Hemodialysis: A model for extreme physiology in a vulnerable patient population.

Hemodialysis (HD) is a lifesaving treatment for patients with end-stage renal disease, which is very efficient in the correction of abnormalities of the internal environment. However, this efficiency also induces significant hemodynamic, thermal, and respiratory stressors. These have parallels with the extreme physiologic demands which are normally mainly experienced by healthy subjects under adverse environmental conditions, with the difference that they must be endured by a vulnerable patient population.

Health-related quality of life in end-stage renal disease patients: the effects of starting dialysis in the first year after the transition period.

Background/aims: Prevalent dialysis patients have low scores of health-related quality of life (HRQOL) which are associated with increased risk of hospitalization and mortality. Also in CKD-5 non-dialysis patients, HRQOL scores seem to be lower as compared with the general population. This study firstly aimed to compare HRQOL between CKD-5 non-dialysis and prevalent dialysis patients in a cross-sectional analysis and to assess longitudinal changes over 1 year after the dialysis initiation.

Novel Insights into the Pathogenesis and Prevention of Intradialytic Hypotension.

Background: Intradialytic hypotension (IDH) is a common complication of haemodialysis (HD) and associated with adverse outcomes, especially when a nadir definition (systolic blood pressure <90 mm Hg) is used. The pathogenesis of IDH is directly linked to the discontinuous nature of the HD treatment, in combination with patient-related factors such as age, diabetes mellitus and cardiac failure.

Summary: Although the decline in blood volume due to removal of fluid by ultrafiltration is the prime mover, thermally induced reflex vasodilation compromises the haemodynamic response to hypovolemia.

Fluid Overload and Inflammation Axis.

Extracellular fluid overload (FO), which is assessed using bioimpedance technologies, is an important predictor of outcome in dialysis patients and in patients with early stages of chronic kidney disease. While traditional cardiovascular abnormalities are assumed to mediate this risk, recently also, the importance of noncardiovascular factors, such as systemic inflammation and malnutrition has been shown. While both FO and inflammation are independent risk factors for mortality, recent studies have shown that their combined presence can lead to a cumulative risk profile.

Microvascular endothelial dysfunction is associated with albuminuria: the Maastricht Study.

Objective: Albuminuria is thought to be a biomarker of microvascular and macrovascular endothelial dysfunction. However, direct evidence for an association of microvascular endothelial dysfunction with albuminuria is limited. In addition, experimental data suggest a stronger association of microvascular endothelial dysfunction with albuminuria in individuals with than in those without diabetes.

Physical Activity in End-Stage Renal Disease Patients: The Effects of Starting Dialysis in the First 6 Months after the Transition Period.

Objectives: Physical inactivity in end-stage renal disease (ESRD) patients is associated with increased mortality, and might be related to abnormalities in body composition (BC) and physical performance. It is uncertain to what extent starting dialysis influences the effects of ESRD on physical activity (PA). This study aimed to compare PA and physical performance between stage 5 chronic kidney disease (CKD-5) non-dialysis and dialysis patients, and healthy controls, to assess alterations in PA during the transition from CKD-5 non-dialysis to dialysis, and to relate PA to BC.

Estimated Glomerular Filtration Rate and Albuminuria Are Associated with Biomarkers of Cardiac Injury in a Population-Based Cohort Study: The Maastricht Study.

Background: Chronic kidney disease (CKD) is associated with an increased cardiovascular disease mortality risk. It is, however, less clear at what point in the course from normal kidney function to CKD the association with cardiovascular disease appears. Studying the associations of estimated glomerular filtration rate (eGFR) and albuminuria with biomarkers of (subclinical) cardiac injury in a population without substantial CKD may clarify this issue.

Impact of fluid status and inflammation and their interaction on survival: a study in an international hemodialysis patient cohort.

In hemodialysis patients extracellular fluid overload is a predictor of all-cause and cardiovascular mortality, and a relation with inflammation has been reported in previous studies. The magnitude and nature of this interaction and the effects of moderate fluid overload and extracellular fluid depletion on survival are still unclear. We present the results of an international cohort study in 8883 hemodialysis patients from the European MONDO initiative database where, during a three-month baseline period, fluid status was assessed using bioimpedance and inflammation by C-reactive protein.

Albuminuria is associated with a higher prevalence of depression in a population-based cohort study: the Maastricht Study.

Background: Depression is common in individuals with chronic kidney disease (CKD). However, data on the association of albuminuria, which together with reduced estimated glomerular filtration rate (eGFR) defines CKD, with depression are scarce and conflicting. In addition, it is not clear when in the course from normal kidney function to CKD the association with depression appears.

Estimated GFR, Albuminuria, and Cognitive Performance: The Maastricht Study.

Background: Reduced estimated glomerular filtration rate (eGFR) and albuminuria have been associated with worse cognitive performance. However, few studies have examined whether these associations are confined to older individuals or may be extended to the middle-aged population.

Study Design: Cross-sectional analyses of a prospective population-based cohort study.

Capillary Rarefaction Associates with Albuminuria: The Maastricht Study.

Albuminuria may be a biomarker of generalized (i.e., microvascular and macrovascular) endothelial dysfunction.

Unraveling the relationship between mortality, hyponatremia, inflammation and malnutrition in hemodialysis patients: results from the international MONDO initiative.

Background/objectives: Hyponatremia is a risk factor for mortality in hemodialysis (HD) patients. It is not well known to which extent the comorbidities, malnutrition, fluid status imbalance and inflammation are related to hyponatremia and affect outcomes.

Subjects/methods: We studied 8883 patients from the European subset of the international MONitoring Dialysis Outcomes initiative.

Kidney disease and aging: A reciprocal relation.

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are overrepresented in elderly patients. This provides specific challenges for the treatment, as the start of dialysis in vulnerable elderly patients may be associated with a rapid decline in functional performance. However, prognosis in elderly patients with ESRD is quite variable and related to the presence of comorbidity and geriatric impairments.

The first year on haemodialysis: a critical transition.

The first year following the start of haemodialysis (HD) is associated with increased mortality, especially during the first 90-120 days after the start of dialysis. Whereas the start of dialysis has important effects on the internal environment of the patient, there are relatively few studies assessing changes in phenotype and underlying mechanisms during the transition period following pre-dialysis to dialysis care, although more insight into these parameters is of importance in unravelling the causes of this increased early mortality. In this review, changes in cardiovascular, nutritional and inflammatory parameters during the first year of HD, as well as changes in physical and functional performance are discussed.

Effects of ultrapure hemodialysis and low molecular weight heparin on the endothelial surface layer.

Background: Chronic kidney disease patients show changes in the endothelial surface layer (ESL). Whether hemodialysis (HD) itself or low molecular weight heparins (LMWH) induce ESL alterations is unknown.

Methods: We studied the ESL in 20 HD patients with Sidestream Dark Field Imaging [measuring perfused boundary region (PBR)] and measurement of ESL constituents in plasma during HD in 2 studies.

Body composition in dialysis patients: a functional assessment of bioimpedance using different prediction models.

Objectives: The assessment of body composition (BC) in dialysis patients is of clinical importance given its role in the diagnosis of malnutrition and sarcopenia. Bioimpedance techniques routinely express BC as a 2-compartment (2-C) model distinguishing fat mass (FM) and fat-free mass (FFM), which may be influenced by the hydration of adipose tissue and fluid overload (OH). Recently, the BC monitor was introduced which applies a 3-compartment (3-C) model, distinguishing OH, adipose tissue mass, and lean tissue mass.

Vascular access vulnerability in intensive hemodialysis: a significant Achilles' heel?

Background: Frequent hemodialysis (HD) may be associated with an increased risk of vascular access complications. Studies addressing vascular access outcomes in frequent HD show conflicting results.

Methods: We searched Medline for trials looking at vascular access outcomes in frequent HD.

Acute hemodynamic response and uremic toxin removal in conventional and extended hemodialysis and hemodiafiltration: a randomized crossover study.

Background: Intensive hemodialysis (HD) may have significant benefits. Recently, the role of extended hemodiafiltration (HDF) has gained interest. The aim of this study was to evaluate the acute effects of extended HD and HDF on hemodynamic response and solute removal.

The Biobank of Nephrological Diseases in the Netherlands cohort: the String of Pearls Initiative collaboration on chronic kidney disease in the university medical centers in the Netherlands.

Despite advances in preventive therapy, prognosis in chronic kidney disease (CKD) is still grim. Clinical cohorts of CKD patients provide a strategic resource to identify factors that drive progression in the context of clinical care and to provide a basis for improvement of outcome. The combination with biobanking, moreover, provides a resource for fundamental and translational studies.

Out of control: accelerated aging in uremia.

Next to a high morbidity, patients with end-stage renal failure (ESRD) suffer from a complex spectrum of clinical manifestations. Both the phenotype of patients with ESRD as well as the pathophysiology of uremia show interesting parallels with the general aging process. Phenotypically, patients with ESRD have an increased susceptibility for both cardiovascular as well as infectious disease and show a reduction in functional capacity as well as muscular mass (sarcopenia), translating into a high prevalence of frailty also in younger patients.

Peritoneal dialysis in patients with heart failure.

Both in dialysis patients and non-uremic patients heart failure is associated with an adverse prognosis. In a state of abrupt worsening of cardiac function, acute cardiogenic shock or decompensated congestive heart failure, acute kidney injury may occur, whereas in a more chronic worsening of cardiac function chronic kidney injury may occur. Recently, the term cardiorenal syndrome was adopted and defined as "a pathophysiological disorder of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ".

'Time and time again': oscillatory and longitudinal time patterns in dialysis patients.

Oscillatory and longitudinal time patterns play a major role in human physiology. In chronic hemodialysis patients, abnormalities in both time patterns have been observed, while time patterns can also influence the response of patients to the treatment. Abnormal oscillatory patterns have been observed for ultradian rhythms (cycle time <20 h), such as an impaired heart rate variability and circadian rhythms, as reflected by reduced day-night blood pressure differences.