An occidental case of cardiomyopathy and selenium deficiency

Selenium - a scoping review for Nordic Nutrition Recommendations 2023

Selenium is an essential trace element in humans, critical to the normal physiology in all animal species. The main form of selenium in food is selenomethionine, selenocysteine and a variety of organic compounds, while inorganic salts mainly occur in food supplements. In animals and humans, selenium occurs as selenocysteine in selenoproteins encoded by 25 genes (specific selenium pool). Several selenoproteins are part of the antioxidant enzyme system and serve as oxido-reductases and in thyroid hormone regulation. SelenoproteinP (SELENOP) transports selenium to peripheral tissues, is the main plasma selenoprotein, and has been used as biomarker of selenium status and intake. SELENOP in plasma represents a saturable pool of selenium and is maximised at a selenium concentration in plasma of about 110 µg/L or an intake of selenomethionine at about 1.2 µg/kg body weight in adults. In Finland, with an estimated selenium intake of 88 µg/day in men and 68 µg/day in women, the average selenium concentration in plasma is about 110 µg/L. Imported wheat from selenium rich areas is an important dietary source in Norway. Dietary intakes in the Nordic and Baltic area vary from 39 to 88 µg/day in men and 22 to 68 µg/day in women, the highest levels were from Finland. Most intervention trials on the effect of selenium supplementation on health outcomes have been carried out in 'selenium-replete'-populations and show no beneficial effect, which from a nutritional point of view would rather not be expected. Some intervention studies conducted in populations low in selenium have showed a beneficial effect. Observational studies suggest an inverse relationship between selenium status and risk of cardiovascular diseases (CVDs), cancer and all-cause mortality, and some other outcomes at low levels of intake (<55 µg/day) or in plasma or serum (<100 µg/L). However, a lack of quantitative data and inconsistencies between studies precludes these studies to be used to derive dietary reference values. At high intakes above 330 to 450 µg/day selenium may cause toxic effects affecting liver, peripheral nerves, skin, nails, and hair. An upper tolerable level (UL) of 255 µg selenium/day in adults was established by EFSA.

[Development and Assessment of a New Oral Selenium Fast-disintegrating Tablets]

Selenium is an essential trace element and its deficiency causes myositis, myocardial damage, and other symptoms. Patients receiving long-term intravenous nutrition or tube-feeding in particular are deficient in essential trace elements, including selenium, and require regular supplementation. In Japan, injectable selenium-containing products are listed on the National Health Insurance drug price list, and oral solutions are prepared and used in hospitals. However, these formulations have problems related to preservation and require complicated administration procedures. In this study, we developed a new fast-disintegrating tablet formulation of selenium, using SmartEx® (D-mannitol·low substituted hydroxypropylcellulose (L-HPC)·fully hydrolyzed polyvinyl alcohol (PVA) mixture) as a coprocessing additive, that can be administered orally or by feeding tube. The tablet formulation had excellent disintegrable capability, sufficient hardness, and did not cause tube blockage when administered in the simple suspension method. In addition, the tablet formulation showed no changes in properties in an accelerated test without packaging for 42 d, indicating that it could be stored for a long period. Fast-disintegrating tablets prepared with SmartEx® are expected to improve the adherence and quality of life of patients who require selenium supplementation.

Selenium Status, Its Interaction with Selected Essential and Toxic Elements, and a Possible Sex-Dependent Response In Utero, in a South African Birth Cohort

Selenium (Se) is an essential trace element and its deficiency in utero may affect fetus development and birth outcomes. The current study aimed to assess serum Se status at delivery and examine the possible association between Se levels and birth outcomes. The interaction of Se with selected essential and toxic elements as well as possible sex-dependent responses in utero were also evaluated. The negative association between Se levels and head circumference of neonates was evident in the total cohort (β = −0.164; p < 0.001) as well as in the pre-term and full-term cohorts. Significant positive correlations were found between maternal serum Se concentrations and zinc (Zn) and copper (Cu) in the total and regional cohorts. In the total cohort, the toxic elements lead (Pb) and arsenic (As) showed a negative correlation with Se levels, while mercury (Hg), aluminum (Al) and cadmium (Cd) showed a positive correlation. The study found a sex-dependent response in utero for Zn, Cu, Pb, Hg, and Al. The findings of the current study may inform reproductive health policy on Se status in South Africa and highlight the need for sensitive methods to measure Se intake during pregnancy and its complex interactions with other micronutrients and environmental pollutants.

The Effects of Ethanol on the Heart: Alcoholic Cardiomyopathy

Alcoholic-dilated Cardiomyopathy (ACM) is the most prevalent form of ethanol-induced heart damage. Ethanol induces ACM in a dose-dependent manner, independently of nutrition, vitamin, or electrolyte disturbances. It has synergistic effects with other heart risk factors. ACM produces a progressive reduction in myocardial contractility and heart chamber dilatation, leading to heart failure episodes and arrhythmias. Pathologically, ethanol induces myocytolysis, apoptosis, and necrosis of myocytes, with repair mechanisms causing hypertrophy and interstitial fibrosis. Myocyte ethanol targets include changes in membrane composition, receptors, ion channels, intracellular [Ca2+] transients, and structural proteins, and disrupt sarcomere contractility. Cardiac remodeling tries to compensate for this damage, establishing a balance between aggression and defense mechanisms. The final process of ACM is the result of dosage and individual predisposition. The ACM prognosis depends on the degree of persistent ethanol intake. Abstinence is the preferred goal, although controlled drinking may still improve cardiac function. New strategies are addressed to decrease myocyte hypertrophy and interstitial fibrosis and try to improve myocyte regeneration, minimizing ethanol-related cardiac damage. Growth factors and cardiomyokines are relevant molecules that may modify this process. Cardiac transplantation is the final measure in end-stage ACM but is limited to those subjects able to achieve abstinence.

Dilated Cardiomyopathy Induced by Chronic Starvation and Selenium Deficiency

Protein energy malnutrition (PEM) has been rarely documented as a cause of cardiovascular abnormalities, including dilated cardiomyopathy. Selenium is responsible for antioxidant defense mechanisms in cardiomyocytes, and its deficiency in the setting of PEM and disease related malnutrition (DRM) may lead to exacerbation of the dilated cardiomyopathy. We report a rare case of a fourteen-year-old boy who presented with symptoms of congestive heart failure due to DRM and PEM (secondary to chronic starvation) along with severe selenium deficiency. An initial echocardiogram showed severely depressed systolic function consistent with dilated cardiomyopathy. Aggressive nutritional support and replacement of selenium and congestive heart failure medications that included diuretics and ACE inhibitors with the addition of carvedilol led to normalization of the cardiac function within four weeks. He continues to have significant weight gain and is currently completely asymptomatic from a cardiovascular standpoint.

Nutrition and Nutritional Support in Critically Ill Patients

The use of intravenous nutritional support has increased dramatically in the last 20 years. Although it is not without controversy, administration of nutritional support is common practice in hospitalized patients including critically ill patients. Malnutrition continues to be reported in a significant number of hospitalized patients. The incidence of malnutrition in critically ill patients may be even higher than that reported in hospitalized patients overall. The consequences of malnutrition in a critically ill patient may be severe. Nutritional assessment and nutritional support can present special challenges to the intensivist. Techniques of nutritional assessment in critically ill patients are evaluated. Guidelines for the determination of the nutritional needs of these patients are outlined. Methods of delivery of nutritional support in critically ill patients are reviewed. Complications of nutritional support are discussed.

Environmental Pathology

Humans are constantly exposed to hazardous pollutants in the environment—for example, in the air, water, soil, rocks, diet, or workplace. Trace metals are important in environmental pathology because of the wide range of toxic reactions and their potential adverse effects on the physiological function of organ systems. Exposures to toxic trace metals have been the subject of numerous environmental and geochemical investigations, and many studies have been published on the acute and/or chronic effects of high-level exposures to these types of agents; however, much fewer data are available concerning the health effects of low-dose chronic exposure to many trace metals. Chronic low-dose exposures to toxic elements such as cadmium and arsenic have been shown to cause these metals to accumulate in tissues over time, leading to multiple adverse effects in exposed individuals.

Role of trace elements in parenteral nutrition support of the surgical neonate

BACKGROUND

Parenteral nutrition (PN) has transformed the outcome for neonates with surgical problems in the intensive care unit. Trace element supplementation in PN is a standard practice in many neonatal intensive care units. However, many of these elements are contaminants in PN solutions, and contamination levels may, in themselves, be sufficient for normal metabolic needs. Additional supplementation may actually lead to toxicity in neonates whose requirements are small.

METHODS

An electronic search of the MEDLINE, Cochrane Collaboration, and SCOPUS English language medical databases was performed for the key words "trace elements," "micro-nutrients," and "parenteral nutrition additives." Studies were categorized based on levels of evidence offered, with randomized controlled trials and meta-analyses accorded the greatest importance at the apex of the data pool and case reports and animal experiments the least importance. Articles were reviewed with the primary goal of developing uniform recommendations for trace element supplementation in the surgical neonate. The secondary goals were to review the physiologic role, metabolic demands, requirements, losses, deficiency syndromes, and toxicity symptoms associated with zinc, copper, chromium, selenium, manganese, and molybdenum supplementation in PN.

RESULTS

Zinc supplementation must begin at initiation of PN. All other trace elements can be added to PN 2 to 4 weeks after initiation. Copper and manganese need to be withheld if the neonate develops PN-associated liver disease. The status of chromium supplementation is currently being actively debated, with contaminant levels in PN being sufficient in most cases to meet neonatal requirements. Selenium is an important component of antioxidant enzymes with a role in the pathogenesis of neonatal surgical conditions such as necrotizing enterocolitis and bronchopulmonary dysplasia. Premature infants are often selenium deficient, and early supplementation has shown a reduction in sepsis events in this age group.

CONCLUSION

Appropriate supplementation of trace elements in surgical infants is important, and levels should be monitored. In certain settings, it may be more appropriate to individualize trace element supplementation based on the predetermined physiologic need rather than using bundled packages of trace elements as is the current norm. Balance studies of trace element requirements should be performed to better establish clinical recommendations for optimal trace element dosing in the neonatal surgical population.

Selenium deficiency and HIV infection

Selenium is a non-metallic chemical element of great important to human health. Low selenium levels in humans are associated with several pathological conditions and are a common finding in HIV infected individuals. We conducted a review of the literature to assess if selenium deficiency or selenium supplementation could play a role in modifying the clinical course of HIV disease. Several studies investigated the role of selenium in disease progression, morbidity and mortality in HIV infected individuals. Larger studies were conducted in countries with poor economic resources and limited access to HAART. According to the majority of published studies low selenium levels appear to have an association with mortality, and selenium supplementation appears to play a beneficial role on survival or on slowing disease progression among HIV infected individuals. The role of selenium supplementation on preventing hospital admission among HIV outpatients was also noticed. The literature suggests an association between selenium deficiency and development of HIV associated cardiomyopathy and furthermore, selenium supplementation appears to improve the cardiac function in HIV infected individuals with cardiomyopathy. However, there is conflicting evidence regarding the role selenium in modifying HIV viral load and immune status in HIV infection.

Selenium therapy of myotonic dystrophy

A patient with myotonic dystrophy (MD) has been treated for two years with selenium and vitamin E. The serum selenium concentration and other relevant variables were continuously studied. The patient showed a marked subjective and objective improvement with increased muscular strength and regression of pathological electromyographic findings. To our knowledge, this is the first report of successful treatment of MD.

The risk of cardiomyopathy in inherited epidermolysis bullosa

BACKGROUND

Case reports have suggested that cardiomyopathy may be a complication of recessive dystrophic epidermolysis bullosa (RDEB).

OBJECTIVE

To determine the risk of congestive heart failure (CHF) or cardiomyopathy in each major EB subtype.

METHODS

These data represent systematic case findings and data collection performed throughout the continental United States from 1986 through 2002, by the National Epidermolysis Bullosa Registry. Study design is cross-sectional (n = 3280) with a nested randomly sampled longitudinal subcohort (n = 450). Frequencies of CHF and cardiomyopathy were determined by patient self-reporting, medical histories and review of medical records. In those who died, death certificates were reviewed and histories obtained from surviving family. Cumulative risks were stratified by cause and EB subtype.

RESULTS

Cardiomyopathy was reported as early as within the first year of life. In patients having no other known risk factors for CHF or cardiomyopathy, the highest risk of cardiomyopathy was seen among patients with Hallopeau-Siemens RDEB (RDEB-HS), with a cumulative risk of 4.51% on or after age 20 years. The cumulative risk of cardiomyopathy was only 1.14% and 0.40% in non-Herlitz junctional EB (JEB) and non-Hallopeau-Siemens RDEB, respectively, and was not observed in any other EB subtype. When patients with coexistent chronic renal failure were included, the cumulative risk for RDEB-HS rose to 18.86% by age 35 years. About 30% of our patients affected with RDEB-HS died of CHF or cardiomyopathy, even those with no other known risk factors.

CONCLUSIONS

CHF and cardiomyopathy are uncommon complications in both major RDEB subtypes and non-Herlitz JEB, and may be fatal.

Essential trace element provision to patients receiving home intravenous nutrition in the United Kingdom

The methods of provision of essential trace elements to patients receiving long-term home intravenous nutrition in the U.K. have been reviewed and their trace element status has been assessed. Over a 2 year period, 57 patients based on 15 hospitals throughout the country were studied. Although biochemical abnormalities of trace element status were frequent, related clinical complications were apparently rare. Zinc provision from commercial preparations generally required further supplementation. Copper requirements were variable. Manganese provision from trace element mixtures and chromium provision from contaminants of other parenteral nutrient solutions were excessive in many cases. Aluminium contamination is not significant in the nutrient solutions currently used in the U.K. The most common depletion state is for selenium which should probably be provided on a routine basis. The clinical consequences of long-term under- or over-provision of trace elements by the intravenous route requires further study.

Clinical features of selenium deficiency in infants receiving long-term nutritional support

OBJECTIVE

Selenium deficiency is a known complication in patients requiring long-term nutritional support; however, the clinical features of selenium deficiency in infants have not been completely described. We describe the clinical features of selenium deficiency in infants.

METHODS

Six infants with selenium deficiency were studied retrospectively, with a focus on the period of nutritional support, the clinical symptoms, and the chronologic changes in serum selenium concentrations before and after the administration of selenite.

RESULTS

The onset of selenium deficiency in five patients occurred at <6 mo of age; selenium deficiency occurred in one patient 14 mo after birth. One patient received parenteral nutrition for 15 mo after birth; the other five patients primarily received an elemental diet for 2-6 mo. In all patients, growth retardation and alopecia with pseudoalbinism were the characteristic symptoms of selenium deficiency. At the time of diagnosis, the serum selenium level in four patients was <2.0 microg/dL and serum selenium levels in two patients were 3.2 and 3.3 microg/dL, respectively. The resolution of hair symptoms corresponded to the level of serum selenium after 1-2 mo and a rapid improvement in growth occurred in all patients after the administration of selenite.

CONCLUSION

The early clinical symptoms of selenium deficiency in infants include growth retardation and alopecia with pseudoalbinism, which are reversible if the patients are treated with adequate amounts of selenite. Clinicians who manage infants receiving long-term nutritional support, including an elemental diet, should be aware of the symptoms associated with selenium deficiency.

The roles of selenium and mercury in the pathogenesis of viral cardiomyopathy

Research on the pathogenesis of nonischemic dilated cardiomyopathy (DCM) has largely been focused on the role of viral pathogens and altered immunity. Trace elements have only rarely been considered; however, clinical observations that trace elements influence cardiovascular disease have been made in populations with extreme dietary deficiency or occupational exposure. Recently, animal models of DCM have been used to explore interactions among trace elements, viral pathogens, and the immune system. Discovery of interactions of trace elements with causes for DCM has heightened awareness of potential contributions of environmental variables to DCM pathogenesis. This article reviews the present knowledge regarding trace elements, in particular selenium and mercury, in the pathogenesis of viral and immune-mediated DCM. Based on recent studies, the authors propose a novel paradigm for the pathogenesis of viral DCM that incorporates trace element imbalance and its interactions with the cellular physiology of viral-induced cardiomyocyte dysfunction.

Nutritional Deficiency of Selenium Secondary to Weight Loss (Bariatric) Surgery Associated with Life-Threatening Cardiomyopathy

Nutritional deficiencies of vitamins and minerals have been associated with reversible and irreversible cardiomyopathic processes. Selenium deficient dilated cardiomyopathy, first described in 1935 in the Keshan Province of China, was sometimes reversed with selenium supplementation. In the past three decades, selenium deficient cardiomyopathy has re-emerged in western medicine secondary to gastrointestinal disorders, long-term total parenteral nutrition (TPN) and gastrointestinal surgery. This report describes a case of selenium deficient cardiomyopathy secondary to the bariatric (weight loss) surgical operation bilio-pancreatic diversion (Scopinaro procedure). This patient presented with life-threatening heart failure nine months after this surgery, having lost 100 kg of body weight. Multiple nutritional deficiencies were detected and corrected including severely depleted selenium levels. Cardiac function and the clinical scenario improved dramatically over three weeks. Screening patients at risk of malnourishment for selenium deficiency as a potential cause of cardiomyopathy is indicated.

Serum selenoprotein-P levels in patients with inflammatory bowel disease

OBJECTIVE

Selenoprotein-P is a selenium-rich serum protein that carries more than 50% of serum selenium. We evaluated changes in serum selenoprotein-P levels in patients with inflammatory bowel disease.

METHODS

Serum selenoprotein-P levels were measured by enzyme-linked immunosorbent assay. Twenty healthy individuals (controls), 34 patients with ulcerative colitis, and 37 patients with Crohn's disease (CD) were studied.

RESULTS

A highly significant correlation was found between the serum selenium and selenoprotein-P levels. There was no significant difference in serum selenoprotein-P levels between healthy controls (average 3.4+/-0.8 microg/mL, n=20) and patients with ulcerative colitis (3.0+/-1.0 microg/mL, n=34). Serum selenoprotein-P levels were significantly lower in patients with CD (average 1.8+/-0.5 microg/mL, n=37). Serum selenoprotein-P levels were significantly lower in the elemental diet group of patients who had CD (average 1.4+/-0.4 microg/mL, n=17) than in the non-elemental diet group of patients who had CD (average 2.1+/-0.3 microg/mL, n=20).

CONCLUSION

We found that the serum selenoprotein-P level is decreased in patients with CD. It may be a useful marker to monitor the systemic selenium status in various disorders.

Selenium deficiency: report of a case

We report an 18-month-old Japanese boy with selenium deficiency. He had dry skin with irregularly shaped, erythematous changes on the cheeks, groin, hip, and extremities, erosions on the external urethral and anal orifices, and sparse, short, thin, light-coloured hair. He had received parenteral nutrition for 5 months because of juvenile polyposis. At presentation, his serum selenium level was less than 2.0 microg/dL (normal range, 10.6-17.4 microg/dL). His skin lesions responded well to supplementary treatment with sodium selenite. His skin symptoms were similar to those attributable to a deficiency of zinc which, like selenium, is an essential trace element. According to the literature, selenium deficiency is responsible for cardiomyopathy, which was diagnosed in our patient. The clinical similarity to zinc deficiency and the literature yielded important clues for a diagnosis of selenium deficiency in this patient.

Nutritional requirements in maintenance hemodialysis

There is a high prevalence of nutritional disorders in maintenance hemodialysis patients. This fact has been recently confirmed because larger routine assessments of MHD patients body composition are now performed. Food records and dietary interviews show spontaneous low intakes of protein and energy in many patients. An increasing dialysis dose above a Kt/V (single pool) of 1.5 may not improve patients nutritional intakes. Inflammation may further impair the balance between protein synthesis and catabolism and cause anorexia. In response to these abnormalities, the management of energy, protein, vitamins, and trace elements intake will be discussed with special emphasis on calcium, phosphorus, enteral support, and parenteral nutrition.

Skeletal muscle disorders associated with selenium deficiency in humans

Skeletal muscle disorders manifested by muscle pain, fatigue, proximal weakness, and serum creatine kinase (CK) elevation have been reported in patients with selenium deficiency. The object of this report was to review the conditions in which selenium deficiency is associated with human skeletal muscle disorders and to evaluate the importance of mitochondrial alterations in these disorders. A systematic literature review using the Medline database and Cochrane Library provided 38 relevant articles. The main conditions associated with selenium deficiency fell into three categories: (1) insufficient selenium intake in low soil-selenium areas; (2) parenteral or enteral nutrition, or malabsorption; and (3) chronic conditions associated with oxidative stress, such as chronic alcohol abuse and human immunodeficiency virus (HIV) infection. In low soil-selenium areas, reversibility of muscle symptoms was similar after selenium supplementation and placebo administration, suggesting a role for other factors in the development of disease. In parenteral or enteral nutrition, or malabsorption, muscle symptoms improved after selenium supplementation in 18 of 19 patients (median delay: 4 weeks). The reason that only a minority of selenium-deficient patients present with skeletal muscle disorders is unclear and is possibly related to cofactors, such as viral infections and drugs. Prospective studies of selenium-deficient myopathies would be useful in critically ill patients, alcohol abusers, and HIV-infected patients.

Selenium status of low-selenium area residents: Polish experience

The concentration of selenium (Se) in human organism varies widely between geographical areas depending on its content in soil and plants, dietary Se intake, bioavailability and retention, mineral interactions and other factors. The study includes healthy inhabitants of different regions of Poland; pregnant women, lactating women, children from 0 to 15 years of age and adults. Systematic determinations allow us to observe changes of the concentration of Se in time, which may be significant for developing preventive action. The results obtained confirm our thesis that Se concentration in the blood of the inhabitants of Poland depends on the region of the country. In recent years, in a considerable number of Polish inhabitants, the concentration of Se in blood plasma has been relatively low-about 50-55 microg/l, and the calculated daily dietary intake about 30-40 microg/day. The low levels of the element in the blood and urine are probably due to its deficiency in the diet.

Host selenium deficiency increases the severity of chronic inflammatory myopathy in Trypanosoma cruzi-inoculated mice

Weanling C3H/HeN mice were fed either a torula yeast-based diet deficient in selenium (Se) or the same diet supplemented with 0.2 ppm Se as sodium selenite. After 4 wk of feeding, the mice were inoculated intraperitoneally with the CA-I strain (clone K98) of Trypanosoma cruzi (TC). Before inoculation, mean serum Se levels were 430 versus 61 ng/ml in adequate and deficient mice, respectively. During the ascending phase of parasitemia, the Se-deficient mice exhibited significantly higher levels of parasites at 22-34 days postinfection (PI). However, no difference was found in the subsequent descending phase. As judged by visual examination at 2-mo-PI, some Se-deficient infected mice presented clinical signs of motor dysfunction. At 3-mo-PI, the end of the observation period, this chronic disease developed into a hind limb flaccid paralysis affecting 5 of 8 infected deficient mice. No signs of paralysis were seen in noninfected mice fed either diet or in infected mice fed the Se-adequate diet. At the histological level, both Se-adequate and Se-deficient infected mice showed mild myocarditis and moderate to severe myositis, with increasing intensity from 1- to 3-mo-PI in both groups. However, the severity of myositis was always more intense in the Se-deficient mice so that prominent areas of skeletal muscle replaced by fibrotic tissue were frequently observed. Thus, it can be concluded that Se deficiency in the murine host increases the severity of TC-induced myositis.

Selenium in the neonate

Selenium is a trace element of tremendous importance in human health. It is a constituent of the antioxidant enzyme. Glutathione peroxidase and therefore is vital to antioxidant defense. Several diseases of the neonate have been shown to be caused at least in part by oxygen free radicals. These include bronchopulmonary dysplasia retinopathy of prematurity necrotising enterocolitis patient ductus arteriosus and neuronal injury of hypoxic ischemic encephalopathy. Good selenium nutrition is therefore of key importance to antioxidant defense in the neonate. The communique reviews the important role that selenium might play in neonatal health & disease.

Nutritional status in dialysis patients: a European consensus

BACKGROUND

Malnutrition is common in dialysis patients and closely related to morbidity and mortality. Therefore, assessment of nutritional status and nutritional management of dialysis patients play a central role in everyday nephrological practice.

METHODS

Achieving a consensus on key points relating to pathogenesis, clinical assessment, and nutritional management of dialysis patients.

RESULTS

The assessment of nutritional status should be based on clinical assessment and biochemical parameters, including history of weight loss, per cent standard weight, body mass index, muscle mass, subcutaneous fat mass, and plasma albumin, creatinine, bicarbonate and cholesterol. Co-morbid conditions should be assessed and C-reactive protein (CRP) measured--as a marker of inflammation--as there is a close relation between malnutrition, on one side, and co-morbid conditions and inflammation on the other. For a more detailed assessment, subjective global assessment of nutritional status is a well-validated tool, and dual-energy X-ray absorptiometry (DEXA) is a useful method for routine assessment of lean body mass. Anthropometric methods are also useful. They are cheap and easy to apply, although less precise than DEXA. The recommended daily protein intake is at least 1.2 g/kg standard body weight and the energy intake 35 kcal/kg standard body weight (BW), in patients <60 years, and 30 kcal/kg standard BW in patients >60 years. The standard bicarbonate level should be at least 22 mmol/l. If CRP is >10 mg/l, it is important to seek and treat the underlying cause. Adequate dialysis (for haemodialysis: Kt/V >1.2) should be ensured and, although no definite evidence of the importance of dialysis water quality is available, the opinion of the authors is that the water quality should be high. The role of the biocompatibility of the dialysis membrane is still not clear. The dietitian plays a pivotal role in the nutritional care of dialysis patients, and patients should be provided with dietary counselling from the start of substitutive treatment in order to meet the recommended nutritional intakes. Dietary counselling can also play an important role in an integrated treatment of hyperphosphataemia, although most patients will also need phosphate binders if they have an adequate protein intake.

CONCLUSION

Malnutrition assessment and treatment is a great challenge for nephrological care. Achieving evidence-based consensus can help in implementing the progress of knowledge in clinical practice.

Rationale for clinical trials of selenium as an antioxidant for the treatment of the cardiomyopathy of Friedreich's ataxia

A pure selenium deficiency is harmful to the heart and causes a fatal dilated congestive cardiomyopathy in animals (white muscle disease) and in man (Keshan disease). Both of these syndromes are selenium-responsive. A deficiency of the micronutrient has also been reported in patients with Friedreich's ataxia and there are histological similarities between Friedreich's cardiomyopathy and Keshan disease. A low selenium status results in reduced selenium-dependent glutathione peroxidase activity. This essential antioxidant enzyme protects membrances from oxidative deterioration, a function it shares in common with vitamin E. As iron-induced mitochondrial lipid peroxidation is central to the pathology of Friedreich's ataxia, the administration of selenium supplements should normalize the antioxidant activity of myocardial glutathione peroxidase and slow the progression of the life-shortening cardiomyopathy associated with this illness.

Tissue level, distribution, and total body selenium content in healthy and diseased humans in Poland

The authors obtained tissue samples taken at autopsy from 46 healthy individuals killed in accidents and from 75 corpses of victims of various diseases to analyze selenium levels. The per-weight-unit basis of selenium levels (all expressed as ng/gm wet tissue) in tissues decreased in the following order: kidney (469) > liver > spleen > pancreas > heart > brain > lung > bone > skeletal muscle (51). The highest proportion of body selenium was found in skeletal muscles (27.5%); much less selenium was found in bones (16%) and blood (10%). In the tissues of cancer corpses, the selenium levels were much lower than levels in controls. The lowest selenium levels were found in the livers of alcoholics. Tissue selenium levels found in the study were significantly lower than levels reported in Japan, United States, Canada, and other countries. The low selenium levels in the tissues of Polish residents result from inadequate selenium levels in the soil. The authors used selenium levels in tissues to calculate the amount of selenium in humans in Poland (i.e., approximately 5.2 mg). This level was similar to levels found in New Zealand (i.e., 3.0-6.1 mg), but it was lower than the mean level found in Germany (i.e., 6.6 mg) and in the United States (i.e., 13.0-20.3 mg).

Propionic acidemia: a rare cause of cardiomyopathy

The symptoms of propionic acidemia, an autosomal recessive disorder involving deficiency of the enzyme propionyl-coenzyme A carboxylase, are highly varied and may present at any time in the patient's life. Cardiomyopathy, a rare complication of this disorder, has been reported in only a small number of pediatric patients. The authors describe a case of adult-onset cardiomyopathy in a 23-year-old female with propionic acidemia diagnosed in early childhood and associated with multiple long-standing comorbidities. The possible mechanisms of propionic acidemia-associated cardiomyopathy, and the importance of early recognition and appropriate management, are discussed. (c)2001 CHF, Inc.

Laboratory support of the clinical nutrition service

This article critically reviews the role of the laboratory services in assessment, monitoring and management of complications in patients requiring nutritional support. It has broadly been divided into three sections. (i) Assessment of protein and energy status: whilst it is stressed that clinical judgement and anthropometric measurements are the most effective methods of evaluation of nutritional requirements, laboratory tests which can be of use in assessment of protein energy status are discussed in detail, including an appraisal of the value of each test in various clinical situations. (ii) Assessment of micronutrient and electrolyte status: the clinical justification for assessment of the various micronutrients and electrolytes is considered. A few selected examples are discussed in detail including an evaluation of the tests of status available and examples of situations where measurement may be clinically helpful. (iii) Effective use of the laboratory: this section attempts to guide the clinician in the most appropriate use of laboratory tests, firstly in the assessment of requirement for aspects of nutritional support, secondly in the continued monitoring and evaluation of the support provided, and thirdly in prevention and treatment of metabolic complications. It is emphasised that clinical nutrition is a multidisciplinary topic requiring input from the laboratory in conjunction with other specialities to provide the best available patient care.

Essentiality of selenium in the human body: relationship with different diseases

In the present review different aspects related to the essential element selenium in the human organism are considered. A large number of human studies have been performed in order to improve knowledge on the influence of this element in the origin and development of several degenerative diseases. Selenium deficiencies among human beings as well as animals are being recognized worldwide to be related to a number of pathologies. This element has also the special characteristic that the range between its essential and toxic character is very close, and consequently daily dietary intake should be appropriately monitored in individuals. Nevertheless, nowadays there is still a lot of controversy about the optimum dietary level of this element in order to cure or to prevent the appearance of diseases such as cirrhosis, cancer, diabetes, or cardiovascular pathologies. Results obtained in several animal and epidemiological studies have indicated that Se could constitute a dietary factor with protective action against several degenerative diseases.

Plasma and urinary selenium in Saudi Arabian patients with dilated cardiomyopathy

We measured selenium (Se) levels in the urine and blood plasma samples of 72 Saudi Arabian patients with dilated cardiomyopathy (DCM) and 70 control subjects of the same origin. To correct for differences in the hydration state of the subjects, the selenium concentration for each urine sample was normalized by dividing it by the concentration of creatinine (CREAT) in the same sample. The median (and range) of the values found for the concentration of Se in plasma, urine, and normalized concentration in urine for the control subjects was 1.306 (0.66-2.50) microM, 0.478 (0.05-2.00) microM, and 56.7 (10.6-426.5) microM Se/M CREAT, respectively, whereas, for the patients, it was 1.246 (0.53-2.45) microM, 0.39 (0.05-1.90) microM, and 75.1 (4.9-656.2) microM Se/M CREAT, respectively. Additionally, the patients were separated into three subgroups according to the severity of their disease state as judged by NYHA procedure, and were then compared to the control group. Only group 4 (the most severe state of the disease) had a significantly lower concentration of urinary Se than the control group. However, the difference became nonsignificant when normalized for CREAT levels. There was no significant difference in the plasma Se levels between the controls and any of the patient groups. As the plasma Se in the control group and in the DCM patients both fell on the low end of the "normal" range, with the patients being marginally lower than the controls, there is no firm evidence from this study to suggest that Se is related to the high incidence rate of DCM found in Saudi Arabia.

Protective effect of gamma-glutamylcysteinylethyl ester on dysfunction of the selenium-deficient rat heart

We investigated the protective effect of intracellular GSH against cardiac dysfunction in selenium (Se)-deficient neonatal rats and cultured fetal rat myocytes. A Se-deficient diet with or without daily subcutaneous injections of gamma-glutamylcysteinylethyl ester (gammay-GCE) (a membrane-permeating GSH precursor) was given to rats from gestation day 4 via the dam to postnatal day 14. Se deficiency induced a 62% incidence of electrocardiographic abnormalities such as sinus arrhythmias or extrasystole, a 63% reduction in dP/dt in the left ventricle, and an increase in thiobarbituric acid reacting substances (TBARS), but no ultrastructural cardiac lesions were observed. Administration of gamma-GCE increased the intracellular GSH concentration ([GSH]i) of both neonatal rat hearts and cultured fetal rat cardiac myocytes. gamma-GCE-like sodium selenite prevented the cardiac dysfunction and the TBARS increment. gamma-GCE also prevented H2O2 toxicity in the cultured myocytes. The Vmax, but not the Km, for GSH of Se-dependent GSH peroxidase (Se-Gpx) activity in Se-deficient rat heart homogenates was one-third that of normal rat heart homogenates. Although gamma-GCE did not affect the Se-Gpx Vmax and Km for GSH, it did induce a substantial and significant increase in [GSH]i, which was postulated to increase the velocity of H2O2 decomposition by Se-Gpx activity 1.6-fold. These data suggest that the increase in [GSH]i may have played a role in preventing the TBARS increase and cardiac dysfunction in Se-deficient rats.

Direct determination of selenium and other trace elements in serum samples by ICP-MS

Selenium belongs to a group of trace elements of special interest in biological samples for clinical diagnosis. Selenium has antioxidizing functions and is essential for providing the organism with triiodothyronine produced from thyroxine. Among several analytical techniques used to determine the Se concentration in serum, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) has been used in the past because of its high sensitivity. Interference problems originating from different ions on the major Se isotopes have been described to be a limiting factor for the direct determination of Se in these matrices. Standard addition calibration or isotope dilution is often required to overcome carbon-enhanced ionisation effects in biological sample matrices. In most cases, the typical serum sample volume which is available for the analysis is limited to 0.5 ml or less, making multiple sample preparation for standard addition calibration impractical. Isotope dilution requires enriched isotopes and substantial sample preparation. Furthermore, the approximate Se concentration in every sample has to be known to adjust the appropriate amount of spike to each sample. Matrix matching with methanol has been described to overcome ionisation effects but we found limiting factors of this application when other trace elements are also determined within one sample run. This paper describes an effective sample preparation method which allows the direct determination of Se in serum without limiting the analytical capabilities for the additional determination of Al, Cu, Ni, Co, Cd, Mn and Zn in a single sample run by ICP-MS. Optimization procedures are presented and results of the analysis of reference samples are discussed, with a comparison of more than 150 serum data with those obtained by the GF-AAS method.

The role of selenium deficiency in dilated cardiomyopathy in Saudi Arabia

BACKGROUND

Selenium deficiency is implicated in the etiology of endemic juvenile dilated cardiomyopathy in China, and in sporadic cases in other countries. The aim of this study was to evaluate the role of selenium deficiency in the pathophysiology of dilated cardiomyopathy in the Saudi Arabian population.

PATIENTS AND METHODS

Plasma and urine selenium concentrations from 72 Saudi patients with confirmed dilated cardiomyopathy were compared with corresponding values from 70 control subjects of the same national origin who had normal ventricular function.

RESULTS

Plasma and urine selenium concentrations (mean+/-SD) were 1.347plusmn;0.45 and 0.49+/-0.37 micromol/L, respectively, for the patient group, and 1.32+/-0.41 and 0.60+/-0.41 micromol/L, respectively, for the control group. The differences in the values between the two groups were statistically insignificant.

CONCLUSION

In the Saudi population, dilated cardiomyopathy is not caused by selenium deficiency.