Parathyroidectomy does not correct hypertension in patients on maintenance hemodialysis.

Both hypertension and secondary hyperparathyroidism (2 degrees HPT) are common features of the uremic syndrome. It has been suggested that 2 degrees HPT causes hypertension in end-stage renal disease (ESRD). We compared predialysis blood pressure (BP), weight and dose of antihypertensive medications (AHM) prescribed in 19 hemodialysis patients 1 month before total parathyroidectomy (PTx), during the first month after PTx, and long-term (mean 16 months) in 12 of 19 patients. At the time of PTx, study patients had a mean age of 47 +/- 9 years, mean duration of ESRD was 112 +/- 57 months, and mean intact parathyroid hormone (PTH) level of 1,181 +/- 552 pg/ml. Mean BP and predialysis weight were equivalent during the month before and the month after PTx. Of 12 patients followed long term, 8 (67%) were receiving AHM before PTx; after PTx; 3 (36%) of 8 discontinued AHM within 1 year, 2 (25%) of 8 required more AHM, while 2 (25%) of 8 continued on their original AHM, and 1 patient who was not on AHM prior to PTx required initiation of AHM after PTx. There was a clinically significant increase in predialysis weight at 1 year after PTx (median 13 lb) and over time (r = 0.7; slope = 0.5; p = 0.07). However, there was neither a clinically nor statistically significant change in either systolic (r = -0.18; slope = -0.01; p = 0.61) or diastolic (r = -0.6; slope = -0.24; p = 0.12) BP over time. We conclude that PTx fails to correct hypertension in hemodialysis patients with 2 degrees HPT.

Severity of AIDS and the response to EPO in uremia.

To determine the factors that govern their response to erythropoietin (EPO), we conducted a cross-sectional study of all patients in four outpatient hemodialysis facilities in Brooklyn, NY, who had end-stage renal disease (ESRD) and human immunodeficiency virus (HIV) infection and were receiving recombinant EPO. We also compared the hematocrit and EPO requirements of these patients to those of a control group of hemodialysis patients without HIV infection. We documented known duration of HIV infection, and total CD4 count was measured once. In both groups, hematocrit was measured weekly for 5 weeks and a mean value calculated for each subject. Transferrin saturation was measured twice and a mean value calculated for each subject. Intensity of hemodialysis was assessed by measuring both percent reduction of urea and serum albumin concentration twice; mean values were calculated for each subject. Twenty-nine (88%) of 33 study subjects had acquired immunodeficiency syndrome. Mean known duration of HIV infection was 49 +/- 32.5 months (median, 48 months), and mean total CD4 count was 143 +/- 152.4 cells/mm3 (median, 72 cells/mm3). Mean hematocrit in the study subjects was 27.4% +/- 4.7% compared with 27.6% +/- 3.7% in the controls (P = 0.69). Mean thrice-weekly EPO dose was higher in the study subjects (90 +/- 52 U/kg body weight) than in the controls (62 +/- 36 U/Kg body weight) (P = 0.001). Among the study subjects, hematocrit had direct univariate correlations with serum albumin concentration (r = 0.43; P = 0.02), transferrin saturation (r = 0.4; P = 0.03), and percent reduction of urea (r = 0.4; P = 0.02), but not with total CD4 count (r = -0.05; P = 0.8) or known duration of HIV infection (r = -0.11; P = 0.55). There was an inverse correlation between hematocrit and dose of EPO (r = -0.5; P = 0.003). Multiple regression analysis showed that transferrin saturation (P = 0.01) and percent reduction of urea (P = 0.003) had direct correlations with hematocrit after adjustment for other factors. There was an inverse relationship between hematocrit and dose of EPO (P = 0.0006). We conclude that in patients with ESRD and HIV infection receiving hemodialysis, the response to EPO (hematocrit) is modulated by the dose of EPO, quantity of hemodialysis, and transferrin saturation, but not by the severity of HIV disease. Hemodialysis patients infected with HIV receive a higher dose of EPO than those without HIV infection.

Uremia therapy in patients with end-stage renal disease and human immunodeficiency virus infection: has the outcome changed in the 1990s?

We conducted a cross-sectional survey to determine the relative course of patients with end-stage renal disease (ESRD) and human immunodeficiency virus (HIV) infection sustained on maintenance hemodialysis. All 34 patients with ESRD and HIV infection receiving hemodialysis in one hospital-based and three community-based outpatient hemodialysis facilities in Brooklyn, NY, were studied. We documented their known duration of HIV infection, duration of ESRD, and hemodialysis prescription, and noted the presence of clinical acquired immunodeficiency syndrome (AIDS). Total CD4 count, serum albumin concentration, and percent reduction of urea (predialysis blood urea nitrogen minus postdialysis blood urea nitrogen, divided by predialysis blood urea nitrogen x 100) were measured. The 34 study subjects (26 men and eight women) included 31 blacks (91%) and three Hispanics (9%) with a mean age of 42 +/- 7.5 years, 29 (85%) of whom had AIDS. Twenty subjects (59%) had a history of intravenous drug abuse. Only six subjects (18%) were receiving an antiretroviral drug (zidovudine = five, dideoxyinosine = one). In 23 subjects (68%), AIDS was diagnosed prior to ESRD and was presumed to be the cause of renal failure (HIV-associated nephropathy). The mean known duration of HIV infection was 50.5 +/- 34 months (median, 48 months); the mean duration of ESRD was 57 +/- 50 months, the mean total CD4 count was 140 +/- 150 cells/microL (median, 70 cells/microL), the mean hematocrit was 28% +/- 5%, and the mean serum albumin concentration was 3.5 +/- 0.37 g/dL. All subjects were receiving erythropoietin for anemia correction. The mean length of the prescribed thrice-weekly hemodialysis sessions was 3.5 +/- 0.4 hours. Our results suggest that the survival of many ESRD patients with HIV infection receiving hemodialysis has improved compared with the uniformly dismal survival rate reported in the 1980s. Decisions on whether to initiate renal replacement therapy in patients with AIDS and advanced renal failure should be individualized because the combination of ESRD and HIV infection does not necessarily signal near-term death.

Overt malignancy in long-term hemodialysis patients.

We studied all 39 patients who were on maintenance hemodialysis for 10 years or more (range, 10 to 24 years) in three free-standing, not-for-profit hemodialysis units to determine the prevalence of malignancy. The three dialysis units have a total patient population of 470, all of whom are cared for by the same group of physicians. From the same dialysis units, we selected a control cohort of 37 patients matched for age, gender, race, and renal diagnosis who were on hemodialysis for 3 years or less (short-term patients). Control patients were selected by randomly choosing the next patient who filled the criteria for duration of dialysis from the roster of all patients at a facility. Clinically overt malignancy during dialytic therapy was determined by history, physical examination, Pap smear, mammogram, and colonoscopy in patients with gastrointestinal bleeding. The mean age (+/-SE) of the long-term patients was 51.8 +/- 1.9 years, and that of the control group was 51.5 +/- 2.4 years (P = .92). Thrice-weekly hemodialysis prescriptions were similar in both groups: long term, 3.5 +/- 0.02 hours; control, 3.4 +/- 0.02 hours (P = .27). No malignancy was detected in either the long-term or the short-term patients, and no patient of either group had a malignancy in the past. Colonic biopsy specimens of four long-term patients who had gastrointestinal bleeding were normal. The prevalence of malignancy was not increased in patients who were on maintenance hemodialysis for 10 years or longer.

Determinants of type of initial hemodialysis vascular access.

Vascular access thrombosis is more common with polytetrafluoroethylene (PTFE) grafts than with native arteriovenous fistulae (AVF). Recent studies report an unexplained excess vascular access morbidity in women on hemodialysis. We studied 92 consecutive end-stage renal disease (ESRD) patients receiving their first permanent hemodialysis vascular access at initiation of hemodialysis to identify variables that determine assignment of either a PTFE graft or a native AVF. Independent variables included: age, gender, race, etiology of ESRD, and whether or not access surgery was electively planned before need for dialytic therapy. The 51 women and 41 men included 65 blacks, 13 Hispanics, 11 whites, and 3 Orientals aged 50 +/- (SD) 16 years. Of the 92 subjects, 54 (59%) received an AVF, while 38 (41%) received a PTFE graft. 36 (94%) of 38 PTFE grafts were placed in the upper arm as compared with 9 (17%) of 54 AVF (p = 0.0001). Also, 45 (83%) of 54 AVF were placed in the forearm as compared with only 2 (6%) of 38 PTFE grafts (p = 0.0001). Women were more likely to receive a PTFE graft - 28 (55%) of 51 - than men - 10 (24%) of 41 (p = 0.003). By contrast, men were more likely to get an AVF - 31 (76%) of 41 - than women - 23 (45 %) of 51 (p = 0.003). The log linear analysis confirmed that this finding was significant (p = 0.0018) for the coefficient of interaction between gender and type of vascular access. No other independent variable had a significant relationship with type of vascular access. We conclude that women with ESRD are more likely to receive a PTFE graft for hemodialysis, while men are more likely to get an AVF. These findings may explain, in part, the reported excess vascular access morbidity in women on hemodialysis.

Resurgence of blood transfusion therapy in erythropoietin treated hemodialysis patients.

Anemia, a major component of the uremia syndrome before the introduction of recombinant human erythropoietin (EPO), was treated primarily with blood transfusions in patients with end-stage renal disease (ESRD). After multi-center trials of EPO in hemodialysis patients showed that blood transfusion requirements fell by > or = 50% in hemodialysis facilities using EPO, it was anticipated that blood transfusion therapy in hemodialysis patients would be eliminated in patients treated with EPO. The authors examined the annual rate of blood transfusions from 1983 to 1992 in hemodialysis patients admitted to an inner city municipal hospital. Hospital computer records were accessed to obtain a list of all patients admitted to the hospital who received a blood transfusion between 1983 and 1992. From these data, lists of transfused hemodialysis patients were generated. The authors compared the mean annual blood transfusion rate per hospital patient in the pre EPO era (1983-1985) with the same rate during the time of EPO trial (1986-1988) and during the time of wide clinical availability of EPO (1989-1992). In addition, the authors examined individual hospital medical records of hemodialysis patients who received transfusions in 1986 and 1992. The mean annual blood transfusion rate was 38% (range, 36-39%) in the pre EPO era, 19% (range, 16-24%) during the years of the EPO trial, and 23% (range, 21-24%) after EPO was widely used in 1989, comparing the latest rate with either of the two earlier times (p < 0.0001). Of all of the years tabulated, the blood transfusion rate was lowest in 1987, the second year of the EPO clinical trial, with only 94 (16%) of 592 hemodialyzed patients given a blood transfusion. The rate of blood transfusions remained low in 1988 (18%) but subsequently has increased. Using 1987 as a reference point, the rate of blood transfusion in hemodialysis patients increased in each of the subsequent years after 1988 (18%, p < 0.33); 1989 (23%, p < 0.001), 1990 (24%, p < 0.0001), 1991 (21%, p < 0.02), and 1992 (23%, p < 0.0001). The authors conclude that, despite the availability and broad use of EPO in uremia therapy since 1989, a significant proportion of hemodialysis patients receiving EPO treatment require blood transfusions for anemia.