MICS covariates. While in Hispanics only, lower serum potassium (<3.6 mEq/L) levels were associated with higher mortality risk. Similar trends were observed for cardiovascular mortality. CONCLUSIONS: Higher potassium levels were associated with higher mortality risk in white and African-American MHD patients, whereas lower potassium levels were associated with higher death risk in Hispanics. Further studies are needed to determine the underlying mechanisms for the differential association between potassium and mortality across race/ethnicity.


Subject(s)
Hyperkalemia/mortality , Kidney Failure, Chronic/mortality , Kidney Failure, Chronic/therapy , Mortality/ethnology , Potassium, Dietary/adverse effects , Renal Dialysis/adverse effects , Black or African American/statistics & numerical data , Aged , Female , Follow-Up Studies , Hispanic or Latino/statistics & numerical data , Humans , Hyperkalemia/blood , Kidney Failure, Chronic/blood , Male , Middle Aged , Potassium, Dietary/blood , Proportional Hazards Models , Risk Assessment , White People/statistics & numerical data
15.
Kidney Int Rep ; 2(2): 271-281, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28439569

ABSTRACT

Obesity, a risk factor for de novo chronic kidney disease (CKD), confers survival advantages in advanced CKD. This so-called obesity paradox is the archetype of the reverse epidemiology of cardiovascular risks, in addition to the lipid, blood pressure, adiponectin, homocysteine, and uric acid paradoxes. These paradoxical phenomena are in sharp contradistinction to the known epidemiology of cardiovascular risks in the general population. In addition to advanced CKD, the obesity paradox has also been observed in heart failure, chronic obstructive lung disease, liver cirrhosis, and metastatic cancer, as well as in the elderly. These are populations in whom protein-energy wasting and inflammation are strong predictors of early death. Both larger muscle mass and higher body fat provide longevity in these patients, whereas thinner body habitus and weight loss are associated with higher mortality. Muscle mass appears to be superior to body fat in conferring an even greater survival. The obesity paradox may be the result of a time discrepancy between competing risk factors, i.e., overnutrition as the long-term killer versus undernutrition as the short-term killer. Hemodynamic stability of obesity, lipoprotein defense against circulating endotoxins, protective cytokine profiles, toxin sequestration of fat mass, and antioxidation of muscle may play important roles. Despite claims that obesity paradox is a statistical fallacy and a result of residual confounding, the consistency of data and other causality clues suggest a high biologic plausibility. Examining the causes and consequences of the obesity paradox may help discover important pathophysiologic mechanisms leading to improved outcomes in patients with CKD.

17.
Semin Dial ; 30(3): 262-269, 2017 05.
Article in English | MEDLINE | ID: mdl-28295607

ABSTRACT

Incremental hemodialysis has been examined as a viable hemodialysis regimen for selected end-stage renal disease (ESRD) patients. Preservation of residual kidney function (RKF) has been the driving impetus for this approach given its benefits upon the survival and quality of life of dialysis patients. While clinical practice guidelines recommend an incremental start of dialysis in peritoneal dialysis patients with substantial RKF, there remains little guidance with respect to incremental hemodialysis as an initial renal replacement therapy regimen. Indeed, several large population-based studies suggest that incremental twice-weekly vs. conventional thrice-weekly hemodialysis has favorable impact upon RKF trajectory and survival among patients with adequate renal urea clearance and/or urine output. In this report, we describe a case series of 13 ambulatory incident ESRD patients enrolled in a university-based center's Incremental Hemodialysis Program over the period of January 2015 to August 2016 and followed through December 2016. Among five patients who maintained a twice-weekly hemodialysis schedule vs. eight patients who transitioned to thrice-weekly hemodialysis, we describe and compare patients' longitudinal case-mix, laboratory, and dialysis treatment characteristics over time. The University of California Irvine Experience is the first systemically examined twice-weekly hemodialysis practice in North America. While future studies are needed to refine the optimal approaches and the ideal patient population for implementation of incremental hemodialysis, our case-series serves as a first report of this innovative management strategy among incident ESRD patients with substantial RKF, and a template for implementation of this regimen.


Subject(s)
Glomerular Filtration Rate/physiology , Hospitals, University , Kidney Failure, Chronic/therapy , Kidney/physiopathology , Renal Dialysis/methods , Adult , Aged , California/epidemiology , Female , Follow-Up Studies , Humans , Kidney Failure, Chronic/epidemiology , Kidney Failure, Chronic/physiopathology , Male , Middle Aged , Retrospective Studies , Survival Rate/trends , Time Factors , Treatment Outcome , Young Adult
18.
Hemodial Int ; 21(4): 507-518, 2017 10.
Article in English | MEDLINE | ID: mdl-27885815

ABSTRACT

INTRODUCTION: Hypoalbuminemia is a predictor of poor outcomes in dialysis patients. Among hemodialysis patients, there has not been prior study of whether residual kidney function or decline over time impacts serum albumin levels. We hypothesized that a decline in residual kidney function is associated with an increase in serum albumin levels among incident hemodialysis patients. METHODS: In a large national cohort of 38,504 patients who initiated hemodialysis during 1/2007-12/2011, we examined the association of residual kidney function, ascertained by urine volume and renal urea clearance, with changes in serum albumin over five years across strata of baseline residual kidney function, race, and diabetes using case-mix adjusted linear mixed effects models. FINDINGS: Serum albumin levels increased over time. At baseline, patients with greater urine volume had higher serum albumin levels: 3.44 ± 0.48, 3.50 ± 0.46, 3.57 ± 0.44, 3.59 ± 0.45, and 3.65 ± 0.46 g/dL for urine volume groups of <300, 300-<600, 600-<900, 900-<1,200, and ≥1,200 mL/day, respectively (Ptrend < 0.001). Over time, urine volume and renal urea clearance declined and serum albumin levels rose, while the baseline differences in serum albumin persisted across groups of urinary volume. In addition, the rate of decline in residual kidney function was not associated with the rate of change in albumin. DISCUSSION: Hypoalbuminemia in hemodialysis patients is associated with lower residual kidney function. Among incident hemodialysis patients, there is a gradual rise in serum albumin that is independent of the rate of decline in residual kidney function, suggesting that preservation of residual kidney function does not have a deleterious impact on serum albumin levels.


Subject(s)
Kidney Failure, Chronic/blood , Kidney Failure, Chronic/urine , Renal Dialysis/methods , Serum Albumin/metabolism , Urine/chemistry , Cohort Studies , Female , Humans , Male , Middle Aged , Retrospective Studies
19.
Panminerva Med ; 59(2): 157-165, 2017 Jun.
Article in English | MEDLINE | ID: mdl-27759735

ABSTRACT

In the management of patients with chronic kidney diseases (CKD), a low-protein diet usually refers to a diet with protein intake of 0.6 to 0.8 grams per kilogram of body weight per day (g/kg/day) and should include at least 50% high-biologic-value protein. It may be supplemented with essential acids or nitrogen-free ketoanalogues if <0.6 g/kg/d. Low-protein diet can reduce proteinuria especially in non-diabetic CKD patients. In hypoalbuminemic patients it may lead to an increase in serum albumin level. By lowering proteinuria, decreasing nitrogen waste products, ameliorating metabolic burden, mitigating oxidative stress and acidosis, and lowering phosphorus burden, a low-protein diet can help delay dialysis start in advanced CKD. Low-protein diet is safe, since most CKD patients can maintain nitrogen balance by mechanisms of decreasing amino acid oxidation and protein degradation in addition to increased utilization of amino acids for protein synthesis. We suggest a dietary protein intake below 1.0 g/kg/day when estimated glomerular filtration rate (eGFR) falls below 60 mL/min/1.73 m2 or when there is solitary kidney or proteinuria at any level of GFR. Protein intake should be reduced progressively based on severity and progression of CKD and patient's nutritional status with a target of 0.6-0.8 g/kg/d in most patients with eGFR <45 mL/min/1.73 m2. The risk of protein-energy wasting can be overcome by careful attention to quantity and quality of the ingested proteins, sufficient energy intake of 30-35 Kcal/kg/d, and use of dietary supplements. Long-term observations and individualized approaches are needed to further demonstrate the benefits and safety of low-protein diet.


Subject(s)
Diet, Protein-Restricted , Proteinuria/therapy , Renal Dialysis/methods , Acidosis , Albumins/metabolism , Amino Acids, Essential , Animals , Body Weight , Dietary Supplements , Disease Progression , Glomerular Filtration Rate , Humans , Kidney Failure, Chronic/therapy , Nitrogen/blood , Nitrogen/chemistry , Nutritional Status , Oxidative Stress , Proteinuria/blood , Risk
20.
Nephrol Dial Transplant ; 32(9): 1549-1558, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-27789782

ABSTRACT

BACKGROUND: Incident hemodialysis patients may experience rapid weight loss in the first few months of starting dialysis. However, trends in weight changes over time and their associations with survival have not yet been characterized in this population. METHODS: In a large contemporary US cohort of 58 106 patients who initiated hemodialysis during 1 January 2007-31 December 2011 and survived the first year of dialysis, we observed trends in weight changes during the first year of treatment and then examined the association of post-dialysis weight changes with all-cause mortality. RESULTS: Patients' post-dialysis weights rapidly decreased and reached a nadir at the 5th month of dialysis with an average decline of 2% from baseline, whereas obese patients (body mass index ≥30 kg/m 2 ) did not reach a nadir and lost ∼3.8% of their weight by the 12th month. Compared with the reference group (-2 to 2% changes in weight), the death hazard ratios (HRs) of patients with -6 to -2% and greater than or equal to -6% weight loss during the first 5 months were 1.08 (95% confidence interval, 1.02-1.14) and 1.14 (1.07-1.22), respectively. Moreover, the death HRs with 2-6% and ≥6% weight gain during the 5th to 12th months were 0.91 (0.85-0.97) and 0.92 (0.86-0.99), respectively. CONCLUSIONS: In patients who survive the first year of hemodialysis, a decline in post-dialysis weight is observed and reaches a nadir at the 5th month. An incrementally larger weight loss during the first 12 months is associated with higher death risk, whereas weight gain is associated with greater survival during the 5th to 12th month but not in the first 5 months of dialysis therapy.


Subject(s)
Body Weight , Kidney Failure, Chronic/mortality , Obesity/physiopathology , Renal Dialysis/mortality , Body Mass Index , Cohort Studies , Female , Humans , Kidney Failure, Chronic/therapy , Male , Middle Aged , Survival Rate , Weight Gain , Weight Loss
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