The Role of Vitamin D and Oxidative Stress in Chronic Kidney Disease.

Chronic kidney disease (CKD) is a major non-communicable disease associated with high rates of premature morbidity and mortality. The prevalence of hypovitaminosis D (deficiency of 25(OH)D or 25D) is greater in racial/ethnic minorities and in patients with CKD than the general population. Low 25D is associated with bone and mineral disorders as well as immune, cardiometabolic and cardiovascular (CV) diseases. Thus, it has been suggested that low 25D contributes to the poor outcomes in patients with CKD. The prevalence of hypovitaminosis D rises progressively with advancing severity of kidney disease with over 30% of patients with CKD stage 3 and 70% patients with CKD stage 5 estimated to have low levels of 25D. This report describes several of the abnormal physiologic and counter-regulatory actions related to low 25D in CKD such as those in oxidative stress and inflammatory systems, and some of the preclinical and clinical evidence, or lack thereof, of normalizing serum 25D levels to improve outcomes in patients with CKD, and especially for the high risk subset of racial/ethnic minorities who suffer from higher rates of advanced CKD and hypovitaminosis D.

Statins and Cardiovascular Disease Outcomes in Chronic Kidney Disease: Reaffirmation vs. Repudiation.

Cardiovascular disease (CVD) burden is several-fold higher in patients with chronic kidney disease (CKD). Although statins have been shown to provide significant CVD benefits in both the general population and patients with CKD, this has not translated into survival advantage in patients with advanced CKD or on dialysis. It has been reported that CVD risk continues to escalate as CKD progresses to end-stage kidney disease (ESKD); however, the CVD risk reduction by statins appears to decline as patients' progress from the early to later stages of CKD. Statins have also been associated with a higher incidence of stroke in ESKD patients. Thus, the CVD benefits of statins in ESKD remain questionable.

Detection of HIV-1 and Human Proteins in Urinary Extracellular Vesicles from HIV+ Patients.

BACKGROUND: Extracellular vesicles (EVs) are membrane bound, secreted by cells, and detected in bodily fluids, including urine, and contain proteins, RNA, and DNA. Our goal was to identify HIV and human proteins (HPs) in urinary EVs from HIV+ patients and compare them to HIV- samples. METHODS: Urine samples were collected from HIV+ (n = 35) and HIV- (n = 12) individuals. EVs were isolated by ultrafiltration and characterized using transmission electron microscopy, tandem mass spectrometry (LC/MS/MS), and nanoparticle tracking analysis (NTA). Western blots confirmed the presence of HIV proteins. Gene ontology (GO) analysis was performed using FunRich and HIV Human Interaction database (HHID). RESULTS: EVs from urine were 30-400 nm in size. More EVs were in HIV+ patients, P < 0.05, by NTA. HIV+ samples had 14,475 HPs using LC/MS/MS, while only 111 were in HIV-. HPs in the EVs were of exosomal origin. LC/MS/MS showed all HIV+ samples contained at least one HIV protein. GO analysis showed differences in proteins between HIV+ and HIV- samples and more than 50% of the published HPs in the HHID interacted with EV HIV proteins. CONCLUSION: Differences in the proteomic profile of EVs from HIV+ versus HIV- samples were found. HIV and HPs in EVs could be used to detect infection and/or diagnose HIV disease syndromes.

Iatrogenic hypernatremia in hemodialysis patients: A result of erroneous online conductivity monitor and conductivity meter reading.

Hyponatremia is common in chronic kidney disease and in end stage kidney disease (ESKD) but hypernatremia is infrequent in ESKD. The incidence of hypernatremia is higher in ambulatory peritoneal dialysis (PD) than in hemodialysis (HD) patients. In PD patients it is often a result of excessive ultrafiltration but in HD it is often a result of dialysate composition errors. Dialysate composition errors can inadvertently cause either hyponatremia or hypernatremia. We present two cases of symptomatic hypernatremia which manifested as increased thirst, excessive weight gain and worsening hypertension in HD patients. The hypernatremia was caused by a combination of errors in online conductivity reading and a faulty hand held conductivity meter. Symptoms were relieved in both patients after replacement of the dialysis machine.

Relationships of clinic size, geographic region, and race/ethnicity to the frequency of missed/shortened dialysis treatments.

BACKGROUND: Significant international differences abound in the adherence of hemodialysis (HD) patients to prescribed treatments. Unfortunately, factors influencing adherence within the United States (US) are not well understood. This study explores the hypothesis that race/ethnicity, geographic region and clinic size are associated with differences in the frequency of missed/shortened treatments. METHODS: A retrospective analysis on all prevalent chronic HD patients treated at Dialysis Clinics Inc. facilities between January 2007 and June 2008. Logistic regression models were computed in which the outcome measures were the odds for missing or shortening treatments. RESULTS: The cohort consisted of 15,340 HD patients of whom 48% were non-Hispanic whites (NHW), 41% African Americans (AA), 6% Hispanics, 2% Native Americans, 2% Asians, and 1% unknown. Patients were older in the Northeast than in the South (p < 0.001) or West (p = 0.0052). The frequency of missed and shortened treatments was lower in the Northeast than other regions, p < 0.0001. Hospitalization rates were lower in the West than the Northeast (p < 0.01) but mortality rates were similar across all regions. The odds ratio and 95% confidence interval for missed [1.31 (1.14-1.52)] and shortened treatments [1.86 (1.73-2.0)] were greater in clinics with >100 patients than in those with <50 patients. Compared to NHW, the frequencies of missed and shortened treatments were higher in AA, Hispanics and Native Americans (p < 0.001) but lower among Asians (p < 0.001). CONCLUSION: The frequency of missed and shortened HD varies significantly by race/ethnicity, geographic region and clinic size. The relationship of clinic size to missed/shortened treatments may warrant consideration when planning new HD facilities.

Heart surgery in end-stage renal disease: is outcome worse for african american patients?

General results of open heart surgery in end-stage renal disease patients (ESRD) have been well-documented. However, it is unknown if the African American subgroup with known decreased access to advanced healthcare services and a higher prevalence rate of ESRD have a worse long-term survival after heart surgery. Thirty of 150 African American patients who underwent open heart surgery by a single surgeon at an urban community hospital between 1996 and 2010 were identified to have ESRD and were on chronic maintenance hemodialysis prior to surgery. Clinical and outcome data from both groups were retrospectively analyzed. There were no significant differences in the baseline demographic characteristics of the patients, but the ESRD cohort showed a significantly higher prevalence of peripheral vascular and cardiovascular diseases [P < 0.001]. Compared to the non-ESRD subjects, the predicted logistic EuroSCORE was 16.4% vs. 9.4%, [P < 0.001], while the observed 30 days operative mortality was 16.6% vs. 4.2% [P < 0.02], respectively. In isolated coronary artery bypass graft cases, operative mortality was 20.8% and 3.0%, respectively. The 5- and 10-year post-surgery survival was 40% and 25% vs. 72% and 57% [P < 0.01], respectively, in the ESRD and non-ESRD groups. Operative mortality and survival was worse in ESRD patients compared to non-ESRD patients based on their preoperative risk scores. Although the operative mortality of our ESRD patients was high, long-term survival was comparable to reports from both the United States Renal Data System and a Japanese ESRD cohort.

Relationship of missed and shortened hemodialysis treatments to hospitalization and mortality: observations from a US dialysis network.

BACKGROUND: The relationship of missed and shortened hemodialysis (HD) to clinical outcomes has not been well characterized in HD patients in the USA. Here we explored the frequency of missed and shortened treatments and their impact on mortality and hospitalization. METHODS: A retrospective review of data from a cohort of 15 340 HD patients treated in facilities operated by Dialysis Clinics, Inc. We compared the frequency of missed and shortened treatments by gender, race, age and treatment schedules [Mondays, Wednesdays, Fridays (MWF) versus Tuesdays, Thursdays, Saturdays (TTS)]. RESULTS: Of the 15 340 patients, 48% were non-Hispanic whites (NHWs), 41% African Americans (AAs), 6% Hispanics, 2% Native American (NA), 2% Asians and 1% other races. The median number of years on HD was 1.8 years and the median follow-up was 12.4 months. The odds of missing at least one treatment in a month were higher in: patients aged <55 years, odds ratio (OR) 1.33 (P<0.0001); in AAs, OR 1.51 (P < 0.0001); in NAs, OR 1.50 (P = 0.0003); and in Hispanics, OR 1.33 (P = 0.0003) compared with NHWs and in patients who dialyzed on TTS compared with MWF, OR 1.33 (P < 0.0001). Similar findings were observed for treatments shortened by at least 10 min per month. Missed and shortened treatments were most prevalent on Saturdays and were also associated with progressive increases in hospitalization and mortality. CONCLUSION: Missed and shortened HD treatments pose a challenge to providers. Improved adherence to prescribed dialysis may decrease the morbidity and mortality.

Chronic kidney disease, prevalence of premature cardiovascular disease, and relationship to short-term mortality.

BACKGROUND: Chronic kidney disease (CKD) is recognized as an independent cardiovascular disease (CVD) risk state, particularly in the elderly, and has been defined by levels of estimated glomerular filtration rate (eGFR) and markers of kidney damage. The relationship between CKD and CVD in younger and middle-aged adults has not been fully explored. METHODS: Community volunteers completed surveys regarding past medical events and underwent blood pressure and laboratory testing. Chronic kidney disease was defined as an eGFR <60 mL x min(-1) x 1.73 m(-2) or urine albumin-creatinine ratio (ACR) > or =30 mg/g. Premature CVD was defined as self-reported myocardial infarction or stroke at <55 years of age in men and <65 years of age in women. Mortality was ascertained by linkage to national data systems. RESULTS: Of 31 417 participants, the mean age was 45.1 +/- 11.2 years, 75.5% were female, 36.8% African American, and 21.6% had diabetes. A total of 20.6% were found to have CKD, with the ACR and eGFR being the dominant positive screening tests in the younger and older age deciles, respectively. The prevalences of premature myocardial infarction (MI), stroke, or death, and the composite were 5.3%, 4.7%, 0.8%, 9.2%, and 2.5%, 2.2%, 0.2%, 4.2% for those with and without CKD, respectively (P < .0001 for composite). Multivariable analysis found CKD (OR 1.44, 95% CI 1.27-1.63), age (OR 1.05 [per year], 95% CI 1.04-1.06), hypertension (OR 1.61, 95% CI 1.40-1.84), diabetes (OR 2.03, 95% CI 1.79-2.29), smoking (OR 1.91, 95% CI 1.66-2.21), and less than high school education (OR 1.59, 95% CI 1.37-1.85) as the most significantly associated factors for premature CVD or death (all P < .0001). Survival analysis found those with premature MI or stroke and CKD had the poorest short-term survival over the next 3 years after screening. CONCLUSIONS: Chronic kidney disease is an independent predictor of MI, stroke, and death among men and women younger than age 55 and 65 years, respectively. These data suggest the biologic changes that occur with kidney failure promote CVD at an accelerated rate that cannot be fully explained by conventional risk factors or older age. Screening for CKD by using both the ACR and eGFR can identify younger and middle-aged individuals at high risk for premature CVD and near-term death.

Dialysis "no-shows" on saturdays: implications of the weekly hemodialysis schedules on nonadherence and outcomes.

BACKGROUND: The prevalence of skipped hemodialysis or no-show is higher among African Americans, younger Sages, smokers and illicit drug users. The effect of the weekly hemodialysis treatment schedules (Mondays, Wednesdays, Fridays (MWF); or Tuesdays, Thursdays, Saturdays (TTS)] on adherence is unknown. METHODS: Our hemodialysis patients were prospectively monitored for compliance over a 12-month duration. Regression analyses were employed for associations between variables and outcomes. RESULTS: A total of 114 African-American patients-mean age 55 +/- 14 and 53% male--were surveyed. Compared to the MWF, the TTS patients had higher rates of no show (2.4% vs. 1.7%, p = NS); shortened hemodialysis time (30% vs. 26%, p = NS); cocaine use (18% vs. 8%, p = 0.09); higher interdialytic weight gain 14.3 +/- 1.8 kg vs. 3.4 +/-1.3 kg, p = 0.005); prolonged length of hospital stay (9 +/- 12 days vs. 4 +/- 5 days, p = 0.02); and higher mortality (16% vs. 8%, p = NS). Compared to other days of the week, the Saturday no-show rate was significantly higher: 31% vs. 13%, 15%, 16%, 17%, 8%, Monday through Friday, respectively. Length of hospital stay correlated with no show (R2 = 0.4, p < 0.0001), while early termination was associated with smoking, cocaine use, female gender, TTS schedule, low serum albumin, hematocrit and adequacy of dialysis (Kt/V) (R2 = 0.6, p = 0.009). CONCLUSIONS: The TTS-scheduled hemodialysis patients are less adherent, and have higher morbidity than the MWF Spatients and a predilection for skipping on Saturdays.

CKD and cardiovascular disease in screened high-risk volunteer and general populations: the Kidney Early Evaluation Program (KEEP) and National Health and Nutrition Examination Survey (NHANES) 1999-2004.

BACKGROUND: Chronic kidney disease (CKD) is recognized as an independent cardiovascular disease risk state. The relationship between CKD and cardiovascular disease in volunteer and general populations has not been explored. METHODS: The National Kidney Foundation Kidney Early Evaluation Program (KEEP) is a community-based health-screening program to raise kidney disease awareness and detect CKD for early disease intervention in individuals 18 years or older with diabetes, hypertension, or family history of kidney disease, diabetes, or hypertension. KEEP volunteers completed surveys and underwent blood pressure and laboratory testing. Estimated glomerular filtration rate (eGFR) was computed, and urine albumin-creatinine ratio (ACR) was measured. In KEEP, CKD was defined as eGFR less than 60 mL/min/1.73 m(2) or ACR of 30 mg/g or greater. Cardiovascular disease was defined as self-reported myocardial infarction or stroke. Data were compared with National Health and Nutrition Examination Survey (NHANES) 1999-2004 data for prevalence of cardiovascular disease risk factors and cardiovascular outcomes. RESULTS: Of 69,244 KEEP participants, mean age was 53.4 +/- 15.7 years, 68.3% were women, 33.0% were African American, and 27.6% had diabetes. Of 17,061 NHANES participants, mean age was 45.1 +/- 0.27 years, 52% were women, 11.2% were African American, and 6.7% had diabetes. In KEEP, 26.8% had CKD, and in NHANES, 15.3%. ACR was the dominant positive screening test for younger age groups, and eGFR, for older age groups, for both populations. Prevalences of myocardial infarction or stroke were 16.5% in KEEP and 15.1% in NHANES (P < 0.001) and 7.8% in KEEP and 3.7% in NHANES (P < 0.001) for individuals with and without CKD, respectively. In adjusted analysis of both KEEP and NHANES data, CKD was associated with a significantly increased risk of prevalent myocardial infarction or stroke (odds ratio, 1.34; 95% confidence interval, 1.25 to 1.43; odds ratio, 1.37; 95% confidence interval, 1.10 to 1.70, respectively). In KEEP, short-term mortality was greater in individuals with CKD (1.52 versus 0.33 events/1,000 patient-years). CONCLUSIONS: CKD is independently associated with myocardial infarction or stroke in participants in a voluntary screening program and a randomly selected survey population. Heightened concerns regarding risks in volunteers yielded greater cardiovascular disease prevalence in KEEP, which was associated with increased short-term mortality.

Cardiorenal consideration as a risk factor for heart failure.

Cardiovascular disease-related factors are responsible for about 50% of the mortality in patients with both chronic kidney disease and end-stage renal disease. Therefore, it is not surprising that 30%-50% of patients with congestive heart failure also have an impaired glomerular filtration rate. This signifies a co-dependence between the kidneys and the heart. The role of anemia, microalbuminuria, calcium, and phosphorus imbalance in this cardiorenal interdependence is discussed in this article.

Cardiovascular risk factor control in communities--update from the ASH Carolinas-Georgia Chapter, the Hypertension Initiative, and the Community Physicians' Network.

The prevalence of hypertension dictates that blood pressure must be managed effectively in primary care. The American Society of Hypertension (ASH) regional chapters and clinical hypertension specialists represent a positive response by ASH to the growing problems of hypertension and metabolic syndrome-related risks and disease. To have a significant public health effect, the impact of clinical hypertension specialists must be leveraged. Key activities in the community include educating other providers locally, delivering care for complex referral patients, and fostering growth of a practice network with a central database in collaboration with academic partners. The database supports practice audit and feedback reports to enhance quality improvement, identify continuing medical education topics, and facilitate clinical trials to test new therapeutic and best-practice approaches to risk factor management. The ASH regional chapters serve as a forum for community and academic hypertension specialists to collaborate with like-minded individuals and organizations. The collaboration among the ASH Carolinas-Georgia chapter, the Hypertension Initiative, and the Community Physicians' Network provides a model for other ASH chapters and health delivery groups to partner in delivering continuing medical education programs focused on cardiovascular risk factor management, recruiting practices into the network, and developing and maintaining a centralized patient database. Evidence suggests that this collaboration is facilitating application of evidence-based medicine and risk factor control.

Morehouse Community Physicians Network (CPN) hypertension registry: patterns of care and opportunities for targeted medical education.

BACKGROUND: Provider-focused strategies for improving outcomes in hypertension have produced mixed results. Studies suggest that the effectiveness of a chosen strategy increases when it is tailored to the specific situation. The hypertension registry includes data on African-American hypertensives who receive care in community-based primary care settings. We examined the registry to identify patterns of care and opportunities for provider-focused interventions to improve patient outcomes. METHODS AND RESULTS: The registry will include all records of hypertensive patients from 50 community-based primary care practices at full enrollment. Data from nine practices were manually abstracted into an electronic database and analyzed. Seven hundred and ten records were included in this report. Approximately 70% are female, average age 47 +/- 13 years, 5.3% are uninsured, and more than 60% have at least a high school education. Registry patients have multiple co-morbid conditions: 28% are diabetic, 8% have left ventricular hypertrophy, 5% have congestive heart failure, 6.5% have renal insufficiency, 5% have cerebrovascular disease, 3.5% have previous myocardial infarction and 2% have peripheral vascular disease. Among those with diabetes, mean glycosylated hemoglobin was 7.4 +/- 2. Pattern of antihypertensive use showed 43% on diuretics, 28% on calcium channel blockers, 24% on angiotensin converting enzyme inhibitors, 20% on beta blockers and 16% on angiotensin receptor blockers. Overall, 37% were at goal blood pressure and among those with diabetes, only 16% reached goal blood pressure. CONCLUSION: We conclude that the blood pressure control rates of African Americans in the registry trail those of the general population. This provides a unique opportunity to study the underlying factors and design tailored interventions to address this disparity in health outcome.

The Community Physicians' Network (CPN): an academic-community partnership to eliminate healthcare disparities.

INTRODUCTION: Disparities in health care are maintained by three primary factors: 1) patient factors which include multiple risk factors and comorbidities; 2) healthcare practitioner factors comprising inconsistent application of practice guidelines due to a limited database of clinical trials of effective therapies in African Americans and other underrepresented minorities; and 3) barriers in the healthcare delivery system resulting in poor access to care. The Morehouse School of Medicine Community Physicians' Network (CPN) was established to address disparities in health care by focusing on provider-specific strategies. OBJECTIVES: To: 1) use disease-specific registries to identify treatment gaps and facilitate quality improvement processes among CPN practices; 2) develop practice-specific and guideline-based educational messages to promote quality care; 3) engage and train CPN-physicians for participation in approved NIH, other government, and industry-supported clinical protocols; and 4) develop a data repository of all CPN-sponsored clinical trials that include significant numbers of African Americans and other underrepresented minorities. METHODS: The disease-specific outpatient registries will have the following features: 1) data structures and data elements will use standard database codes and a data dictionary; 2) HIPPA-compliant data abstraction and data transfer tool; 3) baseline chart review to establish practice patterns and provide practice-specific feedback; 4) annual update of registry; 5) data registry and repository maintained on Morehouse School of Medicine's secure servers; 6) registry publications will include only aggregate data, without identification of contributing practices; 7) an electronic medical records platform will be encouraged as the ultimate data management tool for CPN practices. In addition, up to three continuing medical education (CME) programs each year will feature national speakers and promote evidence-based practice guidelines. RESULTS: Eighty-five primary care and subspecialty practices are actively enrolled in CPN with a total of 385,000 annual outpatient visits. The makeup of insurance status is: HMO/PPO (45%); Medicare only (19%); Medicare HMO (11%); Medicare plus (8%); Medicaid (6%); Uninsured (11%). CONCLUSIONS: The Community Physicians' Network will address specific gaps in the health care of African-American and other minority patients by promoting quality care among its members and by facilitating participation in approved clinical trial protocols. The unique academic community partnership is consistent with the NIH roadmap goal of eliminating healthcare disparities.

Ultralate referral and presentation for renal replacement therapy: socioeconomic implications.

BACKGROUND: Clinical and metabolic complications of late referral (LR) for dialysis therapy have been well documented, but there is a paucity of data on its socioeconomic implications. This study examines the role of lifestyle and socioeconomic status on referral pattern. METHODS: During a 4-year period (1999 to 2002), we retrospectively reviewed records of all patients who initiated dialysis therapy at an urban tertiary-care center. Patients were classified into 3 categories according to the interval between first contact with a nephrologist and initiation of dialysis therapy: contact time of 3 months or longer indicates early referral (ER); 1 to less than 3 months, LR; and less than 1 month, ultralate referral (ULR). RESULTS: Of 460 patients (97% African Americans, 3% Hispanics), 212 patients (46%) were ULR, 168 patients (37%) were LR, and 80 patients (17%) were ER. Compared with ER and LR patients, those with ULR had significantly (P < 0.0001) lower hematocrits (23% versus 29% and 27%), serum albumin levels (3.1 versus 3.3 and 3.2 g/dL [31 versus 33 and 32 g/L]), and glomerular filtration rates (5 versus 8 and 7 mL/min/1.73 m2 [0.08 versus 0.13 and 0.12 mL/s/1.73 m2]), but greater rates of temporary dialysis catheter use (92% versus 39% and 70%) and mortality (40% versus 15% and 26%, respectively). Logistic regression analysis showed an association between mortality and homelessness (odds ratio, 3.8; P < 0.0001), polysubstance abuse (odds ratio, 2.3; P = 0.013), and alcoholism (odds ratio, 2.2; P = 0.009). Alcoholics (odds ratio, 2.5; P = 0.03), substance abusers (odds ratio, 5.5; P = 0.001), and the homeless/unemployed (odds ratio, 6.0; P = 0.004) were more likely to present as ULR cases. Patient-provided explanations for LR and ULR were denial (45%), unawareness of the presence of chronic kidney disease (30%), and economic difficulties (25%). Denial was more prevalent in LR (52%; P = 0.003) and ULR cases (39%; P = 0.003). CONCLUSION: Poor socioeconomic status is a major contributor to delayed referral. More efforts need to be directed at patient and physician chronic kidney disease educational awareness and improved health care access for inner-city and minority populations.

Ability of troponin T to predict angiographic coronary artery disease in patients with chronic kidney disease.

Association between angiographic coronary artery disease and cardiac troponin T levels has been observed in patients with normal kidney function; however, this association remains unsettled in patients with chronic kidney disease (CKD) or end-stage renal disease (ESRD). Over a 12-month period we retrospectively reviewed coronary angiograms (CAs) performed in 194 hospitalized patients with presumed acute myocardial injury. About 50% of the ESRD and 30% of the CKD patients had normal CAs. Troponin T levels significantly correlated with CAs in patients with normal kidney function (r = 0.4, p = 0.005) but not in ESRD and CKD patients (r = 0.2, p = NS, respectively).

Adequacy and survival of autogenous arteriovenous fistula in African American hemodialysis patients.

In African American hemodialysis patients, the prevalence of autogenous arteriovenous fistula (AVF) use is lower yet AVF complications are higher. However, the adequacy and survival rates of AVF in African American patients have not been clarified. These rates were evaluated in this study. A prospective surveillance of AVF was conducted at the Morehouse School of Medicine affiliated dialysis units. A database was generated to adequately document the dates of AVF creation, cannulation, and failure; anatomic fistula sites; and demographic and pertinent clinical information. A total of 167 AVF were created in 140 African American patients between 1997 and 2001. The mean age of the patients was 56 +/- 14 (21-83) years, and the mean duration of follow-up was 40 +/- 3 (1-200) weeks. Only 92 of 167 (55%) AVF were adequate for cannulation; 12% (20 of 167) failed to mature and 33% (55 of 167) developed early failure. Unassisted primary patency rates at 6 and 12 months were 85% and 61%, respectively. Both fistula adequacy and survival were greater in younger (aged < 65 years), male patients and in nondiabetic patients, but the differences were not significant. Logistic regression analysis showed that advanced age (> or = 65 years), female gender, and diabetic state did not significantly alter AVF adequacy. However, the presence of peripheral vascular disease adversely affected AVF adequacy [Odds Ratio 0.4 (confidence interval 0.2-1.0), p = 0.048]. The adequacy and survival rates of AVF in African Americans are comparable with those reported in other populations. Fistula adequacy and survival appear to be independent of ethnicity but dependent on individual comorbid conditions and the integrity of the vasculature. Discriminant AVF site selection and adequate preoperative assessment of the vasculature remain crucial to AVF survival.

Maintaining patency of tunneled hemodialysis catheters--efficacy of aspirin compared to warfarin.

OBJECTIVE: Tunneled hemodialysis catheters (caths) often fail as a result of luminal obstructive thrombus or formation of a fibrin sheath at the tip. Anecdotal and non-randomized studies have indicated that aspirin (A) and/or warfarin (W) can prolong cath patency. We examined the effect of chronic usage of either A or W on primary cath patency. MATERIAL AND METHODS: A prospective cross-sectional monitoring of cath patency was conducted over a 3-year period. Patients were grouped according to their long-term usage of either A (325 mg daily) or W. Patients on neither medication served as a control (C). The end point of the study occurred at cannulation of the patients' arteriovenous fistulae, when there was development of cath-related bacteremia or when there was inability to maintain a blood flow of 250 ml/min. RESULTS: Sixty-three patients with a mean age of 57 +/- 15 years completed the study. There were 21 patients in the A group, 11 in the W group and 31 in the C group. Cath survival was 91%, 73% and 29% at 120 days for the A, W and C groups, respectively (A vs C, p < 0.0001; W vs C, p < 0.0001; A vs W, p = NS). The mean durations of cath patency were 114 +/- 18, 111 +/- 17 and 68 +/- 37 days for the A, W and C groups, respectively (A vs C, p < 0.0001; W vs C, p < 0.0001; A vs W, p = NS). Gastrointestinal (GI) bleeding complication rates were 24%, 18% and 0% for the A, W and C groups, respectively (A vs C, p = 0.02; W vs C, p = 0.02; A vs W, p = NS). The relative risk of GI bleeding associated with aspirin was 0.71 [95% confidence interval (CI) 0.11-4.4, p = 0.7] but among elderly aspirin users it was 1.14 (CI 1.0-1.3, p = 0.008). CONCLUSION: Both aspirin and warfarin are equally effective at prolonging cath patency but their routine use for failing caths cannot be unequivocally recommended because of the increased risk of GI bleeding. Further prospective and randomized studies are called for.

Nephrotic proteinuria as a result of essential hypertension.

BACKGROUND: The presence of nephrotic-range proteinuria in a nondiabetic hypertensive patient is generally indicative of an underlying glomerular disease. A few published reports have noted nephrotic proteinuria in some patients with hypertensive nephrosclerosis. The frequency of this association is unknown. METHODS: We retrospectively reviewed renal biopsy reports on all cases of nephrotic syndrome over an 8-year period (1993-2000). We excluded all cases of diabetes mellitus, lupus, hepatitis, human immunodeficiency virus, and chronic use of nonsteroidal anti-inflammatory drugs. Biopsy specimens showing glomerular eosinophilic hyalinosis lesions, positive immunofluorescence staining, or dense deposits on electron microscopy were also excluded. Thirteen of the remaining 237 (5.5%) biopsy specimens satisfied the standard histological criteria for hypertensive nephrosclerosis. RESULTS: All patients were African-Americans with a mean age of 47.5 +/- 13 years and an average mean arterial blood pressure of 122 +/- 19 mm Hg. The mean values for urinary protein excretion, serum creatinine, albumin, and cholesterol were 8.9 g/day, 3.3 mg/dl, 3.1 g/dl, and 245 mg/dl, respectively. Optimal blood pressure control required at least three antihypertensive agents. Progression to end-stage renal disease occurred over a mean duration of 8.3 +/- 6.5 months. Multivariate regression showed a strong but nonsignificant association between the level of proteinuria at the time of biopsy, duration of hypertension, and number of blood pressure medications (R(2) = 0.56, p = 0.38). CONCLUSIONS: Nephrotic syndrome may be more common in poorly controlled essential hypertension than previously realized. In African-American patients, the differential diagnosis of nephrotic syndrome should include hypertensive nephrosclerosis, but abrogation of renal biopsy is not implied.