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Biomedical subjects

A J Bleyer

Publications and source records attributed to A J Bleyer.

At least 19 recordsLinked to original sources
PubMed2006

Characteristics of sudden death in hemodialysis patients.

Hemodialysis (HD) is an intermittent procedure during which large fluid and electrolyte shifts occur. We hypothesized that sudden death occurrences in HD patients are related to the timing of HD, and that they occur more frequently in the 12 h period starting with dialysis and in the 12 h period at the end of the dialysis-free weekend interval. In a retrospective study, 228 patient deaths were screened to determine if they met the criteria for sudden death. Information was obtained from clinic charts, dialysis center records, and interview of witnesses of the death event. There were 80 HD patients who met the criteria for sudden death. A bimodal distribution of death occurrences was present, with a 1.7-fold increased death risk occurring in the 12 h period starting with the dialysis procedure and a threefold increased risk of death in the 12 h before HD at the end of the weekend interval (P=0.011). Patients with sudden death had a high prevalence of congestive heart failure and coronary artery disease. Only 40% of patients experiencing sudden death were receiving beta-blockers, and the prior monthly serum potassium value was less than 4 mEq/l in 25%. Sudden death is temporally related to the HD procedure. Every other day HD could be beneficial in preventing sudden death. Careful attention to the usage of beta-blockers and to the maintenance of normal serum potassium values is indicated in HD patients at risk for sudden death.

Adrenergic beta-Antagonists↗
PubMed2002

Mutations of the UMOD gene are responsible for medullary cystic kidney disease 2 and familial juvenile hyperuricaemic nephropathy.

INTRODUCTION: Medullary cystic kidney disease 2 (MCKD2) and familial juvenile hyperuricaemic nephropathy (FJHN) are both autosomal dominant renal diseases characterised by juvenile onset of hyperuricaemia, gout, and progressive renal failure. Clinical features of both conditions vary in presence and severity. Often definitive diagnosis is possible only after significant pathology has occurred. Genetic linkage studies have localised genes for both conditions to overlapping regions of chromosome 16p11-p13. These clinical and genetic findings suggest that these conditions may be allelic. AIM: To identify the gene and associated mutation(s) responsible for FJHN and MCKD2. METHODS: Two large, multigenerational families segregating FJHN were studied by genetic linkage and haplotype analyses to sublocalise the chromosome 16p FJHN gene locus. To permit refinement of the candidate interval and localisation of candidate genes, an integrated physical and genetic map of the candidate region was developed. DNA sequencing of candidate genes was performed to detect mutations in subjects affected with FJHN (three unrelated families) and MCKD2 (one family). RESULTS: We identified four novel uromodulin (UMOD) gene mutations that segregate with the disease phenotype in three families with FJHN and in one family with MCKD2. CONCLUSION: These data provide the first direct evidence that MCKD2 and FJHN arise from mutation of the UMOD gene and are allelic disorders. UMOD is a GPI anchored glycoprotein and the most abundant protein in normal urine. We postulate that mutation of UMOD disrupts the tertiary structure of UMOD and is responsible for the clinical changes of interstitial renal disease, polyuria, and hyperuricaemia found in MCKD2 and FJHN.

Alleles↗
PubMed2001

Relationship between underlying renal disease and renal transplantation outcome.

The purpose of this study is to better characterize graft and patient survival posttransplantation by examining survival according to underlying renal disease for all first-time renal allograft recipients in the United Network for Organ Sharing (UNOS) registry. From 1987 through 1996, the UNOS registry collected data on 23,838 living and 67,183 cadaveric renal transplantations. This investigation included all patients undergoing their first renal transplantation for whom the underlying cause of renal failure could be identified and categorized. Gross 1- and 3-year patient and graft survival according to underlying renal disease are included. In addition, a Cox proportional hazards model was created to analyze the effect of underlying disease on graft and patient survival after adjusting for comorbid conditions, demographics, and type of renal transplant (living versus cadaveric). The association between underlying disease and graft and patient survival is shown. Amyloidosis, sickle cell anemia, scleroderma, and radiation nephritis are associated with poor graft and patient survival. The risk ratio for patient mortality was more than twice that for immunoglobulin A nephropathy for a number of conditions, including analgesic nephropathy, amyloidosis, and both forms of diabetes mellitus.

Graft Survival↗
PubMed2000

Tobacco, hypertension, and vascular disease: risk factors for renal functional decline in an older population.

BACKGROUND: A decline in renal function with age has been noted in some but not all individuals. The purpose of this study was to identify risk factors associated with a clinically significant increase in serum creatinine (of at least 0.3 mg/dL) in an older nondiabetic population. METHODS: A retrospective case-control study was performed analyzing data obtained from 4142 nondiabetic participants of the Cardiovascular Health Study Cohort, all at least 65 years of age, who had two measurements of serum creatinine performed at least three years apart. Cases were identified as participants who developed an increase in serum creatinine of at least 0.3 mg/dL, with controls including participants who did not sustain such an increase. RESULTS: There was an increase in the serum creatinine of at least 0.3 mg/dL in 2.8% of the population. In a multivariate "best-fit" model adjusted for gender, weight, black race, baseline serum creatinine, and age, the following factors were associated with an increase in serum creatinine: number of cigarettes smoked per day, systolic blood pressure, and maximum internal carotid artery intimal thickness. CONCLUSIONS: These data suggest that three very preventable or treatable conditions-hypertension, smoking, and prevalent vascular disease, which are associated with large and small vessel disease-are highly associated with clinically important changes in renal function in an older population.

Aged↗
PubMed1999

An international study of patient compliance with hemodialysis.

CONTEXT: International differences in compliance of patients undergoing hemodialysis are poorly characterized and could contribute to international survival differences. OBJECTIVE: To compare international differences in patient compliance with hemodialysis treatments. DESIGN: A prospective observational study of patients undergoing hemodialysis in 1995 and a cross-sectional survey of health care professionals caring for hemodialyzed patients in 1996. SETTING AND PATIENTS: Four dialysis centers in the southeastern United States with 415 patients undergoing hemodialysis, 1 center in Sweden with 84 patients, and 4 centers in Japan with 194 patients participated in the prospective observational study. In the cross-sectional survey, nurses and nephrologists from the United States (n = 49), Japan (n = 21), and Sweden (n = 16) responded to questions regarding the compliance of their patients undergoing hemodialysis. MAIN OUTCOME MEASURES: Percentage of patients who miss a dialysis treatment and number of missed dialysis treatments. RESULTS: Of 415 US patients, 147 missed 699 treatments over a 6-month period (28.1 missed treatments per 100 patient-months or 2.3% of all prescribed treatments). During a 3-month period, there were 0 missed treatments per 100 patient-months for patients from Japan and 0 missed treatments per 100 patient-months for patients from Sweden (P<.001). In the cross-sectional survey, the mean (SD) estimated percentage of patients missing a treatment per month was 4% (3%) for the United States, 0% for Japan, and 0.1% (3%) for Sweden (P<.001). CONCLUSIONS: Noncompliance is much more common in US patients undergoing hemodialysis than Swedish and Japanese patients. The implications of these results for international differences in survival deserve further study.

Cross-Sectional Studies↗
PubMed1999

A reciprocal graph to plot the reciprocal serum creatinine over time.

In patients who have a linear decline in renal function over time, plotting the reciprocal serum creatinine versus time has been found to be useful in monitoring renal disease progression and predicting the start of dialysis. Unfortunately, producing such plots is cumbersome because of the inherent difficulties of plotting a reciprocal number on standard graph paper. This technical note presents a graph in which the y-axis is represented as a reciprocal axis. In this manner, one is able to directly plot the serum creatinine over time and must not rely on plotting the reciprocal value. This approach may make the plotting of such data easier for the nephrologist and make this clinical tool more useful.

Creatinine↗
PubMed1999

A comparison of the calcium-free phosphate binder sevelamer hydrochloride with calcium acetate in the treatment of hyperphosphatemia in hemodialysis patients.

Current phosphate binders used in hemodialysis patients include calcium-based binders that result in frequent hypercalcemia and aluminum-based binders that result in total body aluminum accumulation over time. This investigation describes the use of a calcium- and aluminum-free phosphate-binding polymer in hemodialysis patients and compares it with a standard calcium-based phosphate binder. An open-label, randomized, crossover study was performed to evaluate the safety and effectiveness of sevelamer hydrochloride in controlling hyperphosphatemia in hemodialysis patients. After a 2-week phosphate binder washout period, stable hemodialysis patients were administered either sevelamer or calcium acetate, and the dosages were titrated upward to achieve improved phosphate control over an 8-week period. After a 2-week washout period, patients crossed over to the alternate agent for 8 weeks. Eighty-four patients from eight centers participated in the study. There was a similar decrease in serum phosphate values over the course of the study with both sevelamer (-2.0 +/- 2.3 mg/dL) and calcium acetate (-2.1 +/- 1.9 mg/dL). Twenty-two percent of patients developed a serum calcium greater than 11.0 mg/dL while receiving calcium acetate, versus 5% of patients receiving sevelamer (P < 0.01). The incidence of hypercalcemia for sevelamer was not different from the incidence of hypercalcemia during the washout period. Patients treated with sevelamer also sustained a 24% mean decrease in serum low-density lipoprotein cholesterol levels. Sevelamer was effective in controlling hyperphosphatemia without resulting in an increase in the incidence of hypercalcemia seen with calcium acetate. This agent appears quite effective in the treatment of hyperphosphatemia in hemodialysis patients, and its usage may be advantageous in the treatment of dialysis patients.

Acetic Acid↗
PubMed1999

Administration and pharmacokinetics of high-dose cyclophosphamide with hemodialysis support for allogeneic bone marrow transplantation in acute leukemia and end-stage renal disease.

We report a patient with pre-existing end-stage renal disease (ESRD) who underwent successful matched related donor allogeneic bone marrow transplantation for AML in second complete remission (CR2) using conditioning with high-dose cyclophosphamide (CY, 60 mg/kg/day x 2) and TBI (165 cGy twice daily x 4 days). The timing of hemodialysis after high-dose CY was extrapolated from available data on the pharmacokinetics of high-dose CY and hemodialysis clearance of conventional dose CY and its metabolites. Pharmacokinetic analyses indicated that the elimination of high-dose CY and its alkylating metabolites is impaired in ESRD but is cleared with hemodialysis. The patient's early post-transplant course was uncomplicated, and WBC and platelet engraftment occurred by day +22. Bone marrow examination on day +25 showed trilineage engraftment with no AML; cytogenetics showed 100% donor karyotype. The patient remains in remission with 100% donor karyotype at 3 years post transplant. Clinical results indicate that the administration of high-dose CY is feasible with hemodialysis support for patients with ESRD.

Adult↗
PubMed1999

Sudden and cardiac death rates in hemodialysis patients.

BACKGROUND: Sudden and cardiac death (including death from congestive heart failure, myocardial infarction, and sudden death) are common occurrences in hemodialysis patients. The intermittent nature of hemodialysis may lead to an uneven distribution of sudden and cardiac death throughout the week. The purpose of this study was to assess the septadian rhythm of sudden and cardiac death in hemodialysis patients. METHODS: Data from the United States Renal Data System (USRDS) were obtained to examine the day of death for United States hemodialysis and peritoneal dialysis patients from 1977 through 1997. The days of death were also determined for patients in the Case Mix Adequacy Study of the USRDS. RESULTS: There was an even distribution of sudden and cardiac deaths for patients on peritoneal dialysis, and hemodialysis patients dying of noncardiac deaths also had an even distribution. For all hemodialysis patients, Monday and Tuesday were the most common days of sudden and cardiac death. For patients in the Case Mix Adequacy Study designated as Monday, Wednesday, and Friday dialysis patients, 20.8% of sudden deaths occurred on Monday compared with the 14.3% expected (P = 0.002). Similarly, 20.2% of cardiac deaths occurred on Monday compared with the 14.3% expected (P = 0.0005). Similar trends were found on Tuesday for Tuesday, Thursday, and Saturday dialysis patients. CONCLUSIONS: The intermittent nature of hemodialysis may contribute to an increased sudden and cardiac death rate on Monday and Tuesday for patients enrolled in the USRDS.

Age Factors↗
PubMed1999

Dialysis modality and delayed graft function after cadaveric renal transplantation.

The purpose of this investigation was to compare outcomes in the immediate posttransplant period for hemodialysis (HD) and peritoneal (PD) dialysis patients who received cadaveric renal transplantation. Data were obtained from the United Network of Organ Sharing on all cadaveric graft recipients who were dialysis-dependent at the time of transplantation between April 1994 and December 1995. Baseline characteristics were compared between groups, and multivariate logistic regression was performed with outcome measures including urine production in the first 24 h posttransplantation (U24), requirement for dialysis in the first week posttransplant (FWDIAL), and treatment for acute rejection during the initial hospitalization. The odds of oliguria (not producing urine in the first 24 h) were 1.49 (1.28 to 1.74) times higher in HD versus PD patients. After adjustment for other comorbid conditions including age, gender, race, HLA mismatch, time on dialysis, panel-reactive antibodies, and cold and warm ischemia time, the odds of oliguria were 1.60 (1.14 to 2.25) times higher in black HD patients compared with PD patients and 1.29 (1.06 to 1.57) times higher in white HD patients. In a similar manner, after adjustment for significant comorbid conditions, the odds of requiring dialysis in the first week were 1.56 (1.22 to 2.0) times higher in black HD patients versus PD patients and 1.40 (1.21 to 1.60) times higher in white HD patients. The rate of acute rejection was similar during the first hospitalization. These results suggest that there is an association between hemodialysis and delayed graft function. Differences in biocompatibility between the two modalities could potentially be responsible.

Adult↗
PubMed1999

A randomized trial of sevelamer hydrochloride (RenaGel) with and without supplemental calcium. Strategies for the control of hyperphosphatemia and hyperparathyroidism in hemodialysis patients.

OBJECTIVE: We have previously shown sevelamer hydrochloride (RenaGel) to be an effective and well-tolerated treatment for hyperphosphatemia in hemodialysis patients. PATIENTS AND METHODS: We performed a randomized clinical trial to compare the efficacy of RenaGel alone and RenaGel with calcium, using the serum phosphorus concentration and intact parathyroid hormone (PTH) as the principal outcomes of interest. Calcium (900 mg elemental) was provided as a once-nightly dose on an empty stomach. 71 patients were randomized and included in the intent-to-treat population; 55 completed the 16-week study period (2 weeks washout, 12 weeks treatment, 2 weeks washout). 49% of subjects were taking vitamin D metabolites. RESULTS: Serum phosphorus and PTH rose significantly when patients stopped their phosphate binders during both washout periods. RenaGel and RenaGel with calcium were equally effective at reducing serum phosphorus (mean change -2.4 mg/dL vs. -2.3 mg/dL). RenaGel with calcium was associated with a small increase in serum calcium (mean change 0.3 mg/dL vs. 0.0 mg/dL in RenaGel group, P = 0.09) that was not statistically significant. During the treatment phase, the reduction in PTH tended to be greater in the RenaGel with calcium group (median change -67.0 vs. -22.5 pg/mL in RenaGel group, P = 0.07). Non-users of vitamin D metabolites treated with RenaGel with calcium experienced a significant decrease in PTH (median change -114.5 vs. -22 pg/mL in RenaGel group, P = 0.006). Adverse events were seen with equal frequency in both groups, being generally mild in intensity, and rarely attributable to the drugs. CONCLUSION: We conclude that RenaGel and RenaGel with calcium are similarly effective in the treatment of ESRD-related hyperphosphatemia. Provision of supplemental calcium or metabolites of vitamin D with RenaGel may enhance control of hyperparathyroidism.

Calcium↗
PubMed1998

Clinical correlates of hypertensive end-stage renal disease.

Although there has been much discussion regarding the etiology of hypertensive renal disease, clinical characteristics of this condition have not been thoroughly studied. The purpose of this investigation was to identify clinical correlates of hypertensive end-stage renal disease (ESRD) in a population of patients older than 50 years and to compare these clinical findings with those in a group of ESRD patients with certain known disorders (established diagnoses). Data regarding demographics, cause of ESRD, educational level, presence of diabetes mellitus, angina, myocardial infarction, and peripheral vascular disease were obtained from the Southeastern Kidney Council for patients starting renal replacement therapy between January 1, 1990, and August 1, 1996. Clinical characteristics were compared for white and black patients. Demographic variables and comorbid conditions were compared between groups with general linear regression or logistic regression contrast techniques. A logistic regression model was formed with hypertensive ESRD or established diagnoses as the outcome variable and comorbid and socioeconomic variables as the independent variables. Hypertensive ESRD was diagnosed in 24% of white and 38% of black patients, while established diagnoses were present in 17% of white and 7% of black ESRD patients. The most common established diagnoses were polycystic kidney disease, specified glomerulonephritis, and nephrolithiasis or obstruction. In a logistic regression model, white patients were found more likely to be classified as having hypertensive ESRD if they were older, suffered from angina and other forms of atherosclerosis, smoked, and were less educated. White patients with hypertensive ESRD were more than 2.4 times as likely to suffer from angina as patients with established diagnoses. For black patients, the presence of peripheral vascular disease and female gender were associated with an increased chance of being diagnosed as having hypertensive ESRD. The results of this investigation show that there is a strong association between atherosclerosis and hypertensive ESRD in older white patients. In black patients, the association between atherosclerosis and hypertensive ESRD was also present, but not as strong. The unique association of hypertensive ESRD with atherosclerosis suggests that atherosclerosis is a risk factor for chronic renal failure and that a primary renal microvascular disorder may lead to both hypertension and progressive renal insufficiency.

Age Factors↗
PubMed1998

A case control study of proximal calciphylaxis.

The purpose of this investigation was to describe the clinical presentation of nine patients with calciphylaxis involving the proximal lower extremities or trunk and to compare the clinical characteristics of these patients with those of 347 hemodialysis patients from the same geographic area. Patients were identified primarily through a computer search of pathology records, identifying patients with the term "calciphylaxis" in the biopsy report. All patients had pathologic specimens consistent with calciphylaxis. All the calciphylaxis patients were white and were markedly obese. While two patients had markedly elevated parathyroid hormone levels, most patients did not show severe derangements of calcium phosphate metabolism compared with other dialysis patients. A logistic regression model identified body mass index and low serum albumin 3 months before diagnosis as being highly associated with a diagnosis of calciphylaxis. Diabetes mellitus and parameters of calcium-phosphate metabolism were not significantly associated with proximal calciphylaxis. These findings suggest that white race, morbid obesity, and poor nutritional status are associated with proximal calciphylaxis in dialysis patients.

Aged↗