Prevalence and Associated Factors of Uraemic Pruritus in Continuous Ambulatory Peritoneal Dialysis Patients

Burden of CKD-Associated Pruritus and Adverse Clinical Outcomes in Patients Receiving Dialysis: The Stockholm Creatinine Measurements (SCREAM) Project

RATIONALE & OBJECTIVE

Pruritus is a common but not well-characterized complaint of patients receiving maintenance dialysis. This study sought to quantify the burden of pruritus and its associated adverse health outcomes in this population.

STUDY DESIGN

Observational study.

SETTING & PARTICIPANTS

All patients receiving maintenance dialysis in Stockholm, Sweden, during 2005-2021.

EXPOSURE

Clinically recognized pruritus defined using International Classification of Diseases, Tenth Revision codes or a prescription for antipruritus treatments (including UV therapy).

OUTCOMES

All-cause mortality, severe infection-related hospitalizations (composite of endocarditis, peritoneal dialysis-related peritonitis, hemodialysis/peritoneal dialysis-related catheter infection, sepsis due to Staphylococcus spp., or skin infection) and incident diagnoses of anxiety/depression and sleep disorders.

ANALYTICAL APPROACH

Multivariable logistic regression and cause-specific hazards models to analyze factors associated with prevalent and new-onset pruritus, respectively. Multivariable cause-specific hazards models with time-varying exposure were used to explore the association of prevalent and new-onset pruritus with adverse health outcomes.

RESULTS

Among 3,281 dialysis recipients (median age, 64 years; 66% men; 69% receiving hemodialysis, 77% with incident dialysis), 456 (14%) had pruritus at enrollment. During a median follow-up of 3.3 (IQR, 1.3-9.2) years, 539 (19%) additional patients experienced pruritus. Older age, female sex, a lower serum albumin level, and higher C-reactive protein, serum calcium, and phosphorus levels were independently associated with pruritus. Compared with patients without pruritus, patients with pruritus were at a higher risk of sleep disorders (adjusted HR, 1.96; 95% CI, 1.60-2.39), developing anxiety/depression (adjusted HR, 1.56; 95% CI, 1.23-1.98), and being hospitalized for severe infections (adjusted HR, 1.36; 95% CI, 1.18-1.57), the latter attributed to higher risk of sepsis and peritoneal dialysis-related peritonitis. There was no detectable association between the development of pruritus and all-cause mortality.

LIMITATIONS

Potential misclassification bias if pruritus is not clinically recognized, lack of information on pruritus intensity/severity, use of diagnostic codes for exposure and outcome diagnoses.

CONCLUSIONS

At least one third of patients experience pruritus during their first years undergoing dialysis, and pruritus was consistently associated with adverse health outcomes.

PLAIN-LANGUAGE SUMMARY

Pruritus is a common but not well-characterized symptom of patients receiving dialysis. We analyzed data from 3,281 patients receiving maintenance hemodialysis or peritoneal dialysis in the region of Stockholm, Sweden. At baseline, 14% of patients had pruritus, and pruritus developed in an additional 19% of patients during their time receiving dialysis. We identified conditions associated with the development of pruritus (eg, older age, female sex, lower serum albumin level, and higher C-reactive protein, serum calcium, and phosphorus levels) and observed that the presence of pruritus was associated with higher risks of sleep disorders, developing anxiety and depression, and being hospitalized for severe infections. No association between pruritus and all-cause mortality was identified.

Serum thymus and activation-regulated chemokine level is associated with the severity of chronic kidney disease-associated pruritus in patients undergoing peritoneal dialysis

BACKGROUND

Thymus and activation-regulated chemokine (TARC), which induces a Th2-dominated inflammation, is a well-known biomarker that reflects the severity of atopic dermatitis. The present study aimed to evaluate TARC as a Th2-associated marker with chronic kidney disease-associated pruritus (CKD-aP) in patients with peritoneal dialysis (PD).

METHODS

This single-centre cross-sectional study included patients who underwent PD in our hospital between August 2020 and July 2021. The severity and impaired quality of life (QOL) of CKD-aP were assessed using the visual analogue scale (VAS) and Japanese version of the 5-D itch scale (5D-J), respectively.

RESULTS

A total of 48 patients with PD were included in the present study. Age and dialysis vintage were (mean ± SD) 64.8 ± 12.0 year and (median (IQR)) 38.5 (11.5-91.5) month, respectively. VAS and 5D-J scores were 3.3 ± 2.0 and 10.5 (9.0-12.0), respectively. Serum TARC level was 481.5 (278.9-603.4) pg/mL (upper limits of normal 450 pg/mL) and significantly correlated with VAS (r = 0.39, p = 0.006) and 5D-J score (r = 0.37, p = 0.009). Multivariate linear analysis revealed that higher serum TARC level was significantly associated with VAS (p < 0.001) and 5D-J score (p < 0.001). Furthermore, the serum brain natriuretic peptide level tended to be associated with VAS (p = 0.060) and 5D-J score (p = 0.029).

CONCLUSION

Serum TARC level is an independent predictor of the severity and impaired QOL of CKD-aP in patients with PD, and TARC might be involved in the pathogenesis of CKD-aP.

Itching in dialysis patients: impact on health-related quality of life and interactions with sleep problems and psychological symptoms – results from the RENINE/PROMs registry

Background

Itching (pruritus) is common in dialysis patients, but little is known about its impact on health-related quality of life (HRQOL), sleep problems and psychological symptoms. This study investigates the impact of itching in dialysis patients by looking into the persistence of itching, the effect of itching on the course of HRQOL and the combined effect of itching with sleep problems and with psychological symptoms on HRQOL.

Methods

Data were obtained from the RENINE/PROMs registry and included 2978 dialysis patients who completed patient-reported outcome measures between 2018 and 2020. Itching, sleep problems and psychological symptoms were assessed with the Dialysis Symptom Index (DSI) and HRQOL with the 12-item Short Form Health Survey. Effects of itching on HRQOL and interactions with sleep problems and psychological symptoms were investigated cross-sectionally and longitudinally using linear regression and linear mixed models.

Results

Half of the patients experienced itching and in 70% of them, itching was persistent. Itching was associated with a lower physical and mental HRQOL {−3.35 [95% confidence interval (CI) −4.12 to −2.59) and −3.79 [95% CI −4.56 to −3.03]}. HRQOL remained stable during 2 years and trajectories did not differ between patients with or without itching. Sleep problems (70% versus 52%) and psychological symptoms (36% versus 19%) were more common in patients with itching. These symptoms had an additional negative effect on HRQOL but did not interact with itching.

Conclusions

The persistence of itching, its impact on HRQOL over time and the additional effect on HRQOL of sleep problems and psychological symptoms emphasize the need for recognition and effective treatment of itching to reduce symptom burden and improve HRQOL.

Epidemiology and burden of chronic kidney disease-associated pruritus

Chronic kidney disease–associated pruritus (CKD-aP) is a common, yet underrecognized condition in patients with CKD and end-stage kidney disease (ESKD). Real-world observational studies indicate that CKD-aP affects up to 80% of ESKD patients undergoing haemodialysis (HD), with ∼40% experiencing moderate to severe itch. CKD-aP can negatively impact patients’ mental and physical health-related quality of life (HRQoL) and is also associated with sleep disturbance and depression. Several studies have found that CKD-aP is a predictor of adverse medical outcomes, including an increased risk of hospitalizations and mortality. In this article we review the literature relating to the epidemiology of CKD-aP to describe its prevalence across the treatment spectrum of CKD (non-dialysis, HD, peritoneal dialysis and transplant recipients) and to summarize potential risk factors associated with its development. We also review key data from studies that have evaluated the impact of CKD-aP on HRQoL and medical outcomes.

Chronic Kidney Disease-Associated Itch (CKD-aI) in Children-A Narrative Review

Chronic kidney disease (CKD) is a condition of widespread epidemiology and serious consequences affecting all organs of the organism and associated with significant mortality. The knowledge on CKD is rapidly evolving, especially concerning adults. Recently, more data is also appearing regarding CKD in children. Chronic itch (CI) is a common symptom appearing due to various underlying dermatological and systemic conditions. CI may also appear in association with CKD and is termed chronic kidney disease-associated itch (CKD-aI). CKD-aI is relatively well-described in the literature concerning adults, yet it also affects children. Unfortunately, the data on paediatric CKD-aI is particularly scarce. This narrative review aims to describe various aspects of CKD-aI with an emphasis on children, based on the available data in this population and the data extrapolated from adults. Its pathogenesis is described in details, focusing on the growing role of uraemic toxins (UTs), as well as immune dysfunction, altered opioid transmission, infectious agents, xerosis, neuropathy and dialysis-associated aspects. Moreover, epidemiological and clinical aspects are reviewed based on the few data on CKD-aI in children, whereas treatment recommendations are proposed as well, based on the literature on CKD-aI in adults and own experience in managing CI in children.

Comparison of gabapentin and hydroxyzine in the treatment of pruritus in patients on dialysis

BACKGROUND

Pruritus is one of the most common problems in patients with chronic renal failure. Of all patients with end-stage renal disease (ESRD), 60-80% report pruritus during their life.

AIM

To compare the effect of gabapentin (GBP) and hydroxyzine (HYDZ) in treating pruritus in patients on dialysis.

METHODS

In a double-blind, randomized, crossover clinical trial, 32 patients on dialysis who reported pruritus were assigned randomly to receive either GBP or HYDZ for 6 weeks; the first group received GBP 100 mg/day orally and the second group received HYDZ 25 mg/day orally for 6 weeks. After this 6-week period (Period 1) there was a washout period of 2 weeks then patients were crossed over to the other drug (the first group receiving HYDZ and second group receiving GBP) and followed up for a further 6 weeks (Period 2). A visual analogue scale was used to measure pruritus intensity in the groups before and after the first and second period.

RESULTS

In Period 1, pruritus severity decreased from 7.1 ± 1.46 at baseline to 2.17 ± 1.82 at 6 weeks in the GBP group (P = 0.001) and from 6.83 ± 2.11 to 2.86 ± 1.67 in the HYDZ group (P = 0.001). In Period 2, pruritus severity decreased from 5.1 ± 1.61 at baseline to 1.56 ± 0.82 at 6 weeks in the GBP group (P < 0.01) and from 5.23 ± 2.11 to 2.1 ± 1.87 in the HYDZ group (P = 0.001).

CONCLUSION

Results showed that both HYDZ and GBP significantly improved and controlled pruritus in patients on dialysis, with no significant difference observed between the two drugs.

CKD-Associated Pruritus: New Insights Into Diagnosis, Pathogenesis, and Management

Chronic kidney disease–associated pruritus (CKD-aP) is a common, troubling and in some cases debilitating problem for patients with CKD and end-stage renal disease. Despite a prevalence rate of approximately 20% in CKD and 40% in end-stage renal disease, and a clear association with poorer psychosocial and medical outcomes, this condition is often underreported by patients and overlooked by health care providers. This is likely due, in part, to uncertainty regarding its pathogenesis and treatment. Most commonly, CKD-aP is attributed to toxin build-up, peripheral neuropathy, immune system dysregulation, or opioid dysregulation. Prior treatment studies of CKD-aP have targeted these potential etiologies but have been limited by noncontrolled design, small sample size, and non-uniform definitions of CKD-aP. Recently, several large, randomized controlled trials targeting opioid dysregulation have yielded promising results. These trials have spurred new hope for understanding and treating this condition.

Factors Associated with Uremic Pruritus in Patients Undergoing Peritoneal Dialysis

Aim

The aim of this study was to investigate different intensities of uremic pruritus in the daytime and nighttime, as well as contributing factors, in patients undergoing peritoneal dialysis (PD).

Methods

A total of 46 patients (31 males, 15 females) with a mean age of 59.4±14.7 years and mean PD vintage of 29.2±25.2 months were enrolled in this single-center, prospective, cross-sectional study. The intensity of uremic pruritus in the daytime and nighttime was assessed using a visual analog scale (VAS). The relationships between intensity and various clinical and laboratory parameters were analyzed using multiple linear regression analyses.

Results

The most common site of uremic pruritus was on the back (70%), followed by lower limbs (67%), chest and abdomen (59%), upper limbs (28%), and head and neck (22%). Mean VAS scores were higher in the nighttime compared with the daytime (4.5±3.3 vs. 3.5±2.7, P=0.02). Only male sex was correlated with higher uremic pruritus intensity in the daytime (standard coefficient [β]=0.310, P=0.036). PD vintage (β=0.415, P=0.004) and topical medicines, including moisturizer and topical corticosteroid use (β=0.345, P=0.019), were independently correlated with higher uremic pruritus intensity in the nighttime.

Conclusion

Uremic pruritus intensity was greater in the nighttime than in the daytime in PD patients. Male sex was associated with higher uremic pruritus intensity in the daytime, whereas PD vintage and topical medicine use were associated with higher uremic pruritus intensity in the nighttime.

Changes of Oxytocin and Serotonin Values in Dialysis Patients after Animal Assisted Activities (AAAs) with a Dog—A Preliminary Study

Our study aimed to measure the levels of serotonin and oxytocin in patients affected by end-stage renal disease (ESRD), undergoing dialysis and participating in a program of animal-assisted activities (AAAs) with a dog. Ten patients with comparable levels of ESRD were enrolled. A blood sample was taken before the start of the study in order to establish basal levels. Eleven meetings were held once a week for 3 months during the last hour of dialysis, and blood samples were collected before and after AAAs. Two more meetings, one month apart from each other, were held two months later without the dog but with the same veterinarian zootherapist. Blood was drawn at the beginning and at the end of each meeting. The samples were then processed for the measurement of serotonin and oxytocin, and data obtained were analysed using analysis of variance with mixed effect models. The results show an increasing level of both serotonin and oxytocin between subsequent meetings with the dog and an increasing trend of inter-intervention levels. Overall, the results suggest that AAAs lead to modifications of serotonin and oxytocin levels, which are also accompanied by behavioural changes of patients.

Role of narrow band ultra violet radiation as an add-on therapy in peritoneal dialysis patients with refractory uremic pruritus

AIM

To assess the role of narrow band ultraviolet B (UVB) as a treatment option in peritoneal dialysis patients with refractory uremic pruritus.

METHODS

In this retrospective study, 29 adult patients with end stage renal failure on peritoneal dialysis, and who had refractory uremic pruritus, were given narrow band UVB radiation as an add-on therapy to standard care for a duration of 12 wk. The response to the pruritus was assessed both weekly and at the end of the study period using a visual analogue score (VAS).

RESULTS

The average VAS score at the end of the study was 3.14 ± 1.59, which was significant compared to the baseline value of 7.75 ± 1.02 (P < 0.05). Improvements in symptoms were noted in 19 out of 21 (90.4%) patients. However, relapse occurred in six out of the 19 patients who responded. The dropout rate was high during the study period (33.3%).

CONCLUSION

Narrow band UVB is effective as an add-on therapy in peritoneal dialysis patients with refractory uremic pruritus. However, the present regime is cumbersome and patient compliance is poor.

Prevalence of chronic kidney disease-associated pruritus among adult dialysis patients: A meta-analysis of cross-sectional studies

Chronic kidney disease (CKD)-associated pruritus is a common adverse symptom in patients with end-stage renal disease treated by dialysis. Herein, a systematic review and meta-analysis of the prevalence of CKD-associated pruritus among adult dialysis patients was conducted.An electronic search of PubMed, Web of Science, Elsevier, Wanfang, and Chinese National Knowledge Infrastructure databases was conducted from inception to November 23, 2016, and all cross-sectional studies that reported the prevalence of CKD-associated pruritus in dialysis were collected. The pooled prevalence was estimated by random-effects model. Potential publication bias was evaluated by the funnel plot as well as Begg and Egger tests.After rigorous screening, a total of 42 studies conducted on 11,800 patients were included in this study. The overall prevalence of CKD-associated pruritus among adult dialysis patients was 55% (95% confidence interval [CI], 49-61, I = 97.6%), the stratification of which was 55% (95% CI, 45-65, I = 94.7%) in men and 55% (95% CI, 46-65, I = 93.3%) in women. In hemodialysis (HD) patients, the prevalence of CKD-associated pruritus was 55% (95% CI, 49-62, I = 97.9%), while in peritoneal dialysis (PD) patients, it was 56% (95% CI, 44-68, I = 89.9%). The prevalence of CKD-associated pruritus for mean dialysis duration <40 months was 56% (95% CI, 48-63, I = 75.1%), while that for mean dialysis duration ≥40 months was 50% (95% CI, 36-64, I = 99.1%).The prevalence of CKD-associated pruritus is high in HD and PD. The prevalence among adult dialysis patients is comparable between China and foreign countries as well as between females and males. Studies with the similar disease definition and analysis of the effects of risk factors on CKD-associated pruritus are needed.

Chronic kidney disease-associated pruritus: impact on quality of life and current management challenges

Chronic kidney disease-associated pruritus (CKD-aP) is a distressing, often overlooked condition in patients with CKD and end-stage renal disease. It affects ~40% of patients with end-stage renal disease and has been associated with poor quality of life, poor sleep, depression, and mortality. Prevalence estimates vary based on the instruments used to diagnose CKD-aP, and standardized diagnostic instruments are sorely needed. Treatment studies have often yielded conflicting results. This is likely related to studies that are limited by small sample size, flawed designs, and nonstandardized diagnostic instruments. Several large well-designed treatment trials have recently been completed and may soon influence CKD-aP management.

Type D personality, illness perception, social support and quality of life in continuous ambulatory peritoneal dialysis patients

The previous studies reported Type D was associated with poor quality of life (QoL), increased psychological distress, and impaired health status in cardiac patients. The aim of this study is to assess the relationships among Type D personality, illness perception, social support, and investigate the impact of Type D personality on QoL in continuous ambulatory peritoneal dialysis (CAPD) patients. Type D personality was assessed by the Chinese 14-item Type D Personality Scale (DS14). Illness perceptions were assessed using the Chinese version of the Brief Illness Perception Questionnaire (B-IPQ). Social support status was assessed by the well-validated social support rating scale (SSRS). Patients' QoL was assessed by using Medical Outcomes Short Form 36 (SF-36), respectively. The Type Ds had significantly lower objective support score (8.18 ± 2.56 vs. 9.67 ± 3.28, p = 0.0001), subjective support score (6.71 ± 2.0 vs. 7.62 ± 1.93, p = 0.0001) and utilization of social support score (6.76 ± 2.0 vs. 7.61 ± 1.94, p = 0.0001) than that of the non-type Ds. Type Ds believed their illness had much more serious consequences (7.67 ± 2.64 vs. 6.27 ± 3.45, p < 0.001), and experience much more symptoms that they attributed to their illness (6.65 ± 2.54 vs. 7.31 ± 2.36, p = 0.023). Significant differences were found between Type Ds and non-Type Ds in PCS (40.53 ± 6.42 vs. 48.54 ± 6.21 p < 0.001) and MCS (41.7 1 ± 10.20 vs. 46.35 ± 9.31, p = 0.012). The correlation analysis demonstrated that Type D was negatively associated with physical component score (PCS) (r = -0.29, p < 0.01), mental component score (MCS) (r = -0.31, p < 0.01), and social support (r = -0.24, p < 0.001). Using multiple linear regression analysis, we found that Type D personality was independently associated with PCS (β = -0.32, p < 0.001) and MCS (β = -0.24, p < 0.001). Type D personality was a predictor of poor QoL in CAPD patients. The current study is the first to identify a strong association among Type D, illness perceptions, social support and QoL in CAPD patients. The worse illness perceptions and lower social support level therefore represent possible mechanisms to explain the link between Type D and poor QoL in CAPD patients.