Trace element concentrations in hair, fingernails and plasma of patients with chronic renal failure on hemodialysis and hemofiltration

Metabolic and Nutritional Aspects of Acute Renal Failure in Critically Ill Patients Requiring Continuous Renal Replacement Therapy

Acute renal failure (ARF) is rarely an isolated process but is often a complication of underlying conditions such as sepsis, trauma, and multiple-organ failure in critically ill patients. As such, concomitant clinical conditions significantly affect patient outcome. Poor nutritional status is a major factor in increasing patients' morbidity and mortality. Malnutrition in ARF patients is caused by hypercatabolism and hypermetabolism that parallel the severity of illness. When dialytic intervention is indicated, continuous renal replacement therapy (CRRT) is a commonly used alternative to intermittent hemodialysis because it is well tolerated by hemodynamically unstable patients. This paper reviews the metabolic and nutritional alterations associated with ARF and provides recommendations regarding the nutritional, fluid, electrolyte, micronutrient, and acid-base management of these patients. The basic principles of CRRT are addressed, along with their nutritional implications in critically ill patients. A patient case is presented to illustrate the clinical application of topics covered within the paper.

Disturbances of trace element metabolism in ESRD patients receiving hemodialysis and hemodiafiltration

Introduction

Accumulation of trace elements occurs in conditions of decreased kidney function. In some conditions, increased trace elements can have toxic features. On the other hand, studies are showing that concentration of some trace elements could be decreased in ERSD patients as well. The most important factor affecting trace element concentration in ERSD patients is the degree of renal failure and the usage of replacement therapy.

Materials and methods

We analyzed the trace elements’ (boron, aluminum, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, rubidium, strontium, cadmium, cesium, barium and lead) concentration in the whole blood of 41 ESRD patients who were treated with hemodialysis and hemodiafiltration and also of 61 healthy blood donors. In addition, comparison of trace element blood levels of patients receiving hemodialysis and hemofiltration was carried out. Whole blood trace element concentration was determined using inductive coupled plasma mass-spectrometry (ICPMS).

Results

Levels of boron, aluminum, vanadium, chromium, manganese, zinc, strontium, cadmium, barium and lead were significantly increased in ESRD patients. Significantly decreased levels were observed for nickel, arsenic, selenium and rubidium. Blood levels of cobalt, copper, cadmium and lead in hemodialysis patients were significantly higher compared to patients receiving hemodiafiltration.

Conclusions

ESRD is accompanied with serious and multidirectional changes of trace element blood levels. The highest degree of blood level increases were observed for nonessential and toxic trace elements. Disorders of essential trace elements were manifested in a minor degree. Besides this, there were observed differences of trace element concentrations between ESRD patients receiving hemodialysis and hemo-diafiltration.

Trace elements in the hair of hemodialysis patients

Trace element disturbance is often observed in hemodialysis patients. While trace element concentrations have been reported in blood samples from hemodialysis patients, they have not been well investigated in scalp hair. In the present study, 22 trace elemental concentrations were measured by inductively coupled plasma-atomic emission spectrometry in the scalp hair of 80 male hemodialysis patients and compared with those of 100 healthy male subjects. In hemodialysis patients, the concentrations of beryllium, arsenic, magnesium, chromium, manganese, iron, selenium, molybdenum, iodine, vanadium, and cobalt were significantly higher than those in healthy subjects, while lead, mercury, copper, germanium, and bromine were significantly lower than those in the former group. No significant differences were observed for lithium, aluminum, cadmium, zinc, boron, or nickel. There were significant positive correlations between the duration of hemodialysis and the magnesium and manganese concentrations. There was a significant negative correlation between cadmium concentration and the duration of hemodialysis. There were significant positive correlations between dialysis efficacy (Kt/V) and magnesium, manganese, zinc, and selenium concentrations. In conclusion, trace element concentrations of the scalp hair are different between hemodialysis patients and healthy subjects. Essential trace elements, such as magnesium, manganese, zinc, and selenium, may be affected by the duration of hemodialysis and Kt/V.

Causative factors of taste disorders in the elderly, and therapeutic effects of zinc

Objectives:

To determine the characteristics of causative factors of taste disorders amongst the elderly, and to examine the therapeutic effect of a zinc agent, taking into account age-related factors.

Subjects:

A total of 408 patients with taste disorders were divided into three groups by age: 49 years or younger, 50 to 64 years old, and 65 years or older.

Results:

The incidence of taste disorders caused by drug administration and systemic disease were significantly higher in the elderly group. A serum zinc concentration of 69 µg/dl or lower was found in 33 per cent of the elderly group, significantly more (p < 0.001) than the 19 per cent of the 49 years or younger group with such a concentration. Zinc administration was therapeutically effective in 70 per cent of the whole population studied, and in 74 per cent of the elderly population.

Conclusions:

In the elderly, the incidence of taste disorders caused by drug administration or systemic disease was significantly greater compared with other age groups. The curative effects of zinc administration were not observed to be influenced by age.

74As-arsenate metabolism in Flemish Giant rabbits with renal insufficiency

The metabolic management of carrier-free 74As-arsenate (As(V)) by uremic rabbits of the strain Flemish Giant was studied. Renal insufficiency was induced by nephrectomy of respectively 1 kidney (3/6 nephrectomy) and 1 kidney + 2/3 remaining kidney (5/6 nephrectomy). Marginal renal insufficiency developed in the 3/6 nephrectomized group, while animals of the 5/6 group became severely uremic. Renal excretion of 74As was reduced by 90% in 5/6 nephrectomized animals 4 h after intraperitoneal injection (i.p.) of the animals. The associated uremic syndrome caused a strong decrease in methylation capacity of inorganic arsenic (Asi). The second methylation step from monomethylarsonic acid (MMA) to dimethylarsinic acid (DMA) was more strongly affected than the first one, from arsenite (As(III)) to MMA. The increased availability of Asi led to more extensive binding to insoluble tissue constituents after 5/6 nephrectomy. The decreased renal reduction of As(V) led to a decrease in As(III) and an increase of As(V) and the associated As(V)-transferrin binding in plasma. Uptake of 74As-transferrin by the bone marrow might contribute to uremic anemia.

An evaluation of the biological significance of aluminium in plasma and hair of patients on long-term hemodialysis

In hemodialyzed patients, the risk of toxicity attributed to the body accumulation of aluminium (Al) justifies the need for monitoring Al in various human media. In this study, Al concentrations in the hair and plasma of 78 hemodialyzed patients with chronic renal failure and of 351 healthy volunteers were measured by electrothermal atomic absorption spectrometry with Zeeman effect. Plasma Al concentrations in patients were significantly higher than in the controls and positively correlated with time on dialysis. Hair Al levels were widely distributed with no significant distinction between patients and controls. On the subject of establishing correlation, the authors stress the importance of taking into account the kinetics of the elimination of minerals from hair. Even when this was done, in the patient group there was no statistical link between plasma and hair Al levels. Hair Al analysis is of no value as an indicator of body Al accumulation.

Essential trace elements in humans. Serum arsenic concentrations in hemodialysis patients in comparison to healthy controls

Serum arsenic concentrations of persons suffering from renal failure and undergoing hemodialysis treatment (n = 85) and of healthy controls (n = 25) were determined by hydride-generation AAS technique after microwave digestion. The results were evaluated by comparing the values of both groups, considering physiological factors and individual data, as well as comorbid conditions of the hemodialysis (HD) patients. Serum arsenic levels were diminished in the patient group compared with controls (mean values 8.5 +/- 1.8 ng/mL vs 10.6 +/- 1.3 ng/mL). Furthermore, additional diseases within the hemodialysis group, particularly injuries of the central nervous system (CNS), vascular diseases, and cancer, were correlated to occasionally markedly decreased serum arsenic concentrations. It was concluded that arsenic homeostasis is disturbed by HD treatment and certain additional diseases. Desirable arsenic concentrations in the body seem to be reasonable. This consideration results in the conclusion that arsenic could play an essential role in human health. Thus, reference arsenic concentrations in different human tissues and body fluids should be established in order to recognize not only arsenic intoxication, but also arsenic deficiency. Perhaps arsenic deficiency contributes to the increased death risk of HD patients, and therefore, arsenic supplementations for patients with extremely low serum arsenic concentrations should be taken into account.

Zinc in kidney disease

Abnormalities of Zn metabolism are well documented in patients with chronic renal disease, especially those with nephrotic disease and uremia. The causes of Zn deficiency in kidney disease are not clear. Decreased dietary Zn intake and intestinal absorption, increased endogenous Zn secretion, and increased urinary Zn excretion (as in the nephrotic syndrome and in renal transplant recipients) all may contribute to altered Zn metabolism. Zn depletion may account for decreased taste, sexual and gonadal dysfunction, hyperprolactinemia, glucose intolerance, hyperlipidemia, growth retardation in children, neuropathy, anemia, abnormalities of neutrophil and lymphocyte function, and delayed wound healing. The benefit of pharmacologic doses of Zn, in the treatment of such manifestations, requires further evaluation under controlled conditions. Before use of Zn routinely for therapeutic purposes in uremic subjects, the cause(s) of abnormal Zn metabolism should be identified.

Relationship between hair, serum and bone aluminium in hemodialyzed patients

To establish the predictive value in osteodystrophy of hair aluminium content in patients on hemodialysis, we compared the aluminium levels in serum, cortical and trabecular bone and hair of 40 such patients with the levels in 23 healthy controls. In the patients, mean hair aluminium content was significantly higher than the controls (0.226 mumol/g, range: 0.09-0.500 mumol/g, n = 39 versus 0.126 mumol/g, range: 0.020-0.330 mumol/g, n = 49) but there was a large overlap between the two groups. The patients exhibited a significant correlation between serum and cortical bone aluminium measured by atomic absorption spectrometry (rs = 0.67, n = 37, p less than 0.05), but no correlation between aluminium in hair and in serum or bone, whether cortical or trabecular. Bone histomorphometric studies also indicated that unlike aluminium levels in cortical or trabecular bone, its levels in hair are not predictive of aluminium-induced osteomalacia. Consequently, hair aluminium cannot suitably replace bone and serum aluminium as a criterion of osteodystrophy in hemodialyzed patients.

Scalp hair as an indicator of aluminium exposure: comparison to bone and plasma

1. Aluminium concentrations were measured in hair, plasma and bone samples from different groups of chronic renal insufficient patients and from a control group (75 healthy volunteers plus 21 deceased subjects). A cross-sectional study with 40 haemodialysis patients and two longitudinal studies were undertaken, the first comprising of 12 home haemodialysis patients and the second 16 patients undergoing continuous ambulatory peritoneal dialysis (CAPD). 2. Before introduction of water treatment by reverse osmosis, the hair aluminium levels of home haemodialysis patients were elevated compared to controls. Aluminium in the hair of all other groups were within the normal range. Hair aluminium levels were not related to the daily aluminium intake, nor to the cumulative aluminium intake, nor to bone and plasma aluminium concentrations. 3. Plasma aluminium concentrations in all patients were higher than in the controls. Dialysis without reverse osmosis water treatment increased aluminium plasma levels. After installation of reverse osmosis units there was a decrease in the aluminium concentrations in plasma. In CAPD patients insignificant increases in the aluminium levels in plasma were observed. When low contaminated dialysis fluid was available the plasma aluminium concentrations returned to the initial level. 4. Aluminium concentrations in bone were increased in renal insufficient patients compared with controls. Aluminium bone content increased with increasing cumulative aluminium intake by phosphate binding therapy. 5. Hair analysis is of very limited value for the diagnosis of aluminium exposure. Bone analysis is suitable for the assessment of the individual body burden.