Self-reported Pruritus and Clinical, Dialysis-Related, and Patient-Reported Outcomes in Hemodialysis Patients

RATIONALE & OBJECTIVE

Chronic kidney disease (CKD)-associated pruritus, generalized itching related to CKD, affects many aspects of hemodialysis patients' lives. However, information regarding the relationship between pruritus and several key outcomes in hemodialysis patients remains limited.

STUDY DESIGN

Prospective cohort.

SETTING & PARTICIPANTS

23,264 hemodialysis patients from 21 countries in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 4 to 6 (2009-2018).

EXPOSURE

Pruritus severity, based on self-reported degree to which patients were bothered by itchy skin (5-category ordinal scale from "not at all" to "extremely").

OUTCOMES

Clinical, dialysis-related, and patient-reported outcomes.

ANALYTICAL APPROACH

Cox regression for time-to-event outcomes and modified Poisson regression for binary outcomes, adjusted for potential confounders.

RESULTS

The proportion of patients at least moderately bothered by pruritus was 37%, and 7% were extremely bothered. Compared with the reference group ("not at all"), the adjusted mortality HR for patients extremely bothered by pruritus was 1.24 (95% CI, 1.08-1.41). Rates of cardiovascular and infection-related deaths and hospitalizations were also higher for patients extremely versus not at all bothered by pruritus (HR range, 1.17-1.44). Patients extremely bothered by pruritus were also more likely to withdraw from dialysis and miss hemodialysis sessions and were less likely to be employed. Strong monotonic associations were observed between pruritus severity and longer recovery time from a hemodialysis session, lower physical and mental quality of life, increased depressive symptoms, and poorer sleep quality.

LIMITATIONS

Residual confounding, recall bias, nonresponse bias.

CONCLUSIONS

Our findings demonstrate how diverse and far-reaching poor outcomes are for patients who experience CKD-associated pruritus, specifically those with more severe pruritus. There is need for change in practice patterns internationally to effectively identify and treat patients with pruritus to reduce symptom burden and improve quality of life and possibly even survival.

Reasons for Underreporting of Uremic Pruritus in People With Chronic Kidney Disease: A Qualitative Study

CONTEXT

Uremic pruritus, or itch, is common in people with chronic kidney disease (CKD) and has a negative impact on their lives and well-being. However, for reasons currently unknown, itch often remains unreported and therefore untreated.

OBJECTIVES

To explore reasons for underreporting of itch to provide pointers for improving itch reporting and management in people with CKD.

METHODS

We interviewed adult patients with CKD who self-reported experiencing itching in the last three years (n = 25), nephrologists (n = 10), and nurses (n = 12) from three kidney services in the U.K. Topic guides were informed by previous studies and a theoretical model of self-regulation. We conducted a thematic analysis of verbatim transcripts using framework analysis.

RESULTS

We identified the following three main themes reflecting factors that may influence whether itch is reported: knowledge on causes and treatment of itch (lack of awareness of the relationship between itch and CKD, and lack of knowledge of treatment options); attitudes toward importance of itch as a health issue (patients' and clinicians' attitudes); and prompts for itch assessment during consultations (routine practice, itch as a marker, and itch severity).

CONCLUSION

Underreporting of itch is related to patients being unaware of its causes, accepting it as something to live with, prioritizing other health issues, and the length and timing of consultations. Health care professionals' assessment and management of itch vary widely and are not necessarily evidence-based. Better patient information, development of clinical practice guidelines, and incorporation of routine symptom assessments into care may improve itch reporting and management in people with CKD.

Pruritus and Patient Reported Outcomes in Non-Dialysis CKD

BACKGROUND AND OBJECTIVES

Among patients on hemodialysis, pruritus has been associated with poorer mental and physical quality of life, sleep quality, depression, and mortality. We evaluated patients with nondialysis CKD to describe the prevalence of pruritus, identify associated factors, and investigate associations with patient-reported outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using cross-sectional data from patient questionnaires in the CKD Outcomes and Practice Patterns Study (CKDopps), we asked patients with CKD stages 3-5 (nondialysis) from the United States, Brazil, and France to identify how much they were bothered by pruritus. Response options ranged from "not at all" to "extremely." Log-Poisson regression, yielding prevalence ratios, was used to evaluate associations of moderate-to-extreme pruritus with patient characteristics, CKD stage, self-reported depression symptoms, and restless sleep. Mixed linear regression was used to examine associations between pruritus and physical and mental component summary scores, with lower scores indicating poorer quality of life.

RESULTS

Of the 5658 CKDopps patients enrolled in the United States, Brazil, and France, 3780 (67%) answered the pruritus question. The prevalence of moderate-to-extreme pruritus was 24%, and more likely in older patients, women, and those with stage 5 CKD, lung disease, diabetes, and physician-diagnosed depression. In adjusted models, patients with moderate pruritus had physical and mental component summary scores 3.5 (95% confidence interval [95% CI], -4.6 to -2.3) and 2.3 (95% CI, -3.2 to -1.5) points lower, respectively, than patients without pruritus, and they also had a higher adjusted prevalence of patient-reported depression (prevalence ratio, 1.83; 95% CI, 1.58 to 2.11) and restless sleep (prevalence ratio, 1.69; 95% CI, 1.49 to 1.91) compared with patients without pruritus. These patient-reported outcomes were progressively worse with increasing severity of pruritus.

CONCLUSIONS

Our findings demonstrate high prevalence of pruritus in nondialysis CKD, as well as strong associations of pruritus with poor health-related quality of life, self-reported depression symptoms, and self-reported poor sleep.

Mortality risk in patients on hemodiafiltration versus hemodialysis: a 'real-world' comparison from the DOPPS

Background

With its convective component, hemodiafiltration (HDF) provides better middle molecule clearance compared with hemodialysis (HD) and is postulated to improve survival. A previous analysis of Dialysis Outcomes and Practice Patterns Study (DOPPS) data in 1998-2001 found lower mortality rates for high replacement fluid volume HDF versus HD. Randomized controlled trials have not shown uniform survival advantage for HDF; in secondary (non-randomized) analyses, better outcomes were observed in patients receiving the highest convection volumes.

Methods

In a 'real-world' setting, we analyzed patients on dialysis >90 days from seven European countries in DOPPS Phases 4 and 5 (2009-15). Adjusted Cox regression was used to study HDF (versus HD) and mortality, overall and by replacement fluid volume.

Results

Among 8567 eligible patients, 2012 (23%) were on HDF, ranging from 42% in Sweden to 12% in Germany. Median follow-up was 1.5 years during which 1988 patients died. The adjusted mortality hazard ratio (95% confidence interval) was 1.14 (1.00-1.29) for any HDF versus HD and 1.08 (0.92-1.28) for HDF >20 L replacement fluid volume versus HD. Similar results were found for cardiovascular and infection-related mortality. In an additional analysis aiming to avoid treatment-by-indication bias, we did not observe lower mortality rates in facilities using more HDF (versus HD).

Conclusions

Our results do not support the notion that HDF provides superior patient survival. Further trials designed to test the effect of high-volume HDF (versus lower volume HDF versus HD) on clinical outcomes are needed to adequately inform clinical practices.

International Comparisons of Prevalence, Awareness, and Treatment of Pruritus in People on Hemodialysis

BACKGROUND AND OBJECTIVES

Uremic pruritus in patients on hemodialysis is associated with depression, lower quality of life, and mortality. We studied the prevalence, awareness, and treatment of pruritus to assess how well this important condition is currently managed internationally.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from 35,452 patients on hemodialysis in up to 17 countries from the Dialysis Outcomes and Practice Patterns Study were analyzed to describe pruritus prevalence from 1996 to 2015. Data from 6256 patients and 268 medical directors in 17 countries in 2012-2015 were analyzed to describe predictors, effects, medical directors' awareness, and treatment of pruritus.

RESULTS

Patients very much or extremely bothered by itching declined from 28% in 1996 to 18% in 2015. In 2012-2015, among patients nearly always or always bothered by itching, pruritus had a major effect on work and social life; 18% used no treatment for pruritus, and 17% did not report itching to health care staff. In total, 69% of medical directors underestimated the prevalence of pruritus in their unit. Managing high serum phosphorus and low Kt/V was ranked as the most important intervention, but no relationship was found between these factors and pruritus; 57% of medical directors used oral antihistamines for first-line chronic treatment of pruritus. Gabapentin was used by 45% as first-, second-, or third-line treatment. Nalfurafine was only used in Japan.

CONCLUSIONS

The prevalence of pruritus in people on hemodialysis is decreasing but remains underestimated. Large numbers of patients on hemodialysis with severe pruritus do not receive treatment. There is wide variation in the use of unlicensed medications for the treatment of pruritus. These data provide a benchmark for initiatives to improve the management of uremic pruritus.

MULTIMEDIA

This article contains multimedia at https://vimeo.com/49458473This article contains multimedia at vimeo.com/49455976.

Association between changes in quality of life and mortality in hemodialysis patients: results from the DOPPS

Background

Cross-sectional health-related quality of life (HR-QOL) measures are associated with mortality in hemodialysis (HD) patients. The impact of changes in HR-QOL on outcomes remains unclear. We describe the association of prior changes in HR-QOL with subsequent mortality among HD patients.

Methods

A total of 13 784 patients in the Dialysis Outcomes and Practice Patterns Study had more than one measurement of HR-QOL. The impact of changes between two measurements of the physical (PCS) and mental (MCS) component summary scores of the SF-12 on mortality was estimated with Cox regression.

Results

Mean age was 62 years (standard deviation: 14 years); 59% were male and 32% diabetic. Median time between HR-QOL measurements was 12 months [interquartile range (IQR): 11, 14]. Median initial PCS and MCS scores were 37.5 (IQR: 29.4, 46.2) and 46.4 (IQR: 37.2, 54.9); median changes in PCS and MCS scores were -0.2 (IQR: -5.5, 4.7) and -0.1 (IQR: -6.8, 5.9), respectively. The adjusted hazard ratio (HR) for a 5-point decline in HR-QOL score was 1.09 [95% confidence interval (CI): 1.06-1.12] for PCS and 1.05 (95% CI: 1.03-1.08) for MCS. Adjusting for the second QOL score, the change was not associated with mortality: HR = 1.01 (95% CI: 0.98-1.05) for delta PCS and 1.01 (95% CI: 0.98-1.03) for delta MCS. Categorizing the first and second scores as predictors, only the second PCS or MCS score was associated with mortality.

Conclusions

In our study, only the most recent HR-QOL score was associated with mortality. Hence, the predictive power of a measurement of HR-QOL is not affected by changes in HR-QOL prior to that measurement; more frequent HR-QOL measurements are needed to improve the prediction of outcomes in HD. Further studies are needed to determine the optimal frequency and appropriate instrument to be used for serial measurements.

A programme to spread eGFR graph surveillance for the early identification, support and treatment of people with progressive chronic kidney disease (ASSIST-CKD): protocol for the stepped wedge implementation and evaluation of an intervention to reduce late presentation for renal replacement therapy

Background

Patients who start renal replacement therapy (RRT) for End-Stage Kidney Disease (ESKD) without having had timely access to specialist renal services have poor outcomes. At one NHS Trust in England, a community-wide CKD management system has led to a decline in the incident rate of RRT and the lowest percentage of patients presenting within 90 days of starting RRT in the UK. We describe the protocol for a quality improvement project to scale up and evaluate this innovation.

Methods

The intervention is based upon an off-line database that integrates laboratory results from blood samples taken in all settings stored under different identifying labels relating to the same patient. Graphs of estimated glomerular filtration rate (eGFR) over time are generated for patients <65 years with an incoming eGFR <50 ml/min/1.73 m² and patients >65 years with an incoming eGFR <40 ml/min/1.73 m². Graphs where kidney function is deteriorating are flagged by a laboratory scientist and details sent to the primary care doctor (GP) with a prompt that further action may be needed.

We will evaluate the impact of implementing this intervention across a large population served by a number of UK renal centres using a mixed methods approach. We are following a stepped-wedge design. The order of implementation among participating centres will be randomly allocated. Implementation will proceed with unidirectional steps from control group to intervention group until all centres are generating graphs of eGFR over time.

The primary outcome for the quantitative evaluation is the proportion of patients referred to specialist renal services within 90 days of commencing RRT, using data collected routinely by the UK Renal Registry. The qualitative evaluation will investigate facilitators and barriers to adoption and spread of the intervention. It will include: semi-structured interviews with laboratory staff, renal centre staff and service commissioners; an online survey of GPs receiving the intervention; and focus groups of primary care staff.

Discussion

Late presentation to nephrology for patients with ESKD is a source of potentially avoidable harm. This protocol describes a robust quantitative and qualitative evaluation of a quality improvement intervention to reduce late presentation and improve the outcomes for patients with ESKD.

Associations of self-reported physical activity types and levels with quality of life, depression symptoms, and mortality in hemodialysis patients: the DOPPS

BACKGROUND AND OBJECTIVES

Physical activity has been associated with better health status in diverse populations, but the association in patients on maintenance hemodialysis is less established. Patient-reported physical activities and associations with mortality, health-related quality of life, and depression symptoms in patients on maintenance hemodialysis in 12 countries were examined.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In total, 5763 patients enrolled in phase 4 of the Dialysis Outcomes and Practice Patterns Study (2009-2011) were classified into five aerobic physical activity categories (never/rarely active to very active) and by muscle strength/flexibility activity using the Rapid Assessment of Physical Activity questionnaire. The Kidney Disease Quality of Life scale was used for health-related quality of life. The Center for Epidemiologic Studies Depression scale was used for depression symptoms. Linear regression was used for associations of physical activity with health-related quality of life and depression symptoms scores. Cox regression was used for association of physical activity with mortality.

RESULTS

The median (interquartile range) of follow-up was 1.6 (0.9-2.5) years; 29% of patients were classified as never/rarely active, 20% of patients were classified as very active, and 20.5% of patients reported strength/flexibility activities. Percentages of very active patients were greater in clinics offering exercise programs. Aerobic activity, but not strength/flexibility activity, was associated positively with health-related quality of life and inversely with depression symptoms and mortality (adjusted hazard ratio of death for very active versus never/rarely active, 0.60; 95% confidence interval, 0.47 to 0.77). Similar associations with aerobic activity were observed in strata of age, sex, time on dialysis, and diabetes status.

CONCLUSIONS

The findings are consistent with the health benefits of aerobic physical activity for patients on maintenance hemodialysis. Greater physical activity was observed in facilities providing exercise programs, suggesting a possible opportunity for improving patient outcomes.

Recovery time, quality of life, and mortality in hemodialysis patients: the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND

There is limited information about the clinical and prognostic significance of patient-reported recovery time.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

6,040 patients in the DOPPS (Dialysis Outcomes and Practice Patterns Study).

PREDICTOR

Answer to question "How long does it take you to recover from a dialysis session?" categorized as follows: fewer than 2, 2-6, 7-12, or longer than 12 hours.

OUTCOMES & MEASUREMENTS

Cross-sectional and longitudinal associations between recovery time and patient characteristics, hemodialysis treatment variables, health-related quality of life (HRQoL), and hospitalization and mortality.

RESULTS

32% reported recovery time shorter than 2 hours; 41%, 2-6 hours; 17%, 7-12 hours; and 10%, longer than 12 hours. Using proportional odds (ordinal) logistic regression, shorter recovery time was associated with male sex, full-time employment, and higher serum albumin level. Longer recovery time was associated with older age, dialysis vintage, body mass index, diabetes, and psychiatric disorder. Greater intradialytic weight loss, longer dialysis session length, and lower dialysate sodium concentration were associated with longer recovery time. In facilities that used uniform dialysate sodium concentrations for ≥90% of patients, the adjusted OR of longer recovery time, comparing dialysate sodium concentration<140 vs 140 mEq/L, was 1.72 (95% CI, 1.37-2.16). Recovery time was correlated positively with symptoms of kidney failure and kidney disease burden score and inversely with HRQoL mental and physical component summary scores. Using Cox regression, adjusting for potential confounders not influenced by recovery time, it was associated positively with first hospitalization and mortality (adjusted HRs for recovery time>12 vs 2-6 hours 1.22 [95% CI, 1.09-1.37] and 1.47 [95% CI, 1.19-1.83], respectively).

LIMITATIONS

Answers are subjective and not supported by physiologic measurements.

CONCLUSIONS

Recovery time can be used to identify patients with poorer HRQoL and higher risks of hospitalization and mortality. Interventions to reduce recovery time and possibly improve clinical outcomes, such as increasing dialysate sodium concentration, need to be tested in randomized trials.

Associations of frequency and duration of patient-doctor contact in hemodialysis facilities with mortality

It is unknown whether regular patient-doctor contact (PDC) contributes to better outcomes for patients undergoing hemodialysis. Here, we analyzed the associations between frequency and duration of PDC during hemodialysis treatments with clinical outcomes among 24,498 patients from 778 facilities in the international Dialysis Outcomes and Practice Patterns Study (DOPPS). The typical facility PDC frequency, estimated by facility personnel, was high (more than once per week) for 55% of facilities, intermediate (once per week) for 24%, and low (less than once per week) for 21%. The mean ± SD estimated duration of a typical interaction between patient and physician was 7.7 ± 5.6 minutes. PDC frequency and duration varied across DOPPS phases and countries; the proportion of facilities with high PDC frequency was 17% in the United States and 73% across the other countries. Compared with high PDC frequency, the adjusted hazard ratio (HR) for all-cause mortality was 1.06 (95% confidence interval [CI], 0.96 to 1.17) for intermediate PDC frequency and 1.11 (95% CI, 1.01 to 1.23) for low PDC frequency (P=0.03 for trend). Furthermore, each 5-minutes-shorter duration of PDC was associated with a 5% higher risk for death, on average (HR, 1.05; 95% CI, 1.01 to 1.09), adjusted for PDC frequency and other covariates. Multivariable analyses also suggested modest inverse associations between both PDC frequency and duration with hospitalization but not with kidney transplantation. Taken together, these results suggest that policies supporting more frequent and longer duration of PDC may improve patient outcomes in hemodialysis.

Systematic kidney disease management in a population with diabetes mellitus: turning the tide of kidney failure

PROBLEM

A significant proportion of patients with diabetes mellitus do not get the benefit of treatment that would reduce their risk of progressive kidney disease and reach a nephrologist once significant loss of kidney function has already occurred.

DESIGN

Systematic disease management of patients with diabetes and kidney disease.

SETTING

Diverse population (approximately 800,000) in and around Birmingham, West Midlands, UK.

KEY MEASURES FOR IMPROVEMENT

Number of outpatient appointments, estimated glomerular filtration rate (eGFR) at first contact with nephrologist, number of patients starting kidney replacement therapy (KRT) and mode of KRT at start.

STRATEGY FOR CHANGE

Identification of patients with low or deteriorating trend in eGFR from weekly database review, specialist diabetes-kidney clinic, self-management of blood pressure and transfer to multidisciplinary clinic >12 months before end-stage kidney disease.

EFFECTS OF CHANGE

New patients increased from 62 in 2003 to 132 in 2010; follow-ups fell from 251 to 174. Median eGFR at first clinic visit increased from 28.8 ml/min/1.73 m(2) (range 6.1-67.0) in 2000/2001 to 35.0 (11.1-147.5) in 2010 (p<0.006). In 2010, the number of patients starting KRT fell 30% below the projected activity using 1993-2003 data as baseline (p<0.003). The proportion starting KRT with either a kidney transplant, peritoneal dialysis or haemodialysis via an arteriovenous fistula increased from 26% in 2000 to 55% in 2010.

LESSONS LEARNED

Systematic disease management across a large population significantly improves patient outcomes, increases the productivity of a specialist service and could reduce healthcare costs compared with the current model of care.

Facility hemodialysis vascular access use and mortality in countries participating in DOPPS: an instrumental variable analysis

BACKGROUND

Previously, the Dialysis Outcomes and Practice Patterns Study (DOPPS) has shown large international variations in vascular access practice. Greater mortality risks have been seen for hemodialysis (HD) patients dialyzing with a catheter or graft versus a native arteriovenous fistula (AVF). To further understand the relationship between vascular access practice and outcomes, we have applied practice-based analyses (using an instrumental variable approach) to decrease the treatment-by-indication bias of prior patient-level analyses.

STUDY DESIGN

A prospective observational study of HD practices.

SETTING & PARTICIPANTS

Data collected from 1996 to 2004 from 28,196 HD patients from more than 300 dialysis units participating in the DOPPS in 12 countries.

PREDICTOR OR FACTOR

Patient-level or case-mix-adjusted facility-level vascular access use. OUTCOMES/MEASUREMENTS: Mortality and hospitalization risks.

RESULTS

After adjusting for demographics, comorbid conditions, and laboratory values, greater mortality risk was seen for patients using a catheter (relative risk, 1.32; 95% confidence interval, 1.22 to 1.42; P < 0.001) or graft (relative risk, 1.15; 95% confidence interval, 1.06 to 1.25; P < 0.001) versus an AVF. Every 20% greater case-mix-adjusted catheter use within a facility was associated with 20% greater mortality risk (versus facility AVF use, P < 0.001); and every 20% greater facility graft use was associated with 9% greater mortality risk (P < 0.001). Greater facility catheter and graft use were both associated with greater all-cause and infection-related hospitalization. Catheter and graft use were greater in the United States than in Japan and many European countries. More than half the 36% to 43% greater case-mix-adjusted mortality risk for HD patients in the United States versus the 5 European countries from the DOPPS I and II was attributable to differences in vascular access practice, even after adjusting for other HD practices. Vascular access practice differences accounted for nearly 30% of the greater US mortality compared with Japan.

LIMITATIONS

Possible existence of unmeasured facility- and patient-level confounders that could impact the relationship of vascular access use with outcomes.

CONCLUSIONS

Facility-based analyses diminish treatment-by-indication bias and suggest that less catheter and graft use improves patient survival.

A fresh start for hospital IT systems?

The Health Informatics Report published by the Department of Health in July this year admits that delivering electronic care record systems in hospitals ‘has not progressed as quickly as people would wish’. It recognizes that ‘there is a need for interim initiatives so patient information can be made available across different IT systems, different care providers and different care settings ahead of strategic systems’ (Department of Health, 2008). With local development no longer held back in anticipation of the ‘strategic systems’, where should IT developers and clinicians focus their collective efforts?

Travel time to dialysis as a predictor of health-related quality of life, adherence, and mortality: the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND

Longer travel time to the dialysis unit creates a substantial burden for many patients. This study evaluated the effect of self-reported 1-way travel time to hemodialysis on mortality, health-related quality of life (HR-QOL), adherence, withdrawal from dialysis therapy, hospitalization, and transplantation.

STUDY DESIGN

Prospective observational cohort.

SETTING & PARTICIPANTS

Patients enrolled in the Dialysis Outcomes and Practices Patterns Study who completed a patient questionnaire (n = 20,994).

PREDICTOR

One-way travel time to hemodialysis treatment, categorized as 15 or less, 16 to 30, 31 to 60, and longer than 60 minutes. Covariates included demographics, comorbid conditions, serum albumin level, time on dialysis therapy, and country.

OUTCOME & MEASUREMENT

HR-QOL was examined by using a linear mixed model. Cox proportional hazards regression was used to examine associations with mortality, withdrawal from dialysis therapy, hospitalization, and transplantation.

RESULTS

Longer travel time was associated with greater adjusted relative risk (RR) of death (P = 0.05 for overall trend). Adjusted HR-QOL subscales were significantly lower for those with longer travel times compared with those traveling 15 minutes or less. There were no associations of travel time with withdrawal from dialysis therapy (P = 0.6), hospitalization (P = 0.4), or transplantation (P = 0.7).

LIMITATIONS

The questionnaire nonresponse rate was substantial, and nonresponders were older, with more comorbid conditions. Travel time was assessed by using a single nonvalidated question.

CONCLUSIONS

Longer travel time is associated significantly with greater mortality risk and decreased HR-QOL. Exploring opportunities to decrease travel time should be incorporated into the dialysis clinical routine.

Sleep quality predicts quality of life and mortality risk in haemodialysis patients: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND

Poor sleep quality (SQ) affects many haemodialysis (HD) patients and could potentially predict their morbidity, mortality, quality of life (QOL) and patterns of medication use.

METHODS

Data on SQ were collected from 11,351 patients in 308 dialysis units in seven countries in the Dialysis Outcomes and Practice Patterns Study (DOPPS) between 1996 and 2001 through a patient self-reported SQ scale, ranging from 0 (worst) to 10 (best). A score of <6 reflected poor SQ. Sleep disturbance was also assessed by self-reported daytime sleepiness, feeling drained and nocturnal awakening. Logistic and multiple linear regression were used to assess predictors of SQ and associations with QOL. Cox regression examined associations with mortality. Analyses accounted for case-mix, facility clustering and country.

RESULTS

Nearly half (49%) of patients experienced poor SQ. Mean SQ scores varied by country, ranging from 4.9 in Germany to 6.5 in Japan. Patients with poor SQ were more likely to be prescribed antihistamines, antidepressants, anti-inflammatories, narcotics, gastrointestinal (GI) medications, anti-asthmatics or hypnotics. Physical exercise at least once a week (vs < once a week) was associated with lower odds of poor SQ (AOR = 0.55-0.85, P < 0.05). Poorer SQ was associated with significantly lower mental and physical component summary (MCS/PCS) scores (MCS scores 1.9-13.2 points lower and PCS scores 1.5-7.7 points lower when SQ scores were <10 vs 10). The RR of mortality was 16% higher for HD patients with poor SQ.

CONCLUSIONS

Poor SQ is common among HD patients in DOPPS countries and is independently associated with several QOL indices, medication use patterns and mortality. Assessment and management of SQ should be an important component of care.

Starting and withdrawing haemodialysis--associations between nephrologists' opinions, patient characteristics and practice patterns (data from the Dialysis Outcomes and Practice Patterns Study)

BACKGROUND

The incidence and prevalence of haemodialysis vary widely across countries. The variation may be attributable to differences in the incidence of end-stage renal disease and/or in the availability of haemodialysis. Previous studies have identified differences in nephrologists' opinions about the availability of haemodialysis and its appropriateness for patients with comorbidities. We studied the associations between nephrologists' opinions, availability of haemodialysis, patient characteristics and comorbidities, and facilities' withdrawal rates.

METHODS

Most of our analyses used data from 242 haemodialysis units in six countries (France, Germany, Italy, Spain, UK and the USA) in the first phase of the Dialysis Outcomes and Practice Patterns Study (DOPPS I). Opinions about access to and practice patterns in dialysis facilities, measured by the level of agreement with standardized statements, were collected from medical directors and nurse managers. A sub-analysis considered data from corresponding facilities in DOPPS II.

RESULTS

We found wide variations in the prevalence of waiting lists for new dialysis patients (UK 60%; USA 25%; Germany 0%; P < 0.05), in agreement with starting haemodialysis for patients with advanced age, dementia and comorbidities (UK, France < USA < other countries; P < 0.05), and in agreement with withdrawing dialysis (other countries < UK/USA; P < 0.05). The estimated glomerular filtration rate at the start of dialysis was not significantly different in units with waiting lists. Significant associations were found between nephrologists' opinions and the odds of patients being > or =80 years old, and between opinions and the rate and relative risk of withdrawal of haemodialysis. No significant associations were found between opinions and patients' comorbidities or dependency.

CONCLUSION

Differences within and across countries in nephrologists' opinions regarding starting and withdrawing haemodialysis reflect differences in access to haemodialysis and the practice of withdrawal of haemodialysis in their facilities.

Severe acute renal failure in adults: place of care, incidence and outcomes

BACKGROUND

Department of Health guidelines recommend specialist critical care facilities for patients with severe single-organ failure such as acute renal failure (ARF). Prospective studies examining incidence, causes and outcomes of ARF outside of intensive care settings are lacking.

AIM

To determine the incidence, causes, place of care and outcomes of severe single-organ ARF.

DESIGN

Prospective observational study.

METHODS

For 6 weeks in June-July 2003, renal physicians were contacted daily, and ICUs on alternate days, to identify cases of severe single-organ ARF in the Greater Manchester area. All patients with serum creatinine >or=500 micromol/l and not requiring other organ support were included. Patients with end-stage renal disease were excluded. Survivors were followed up at 90 days and 1 year from admission. Two independent consultant nephrologists assessed each case using anonymized summaries.

RESULTS

Eighty-five patients had multi-organ ARF and 28 had severe single-organ ARF (380 and 125 pmp/year, respectively). Of those with single-organ ARF, 10 (36%) had known pre-existing chronic kidney disease. Renal replacement therapy (RRT) was required in 15 (54%). Total bed occupancy on ICUs relating to single-organ ARF was 59 days (range per patient 1-21). At 90 days, 18 (64%) were alive, and 17 (94%) had independent renal function. At 1 year, 4/18 had died, none receiving RRT at the time of death. Survivors all had independent renal function. In 13 (46%) cases there was an unacceptable delay in patient transfer and in 7 (25%), delays in assessment or commencement of RRT may have adversely affected patient outcome.

DISCUSSION

The incidence of ARF treated with RRT is rising. Delays in transfer to renal services may result in inappropriate ICU bed use, and may adversely affect patient outcomes. There are serious problems regarding the appropriate use of expensive and limited medical resources in the critical care area, and in providing safe and effective treatment of patients with ARF.

HMG-coenzyme a reductase inhibitor use is associated with mortality reduction in hemodialysis patients

BACKGROUND

Cardiovascular disease is the most common cause of mortality in patients with end-stage renal disease. Cardiovascular benefits of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have been clearly established in the general population, but not in dialysis patients. This study examined statin prescription patterns and assessed the relationship between statin prescription and clinical outcomes in hemodialysis (HD) patients.

METHODS

Data were analyzed from the Dialysis Outcomes and Practice Patterns Study, a prospective observational study of HD patients randomly selected from representative dialysis facilities in France, Germany, Italy, Spain, the United Kingdom, Japan, and the United States. Predictors of statin prescription were investigated by means of logistic regression. Cox regression models tested the association between statin prescription and risk for mortality and cardiac events, with adjustments for common demographic factors and comorbid conditions.

RESULTS

Statins were prescribed for 11.8% of HD patients overall. Most facilities (81.2%) prescribed statins to less than 20% of their patients. Patients prescribed statins had a 31% lower relative risk for death compared with those not prescribed statins (P < 0.0001). Statins were associated with a 23% lower cardiac mortality risk (P = 0.03) and a 44% lower noncardiac mortality risk (P < 0.0001). At a facility level, prescribing statins was associated with lower overall mortality rate, with a 5% lower risk for every 10% increase in number of patients prescribed statins within the facility (P = 0.02).

CONCLUSION

Statin prescription is associated with reduced mortality in HD patients, providing additional support for the value of statin therapy in this patient group.

Patterns of hepatitis C prevalence and seroconversion in hemodialysis units from three continents: the DOPPS

BACKGROUND

Hepatitis C virus (HCV) remains a problem within hemodialysis units. This study measures HCV prevalence and seroconversion rates across seven countries and investigates associations with facility-level practice patterns.

METHODS

The study sample was from the Dialysis Outcomes and Practice Patterns Study (DOPPS), a prospective, observational study of adult hemodialysis patients randomly selected from 308 representative dialysis facilities in France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States. Logistic regression was used to model odds of HCV prevalence, and Cox regression was used to model time from study entry to HCV seroconversion.

RESULTS

Mean HCV facility prevalence was 13.5% and varied among countries from 2.6% to 22.9%. Increased HCV prevalence was associated with longer time on dialysis, male gender, black race, diabetes, hepatitis B (HBV) infection, prior renal transplant, and alcohol or substance abuse in the previous 12 months. Approximately half of the facilities (55.6%) had no seroconversions during the study period. HCV seroconversion was associated with longer time on dialysis, human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), HBV infection, and recurrent cellulitis or gangrene. An increase in highly trained staff was associated with lower HCV prevalence (OR = 0.93 per 10% increase, P= 0.003) and risk of seroconversion (RR = 0.92, P= 0.07). Seroconversion was associated with an increase in facility HCV prevalence (RR = 1.36, P < 0.0001), but not with isolation of HCV-infected patients (RR = 1.01, P= 0.99).

CONCLUSION

There are differences in HCV prevalence and rate of seroconversion at the country and the hemodialysis facility level. The observed variation suggests opportunities for improved HCV outcomes.

Vascular access results from the Dialysis Outcomes and Practice Patterns Study (DOPPS): performance against Kidney Disease Outcomes Quality Initiative (K/DOQI) Clinical Practice Guidelines

BACKGROUND

The Kidney Disease Outcomes Quality Initiative Guidelines for Vascular Access in hemodialysis patients recommend native arteriovenous (AV) fistulae over AV grafts or catheters for permanent vascular access. They recommend letting fistulae mature > or =1 month before cannulation.

METHODS

The Dialysis Outcomes and Practice Patterns Study (DOPPS) provides an unparalleled means to examine vascular access practice patterns and guidelines internationally, with particular attention to associations with mortality risk.

RESULTS

Most patients in Europe and Japan dialyze through AV fistulae and very few use AV grafts; in the United States, more patients use grafts than fistulae. Patients who receive nephrologic care for over 30 days before starting dialysis have significantly higher chances of commencing via AV fistula. Medical directors of dialysis facilities in the United States commonly prefer grafts; in Europe and Japan, most prefer fistulae. In the United States, there is a relatively long average time between fistula creation and cannulation but significantly worse fistula survival than that seen in Europe. Tunneled catheters pose a higher mortality risk than permanent accesses and are associated with increased risk of failure of a subsequent fistula. The percentage of prevalent patients in the DOPPS countries using catheters has increased in recent years. DOPPS data suggest that performance in some countries falls short of practices achieved in other countries. AV fistula use is low in the United States but has been improving. The trend of increasing use of catheters in most countries is discouraging.

CONCLUSION

The DOPPS will continue to monitor practice trends and explore whether greater application of guidelines will lead to fewer access complications and improved longevity for hemodialysis patients.

Association of comorbid conditions and mortality in hemodialysis patients in Europe, Japan, and the United States: the Dialysis Outcomes and Practice Patterns Study (DOPPS)

Mortality rates among hemodialysis patients vary greatly across regions. Representative databases containing extensive profiles of patient characteristics and outcomes are lacking. The Dialysis Outcomes and Practice Patterns Study (DOPPS) is a prospective, observational study of representative samples of hemodialysis patients in France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States (US) that captures extensive data relating to patient characteristics, prescriptions, laboratory values, practice patterns, and outcomes. This report describes the case-mix features and mortality among 16,720 patients followed up to 5 yr. The crude 1-yr mortality rates were 6.6% in Japan, 15.6% in Europe, and 21.7% in the US. After adjusting for age, gender, race, and 25 comorbid conditions, the relative risk (RR) of mortality was 2.84 (P < 0.0001) for Europe compared with Japan (reference group) and was 3.78 (P < 0.0001) for the US compared with Japan. The adjusted RR of mortality for the US versus Europe was 1.33 (P < 0.0001). For most comorbid diseases, prevalence was highest in the US, where the mean age (60.5 +/- 15.5 yr) was also highest. Older age and comorbidities were associated with increased risk of death (except for hypertension, which carried a multivariate RR of mortality of 0.74 [P < 0.0001]). Variability in demographic and comorbid conditions (as identified by dialysis facilities) explains only part of the differences in mortality between dialysis centers, both for comparisons made across continents and within the US. Adjustments for the observed variability will allow study of association between practice patterns and outcomes.

Mortality and hospitalization in haemodialysis patients in five European countries: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND

Mortality and hospitalization rates are reported for nationally representative random samples of haemodialysis patients treated at randomly selected dialysis facilities in five European countries participating in the Dialysis Outcomes and Practice Pattern Study (DOPPS) (France, Germany, Italy, Spain and the UK).

RESULTS

In the UK, 28.1% of haemodialysis patients received prior peritoneal dialysis treatment compared with 4.2-8.3% in other countries. Kidney transplantation rates ranged from 3.3 (per 100 patient years) in Italy to 11.6 in Spain. The relative risk (RR) of mortality, adjusted for age, sex and diabetes status was significantly higher in the UK (RR = 1.39, P = 0.02) compared with Italy (reference) and increased in association with age (RR = 1.60 for every 10 years older, P <0.001), diabetes as cause of end-stage renal disease (ESRD) (RR = 1.55, P < 0.001), male patients <65 years (RR = 1.29, P = 0.02) and peritoneal dialysis in the 12 months prior to starting haemodialysis (RR = 1.72, P = 0.06). Hospitalization for cardiovascular disease was highest in France and Germany (0.40 and 0.43 hospitalizations per patient year, respectively) and lowest in the UK (0.19), although cardiovascular comorbidity was similar in the UK and France. Hospitalization rates for vascular access-related infection ranged from 0.01 hospitalizations per patient year in Italy to 0.08 in the UK, consistent with the higher dialysis catheter use in the UK (25%) vs Italy (5%). Hospitalization risk was significantly higher in France than in other Euro-DOPPS countries and was significantly (P < 0.05) associated with prior peritoneal dialysis therapy, peripheral vascular disease, gastrointestinal bleeding in the prior 12 months, diabetes, cancer, cardiac disease, psychiatric disease and recent onset of ESRD (within 30 days of study entry).

CONCLUSIONS

The large differences in haemodialysis practice and outcomes in the Euro-DOPPS countries suggest opportunities for improvement in patient care.

Haemodialysis prescription, adherence and nutritional indicators in five European countries: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND

The Dialysis Outcomes and Practice Patterns Study (DOPPS) is a prospective, observational study designed to evaluate practice patterns in random samples of haemodialysis facilities and patients across three continents. Participating countries include France, Germany, Italy, Spain and the UK (Euro-DOPPS), Japan and the USA. DOPPS data collection has used the same questionnaires and protocols across all participating countries to assess components of dialysis therapy and outcomes. This study focuses on dialysis prescription, adherence and nutrition among the Euro-DOPPS countries.

METHODS

In each Euro-DOPPS country, patients were selected randomly from 20-21 representative facilities. Simple means and frequencies were calculated to compare relevant data elements to gain insights into differences in therapeutic aspects among nationally representative patients. Participants entering the study within 90 days of beginning dialysis therapy were excluded from these analyses.

RESULTS

Among the five countries, mean delivered dose as measured by normalized urea clearance (Kt/V) varied from 1.28 to 1.50 and was accompanied by differences in dialysis prescription components, including blood flow rates, treatment times, and dialyser membrane and flux characteristics. By country, a nearly 2-fold difference was observed in indicators of patient adherence and management (skipping and shortening dialysis, hyperkalaemia, hyperphosphataemia and high interdialytic weight gain). Indicators of malnutrition varied substantially.

CONCLUSIONS

This study demonstrates differences in the management of haemodialysis patients across Euro-DOPPS and offers opportunities for improving dialysis dose, adherence and nutrition. Correlation of differences in practice patterns at the dialysis unit level with patient outcomes will offer new insights into improving dialysis therapy.

Nonadherence in hemodialysis: associations with mortality, hospitalization, and practice patterns in the DOPPS

BACKGROUND

Nonadherence among hemodialysis patients compromises dialysis delivery, which could influence patient morbidity and mortality. The Dialysis Outcomes and Practice Patterns Study (DOPPS) provides a unique opportunity to review this problem and its determinants on a global level.

METHODS

Nonadherence was studied using data from the DOPPS, an international, observational, prospective hemodialysis study. Patients were considered nonadherent if they skipped one or more sessions per month, shortened one or more sessions by more than 10 minutes per month, had a serum potassium level openface>6.0 mEq/L, a serum phosphate level openface>7.5 mg/dL (>2.4 mmol/L), or interdialytic weight gain (IDWG)>5.7% of body weight. Predictors of nonadherence were identified using logistic regression. Survival analysis used the Cox proportional hazards model adjusting for case-mix.

RESULTS

Skipping treatment was associated with increased mortality [relative risk (RR) = 1.30, P = 0.01], as were excessive IDWG (RR = 1.12, P = 0.047) and high phosphate levels (RR = 1.17, P = 0.001). Skipping also was associated with increased hospitalization (RR = 1.13, P = 0.04), as were high phosphate levels (RR = 1.07, P = 0.05). Larger facility size (per 10 patients) was associated with higher odds ratios (OR) of skipping (OR = 1.03, P = 0.06), shortening (OR = 1.03, P = 0.05), and IDWG (OR = 1.02, P = 0.07). An increased percentage of highly trained staff hours was associated with lower OR of skipping (OR = 0.84 per 10%, P = 0.02); presence of a dietitian was associated with lower OR of excessive IDWG (OR = 0.75, P = 0.08).

CONCLUSION

Nonadherence was associated with increased mortality risk (skipping treatment, excessive IDWG, and high phosphate) and with hospitalization risk (skipping, high phosphate). Certain patient/facility characteristics also were associated with nonadherence.

Creation, cannulation and survival of arteriovenous fistulae: data from the Dialysis Outcomes and Practice Patterns Study

BACKGROUND

An arteriovenous (A-V) fistula is the optimal vascular access for hemodialysis. The National Kidney Foundation Dialysis Outcomes Quality Initiative (DOQI) recommends that fistulae should mature for at least one month before cannulation, but this recommendation is not evidence-based. If fistulae are created prior to ESRD and cannulation is possible earlier without compromising fistula survival, the need for temporary catheters would be reduced.

METHODS

Prospective observational data were analyzed for a random sample (N = 3674) of incident patients at the time of initiating hemodialysis, hemofiltration or hemodiafiltration in 309 facilities in France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States, taking part in the Dialysis Outcomes and Practice Patterns Study (DOPPS).

RESULTS

Although the proportion of patients who had pre-dialysis care by a nephrologist differed little between countries, there were large variations in the proportion of patients who commenced hemodialysis via an A-V fistula, A-V graft or central venous catheter. The usual time interval between referral and creation of A-V fistulae also differed greatly between countries. For new hemodialysis (HD) patients initiating HD with an A-V fistula (N = 894) the following results were observed: (1). median time to first cannulation varied greatly between countries: Japan and Italy (25 and 27 days), Germany (42 days), Spain and France (80 and 86 days), UK and US (96 and 98 days). (2). No association was found between cannulation <or=28 days versus>28 days for patient characteristics of age, gender, and fifteen different classes of patient co-morbid factors. (3). Risk of A-V fistula failure was increased for incident patients who had a prior temporary access [relative risk (RR) = 1.81, P = 0.01] or who were female (RR = 1.52, P = 0.02). (4). Cannulation <or=14 days after creation was associated with a 2.1-fold increased risk of subsequent fistula failure (P = 0.006) compared to fistulae cannulated>14 days. (5) No significant difference in A-V fistula failure was seen for fistulae cannulated in 15 to 28 days compared with 43 to 84 days.

CONCLUSION

Significant differences in clinical practice currently exist between countries regarding the creation of A-V fistulae prior to starting hemodialysis and the timing of initial cannulation. Cannulation within 14 days of creation is associated with reduced long-term fistula survival. Fistulae ideally should be left to mature for at least 14 days before first cannulation.

A comparison of hospital readmission rates between two general physicians with different outpatient review practices

BACKGROUND

There has been a relentless increase in emergency medical admissions in the UK over recent years. Many of these patients suffer with chronic conditions requiring continuing medical attention. We wished to determine whether conventional outpatient clinic follow up after discharge has any impact on the rate of readmission to hospital.

METHODS

Two consultant general physicians with the same patient case-mix but markedly different outpatient follow-up practice were chosen. Of 1203 patients discharged, one consultant saw twice as many patients in the follow-up clinic than the other (Dr A 9.8% v Dr B 19.6%). The readmission rate in the twelve months following discharge was compared in a retrospective analysis of hospital activity data. Due to the specialisation of the admitting system, patients mainly had cardiovascular or cerebrovascular disease or had taken an overdose. Few had respiratory or infectious diseases. Outpatient follow-up was focussed on patients with cardiac disease.

RESULTS

Risk of readmission increased significantly with age and length of stay of the original episode and was less for digestive system and musculo-skeletal disorders. 28.7% of patients discharged by Dr A and 31.5 % of those discharged by Dr B were readmitted at least once. Relative readmission risk was not significantly different between the consultants and there was no difference in the length of stay of readmissions.

CONCLUSIONS

Increasing the proportion of patients with this age- and case-mix who are followed up in a hospital general medical outpatient clinic is unlikely to reduce the demand for acute hospital beds.

Assessment of ultrasound guided percutaneous ethanol injection and parathyroidectomy in patients with tertiary hyperparathyroidism

BACKGROUND

Tertiary hyperparathyroidism continues to cause significant morbidity in patients with chronic renal failure. This is frequently resistant to medical management and may ultimately require a surgical parathyroidectomy. Recent studies have reported upon the technique of percutaneous ethanol ablation for both primary and tertiary hyperparathyroidism. In this study we report on a 5 year experience using ethanol injection and compare the results with surgical parathyroidectomy.

METHODS

A prospective study in 39 patients with tertiary hyperparathyroidism, 25 were dialysis dependent and 14 had a functioning renal allograft. Twenty-two patients underwent percutaneous fine needle ethanol injection (PFNEI) and 17 underwent surgical parathyroidectomy.

RESULTS

A > 30% reduction in intact parathyroid hormone (iPTH) was achieved in 11 of 22 patients undergoing PFNEI after a mean of 1.8 +/- 1.4 injections per gland. In four patients, symptomatic hyperparathyroidism recurred and they required further PFNEI or surgical parathyroidectomy at 17, 28, 46, and 48 months later. There was no significant reduction in iPTH in 11 patients following PFNEI after a mean of 2.5 +/- 1.3 injections per gland. They all required a subsequent surgical parathyroidectomy for symptomatic hyperparathyroidism. Four patients developed a laryngeal nerve palsy following PFNEI, two of which were permanent. Seventeen patients underwent successful surgical parathyroidectomy as a primary procedure.

CONCLUSION

Whilst PFNEI is successful in primary hyperparathyroidism, when typically only one adenoma is present, the effectiveness of PFNEI is unpredictable and the long term results are poor compared with those of surgical parathyroidectomy in tertiary hyperparathyroidism. The procedure is not without complications and makes subsequent surgery more difficult. Therefore it can only be recommended for patients with a known single parathyroid gland such as patients in whom hyperparathyroidism has recurred following a previous surgical subtotal parathyroidectomy and who are unsuitable for further surgery.

Assessment of renal osteodystrophy in dialysis patients: use of bone alkaline phosphatase, bone mineral density and parathyroid ultrasound in comparison with bone histology

Bone biopsies were studied in 73 patients to determine if a two-site radioimmunometric assay for serum bone alkaline phosphatase (BAP), total serum alkaline phosphatase (ALP), serum intact parathyroid hormone (iPTH), hand X-rays, regional bone mineral density (BMD) measurements and parathyroid enlargement detected by ultrasonography could accurately predict renal osteodystrophy. In the patients studied 57 had hyperparathyroid bone disease, 4 mixed renal osteodystrophy, 3 adynamic bone disease, 1 osteomalacia and 8 normal histology. Serum BAP, ALP and iPTH correlated positively with mineral apposition rate, osteoblastic, osteoid and eroded surface. In the diagnosis of hyperparathyroid bone disease serum iPTH was the most sensitive investigation, detecting 81% of patients at a level > 100 pg/ml but with a specificity of only 66%. Serum BAP was more sensitive, 70% at a level of > 10 ng/ml, than serum total ALP, 30% at a level of 300 IU/l, with similar specificities, 92 and 100%, respectively. Ultrasound detection of an enlarged parathyroid gland had a sensitivity of 64% and a specificity of 100% for the diagnosis of hyperparathyroid bone disease. Hand X-rays had a poor sensitivity, 47%, but a high specificity, 92%, for the detection of hyperparathyroid bone disease. The majority of patients had regional BMD values within the normal reference range and this test was of poor discriminatory value. The non-invasive markers were unable to distinguish between patients with low turnover, mild hyperparathyroidism and patients with normal histology. In conclusion the measurement of serum iPTH is a useful screening tool for the detection of hyperparathyroid bone disease which can be confirmed by the finding of a raised serum BAP or parathyroid enlargement. For definitive diagnosis, however, the gold standard remains bone biopsy and at present one cannot recommend any non-invasive method as an adequate substitute.

Effect of cholesterol on the position of segmental lesions in unilaterally nephrectomized rats

Different positions of segmental lesions within glomeruli may correspond to different pathogenetic mechanisms. The effect of a high cholesterol diet on the position of lesions had not previously been investigated. This was studied in rats following unilateral nephrectomy, as a change in position would suggest a different mechanism of damage. Thirty-two female WAG/ola rats had unilateral nephrectomy. Half the rats were given a diet supplemented with 4 per cent cholesterol and 1 per cent cholic acid. At death, six at 10 weeks after nephrectomy and the rest at 24 weeks, kidney sections were examined microscopically. There were significantly more segmental lesions in the cholesterol-fed rats than in the controls, and these lesions were almost entirely at the glomerular hilum in both groups. Significantly more glomeruli contained foamy cells in the cholesterol-fed group, both within lesions and away from them. These findings confirmed that in reduced renal mass, segmental lesions are mainly hilar. The diet increases the number of glomeruli affected by lesions, but these are still mainly hilar. Therefore one possibility is that hypercholesterolaemia worsens the hyperfiltration effect on glomeruli. The diet also produces foamy cells scattered throughout the glomeruli but these do not appear to develop into segmental lesions.

Perspectives in multiple myeloma: survival, prognostic factors and disease complications in a single centre between 1975 and 1988

One hundred and forty-one patients with multiple myeloma, diagnosed at the City Hospital, Nottingham between January 1975 and October 1986, were followed until death or for at least two years in a retrospective study. Overall median survival was 25 months, with no significant improvement occurring during the study period; increasing age, ESR and serum creatinine concentration at diagnosis were independent predictors of shortened survival. Renal impairment developed in 56 per cent of patients but only 7 per cent died of renal failure. At least one episode of infection occurred in 55 per cent of patients, most commonly in the first month. There was a significant rise in the overall incidence of infection and in the proportion caused by Gram-negative bacteria during the study period. Raised serum urea and low haemoglobin concentrations at diagnosis were independent risk factors for subsequent infection. Infection was associated with 2.75-fold increased risk of death, independent of other risk factors. Prevention of infection is an important aim for improvements in the survival of patients in multiple myeloma.

Anthropometry underestimates body protein depletion in haemodialysis patients

The body composition of 62 haemodialysis patients (41 males) and 63 controls (30 males) was assessed using anthropometry and in vivo neutron activation analysis of body nitrogen. There was no significant difference between patients and controls in body mass index (BMI) and percentage body fat. Arm muscle circumference was significantly reduced in males. Lean body mass was strongly correlated with body nitrogen in controls (r = 0.951) but less so in patients (r = 0.876). The mean standardised body nitrogen index (NI) was reduced in male patients by 13% (95% confidence interval -9 to -17%) and in females by 4% (95% confidence interval +4 to -12%). Of the 16 patients with a NI below the control range, arm muscle circumference was below the control range in only 3 and BMI less than 18 kg/m2 in 2. NI was correlated negatively with the duration of renal replacement therapy, duration of haemodialysis, the number of previous failed transplants and the total dose of steroids received but not with current energy or protein intakes. Steroid dose was the only significant independent variable. Anthropometry underestimates body protein depletion in haemodialysis patients and the degree of protein loss is related to the cumulative dose of corticosteroids previously received.

Cholesterol feeding following unilateral nephrectomy in the rat leads to glomerular hypertrophy

Experimental glomerulosclerosis is associated with hyperlipidaemia and the deposition of lipid in glomeruli. Glomerulosclerosis is typically preceded by glomerular hypertrophy. To investigate a possible pathogenic role of lipids in glomerulosclerosis, glomerular structure and cellular composition were studied in rats fed either a control diet or one supplemented with 4% cholesterol and 1% cholic acid for 21 weeks following unilateral nephrectomy. On the cholesterol diet there were significant increases in glomerular cross-sectional area (13.11 +/- 0.39 x 10(3) vs. 11.13 +/- 0.44 x 10(3) mu 2, p less than 0.01) and mesangial area (1.81 +/- 0.07 x 10(3) vs. 1.50 +/- 0.08 x 10(3) mu 2, p less than 0.02). These changes were significantly correlated with proteinuria, which was significantly greater on the cholesterol diet (mean area under curve for duration of diet = 3.11 +/- 0.38 vs. 1.42 +/- 0.35 g, p less than 0.02). There was a significant increase in glomerular leukocytes on the cholesterol diet (4.10 +/- 0.44 vs 2.86 +/- 0.25 OX-1 positive cells/10(4) mu 2, p less than 0.05). Mesangial foam cells, derived from macrophages, were associated with adhesions to Bowman's capsule. These results demonstrate that hyperlipidaemia exacerbates the development of glomerular hypertrophy and that this may be mediated by factors released during the phagocytosis of lipoprotein deposits by macrophages.

The role of lipids in the pathogenesis of glomerulosclerosis in the rat following subtotal nephrectomy

Similarities between atherosclerosis and glomerulosclerosis suggest that hyperlipidaemia may contribute to glomerular injury. Dietary supplementation with 4% cholesterol + 1% cholic acid was administered to rats 4 weeks after 1 1/3 nephrectomy and continued for 7 weeks. There was a significant increase in serum cholesterol (peak = 11.52 +/- 1.09 mmol l-1 vs. 4.73 +/- 0.31 on control diet, P less than 0.001) and triglyceride concentrations (peak = 2.31 +/- 0.27 mmol l-1 vs. 1.41 +/- 0.29, P less than 0.05) and a marked increase in beta-migrating lipoproteins. The severity of hypercholesterolaemia was significantly correlated with proteinuria (control diet: r = 0.600, cholesterol diet: r = 0.672, P less than 0.0001) as was hypertriglyceridaemia (control diet: r = 0.544, cholesterol diet: r = 0.678, P less than 0.0001). The percentage of glomeruli containing lipid deposits was increased from 21% to 60% (P less than 0.05). The kidney total cholesterol content was increased from 29.2 +/- 0.8 to 47.7 +/- 3.3 mumols g-1 dry weight (P less than 0.0001), with esterified cholesterol increasing from 7.5 +/- 0.4% to 14.5 +/- 2.1% of total (P less than 0.01). Serum cholesterol concentration was significantly correlated with both glomerular lipid deposition (rs = 0.7195, P less than 0.0001) and tissue total cholesterol content (rs = 0.6053, P less than 0.001). Lipid vacuolation was prominent in the paramesangium and within mesangial cells. Despite these changes hypertension, uraemia, proteinuria and glomerulosclerosis were not significantly increased on the cholesterol diet. Cholesterol deposition in the glomeruli occurs secondary to hyperlipidaemia in rats following subtotal nephrectomy but over 7 weeks no exacerbation of glomerulosclerosis is detectable.

Receptor-mediated endocytosis of low-density lipoprotein by cultured human glomerular cells

Lipoproteins might be involved in the pathogenesis of glomerular damage. Uptake of low-density lipoprotein (LDL) by cultured human glomerular cells has been studied using LDL, labelled with the fluorescent probe 1,1'-dioctadecyl-3,3,3'3'-tetramethyl-indocarbocyanine perchlorate (diI). Cells have been characterised using phase-contrast microscopy, monoclonal antibodies and lectins. Differentiated glomerular epithelial cells, epithelial-like cells and mesangial cells all took up diI-LDL. Uptake was specific for LDL, of high affinity and inhibited by excess unlabelled LDL, heparin and preloading the cells with cholesterol. Binding of diI-LDL to the cell surface was restricted to discrete areas which were arranged in linear arrays on mesangial cells. Endocytosis of surface-bound diI-LDL occurred within 3 min and breakdown of internalised diI-LDL within 30 min. These results indicate that cultured human glomerular cells take up LDL by receptor-mediated endocytosis.