Importance of low serum intact parathyroid hormone as a predictor of mortality in hemodialysis and peritoneal dialysis patients: 14 years of prospective observation.

Excess parathyroid hormone (PTH) has long been considered detrimental to the health of patients with end-stage renal disease. PTH has been implicated as a multisystem uremic toxin, and hyperparathyroidism can be a debilitating complication in dialyzed patients. We have studied prospectively the relationship of enrollment serum intact PTH and various demographic characteristics and other biochemical parameters to all-cause mortality in 345 hemodialysis (HD) and 277 peritoneal dialysis (PD) patients. We monitored the patients for 14 years. Observed survival and survival after adjustment for age, race, gender, months on dialysis at enrollment, diabetic status, and nutritional markers were significantly better for patients with enrollment PTH greater than 200 pg/mL than for patients with PTH 65 to 199 pg/mL and patients with PTH less than 65 pg/mL. Enrollment serum PTH was an independent predictor of survival in HD and PD patients. For HD patients, age and months on HD at enrollment were associated inversely with PTH level, whereas black race, creatinine, and phosphorus were associated directly with PTH. For PD patients, age, diabetes, and months on PD at enrollment were inverse predictors, whereas black race, albumin, creatinine, and phosphorus were associated positively with PTH. Lower than expected levels of PTH in uremic patients is associated with increased mortality. We hypothesize that inadequate protein intake or phosphorus intake or both result in impaired development of the expected secondary hyperparathyroidism and in the excess mortality risk inherent with malnutrition.

Serum prealbumin predicts survival in hemodialysis and peritoneal dialysis: 10 years of prospective observation.

Malnutrition is a major factor contributing to the high mortality rate in hemodialysis (HD) and peritoneal dialysis (PD) patients. We and others have reported previously that single enrollment levels of serum biochemical markers, such as albumin, cholesterol, creatinine, and prealbumin, are correlated directly with mortality in HD and PD patients. We have studied prospectively the relationship of enrollment prealbumin levels, demographic characteristics, and other biochemical markers to all causes of mortality in 130 HD and 128 PD patients who were monitored for 10 years. The Kaplan-Meier method was used to compute observed survival, and the Cox proportional hazards model was used to identify independent predictors of mortality risk. For HD patients, enrollment serum prealbumin remained a strong independent predictor of long-term survival after adjusting for age, race, gender, months on dialysis, diabetic status, and other nutritional markers. In PD and HD patients, observed and adjusted survivals (after adjusting for aforementioned confounding variables) of patients with prealbumin greater than 30 mg/dL were significantly higher than survivals of patients with prealbumin less than 30 mg/dL. For HD and PD patients, age and diabetes were associated inversely with prealbumin concentration, whereas levels of albumin, creatinine, and total cholesterol were associated directly with prealbumin concentration. In this study, prealbumin was the best biochemical predictor of mortality for HD patients and a useful tool to assess nutritional risk in HD and PD patients.

Outcome of percutaneous endoscopic gastrostomy feeding in patients on peritoneal dialysis.

Protein malnutrition is now well established as an important contributory factor to the high mortality in peritoneal dialysis (PD) patients. Low dietary protein calorie intake is one of the factors leading to protein malnutrition. If PD patients develop difficulty eating, percutaneous endoscopic gastrostomy (PEG) feeding may prove beneficial in providing adequate nutrition. Studies on the effectiveness of PEG feeding in PD patients are limited to pediatric patients. The objective of the present study was to assess the outcome of PEG feeding in adult patients with end-stage renal disease (ESRD) on PD. We retrospectively reviewed charts from May 1992 to February 2000 of 10 consecutive patients in our center who had had feeding tubes inserted. The patients' ages ranged from 37 to 81 years, with mean age of 65. Of the 10 patients, 7 were male, 5 were diabetic, and 1 was infected with the human immunodeficiency virus. Two patients had cerebrovascular accident (CVA) with dysphagia, 3 had multi-infarct dementia, 2 had anoxic encephalopathy, 2 had dementia, and 1 had calciphylaxis with anorexia. Of the 10 patients, 9 failed to eat because of neurologic disorders. Two patients who had functioning PEG feedings before starting PD had no complications. Only 2 of 8 patients already on PD continued with long-term PD after a PEG was inserted. Both patients whose PD was not interrupted at the time of PEG placement immediately developed peritonitis. Of the 6 patients who were maintained on hemodialysis (HD), 2 developed peritonitis within one week of starting PEG feedings. The other 4 had no complications from PEG feedings while being maintained on HD, but 1 developed peritonitis when PD was resumed. Of the 5 patients who developed peritonitis, 3 experienced fungal peritonitis. In PD patients, PEG feeding is associated with frequent complications. However, PEG placement prior to PD initiation appears to be safe. Maintaining patients on HD for at least 6 weeks appears to decrease the incidence of peritonitis, but does not eliminate it. Use of anti-fungal prophylaxis and maintenance of the patient on HD for longer than 6 weeks may produce better results.

Survival on hemodialysis and peritoneal dialysis over 12 years with emphasis on nutritional parameters.

We analyzed the prognostic importance of nutritional markers and mortality data in 537 hemodialysis (HD) and 422 peritoneal dialysis (PD) patients followed for up to 12 years. Patients on HD had a 44% lower risk of mortality than did those treated with PD (P: < 0.0001). The difference in mortality between the modalities was even more striking among diabetics but less striking among younger patients. Over a 12-year period, survival of dialysis patients with lower enrollment levels of albumin, creatinine, and parathyroid hormone (PTH) were significantly lower. In multivariate Cox's proportional hazards models, serum prealbumin and enrollment PTH level of <65 pg/mL were independent predictors of mortality both in HD and PD patients. In conclusion, HD patients had higher cumulative survival than PD patients over a 12-year period. Nutritional markers at enrollment continue to be strong predictors of mortality for up to 12 years.

Reticulocyte hemoglobin content predicts functional iron deficiency in hemodialysis patients receiving rHuEPO.

Early detection of iron sufficiency at the level of the erythropoietic cell is necessary to optimize management of uremic anemia with recombinant human erythropoietin (rHuEPO). "Absolute" and "functional" iron deficiency are the most important factors causing resistance to administered rHuEPO. Transferrin saturation and serum ferritin measurements have been noted to be insensitive and inaccurate measures to detect functional iron deficiency. Recently, the reticulocyte hemoglobin content (CHr) has been shown to be a sensitive and specific indicator of functional iron deficiency in nondialysis patients treated with rHuEPO. The purpose of this study is to compare CHr with currently used indices of iron sufficiency in rHuEPO-treated hemodialysis (HD) patients. In study 1, 364 stable HD patients were studied at two outpatient dialysis centers. CHr was normally distributed, with a mean value of 28.3 pg, and was consistent over two consecutive monthly samples in each center. CHr was weakly but consistently correlated with transferrin saturation and serum ferritin. CHr and reticulocyte number were inversely correlated with red blood cell (RBC) number, suggesting that the erythropoietic stimulus of routinely administered rHuEPO may have resulted in functional iron deficiency. Month-to-month changes in CHr correlated weakly with changes in serum iron and percent transferrin saturation, but not at all with changes in serum ferritin. When we analyzed those patients with baseline CHr less than 26 pg, a level strongly suggestive of functional iron deficiency, these correlations strengthened, and in addition, month-to-month changes in CHr correlated strongly and directly with concomitant changes in RBC count, hemoglobin, and hematocrit, suggesting that rising CHr was indicative of an erythropoietic response. In study 2, 79 patients received a single-dose infusion of 500 mg iron dextran. After intravenous iron, CHr rose within 48 hours, peaked at 96 hours, and then fell toward baseline. Patients who were iron deficient by standard measures (serum ferritin < 100 ng/mL or transferrin saturation less than 20%) had a greater and a sustained CHr response to intravenous iron dextran. A CHr less than 28 pg at baseline predicted functional iron deficiency, defined as a corrected reticulocyte increase of greater than 1% to iron dextran, more accurately than transferrin saturation, ferritin, or their combination. Eighty-two percent of individuals who were iron deficient at baseline responded to intravenous iron with an increase in CHr of greater than 2 pg. Sixty percent of patients who were iron sufficient by usual iron indices also responded to intravenous iron with a CHr rise of greater than 2 pg, suggesting that they were, in fact, functionally iron deficient despite "normal" conventional iron parameters. We conclude that CHr may be a more sensitive marker of functional iron deficiency in rHuEPO-treated hemodialysis patients than percent transferrin saturation and ferritin, particularly in those with "normal" conventional iron parameters.

Predictive value of nutritional markers (albumin, creatinine, cholesterol, and hematocrit) for patients on dialysis for up to 30 years.

Mortality among end-stage renal disease patients in the United States remains unacceptably high despite progress in the management of renal replacement therapy. Consequently, there are few reports of long-term survivors on dialysis. We have analyzed characteristics of long-term (10 to 15 years, N = 40) and very long-term (15 to 30 years, N = 18) survivors on hemodialysis and long-term survivors (more than 10 years, N = 28) on peritoneal dialysis and compared them with "average survivors" (< 5 years, N = 65 for hemodialysis and N = 101 for peritoneal dialysis). Among hemodialysis patients, long- and very long-term survival was associated with younger age, nondiabetic status, black race, and male gender (P < 0.05 for all variables). Enrollment creatinine was higher among long- and very long-term survivors, whereas albumin and hematocrit increased significantly during the period of observation among long- and very long-term survivors compared with average survivors. Enrollment age, nondiabetic status, and albumin level predicted prolonged survival even after adjustments for confounding variables. Among peritoneal dialysis patients, younger age and nondiabetic status predicted prolonged survival. Black race was associated with improved survival, but the association was not statistically significant. Enrollment levels of albumin and creatinine were significantly higher among long-term survivors and the cholesterol increased during the period of observation in long-term survivors. Thus, demographic and biochemical indices reflecting nutritional status can predict prolonged survival in hemodialysis and peritoneal dialysis. Patient survival for periods of up to 30 years is possible on renal replacement therapy. Analyses of these outlier patients may offer clues to prolonged survival.

Enrollment parathyroid hormone level is a new marker of survival in hemodialysis and peritoneal dialysis therapy for uremia.

The relatively high morbidity and mortality during dialytic therapy for end-stage renal disease (ESRD) in the United States is the subject of current inquiry. Identified risk factors for excess mortality include advanced age, diabetes, and malnutrition exemplified by a low serum albumin level. Parathyroid hormone (PTH) has long been thought to contribute to the toxicity of the uremic syndrome. We reviewed the course of patients maintained by hemodialysis (HD) and peritoneal dialysis (PD) to detect any correlation between the level of PTH when beginning dialytic therapy and subsequent morbidity and mortality. Study cohorts consisted of 175 HD and 113 PD patients followed for up to 9 years. Demographic characteristics such as age, race, gender, diabetic status, and prior months on dialysis, as well as biochemical parameters including albumin, creatinine, cholesterol, intact PTH, calcium, and phosphorus levels at enrollment were evaluated for their effect on patient survival. Expected survival was calculated by Cox proportional hazards analysis. Older age and lower enrollment serum creatinine level were associated with increased mortality in both HD and PD patients, whereas low serum albumin and low serum cholesterol levels also predicted high mortality in HD patients. In both HD and PD, patients with enrollment PTH level of < or = 65 pg/mL had more than twice the mortality risk of those with PTH > or = 200 pg/mL. Both observed and expected survival of patients with low PTH were significantly lower than the survival in patients with higher PTH. Five-year HD survivors and four-year PD survivors had significantly higher PTH levels at initiation of dialytic therapy than did those with shorter survival. PTH level correlated with serum creatinine and serum albumin in HD but only with serum creatinine in PD, supporting the inference that patients with high enrollment PTH were better nourished than those with lower PTH.

Prealbumin is the best nutritional predictor of survival in hemodialysis and peritoneal dialysis.

Patients undergoing dialytic therapy for end-stage renal disease (ESRD) have greater morbidity and mortality than age-matched individuals with similar demographics in the general population. Risk factors for early death during treatment for ESRD include advanced age, diabetes, hypertension, and malnutrition. We questioned whether the level of serum prealbumin at the start of uremia therapy might serve as a marker of subsequent survival in patients treated with maintenance hemodialysis (HD) and peritoneal dialysis (PD). Study cohorts included 111 HD and 78 PD patients followed for up to 5 years. Selected demographic characteristics and biochemical variables were tested for correlation with survival in each cohort. Variables evaluated included age, race, gender, diabetic status, and serum concentrations of albumin, creatinine, cholesterol, and prealbumin. For comparison, expected survival was calculated with Cox proportional hazards analysis, which accounts for confounding variables. We found that a higher relative risk (RR) of death in HD patients correlated with older age, the diagnosis of diabetes, and a serum prealbumin < 30 mg/dL. In PD patients, older age and the presence of diabetes correlated with a higher RR of death than in the standard population. When nutritional variables were analyzed separately, prealbumin < 30 mg/dL was the strongest variable that predicted mortality in HD patients (RR = 2.64, P = 0.002) and also predicted increased risk of mortality in PD patients (RR = 1.8, P = 0.035). Observed and expected survival was significantly higher in patients with enrollment prealbumin greater than 30 mg/dL in both HD and PD. The serum prealbumin level correlated significantly with other measures of nutrition, including serum albumin, serum creatinine, and serum cholesterol, in both HD and PD patients. Among tested markers of nutritional status, prealbumin level appears to be the single best nutritional predictor of survival in ESRD patients.

Dyslipidemia in renal disease.

In summary, dyslipidemia is a common feature of various renal syndromes. Whether this perturbed lipid metabolism results in accelerated atherosclerosis and increased cerebrovascular and cardiovascular morbidity and mortality remains a subject of inquiry. Also undefined is the role of dyslipidemia in the progression of renal injury. The malnutrition that becomes a dominant morbid feature in patients on maintenance renal replacement therapy provides a caveat against aggressive intervention for modest hyperlipidemia once dialysis is instituted. Individualized assessment of end organ atherosclerotic disease and cardiovascular risk factors should form the basis for modification of the treatment plan (ie, pharmacological intervention) should nonpharmacological means prove ineffective.

Anemia severity and missed dialysis treatments in erythropoietin-treated hemodialysis patients.

Neither the sociodemographic correlates nor the biochemical/clinical consequences of missed dialysis treatments have been well defined. During a 10 week period, the authors enumerated missed dialysis treatments among 430 patients randomly selected from a pool of 1,395 hemodialysis patients. A forward logistic regression model was used to determine whether a relationship existed between missed dialysis treatments and the following independent variables: age, gender, race, renal diagnosis, length of time on maintenance hemodialysis, co-morbidity index, modified Karnofsky score, employment status, household residents, and laboratory indices. Forty-three (10%) of 430 patients missed a total of 96 treatments. Despite equivalent treatment with erythropoietin, patients who missed dialysis treatment(s) had a lower mean hematocrit (27 +/- 4.3%) at the end of the study than those patients who underwent all treatments (29 +/- 4.5%) (p = 0.0287). Mean serum albumin and creatinine levels were equivalent in compliant and noncompliant patients. Recent starts (p = 0.0048), and younger patients (p = 0.0424) were most likely to miss dialysis treatment(s). One of the major consequences of missed dialysis treatment(s) is exacerbation of anemia, and younger patients and freshly started patients are more likely to miss scheduled dialysis treatments than their respective counterparts.

Correlates of vascular access and nonvascular access-related hospitalizations in hemodialysis patients.

Four hundred and thirty randomly selected hemodialysis patients, aged 20 years and over, were studied to identify risk factors for vascular access and nonvascular access-related hospitalizations in the immediately preceding 1 year. Risk estimates for hospitalization were assessed using a multinominal logistic analysis model. We measured functional status, utilizing a 14-point Karnofsky scale, and in a separate analysis of covariance, in which Karnofsky score was the outcome, we examined the relationships of age, gender, ethnicity, renal diagnosis, and hospitalization. Individual comparisons were adjusted for multiple comparison bias by Tukey's Honest Difference method. There were a total of 508 hospitalizations of which 322 (63%) lasted > or = 1 week. Two hundred and sixty (60%) patients were hospitalized at least once; 105 (24.4%) for access problems only, 115 (27%) for a nonaccess problem only, and 40 for access and nonaccess-related problems. Access-related problems, accounted for 48% of all hospitalizations. The risk of hemodialysis vascular access morbidity was increased in women (p < 0.028) and white (p < 0.048) hemodialysis patients. Neither diabetic nor elderly hemodialysis patients were at greater risk for access hospitalization than their respective counterparts, though a greater proportion of the access hospitalizations in the elderly (> or = 64 years) lasted > or = 1 week (p < 0.0006). More access-related hospitalizations in blacks (64.5%), lasted for > or = 1 week than in whites (40.6%) (p < 0.001). Hispanics (p < 0.043), whites (p < 0.002), and the older patients (p < 0.054) were at greater risk for nonaccess hospitalization than blacks and younger patients, respectively. Even after adjusting for age, race, and diabetes, each decrease of one unit in the modified Karnofsky score was associated with a 3-4% increased risk for all types of hospitalization (p < 0.001)--poor functional status is associated with increased risk for all hospitalizations. We conclude that the risk for hemodialysis vascular access morbidity is increased in women and white hemodialysis patients. Poor functional status is associated with increased risk for all hospitalizations.

Predictors of survival in continuous ambulatory peritoneal dialysis patients: a five-year prospective study.

Our objective was to examine the influence of various demographic, clinical, and enrollment biochemical variables on the long-term survival of continuous ambulatory peritoneal dialysis (CAPD) patients. This was a prospective cohort study investigating the relationship between demographics and enrollment biochemical markers and mortality in CAPD patients in a CAPD unit in a large tertiary care teaching hospital. One hundred and sixty-nine patients in the CAPD program were enrolled between 1989 and 1994, and were followed up to 60 months. Independent predictors of mortality determined by Cox proportional hazards model included age, diabetes, serum albumin and creatinine. Enrollment level of serum albumin, and creatine can predict mortality in CAPD patients up to 60 months. Markers of visceral and somatic nutrition at enrollment are important predictors of mortality in CAPD patients up to five years.

Is an elevated level of serum lipoprotein (a) a risk factor for cardiovascular disease in CAPD patients?

Cardiovascular disease (CVD) is the single most important cause of mortality in hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. An increased lipoprotein (a) [Lp(a)] level in HD patients is associated with CVD. However, Lp(a) levels in CAPD patients are controversial, and their association with CVD has not been established. In the present study, prevalent CAPD and HD patients [excluding those who were human immunodeficiency virus (HIV)-positive] attending the Long Island College Hospital from June, 1990 to July, 1995 underwent analysis of lipid profile including Lp(a). Total and low-density lipoprotein cholesterol, triglycerides, apolipoprotein (apo) A, and apo B were all significantly increased in CAPD patients compared to HD patients. Serum Lp(a) levels were also significantly higher in CAPD patients than in HD patients (51 +/- 32 vs 34 +/- 23 mg/dL, p < 0.001). CAPD patients who had a history of myocardial infarction (MI) or coronary artery disease (CAD) at enrollment had significantly higher Lp(a) levels compared to those who did not have a history of MI or CAD. CAPD patients who died of CVD had higher Lp(a) levels than patients who died of non-CVD causes. In the Cox model with backward stepwise selection, a history of CVD was associated with a significantly elevated relative risk (RR) of mortality (RR = 1.84, p = 0.014). Expected survival by all causes of mortality and by cardiac mortality was significantly shorter in patients with a history of CVD than in those without a history of CVD. Thus, elevated Lp(a) is related to increased CVD and therefore may contribute to increased mortality in CAPD patients.

Markers for survival in dialysis: a seven-year prospective study.

Serum biochemical markers suggestive of undernutrition are directly correlated with mortality in hemodialysis and peritoneal dialysis patients. In particular, serum albumin is the most powerful predictor of survival. We have prospectively examined the relationship of single baseline measurements of serum albumin, cholesterol, creatinine, apoproteins, and prealbumin in 250 hemodialysis patients and 140 patients maintained on continuous ambulatory peritoneal dialysis (CAPD) monitored up to 7 years (1987 to 1994). Other variables studied included age, race, gender, diabetes, and number of months on dialysis. Observed survival was computed by the Kaplan-Meier method. Cox's proportional hazards model was used to determine independent predictors of mortality risk. Age, diabetes, prior months on dialysis, and low levels of serum albumin, creatinine, and cholesterol were important and independent predictors of mortality risk in hemodialysis patients. For peritoneal dialysis patients, the independent predictors of mortality risk were age, diabetes, and low serum albumin and serum creatinine. Prealbumin, a serum protein with rapid turnover and relatively small pool, was an important and independent risk predictor in both hemodialysis and CAPD patients. In addition, prealbumin was more highly correlated with other nutritional markers than was albumin. In summary, these findings suggest that biochemical measures associated with visceral and somatic protein depletion are predominant long-term mortality risk factors in patients maintained on hemodialysis and CAPD.

Pathobiology and functional status of long-term hemodialysis patients.

There may be cumulative 'metabolic scars' after a decade or more of long-term hemodialysis. We studied 39 patients who have been on maintenance hemodialysis for 10-24 years to determine their functional status and pathobiology. The 39 long-term (> or = 10 years) patients were compared with a control cohort of 37 age-, gender-, race-, and renal-diagnosis-matched patients on hemodialysis for < or = 3 years. The functional status was measured using a modified Karnofsky scale, and the employment status was noted as well. Details of hospitalizations and intercurrent infections requiring outpatient oral or intravenous antibiotic therapy during the preceding year were obtained. Comorbid medical conditions were documented, and basic laboratory tests were performed. The mean age of the long-term patients was 51.8 +/- (SE) 1.9 years, and the mean age of the control group was 51.5 +/- 2.4 years (p = 0.92). Three times weekly hemodialysis prescriptions were similar in both groups (long-term: 3.5 +/- 0.02 h, control: 3.4 +/- 0.02 h; p = 0.27). The mean modified Karnofsky scores were equivalent in both groups. The rate of hospitalization during the preceding year was higher among the long-term patients (0.92 +/- 0.19/patient year) than in the control patients (0.51 +/- 0.15/patient year; p = 0.09). The long-term patients had more intercurrent infections (1.23 +/- 0.21) than the controls (0.68 +/- 0.16; p = 0.04). (ABSTRACT TRUNCATED AT 250 WORDS)

Correlates of vascular access occlusion in hemodialysis.

Vascular access occlusion results in significant morbidity in hemodialysis patients. Age, diabetes, and synthetic grafts (polytetrafluoroethylene [PTFE]) have been associated with vascular access occlusion in univariate analysis. However, the independent risk associated with each of these factors has not been assessed adjusting for confounding among the factors or by other variables, such as blood pressure (BP) or hematocrit. The influence of serum lipoprotein(a) [Lp(a)] and fibronectin on vascular access occlusion has not been widely studied despite their theoretical or demonstrated importance in vascular bypass occlusion. In a cohort study of 124 hemodialysis patients monitored for up to 14 months, we reported that Lp(a) values in the upper tertile (> or = 57 mg/dL) were associated with vascular access occlusion risk in white and Hispanic patients, but not in black patients. We now report an expanded analysis of this data set to determine the independent correlates of vascular access occlusion. Variables tested included age, race, gender, diabetes, access type (PTFE v endogenous), treatment time, systolic BP, hematocrit, heparin and erythropoietin dosage, and serum levels of Lp(a) and fibronectin. In univariate analysis, access occlusion was associated with age, diabetes, PTFE, Lp(a) > or = 57 mg/dL, serum fibronectin, and reduced BP. The independent correlates of first access occlusion were determined with the Cox proportional hazards model. Since the overall model included a significant race x Lp(a) interaction term, we stratified by race. In black patients, risk correlated directly with PTFE (P < 0.01) and inversely with systolic BP (P < 0.001), whereas for white and Hispanic patients, age (P = 0.04) and Lp(a) > or = 57 mg/dL (P = 0.05) were associated with increased risk. In summary, vascular access occlusion was found to be associated with a number of factors. Important independent correlates were PTFE and lower BP in black patients, and age and serum Lp(a) > or = 57 mg/dL in white and Hispanic patients. Diabetes mellitus and increased serum fibronectin may contribute additional risk.

Pervasive failed rehabilitation in center-based maintenance hemodialysis patients.

At its inception in 1972, the end-stage renal disease (ESRD) program was conceived with a set of assumptions about cost, rate of growth, and treatment outcomes in its client population. Despite the potential to correct anemia with recombinant erythropoietin (EPO) introduced in 1987 and improved survival, the level of physical activity among some segments of the hemodialysis population remains suboptimal. This study was undertaken, among other reasons, to identify correlates of poor functional status as measured by a modified Karnofsky scale. Using a modified Karnofsky scale, we measured the functional status of 430 patients who had been treated by hemodialysis for at least 1 year and some of whom were also receiving concomitant treatment with EPO. Patients studied were randomly selected from eight dialysis units in urban New York and suburban New Jersey. A Karnofsky score of less than 70 indicated frank disability--the subject was unable to perform routine living chores without assistance. In addition, current vocational activity was ascertained, and comorbid conditions were quantified. The necessity for wheelchair dependence was noted for each patient. The mean age (+/- SD) of the study population was 56 +/- 14 years (range, 21 to 92 years). Subjects had been on maintenance hemodialysis for 4.09 +/- 3.8 years (range, 1 to 23 years). The study group included 215 men and 215 women, of whom 65% were black, 27% white, 6% Hispanic, and 2% Asian; 36.5% had diabetes mellitus. Although 376 members (87%) of the study group were under treatment with EPO, the mean hematocrit of the study population was only 29% +/- 4.5%.(ABSTRACT TRUNCATED AT 250 WORDS)