Preventing Malnutrition in the Long-term Peritoneal Dialysis Patient

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.

Malnutrition: Detection and Intervention

Malnutrition is common in patients with renal failure. Causes of malnutrition in this population are varied and sometimes specific to the method of renal replacement therapy. No single marker absolutely identifies malnutrition or tracks changes in status. Renal dietitians use a variety of parameters and techniques to identify malnutrition because many of the traditional markers can be skewed by renal disease and its comorbidities. Once malnutrition is identified, treatment is also complex and not well defined. Treatment is usually progressive in nature, ranging from intense nutritional counseling to total parenteral nutrition. Further research is needed to define optimal nutrition status, to refine techniques to maintain optimal nutrition status, to simplify the identification of malnutrition, and to improve the treatment for malnutrition.

Weight deficit in patients on continuous ambulatory peritoneal dialysis

Small solute clearances were compared between two groups of patients on continuous ambulatory peritoneal dialysis (CAPD), an underweight group with a ratio of actual-to-ideal weight (W/IW) less than 0.9 and a normal-weight group with W/IW between 0.9 and 1.2 at the first clearance study after initiation of CAPD. Adequate clearance levels were set according to the K/DOQI guidelines. Duration of follow-up during CAPD and time on CAPD until the first clearance study was similar in the two groups. Initial weekly Kt/V urea and creatinine clearance also were similar. Kt/V urea values were adequate in 41.8% of the underweight subjects and 41.0% of the normal-weight subjects (not significant). Corresponding percentages for creatinine clearance were 36.4% and 39.7% (not significant). Serum creatinine and albumin concentration, creatinine excretion, and lean body mass estimated from creatinine kinetics were lower in the underweight group. Weight measurements from initiation of CAPD were available in 37 underweight patients. At initiation of CAPD, 31 subjects had W/IW less than 0.9, and 6 subjects had W/IW greater than 0.9. Chronic catabolic illness was present at CAPD initiation in 19 patients. Among the 37 patients, 17 lost weight and 6 gained weight during the course of CAPD. Compared with patients who lost weight, those who gained weight were younger (35.6 +/- 9.3 years old versus 58.4 +/- 15.0 years old; P = 0.0069) and had a higher percent of women (80.0% versus 11.8%; P = 0.0093), higher initial weekly Kt/V urea (2.58 +/- 0.50 versus 1.91 +/- 0.24; P = 0.0087), and a higher percent of adequate Kt/V urea (80.0% versus 11.8%; P = 0.0093). Small solute clearances do not differ between underweight CAPD patients and normal-weight CAPD patients. Underweight CAPD patients usually start CAPD with a weight deficit and have associated catabolic illnesses. Catabolic illness is the sole cause of weight deficit in 40% of the underweight CAPD patients and is present in the remaining 60%. The role of inadequate clearances in the development of weight deficit in CAPD populations is difficult to assess. It seems, however, that adequate Kt/V urea may be necessary for weight gain in underweight CAPD patients.