Dialysis vintage is associated with a high prevalence and severity of unpleasant symptoms in patients on hemodialysis

Abstract

Background

The burden of physical and emotional symptoms caused by somatic illness is present in most dialysis patients. However, it’s unclear how symptom burden varies among patients with different dialysis vintages. We sought to examine differences in the prevalence and severity of unpleasant symptoms in hemodialysis patients with diverse dialysis vintage cohorts.

Methods

This cross-sectional study included patients on maintenance hemodialysis at the Second Hospital of Anhui Medical University. We used the Dialysis Symptom Index (DSI) to determine the associated unpleasant symptoms, which is a validated survey to assess symptom burden/severity (higher scores indicate more severe symptoms), over June 2022 – September 2022.

Results

We studied 146 patients: 35 (24%) had a dialysis vintage of ≤12 months (group 1) and 111 (76%) had a dialysis vintage of >12 months (group 2). Concerning Group 1 patients, the prevalence and severity of unpleasant symptoms were significantly higher in Group 2, the most common individual symptoms included feeling tired or lack of energy and trouble falling asleep (i.e., 75–85% of patients in each group), with dialysis vintage being an independent influencing factor (adjusted OR, 0.19; 95% CI, 0.16 to 0.23). Lower hemoglobin levels, iron stores, and dialysis adequacy levels are correlated with longer dialysis vintage.

Conclusion

We observed a high prevalence of unpleasant symptoms and symptom clusters in a diverse dialysis vintages hemodialysis cohort. Further studies are needed to accurately and routinely define the symptom burden of chronic patients with chronic kidney disease (CKD).

Keywords:

• Hemodialysis
• dialysis intage
• unpleasant symptoms
• chronic kidney disease
• clinical characteristics

Introduction

Physical and emotional health are important factors in the ability to live, work and study actively. Especially for patients with chronic illnesses, symptoms related to physical and emotional illnesses not only affect the quality of their daily life but also play a key role in the adequacy of treatment for their physical illnesses [1,2]. Research shows that individuals with chronic kidney disease (CKD) experience a significantly higher burden of adverse symptoms, including fatigue and anxiety, compared to the general population. This burden is estimated to be three times greater. Furthermore, the risk of mortality rates and the need for dialysis tend to be higher in CKD patients [3,4]. Despite the higher burden of unpleasant symptoms in end-stage renal disease (ESRD), most dialysis patients often consider the priority of relieving clinical symptoms and neglect the treatment of unpleasant symptom burden, which leads to the under-treatment of somatic illnesses [5]. Therefore, it is crucial to incorporate regular screening for unpleasant emotions in patients with CKD as part of clinical treatment. Providing high-quality care to patients can enhance their self-management skills and medication compliance, improve their quality of life, and significantly alleviate negative emotions [6].

However, ascertainment of CKD- associated symptoms in dialysis patients may be difficult because of their vague nature and conflation with other co-existing comorbidities [5]. In addition, limited patient-provider communication time and the adaptation of some patients to develop related symptoms over time can prevent this symptom burden from being adequately assessed [7]. Validated assessment tools can facilitate the resolution of these issues. The Dialysis Symptom Index (DSI) consists of a 30-item survey assessing the presence and severity of unpleasant symptoms and is the most frequently used instrument for CKD and ESRD patients [8,9].

Although many epidemiological studies have attempted to use the Dialysis Symptom Index to explore the prevalence and severity of unpleasant symptoms [8,10,11], comparisons of symptom burden across diverse dialysis vintage groups are poorly understood. To address this knowledge gap, we conducted a single-center cross-sectional cohort study in the dialysis center of the Second Hospital of Anhui Medical University, examining the prevalence and severity of unpleasant symptoms and the difference in diverse dialysis vintage groups.

Methods and materials

Study population

The study population was a cohort of adult patients undergoing maintenance hemodialysis from the Second Hospital of Anhui Medical University, a single-center, cross-sectional study conducted between June 2022 and September 2022. The inclusion criteria were (1) age ≥18 years, (2) having been receiving treatment at a hemodialysis center for at least eight consecutive weeks, and (3) having completed at least one dialysis symptom index survey. The exclusion criteria were: (1) age >75 years, (2) presence of comorbid malignant tumors and infections based on clinical/laboratory findings, and (3) inability to provide consent without a proxy.

For each participant, we recorded socio-demographics, comorbid conditions, dialysis treatment characteristics (e.g., vascular access type), and validated surveys of patient-centered outcomes (e.g., Dialysis Symptom Index) at the time of inclusion in the study. All patients received 4-h of hemodialysis, three times a week. The Ethics Committee of our hospital approved the study protocol (approval number No. PJ-YX2020-006).

Dialysis symptom index assessment

The Dialysis Symptom Index (DSI) questionnaire was collected in the form of an online questionnaire while patients were undergoing hemodialysis treatment. The DSI is a validated instrument of 30 questions to assess the severity of unpleasant emotions in hemodialysis patients, each of which addresses a specific physical or emotional symptom [8,10]. Patients are required to report symptoms that had been present during the previous week by responding “yes” or “no” for each symptom. Severity is assessed using a five-point Likert scale, with each score of the answer ranging from 0 to 5 (i.e., a response of “0” indicates “no,” whereas a response of “5” indicates “yes: very much”). The total score of the symptom burden represents the sum of individual severity scores, ranging from 0 to 150, with higher scores indicating greater overall severity of symptoms.

Dialysis vintage

Dialysis vintage was defined as the period between the date of hemodialysis initiation and the date of study entry (i.e., the date of baseline Dialysis Symptom Index assessment). Measured by “month” (i.e., dialysis days in the month ≥16 days defined as one month). Patients were divided into a group of patients with ≤12 months of dialysis (Group 1) and a group of patients with >12 months of dialysis (Group 2) according to dialysis vintage [12].

Statistical analyses

According to the variable type, we used chi-square tests and Mann–Whitney U tests to compare baseline characteristics across dialysis year groups (e.g., dialysis vintage). We first examined the distribution of the Dialysis Symptom Index severity scores in the different dialysis vintage groups and adopted a stepwise linear regression method to examine the association between dialysis vintage and Dialysis Symptom Index scores. Linear regression analyses were also performed for heteroskedasticity using the Breusch-Pagan method. Multivariate analyses were adjusted for age, sex, and diabetes status. To determine whether symptoms differed across different dialysis vintage groups, we separately examined score distributions and the prevalence of individual symptoms across dialysis vintage groups. We then analyzed the correlation between individual symptoms from the Dialysis Symptom Index surveys using Pearson’s correlations. Additionally, patients on maintenance hemodialysis of crucial laboratory parameters (i.e., hemoglobin, serum albumin, Tsat, Kt/V, calcium, phosphate, creatinine, and parathyroid hormone (PTH)) measured during the questionnaire of the Dialysis Symptom Index (DSI), we then compared the most comparable clinical laboratory value between two groups. Analyses and figures were generated using IBM SPSS Statistics version 26.0 (Statistical Product and Service Solutions, USA) and Origin version 2021(Origin, USA).

Results

Total dialysis symptom index symptom burden or severity

After applying a standardized dialysis symptom index assessment, the study cohort ultimately consisted of 146 patients on maintenance hemodialysis: 35 (24%) had a dialysis vintage ≤12 months (group1), and 111 (76%) had a dialysis vintage >12 months (group2). Table 1 shows the baseline characteristics of the two patient groups. In the entire cohort of patients on maintenance hemodialysis, with a mean ± SD age of 60 ± 11 years, 8% were male, and 64% had diabetes. The two groups of patients were similar in age, sex, diabetes, dialysis access, marital status, BMI, and post-weight. Conversely, the total Dialysis Symptom Index symptom burden and severity scores differed significantly between the two groups differences. The median (IQR) and minimum-maximum total symptom severity scores of the Dialysis Symptom Index for the entire cohort were 38 (30, 47) and 12–106, respectively. Upon comparing the distribution of the total Dialysis Symptom Index symptom severity scores across the two groups, the median (IQR) number of group 2 patients was higher (40 {32, 47}) yet tended to be lower in group 1 patients (32 {26, 41}).

Table 1. Baseline characteristics of patients across Group1/Group2.

	Overall	Group 1	Group 2
	(n = 146)	(n = 35)	(n = 111)	P-value
Age (mean ± SD), years	60 ± 11	58 ± 12	60 ± 10	0.22
Sex, % male	59	51	61	0.30
Vintage (min-max), months	2–298	≤12	>12	<0.01
Median (IQR)	80 (14, 116)	9 (5, 11)	93 (73, 121)
Mean ± SD	81 ± 61	9 ± 3	104 ± 52
DSI score (min-max)	12–106	12–74	21–106	<0.01
Median (IQR)	38 (30, 47)	32 (26, 41)	40 (32, 47)
Mean ± SD	42 ± 17	36 ± 14	44 ± 17
Diabetes (%)	64	63	65	0.83
Access (%)
AVG/AVF	88	86	88	0.69
Catheter	12	14	12
Marital status (%)
Married	43	46	42	0.94
Single	45	43	46
Other	12	11	12
BMI (mean ± SD), kg/m^2	28.5 ± 2.9	28.4 ± 3.2	28.6 ± 2.8	0.85
Post weight (mean ± SD), lbs	162 ± 14	160 ± 15	163 ± 13	0.32

SD: standard deviation; AVG/AVF: arteriovenous graft/arteriovenous fistula; BMI: body mass index; kg/m², kilogram/meter squared; Post weight: post-dialysis weight; lbs: pounds.

Table 2 shows the association of nine independent variables with the total Dialysis Symptom Index symptom burden or severity scores in 146 patients on maintenance hemodialysis using linear regression analysis. Dialysis vintage was positively associated with total Dialysis Symptom Index scores. In univariable analysis, patients reported that the total Dialysis Symptom Index score was 0.2 points more bothersome for every dialysis vintage more month (95% CI 0.17 to 0.23; p < 0.01), as well as the total Dialysis Symptom Index score was 0.29 points more bothersome for every dialysis post weight more pound (95% CI 0.09 to 0.48; p < 0.01). In multivariable analyses after adjustment for dialysis vintage and dialysis post weight, only dialysis vintage remained associated with the total Dialysis Symptom Index scores (0.19; 95% CI 0.16 to 0.23; p < 0.01).

Table 2. Regression coefficients of dialysis symptom index scores based on 9 independent variables.

	Unadjusted		Adjusted
Modle	Coefficient (95% CI)	P	Coefficient (95% CI)	P
Age	–0.01 (–0.27 to 0.26)	0.98	–0.11 (–0.30 to 0.08)	0.26
Sex	0.70 (–4.95 to 6.36)	0.81	2.40 (–1.66 to 6.45)	0.24
Vintage	0.20 (0.17 to 0.23)	<0.01	0.19 (0.16 to 0.23)	<0.01
Diabetes	–5.21 (–10.94 to 0.51)	0.07	–1.02 (–5.24 to 3.20)	0.63
Access	3.05 (–5.40 to 11.50)	0.48
Marital status
Married	3.55 (–5.72 to 12.82)	0.45
Single	5.48 (–3.74 to 14.71)	0.24
BMI	0.21 (–0.75 to 1.17)	0.66
Post weight	0.29 (0.09 to 0.48)	<0.01	0.09 (–0.06 to 0.24)	0.26

BMI: body mass index; Post weight: post-dialysis weight.

The total Dialysis Symptom Index symptom burden or severity scores were not associated with age, sex, diabetes, access, marital status, or BMI. Only dialysis vintage was significantly associated with total Dialysis Symptom Index scores. We did not find evidence of heteroscedasticity in any of our analyses.

Individual symptoms burden or severity

We first examined the prevalence of individual symptoms from the Dialysis Symptom Index in the overall cohort (Figure 1), and with respect to group 1, the prevalence of individual symptoms was significantly higher in group 2(more people with symptoms in the group). Additionally, given the abovementioned differences in the distribution of Dialysis Symptom Index scores across the two groups of patients, we also compared the prevalence and scores of individual symptoms among patients in groups 1 and 2, with similar patterns observed across the two groups. The most common symptoms of group 1 patients were feeling tired or lack of energy (85.7%), dry skin (80%), trouble falling asleep (71.4%), dry mouth (68.6%), and feeling anxious (80%) (Figure 2). In comparison, the most common individual symptoms in group 2 patients included trouble falling asleep (83.8%), feeling tired or lack of energy (82.9%), dry mouth (77.5%), feeling sad (73.9%), and muscle cramps (67.6%) (Figure 3). However, we observed that the severity of individual symptoms from the Dialysis Symptom Index was significantly higher in group 2 than in group 1 (Table 3). Especially for symptoms related to emotional conditions (i.e., feeling anxious, feeling sad, worrying, and feeling nervous), the difference was statistically significant.

Figure 1. Prevalence of individual symptoms across the overall cohort.

Figure 2. Prevalence of individual symptoms across group 1.

Figure 3. Prevalence of individual symptoms across group 2.

Table 3. Scores of individual symptoms across Group1/Group2.

Individual symptoms	Overall (mean ± SD)	Group1 (mean ± SD)	Group 2 (mean ± SD)	P-value
Itching	1.77 ± 1.53	1.37 ± 1.48	1.89 ± 1.53	0.08
Dry skin	2.01 ± 1.37	1.77 ± 1.20	2.09 ± 1.42	0.24
Trouble falling asleep	2.03 ± 1.44	1.94 ± 1.53	2.05 ± 1.41	0.69
Trouble staying asleep	1.59 ± 1.41	1.29 ± 1.47	1.68 ± 1.38	0.15
Numbness or tingling in feet	1.02 ± 1.22	0.97 ± 1.11	1.04 ± 1.25	0.79
Muscle cramps	1.51 ± 1.36	1.34 ± 1.47	1.56 ± 1.32	0.42
Swelling in legs	1.06 ± 1.18	1.03 ± 1.11	1.07 ± 1.21	0.85
Restless legs or difficulty keeping legs still	0.97 ± 1.33	0.94 ± 1.33	0.97 ± 1.33	0.91
Bone or joint pain	0.86 ± 1.24	0.80 ± 1.09	0.87 ± 1.28	0.76
Shortness of breath	1.24 ± 1.41	1.20 ± 1.12	1.25 ± 1.49	0.85
Cough	1.03 ± 1.32	0.97 ± 1.18	1.05 ± 1.36	0.75
Muscle screness	1.33 ± 1.47	0.97 ± 1.46	1.44 ± 1.45	0.10
Feeling tired or lack of energy	2.01 ± 1.22	1.86 ± 1.17	2.05 ± 1.24	0.41
Feeling anxious	1.66 ± 1.45	1.20 ± 1.21	1.80 ± 1.48	<0.05
Feeling irritable	1.33 ± 1.50	1.26 ± 1.32	1.35 ± 1.56	0.75
Feeling sad	1.79 ± 1.40	1.26 ± 1.29	1.96 ± 1.39	<0.01
Difficulty concentrating	1.17 ± 1.39	0.89 ± 1.41	1.26 ± 1.37	0.17
Headache	1.15 ± 1.45	1.03 ± 1.42	1.19 ± 1.46	0.57
Decreased appetite	1.22 ± 1.39	1.00 ± 1.26	1.29 ± 1.42	0.29
Diarrhea	1.29 ± 1.56	1.00 ± 1.41	1.38 ± 1.59	0.21
Nausea	1.51 ± 1.43	1.26 ± 1.25	1.59 ± 1.48	0.24
Vomiting	1.06 ± 1.47	1.03 ± 1.46	1.07 ± 1.47	0.88
Dry mouth	1.55 ± 1.31	1.37 ± 1.12	1.61 ± 1.36	0.35
Constipation	1.18 ± 1.50	1.17 ± 1.25	1.19 ± 1.57	0.95
Chest pain	1.14 ± 1.56	0.91 ± 1.52	1.21 ± 1.56	0.34
Lightheadedness or dizziness	1.26 ± 1.49	1.14 ± 1.50	1.30 ± 1.48	0.60
Worrying	1.42 ± 1.38	0.89 ± 0.98	1.59 ± 1.44	<0.05
Feeling nervous	1.63 ± 1.60	1.14 ± 1.53	1.78 ± 1.59	<0.01
Decreased interest in sex	1.55 ± 1.55	1.34 ± 1.47	1.62 ± 1.57	0.36
Difficulty becoming sexually aroused	1.66 ± 1.57	1.54 ± 1.42	1.70 ± 1.61	0.60

We also used the adjusted Pearson correlation to analyze the correlations of individual symptoms from the Dialysis Symptom Index (Figure 4). The most relevant combination of symptoms was (1) dry skin + itching (r = 0.60), (2) decreased interest in sex + difficulty becoming sexually aroused (r = 0.45), (3) nausea + vomiting (r = 0.44), (4) worrying + dry skin (r = 0.38), and (5) feeling sad + feeling anxious (r = 0.35).

Figure 4. (Pearson) correlation analysis between individual symptoms.

Crucial clinical characteristics

Additionally, 146 patients had crucial laboratory parameters in the Dialysis Symptom Index (DSI) questionnaire (Table 4). We then compared the dissimilarity between the crucial laboratory parameters of the two groups. Hemoglobin levels, transferrin saturation, and dialysis adequacy levels were significantly lower in group 2 than in group 1. Lower hemoglobin levels, iron stores, and dialysis adequacy levels were correlated with higher dialysis vintage. Meanwhile, the serum albumin, phosphorus, calcium, creatinine, and PTH levels were similar in group 1 and group 2 patients on maintenance hemodialysis, with no statistical significance.

Table 4. Key clinical characteristics across Group1/Group2.

Laboratory parameters	Overall (mean ± SD)	Group1 (mean ± SD)	Group 2 (mean ± SD)	p-Value
Hb (g/dl)	11.5 ± 0.4	11.9 ± 0.3	11.7 ± 0.4	<0.05
Tsat (%)	25 ± 4	26 ± 4	25 ± 3	<0.05
spKt/V	1.43 ± 0.11	1.51 ± 0.12	1.40 ± 0.10	<0.01
Albumin (g/l)	42.4 ± 4.8	44.5 ± 6.0	42.9 ± 4.3	0.08
Phosphorus (mg/dl)	4.8 ± 1.5	4.7 ± 1.6	4.9 ± 1.4	0.49
Calcium (mg/dl)	8.9 ± 1.1	9.1 ± 1.2	9.0 ± 1.1	0.40
Creatinine (mg/dl)	7.9 ± 0.8	7.8 ± 0.8	8.1 ± 0.9	0.08
PTH (pg/mL)	352 ± 186	309 ± 166	369 ± 190	0.10

Discussion/conclusion

In a well-characterized, single-center cross-sectional cohort of patients on maintenance hemodialysis with diverse dialysis vintage backgrounds who underwent protocolized Dialysis Symptom Index surveys, we found that the total Dialysis Symptom Index symptoms and individual symptom burden or severity differed across diverse dialysis vintage patients on maintenance hemodialysis. Our findings indicated that patients with a longer dialysis vintage reported a more significant symptom burden.

To date, a growing number of studies have used the Dialysis Symptom Index to assess patients’ physical and emotional symptoms during maintenance hemodialysis [8,10,11,13]. A racially/ethnically diverse, multi-center prospective cohort from the NIH Malnutrition, Diet, and Racial Disparities in Chronic Kidney Disease (MADRID) study described the application of the Dialysis Symptom Index in Southern California patients on maintenance hemodialysis across 16 outpatient dialysis facilities; the median (IQR) number of symptoms reported by participants tended to be higher in non-Hispanic White and Hispanic White patients (26 {16,54} and 25 {12,37}, respectively), yet tended to be lower in Black and Asian/Pacific Islander patients (22 {9,30}) and 19 {13,46}], respectively). Among the queried symptoms, the most common individual symptoms were feeling tired/lack of energy (71.3%), dry skin (61.5%), trouble falling asleep (44.3%), muscle cramps (42.6%), and itching (42.6%); the most prevalent symptom clusters included feeling tired/lack of energy + trouble falling asleep (37.7%); trouble falling asleep + trouble staying asleep (34.4%), and feeling tired/lack of energy + trouble staying asleep (32.0%) [8]. In another study of 137 patients on maintenance hemodialysis who underwent the Dialysis Symptom Index across the Hemodialysis Unit of the Catholic University of Rome, nearly all participants reported having one or more symptoms; the severity of dry skin, trouble staying asleep, difficulty concentrating, and bone/joint pain was significantly higher in fatigued than in non-fatigued patients [10].

Additionally, several international groups have sought to use a modified version of the Dialysis Symptom Index to accommodate patients undergoing maintenance hemodialysis in specific countries [11,13]. Similarly, a study of 150 ESRD patients undergoing hemodialysis across two dialysis centers of a university hospital and a specialized kidney hospital in Bangkok. According to the THAI version of the Dialysis Symptom Index, 148 patients (98.7%) reported one or more symptoms, with an average of 7.22 ± 6.92. The most severe symptoms were itching (71.11%), followed by dry skin (67.82%), muscle soreness (57.23%), dry mouth (55.24%), muscle cramps (52.75%), and trouble staying asleep (52.75%).

Currently, hemodialysis remains the primary treatment for maintaining the quality of life in patients with chronic kidney disease [14,15]. Most dialysis patients routinely receive maintenance hemodialysis treatment, even for decades, meaning that dialysis vintage for patients also increases, which is a promising independent risk factor. A cross-sectional cohort study that described the association between dialysis vintage and kidney transplant outcomes found that prolonged waiting times on dialysis (e.g., dialysis vintage) for >1 year were associated with higher mortality and a higher rate of composite outcomes after transplantation [16]. Another study reported that adrenal function was associated with dialysis vintage in patients on maintenance hemodialysis, and adrenal function decreased with an increase in dialysis vintage. Long-term dialysis patients may be more susceptible to adrenal insufficiency [17]. While these findings suggest that unpleasant symptoms and dialysis vintage play an independent role in patients undergoing maintenance hemodialysis, there is a paucity of data exploring the potential relationship between them. To address this knowledge gap, we sought to characterize the burden of unpleasant symptoms using the Dialysis Symptom Index in a single-center, cross-sectional hemodialysis cohort with variable dialysis vintage. We found that the prevalence and severity of reported unpleasant symptoms were significantly higher among patients with longer dialysis vintage. Concerning the types of symptoms, there were commonalities across the two groups, with two groups of patients indicating that feeling tired or lack of energy and trouble falling asleep were the most common individual symptoms (i.e., 75–85% of patients in each group). At the same time, there was significant variability in the common symptoms reported. Of particular note, individual symptoms related to emotional status (i.e., feeling anxious, feeling sad, worrying, and feeling nervous) in the Dialysis Symptom Index are also more prevalent in dialysis patients who have been on dialysis longer. It may be that the longer the duration of dialysis experienced, the less capable the patient will be in self-management and the more likely they will be to experience a range of emotional problems such as anxiety. These distinctions highlight the need for further research to explore how underlying factors influence symptom burden across variability of dialysis vintage [18–20] while emphasizing the importance of individualized treatment in managing symptoms in dialysis patients [21].

Another noteworthy finding of our study was the prevalent correlation of specific individual symptoms (i.e., not occurring independently). There has been growing recognition that symptom clusters of two or more concurrent symptoms may be interrelated. Considering their underlying etiology and the possibility of altering other symptoms may have a more significant impact than isolated symptoms [8,22]. In the present study, we observed that the most strongly associated symptom pairings were related to dermatological conditions, sexual desire, and impaired emotional emotions. Considering the high association of these unpleasant individual symptoms suggests that in the future treatment of unpleasant symptoms, we no longer focus on only one symptom in dialysis patients and uncover their potential additional symptoms. It may substantially improve the quality of life and treatment of somatic illnesses in most dialysis patients.

New studies suggest that CKD patients undergoing long-term hemodialysis often fail to resolve uremic toxin symptoms and may develop additional risk factors [23]. In our study comparing key laboratory parameters of outpatient dialysis between two diverse dialysis vintage patient groups, we found that patients with longer dialysis vintage had significantly lower hemoglobin levels, transferrin saturation levels, and dialysis adequacy levels. These risk factors for CKD may be the result of toxin accumulation caused by patients receiving dialysis treatment for years, and further studies are needed to pinpoint their mechanistic basis in the dialysis population.

The strength of our study is that the study population is a well-characterized cohort of patients on maintenance hemodialysis, ensuring the comprehensiveness of the detailed data collected on the patients. Second, the rigorous use of the symptom assessment tool has been validated in the dialysis population. However, our study had some limitations. First, while we had the opportunity to examine a well-characterized cross-sectional cohort, our recruitment was restricted to one dialysis unit at the Second Hospital of Anhui Medical University, which can lead to the limited sample size of our study population, and our findings may not be generalizable to other geographic regions. Second, although many dialysis patients experience multiple symptoms simultaneously, these symptom clusters cannot be assessed using a comprehensive, validated symptom assessment survey such as the Dialysis Symptom Index. Finally, we could not examine the relationship between specific dialysis treatment characteristics (i.e., intra-dialytic medications) and dialysis vintage due to data limitations.

In conclusion, we observed a substantial burden of unpleasant symptoms in a diverse, cross-sectional hemodialysis cohort, along with significant differences in the prevalence and severity of unpleasant symptoms and symptom types across diverse dialysis vintage groups. We also found that symptoms related to emotional conditions were significantly more frequent in patients with prolonged dialysis vintage. These findings underscore the critical need to accurately and routinely define the symptom burden of chronic patients on maintenance hemodialysis and may help investigate common underlying pathogenic mechanisms of symptoms. At the same time, future research should focus on identifying how these mechanisms contribute to unpleasant symptoms, with the ultimate goal of improving health outcomes and quality of life for CKD patients on dialysis.

Ethical standards

Participants provide informed consent, and this study was reviewed and approved by the establishment and application of a multi-center prospective cohort of maintenance hemodialysis patients approval no. PJ-YX2020-006.

Authors’ contributions

The authors confirm the contribution to the paper as follows: study conception and design: Li Zhu, Xun Liang Li; Analysis of data: Li Zhu; Interpretation of results: Li Zhu, Xun Liang Li, Rui Si, De Guang Wang; Draft manuscript preparation: Li Zhu and Xun Liang Li. All authors have reviewed the results and approved the final version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statment

The data that support the findings of this study are not publicly available due to containing information that could compromise the privacy of research participants. Further inquiries can be directed to the corresponding author.

Additional information

Funding

This work was supported by research grants from the Natural Science Foundation of Anhui Province, 2008085MH244 (De-Guang Wang), Incubation Program of National Natural Science Foundation of China of The Second Hospital of Anhui Medical University, 2020GMFY04 (De-Guang Wang), Clinical Research Incubation Program of The Second Hospital of Anhui Medical University, 2020LCZD01 (De-Guang Wang). The funders of this study did notplay any role in the study design, collection, analysis, and interpretation of data, writing of thereport, or decision to submit the report for publication.