Androgen versus erythropoietin for the treatment of anemia in hemodialyzed patients: a prospective study

Effect of Androgens on Anemia and Malnutrition in Renal Failure: Implications for Patients on Peritoneal Dialysis

Objective

To analyze the implications of the potential use of androgens in peritoneal dialysis patients, focusing on their effects on hematologic and nutritional parameters. This manuscript reviews the different compounds for clinical use, dosage schedules, adverse effects, and how therapy with androgens might be used to treat anemia and malnutrition in these dialysis patients.

Data Sources

Studies in the literature dealing with the effects of androgens on hematologic and nutritional parameters, and their role in uremic anemia and malnutrition.

Study Selection

Studies in which uremic patients received androgens as therapy for anemia or malnutrition.

Data Extraction

Data were abstracted from all of these studies.

Results

This review shows that androgens are anabolic substances that also have significant actions on erythropoiesis. A number of clinical studies in uremic patients have found that these compounds have beneficial effects on hematologic parameters and nutritional status, similarly to other therapies, such as recombinant human erythropoietin and recombinant human growth hormone, respectively.

Conclusions

Androgens have been shown to have a beneficial effect on anemia due to renal disease and on nutritional status in uremic patients. Further studies need to be done with larger groups of patients. Objectives for additional research are suggested.

Prevalence and Correlates of Anemia and Uncontrolled Anemia in Chronic Hemodialysis Patients – The Campania Dialysis Registry

Background

This study investigated prevalence and correlates of anemia and uncontrolled anemia in chronic hemodialysis patients.

Methods

A cross-sectional analysis was performed on registry data for 2,746 chronic (<6 months) hemodialysis patients aged 25–84. Data collection included years of dialysis, hours of dialysis/wk, disease causing hemodialysis, body mass index (BMI), erythropoietin (EPO) treatment, hemoglobin, markers of viral hepatitis, serum albumin, calcium, and phosphorus.

Results

Prevalence was 88.7% for anemia (hemoglobin <11 g/100 mL and EPO treatment at any Hb level), 39.4% for uncontrolled anemia (hemoglobin<11 g/100 mL). Gender, years of dialysis, hereditary cystic kidney disease (HCKD), and low BMI (<24 kg/m2) were independent correlates of anemia (P<0.001). Gender, HCKD, low BMI, serum albumin and calcium were independent correlates of uncontrolled anemia (P<0.05). An interaction was found between age (not correlated with anemia and uncontrolled anemia) and the association of gender with uncontrolled anemia (P<0.05). EPO doses were higher in patients with high prevalence of uncontrolled anemia than in patients with low prevalence (i.e., women vs men, other diseases vs HCKD, low vs not-low BMI, P<0.01). Gender, years of dialysis, HCKD, BMI, serum albumin, and calcium were independent correlates of the hemoglobin/EPO dose ratio in patients on EPO treatment (P<0.05).

Conclusion

Anemia and uncontrolled anemia are more frequent in hemodialysis patients with short-term dialysis, diseases other than HCKD, low BMI, and female gender. Gender effect was lower in elderly patients. Uncontrolled anemia was also associated with low serum albumin and calcium, suggesting that these parameters are indices of EPO resistance.

Androgens for the anaemia of chronic kidney disease in adults

BACKGROUND

Anaemia occurs when blood contains fewer red blood cells and lower haemoglobin levels than normal, and is a common complication among adults with chronic kidney disease (CKD). Although a number of approaches are applied to correct anaemia in adults with CKD, the use of androgen therapy is controversial.

OBJECTIVES

The aim of this review was to determine the benefits and harms of androgens for the treatment of anaemia in adult patients with CKD.

SEARCH METHODS

We searched CENTRAL, the Cochrane Renal Group's Specialised Register, the Chinese Biomedicine Database (CBM), CNKI, VIP and reference lists of articles without language restriction. The most recent search was conducted in August 2014.

SELECTION CRITERIA

All randomised controlled trials (RCTs) that assessed the use of androgens for treating anaemia of CKD in adults were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias in the included studies. Meta-analyses were performed using relative risk (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals (CI).

MAIN RESULTS

We included eight studies that reported data from 181 participants. Study quality was assessed as moderate in six studies, one was low quality, and one was high quality. The small number of included studies, and low participant numbers adversely influenced evidence quality overall.We found limited evidence (1 study, 24 participants) to indicate that oxymetholone can increase haemoglobin (Hb) (MD 1.90 g/dL, 95% CI 1.66 to 2.14), haematocrit (HCT) (MD 27.10%, 95% CI 26.49 to 27.71), change in albumin (MD 4.91 g/L, 95% CI 3.69 to 6.13), alanine aminotransferase (ALT) (MD 54.50 U/L, 95% CI 43.94 to 65.06), and aspartate aminotransferase (AST) (MD 47.33 U/L, 95% CI 37.69 to 56.97); and decrease high-density lipoprotein (HDL) (MD -15.66 mg/dL, 95% CI -24.84 to -6.48). We also found that compared with erythropoietin alone, nandrolone decanoate plus erythropoietin may increase HCT (3 studies, 73 participants: MD 2.54%, 95% Cl 0.96 to 4.12). Compared with erythropoietin (1 study, 27 participants), limited evidence was found to suggest that nandrolone decanoate can increase plasma total protein (MD 0.40 g/L, 95% CI 0.13 to 0.67), albumin (MD 0.20 g/L, 95% CI 0.01 to 0.39), and transferrin (MD 45.00 mg/dL, 95% CI 12.61 to 77.39) levels. Compared with no therapy (remnant kidney), evidence was found to suggest that nandrolone decanoate can increase Hb (2 studies, 33 participants: MD 1.04 g/dL, 95% Cl 0.66 to 1.41) and HCT (1 study, 24 participants: MD 3.70%, 95% Cl 0.68 to 6.72). Compared with no therapy (anephric), evidence was found (1 study, 5 participants) to suggest that nandrolone decanoate can increase Hb (MD 1.30 g/dL, 95% Cl 0.57 to 2.03), but nandrolone decanoate did not increase HCT (MD 2.00%, 95% Cl -0.85 to 4.85).However, oxymetholone was not found to reduce blood urea nitrogen (BUN), serum creatinine (SCr), cholesterol, or triglycerides; or increase plasma total protein, prealbumin, or transferrin. No evidence was found to indicate that nandrolone decanoate increased prealbumin or decreased BUN, SCr, AST, ALT, cholesterol, triglycerides, HDL or low-density lipoprotein (LDL). Adverse events associated with androgen therapy were reported infrequently.

AUTHORS' CONCLUSIONS

We found insufficient evidence to confirm that use of androgens for adults with CKD-related anaemia is beneficial.

Serum testosterone levels and mortality in men with CKD stages 3-4

BACKGROUND

Hypogonadism in men (total testosterone <350 ng/dL) is associated with higher risk of cardiovascular disease and mortality in men on dialysis therapy. We evaluated the association of hypogonadism with all-cause mortality in men with non-dialysis-dependent chronic kidney disease (CKD).

STUDY DESIGN

Retrospective, cohort study.

SETTING & PARTICIPANTS

2,419 men with CKD stages 3-4 (estimated glomerular filtration rate, 15-59 mL/min/1.73 m2) who had total testosterone measured for cause between January 1, 2005, and October 31, 2011, at a tertiary-care center in Cleveland, OH.

PREDICTORS

Total testosterone measured using an immunoassay measurement in 3 forms: (1) categorized as low or testosterone replacement therapy versus normal, (2) continuous log testosterone, and (3) quintiles (100-226, 227-305, 306-392, 393-511, and 512-3,153 ng/dL).

OUTCOMES

Factors associated with low total testosterone level and the association between low total testosterone level and all-cause mortality were evaluated using logistic regression, Cox proportional hazard models, and Kaplan-Meier survival curves.

RESULTS

Hypogonadism was found in 1,288 of 2,419 (53%) men. In a multivariable logistic regression analysis, African American ethnicity and higher estimated glomerular filtration rate were associated with lower odds of having hypogonadism. Diabetes and higher body mass index were associated with higher odds of having hypogonadism. 357 of 2,419 (15%) patients died during a median follow-up of 2.3 years. In the multivariate Cox model, testosterone level <350 ng/dL or testosterone replacement therapy was not associated with mortality. In a multivariable model also adjusted for testosterone supplementation, higher log testosterone was associated with significantly lower mortality (HR per 1 log unit, 0.70; 95% CI, 0.55-0.89). When compared to the highest quintile, the second lowest quintile of testosterone was associated with higher mortality (HR, 1.53; 95% CI, 1.09-2.16).

LIMITATIONS

Single-center study, timing of testosterone testing, lack of adjustment for proteinuria, and sampling bias.

CONCLUSIONS

Low total testosterone level may be associated with higher mortality in men with CKD stages 3-4, but more studies are needed.

The sex difference in haemoglobin levels in adults - mechanisms, causes, and consequences

Men and women have different mean haemoglobin levels in health in venous blood - women have mean levels approximately 12% lower than men. A similar sex-related difference in haemoglobin levels in adult animals is found in many species of mammals, birds and reptiles, indicating that it is an important physiological phenomenon. It is probably a direct effect of sex hormones, both oestrogen and androgens, on erythropoiesis. However, since there is no difference in erythropoietin levels between the sexes, this effect most likely takes place in the kidney, rather than in the bone marrow. Oestrogens dilate and androgens constrict the renal microvasculature: dilation and vasoconstriction in vessels below 300 μm in diameter respectively increase and decrease the haematocrit in blood in arterioles, capillaries and venules, altering the oxygen delivery per unit red cell mass, and providing a mechanism for varying the red cell mass without compensatory changes in erythropoiesis.

KDOQI US commentary on the 2012 KDIGO Clinical Practice Guideline for Anemia in CKD

The 2012 KDIGO (Kidney Disease: Improving Global Outcomes) Clinical Practice Guideline for Anemia in Chronic Kidney Disease provides clinicians with comprehensive evidence-based recommendations to improve patient care. In this commentary, we review these recommendations and the underlying evidence. Most recommendations are well reasoned. For some, the evidence is unclear and recommendations require some qualification. While the KDIGO guideline stresses the potential risks of intravenous iron therapy, withholding iron might have its own risks. The recommendation to avoid hemoglobin levels falling below 9 g/dL sets a lower bound of "acceptability" that may increase blood transfusion. Given the lack of research supporting the optimal transfusion strategy for end-stage renal disease patients, it is difficult to weigh the risks and benefits of red blood cell transfusion. We find a paucity of evidence that hemoglobin concentration targeted between 11 and 11.5 g/dL is associated with a safety risk. Although the evidence that erythropoiesis-stimulating agent use improves patient quality of life is poor, it is possible that the instruments used to measure quality of life may not be well attuned to the needs of chronic kidney disease or dialysis patients. Our last section focuses specifically on the recommendations to treat anemia in children.

Meta-Analysis of Randomized Controlled Trials on Androgens versus Erythropoietin for Anaemia of Chronic Kidney Disease: Implications for Developing Countries

Androgens which are relatively cheap were used in the treatment of anaemia in dialysis patients before the advent of Erythropoietin (EPO). However, there are concerns about their efficacy and side effects. Aims. To examine the efficacy and harms of androgens for the treatment of anaemia of chronic kidney disease (CKD) compared to EPO. Settings and Design. A systematic review and meta-analysis using an a priori protocol. Methods and Materials. We searched several databases for randomized controlled trials using the key terms anaemia, chronic kidney disease, and androgens, without language restrictions. We also searched reference lists of relevant articles. Statistical Analysis Used. Data was analyzed using Review manger 5 software. We summarized treatment effects as relative risks and mean differences, with 95% confidence intervals using a random-effect model. We tested for heterogeneity with Chi² and the I² statistics. Results. We identified four eligible trials involving 114 participants, majority (83.33%) of whom were males, mostly over 50 years of age. The pooled difference in mean haemoglobin between the nandrolone and EPO arms at the end of the trials was −0.11 (CI −0.80 to 0.58) which is not statistically significant. Conclusions. This meta-analysis revealed no difference between nandrolone and EPO for the treatment of anaemia of CKD in men over 50 years. Therefore, nandrolone can be used for the treatment of anaemia of CKD in this category of patients, in resource-limited countries. However, further studies are needed to determine the long-term safety of nandrolone in men over 50 years old, as well as its effectiveness and safety in females in general, and males less than 50 years of age.

Androgens and erythropoiesis: past and present

Association between androgens and erythropoiesis has been known for more than seven decades. Androgens stimulate hematopoietic system by various mechanisms. These include stimulation of erythropoietin release, increasing bone marrow activity and iron incorporation into the red cells. Before the discovery of recombinant erythropoietin (rhEpo), androgens were used in the treatment of anemia associated with renal disease, bone marrow suppression, and hypopituitarism. Anabolism is an additional advantage of androgen therapy. Furthermore, in light of recent reports regarding adverse effects of rhEpo, the role of androgen therapy in various types of anemias should be readdressed. Polycythemia remains a known side effect of androgen therapy. In this review, we will briefly discuss the initial animal and human studies which demonstrated the role of androgens in the treatment of anemia, their mechanism of action, a detailed account of the efficacy of androgens in the treatment of various anemias, the erythropoietic side effects of androgens and finally, the relationship between hematocrit levels and cardiovascular disease.

Hormonal adjuvants for the treatment of renal anaemia

Hormonal adjuvants, besides being erythropoietic agents, broaden the spectrum of therapeutic options for the treatment of the anaemia of chronic kidney disease (CKD). Lowering elevated parathyroid hormone levels by oral calcium supplementation and phosphate restriction, by varying dialysate calcium concentrations, by administration of vitamin D3 derivatives and, in the near future, by treatment with calcimimetics may prove efficient in some patients to fight extensive requirements of erythropoietic agents. Clinical evidence for a principal role of secondary hyperparathyroidism in resistance to erythropoietin, however, is lacking. Active vitamin D3 derivatives, in addition to their beneficial effects on secondary hyperparathyroidism, appear to exert a direct, stimulatory action on erythroid precursor cells and possibly also an inhibitory action on collagen synthesis by bone marrow stromal cells. Growth hormone (GH) induces insulin-like growth factor (IGF)-1, which in turn counteracts apoptosis similarly to erythropoietin, and fosters proliferation of burst- and colony-forming units-erythroid (BFU-E, CFU-E). If erythropoietic agents improve survival of CKD patients, a similar benefit should apply for strategies that increase synthesis and bioavailabilty of IGF-1. The latter appears to be reduced in CKD patients, and zinc supplementation potentially enhances it via an increase in free IGF-1. Finally, androgens also exert anti-anaemic effects. Nandrolone decanoate constitutes the only androgen currently applicable for selected male dialysis patients over the age of 50 years. It should not be given to women, however, because of serious side effects. Collectively, hormonal interventions offer the potential to reduce requirements of erythropoietic agents, and some may also improve physical performance.

Gonadal dysfunction in systemic diseases

Gonadal function is significantly affected in many acute and chronic systemic diseases. As the function of the testes and the ovaries is determined by the integrity of the hypothalamic-pituitary-gonadal axis, it is obvious that a systemic disease may affect one or more levels of the axis in such a manner that the gonadal dysfunction may have various clinical and laboratory manifestations. In this brief review, the most common disturbances seen in the main systemic diseases will be discussed.

Pharmacologic adjuvants to epoetin in the treatment of anemia in patients on hemodialysis

Anemia is a common complication of chronic kidney disease, particularly in patients who are on dialysis. The use of recombinant human erythropoietin has led to the eradication of severe anemia in the dialysis population. Correction of anemia in these patients has been associated with better quality of life and clinical outcomes. Some hemodialysis patients have anemia that either is relatively refractory to epoetin therapy or requires very high doses of epoetin (i.e., hyporesponsiveness), despite having adequate iron stores, and are thus unable to achieve or maintain target hemoglobin levels. Several pharmacologic agents have been studied for effects on improving response to epoetin, either to counter hyporesponsiveness or simply to reduce epoetin use for purely economic reasons. This review examines the available literature regarding the efficacy of these potential pharmacologic adjuvants to epoetin in the treatment of anemia in patients on maintenance hemodialysis, with special emphasis on androgens, vitamin C (ascorbic acid), and L-carnitine. A review of published guidelines and recommendations for use of these agents in hemodialysis patients is provided.

Eating Behavior Disorders in Uremia: A Question of Balance in Appetite Regulation

Eating and appetite disorders are frequent complications of the uremic syndrome which contribute to malnutrition in dialysis patients. The data suggest that uremic anorexia may occur with or without abdominal and visceral fat accumulation despite a lower food intake. This form of obesity (i.e., with low food intake and malnutrition) is more common in dialysis patients than obesity with high food intake. This article reviews the current knowledge regarding mechanisms responsible for appetite regulation in normal conditions and in uremic patients. Anorexia in dialysis patients has been historically considered as a sign of uremic toxicity due to "inadequate" dialysis as judged by uncertain means ("middle molecule" accumulation, Kt/V, "peak-concentration hypothesis," and others). We propose the tryptophan-serotonin hypothesis, based on a uremia-induced disorder in patients' amino acid profile--low concentrations of large neutral and branched-chain amino acids with high tryptophan levels. A high rate of tryptophan transport across the blood-brain barrier increases the synthesis of serotonin, a major appetite inhibitor. Inflammation may also play a role in the genesis of anorexia and malnutrition. For example, silent infection with Helicobacter pylori may be a source of cytokines with cachectic action; its eradication improves appetite and nutrition. The evaluation of appetite should take into account cultural and social aspects. Uremic patients showed a universal trend to carbohydrate preference and red meat refusal compared to healthy people. In contrast, white meat was less problematic. Uremic patients also have a remarkable attraction for citrics and strong flavors in general. Eating preferences or refusals have been related to the predominance of some appetite peptide modulators. High levels of cholecystokinin (CCK) (a powerful anorexigen) are associated with early satiety for carbohydrates and neuropeptide Y (NPY) (an orexigen) with repeated food intake. Obesity and elevated body mass index often falsely suggest a good nutritional status. In uremic patients (a hyperinsulinemia state), disorders in the regulation of fat distribution (insulin, leptin, insulin-like growth factor [IGF]-1, fatty acids, and disorders in receptors for insulin, lipoprotein lipase, mitochondrial uncoupling protein-2, and beta 3 adrenoreceptors) may cause abdominal fat accumulation without an increase in appetite. Finally, appetite regulation in uremia is highly complex. Disorders in adipose tissue, gastrointestinal and neuropeptides, retained or hyperproduced inflammatory end products, and central nervous system changes may all play a role. Uremic anorexia may be explained by a hypothalamic hyperserotoninergic state derived from a high concentration of tryptophan and low branched-chain amino acids.

Past, present and future of erythropoietin use in the elderly

More than a decade has passed since the first patient with end-stage renal failure was treated with erythropoietin (EPO) and more than 85% of patients now receive this therapy. In the year 2002 more than 60% of dialysis patients will be elderly, and the treatment of anemia will be more complex due to the aditional causes: folate, iron and vitamin deficiency in this population. Correction of anemia with EPO brings about partial regression of left ventricular hypertrophy and some data suggest that such treatment reduces cardiovascular mortality in patients without advance cardiac disease. Normalization of hematocrit with EPO increases oxygen supply to the brain tissue with improvement in brain function. The improvement in the ability to recognize, discriminate and hold stimuli in memory for difficult tasks is particularly important for elderly people. No differences have been noted in the incidence of clotting of vascular access in patients treated with EPO compared with hemodialysis patients not so treated. Also no one has demostrated that treatment with EPO accelerates renal decline in patients with progressive renal insufficiency. In elderly people with anemia secondary to advanced renal failure, EPO therapy improves physical, cognitive and sexual function, and health related quality of life.

Effects of adjuvant androgen on anemia and nutritional parameters in chronic hemodialysis patients using low-dose recombinant human erythropoietin

BACKGROUND

Recombiant human erythropoietin (epoetin) has greatly contributed to improvement of the anemia of chronic renal failure patients on hemodialysis. However, the reduced erythropoietic effect to epoetin and its high cost have induced lots of supplementary treatments. Therefore, we performed a prospective study to evaluate the effects of adjuvant low-dose androgen therapy in patients using a lower-dose of epoetin than the commonly recommended dose on anemia and the nutritional parameters.

METHODS

17 patients of hemoglobin (Hgb) less than 9 g/dL even after being treated with 1,000 U epoetin subcutaneously (s.c.) 3 times per week on a stable status for more than 6 months, who were on hemodialysis at our institution were examined. They were injected with the same dose of epoetin s.c. and nandrolone decanoate 100 mg intramuscularly (i.m.) weekly for another 6 months. Blood test was performed every month before therapy for 6 months and after therapy for 6 months and the mean values were reviewed for comparison.

RESULTS

Hgb (7.75 +/- 0.9 vs 8.99 +/- 1.39 g/dL, p < 0.01) and hematocrit (Hct) (23.68 +/- 2.85 vs 26.66 +/- 3.91%, p < 0.01) were apparently changed before and after adjuvant therapy. Hgb and Hct, weekly dose of epoetin were not statistically different in 9 male patients before and after adjuvant therapy. The weekly dose of epoetin was not statistically different in 8 female patients, but Hgb and Hct (8.02 +/- 0.6 vs 9.72 +/- 1.31 g/dL, 24.54 +/- 1.7 vs 28.74 +/- 3.06%, p < 0.01) were statistically different before and after adjuvant therapy. In comparison between male and female groups, weekly doses of epoetin and nandrolone decanoate were significantly greater in the female group than the male group (epoetin: 50.66 +/- 6.23 vs 61.18 +/- 8.76 U/kg/week, nandrolone decanoate: 1.69 +/- 0.2 vs 2.04 +/- 0.29 mg/kg/week, p < 0.05).

CONCLUSION

Our data show that the adjuvant androgen therapy is effective for the anemia of hemodialysis patients who did not recover from anemia even after being continuously treated with low-dose epoetin.

Molecular biology of the androgen receptor

Androgen receptor (AR) is a member of the steroid hormone receptor family of molecules. AR primarily is responsible for mediating the physiologic effects of androgens by binding to specific DNA sequences that influence transcription of androgen-responsive genes. The three-dimensional structure of the AR ligand-binding domain has shown it is similar to other steroid hormone receptors and that ligand binding alters the protein conformation to allow binding of coactivator molecules that amplify the hormone signal and mediate transcriptional initiation. However, AR also undergoes intramolecular interactions that regulate its interactions with coactivators and influence its activity. A large number of naturally occurring mutations of the human AR gene have provided important information about AR molecular structure and intermolecular interactions. AR is also a critical mediator of prostate cancer promotion, conferring growth signals to prostate cancer cells throughout the natural history of the disease. Late-stage prostate cancer, unresponsive to hormonal deprivation, sustains AR signaling through a diverse array of molecular strategies. Variations in the AR gene may also confer genetic predisposition to prostate cancer development and severity. Further understanding of AR action and new strategies to interfere with AR signaling hold promise for improving prostate cancer therapy.

Androgen therapy for anemia in elderly uremic patients

Androgens were the mainstay of treatment of renal anemia prior to the introduction of recombinant human erythropoietin. With the introduction of this recombinant hormone, the protocols of treatment of anemia were completely modified, and the use of androgens was relegated to the background. However, several authors have continued showing interest in the use of androgenic steroids for the treatment of anemia. This review examines several aspects of aging on androgenic hormones and hematopoiesis, the effects of androgen administration on hematological parameters, the side effects of these compounds and the future of this treatment for anemia in renal patients.

Randomized prospective comparison between erythropoietin and androgens in CAPD patients

BACKGROUND

Anemia and malnutrition are significant complications in peritoneal dialysis (PD) patients. Previous studies in hemodialysis have shown that androgens are effective as therapy for anemia; however, this has not been tested in a randomized prospective trial in PD patients. Furthermore, the anabolic properties of androgens may exert additional benefits on the nutritional status in this population.

METHODS

Twenty-seven stable male patients over 50 years who were under maintenance continuous ambulatory peritoneal dialysis (CAPD) therapy were randomized to receive recombinant human erythropoietin (rHuEPO; N = 14) or nandrolone decanoate (ND; 200 mg/week IM; N = 13) as therapy for anemia. The evolution of hematologic parameters and the impact on both nutritional anthropometric and biochemical variables were evaluated after six months of treatment.

RESULTS

Hemoglobin and hematocrit experienced similar increases in both groups: from 8.5 +/- 0.9 g/dL and 25.8 +/- 2.7% to 11.7 +/- 0.6 g/dL and 34.7 +/- 1.6% (P < 0.001) in patients receiving rHuEPO, and from 8.9 +/- 0.8 and 27 +/- 2.2% to 11.8 +/- 0.4 g/dL and 35.1 +/- 1.5% (P < 0.001) in subjects treated with ND. At the end of the study, out of the diverse nutritional variables included in this investigation, only weight and body mass index significantly increased in the rHuEPO group. Conversely, both anthropometric [weight, body mass index, triceps skinfold, mid-arm circumference (MAC) and mid-arm muscle circumference (MAMC)] and biochemical parameters (serum total proteins, albumin, prealbumin and transferrin) were significantly increased in patients treated with ND. In this group, serum urea nitrogen, urea net excretion and protein equivalent of nitrogen appearance significantly decreased. These facts, together with an increase in serum creatinine and no changes in dietary intake during the study, suggest a rise in muscle mass related to an anabolic effect of nandrolone decanoate. Interestingly, serum levels of insulin-like growth factor type 1 (IGF-1) increased in patients on the androgen group compared to subjects treated with rHuEPO. Moreover, there was a positive and significant correlation between the rise in IGF-1 concentrations and the increase in hemoglobin, hematocrit, MAC and MAMC.

CONCLUSIONS

Androgens therapy improved the anemia in elderly male CAPD patients in a similar manner to that observed with rHuEPO. Furthermore, compared with rHuEPO, androgen administration was associated with beneficial effects on nutritional status. The mechanism of action of androgens on hematologic and nutritional parameters might be mediated, at least in part, by IGF-1.

Anorexia in end-stage renal disease: pathophysiology and treatment

Anorexia is a frequent complication of uraemic syndrome, which contributes to malnutrition in dialysis patients. Uraemic anorexia has been associated with many factors. This paper reviews the current knowledge about mechanisms responsible for uraemic anorexia, the treatments and new drugs used to control the loss of appetite. Traditionally, anorexia in dialysis patients has been considered as a sign of uraemic toxicity, therefore, two hypotheses have been proposed, the 'middle molecule' and 'peak-concentration' hypotheses, both of which are still unproved. Recently, our group proposed the tryptophan-serotonin hypothesis, which is based on a disorder in the amino acid profile acquired in the uraemic status. This is characterised by low concentrations of large neutral and branched chain amino acids (LNAA/BCAA) in the cerebrospinal fluid. This situation permits a high level of tryptophan transport across the blood-brain barrier, causing an increase in the synthesis of serotonin (responsible for appetite inhibition). There are two main treatment targets for anorexia in dialysis patients. The first is to decrease the free plasma tryptophan concentration and transport across the blood brain barrier to the cerebrospinal fluid, thus decreasing the intracerebral serotonin levels. Nutritional formulae enriched with LNAA and BCAA have this effect. Secondly, plasma levels of cytokines with cachectin effect (TNF-alpha), should be decreased. This also induces a decrease in LNAA and BCAA levels. In this group are megestrol acetate, anti-TNF-alpha antibodies, thalidomide, pentoxifyilline, n-3 fatty acids and possibly nandrolone decanoate. Additionally, other targets should be explored including antagonists of cholecystokinin (a potent anorexigen retained by renal failure), analogues of neuropeptide Y (the most potent orexigen), cannabinoids, cyproheptadine, hydrazine sulfate. In conclusion, uraemic anorexia is a complex complication associated with malnutrition, high morbidity and mortality. The pharmacological treatment should address key points in the pathogenesis of uraemic anorexia, reducing intra-cerebral concentration of serotonin with LNAA/BCAA oral diet formulae and the plasma levels of pro-inflammatory molecules. Others forms of treatment should also be explored.

Use of androgens in patients with renal failure

Anabolic steroids have been used for the treatment of the anemia of chronic renal failure for more than 25 years. Due to concerns over adverse effects, their use historically has been limited to nandrolone decanoate given to men, usually over age 50, who have intact kidneys. The introduction of epoetin alfa in 1989 has led to reduced androgen use for the treatment of anemia. Nevertheless, there continues to be scientific investigation into the possible role that androgens may play in combination with or as an alternative to erythropoietin. Whether combination therapy will prove to be useful remains to be determined in a large, prospective, randomized trial. There is little likelihood, based on present literature, that androgen therapy alone will replace epoetin alfa in U.S. dialysis units. This topic was addressed recently by the Anemia Work Group of the National Kidney Foundation Dialysis Outcomes Quality Initiative (27). While acknowledging androgen treatment may be less expensive than epoetin alfa, the group stated that the potential risks of primary androgen therapy alone make this form of treatment "unacceptable." The work group did not offer any recommendations on the combined use of erythropoietin and androgens, stating that published data are inconclusive. If future reimbursement policies are changed to include epoetin alfa within a capitated rate, economic incentives may lead to increased use of androgens to achieve targeted hematocrit values. The potential value of anabolic steroids for treating malnutrition in dialysis patients is an intriguing idea. Very little has been done to explore this issue, and this clinical practice has not become widespread nor universally recommended (28). Prospective clinical trials in this area may be warranted as well.

Androgen therapy in chronic renal failure

Chronic renal failure, dialysis and transplantation have major effects on male reproductive health because of the impairment of spermatogenesis, steroidogenesis and sexual function. Hypothalamo-pituitary testicular dysfunction in uraemia is manifest clinically as delayed growth and puberty, sexual dysfunction, androgen deficiency, impaired spermatogenesis and infertility. Apart from renal anaemia, there are at present no proven indications for androgen therapy in chronic renal failure. This chapter reviews the basis and scope for various clinical applications of gonadotropin and androgen therapy as an adjunct to the standard medical care of chronic renal failure. The therapeutic possibilities implied by experimental and clinical findings suggesting that uraemic hypogonadism may be a functional state of gonadotropin deficiency are emphasized.

A 6-month study of low-dose recombinant human erythropoietin alone and in combination with androgens for the treatment of anemia in chronic hemodialysis patients

Two previous short-term studies (12 weeks and up to 16 weeks) that used androgens to supplement recombinant human erythropoietin (rHuEPO) for the treatment of the anemia associated with end-stage renal disease showed divergent results. Both studies were limited by their brief duration, since the hematopoietic effect of androgens does not peak until 5 months. Therefore, we conducted a 6-month, prospective, randomized trial comparing low-dose rHuEPO alone and in combination with androgens for the treatment of the anemia of end-stage renal failure. Nineteen anemic chronic hemodialysis patients were randomized into two groups. Group A (n = 10) received 1,500 U rHuEPO intravenously three times a week for 26 weeks. Group B (n = 9) received the same dose of rHuEPO plus nandrolone decanoate 100 mg intramuscularly weekly. Baseline transferrin saturation, serum ferritin, intact serum parathyroid hormone, plasma aluminum, and hematocrit levels were not significantly different between the groups. At study completion, both groups showed a significant increase in mean hematocrit compared with baseline (group A: 24.8% +/- 1.4% to 28.3% +/- 2.8%, P = 0.003; group B: 25.1% +/- 1.5% to 33.2% +/- 4.5%, P = 0.001). The increase in hematocrit in the rHuEPO plus androgen-treated group was statistically greater than in the rHuEPO-alone group (8.2% +/- 4.4% v 3.5% +/- 2.8%; P = 0.012). With the exception of mild discomfort at the injection site, there were no significant side effects from nandrolone. We conclude that the combination of low-dose rHuEPO and nandrolone decanoate is effective treatment for the anemia of end-stage renal failure.