Archive \ Volume.12 2021 Issue 2

Comparative Analysis of Chronic Kidney Disease-Associated Pruritus: A Multi-Ethnic Study among Patients on Hemodialysis

Inayat Ur Rehman^1,2*, Lee Learn Han¹, Tahir M Khan^1,3, Yaser Alworafi^4,5, Amal Suleiman⁶

¹School of Pharmacy, Monash University, Bandar Sunway, SELANGOR, Malaysia. ²Department of Pharmacy, Abdul Wali Khan University, MARDAN, Pakistan. ³Institute of Pharmaceutical Science, University of Veterinary and Animal Science UVAS Lahore, Pakistan. ⁴College of Pharmacy, University of Science and Technology of Fujairah, Fujairah, UAE. ⁵College of Pharmacy, University of Science and Technology, Sana'a, Yemen. ⁶College of Pharmacy, University of Almaarefa, Riyadh 11597 - Kingdom of Saudi Arabia.

Abstract

To date, no study has compared the prevalence of chronic kidney disease-associated pruritus (CKD-aP) among patients on hemodialysis in Pakistan (a developing country with poor health resources) and Malaysia (a newly industrialized country with adequate health resources). The aim was to compare CKD-aP between Pakistani and Malaysian patients on hemodialysis and factors associated with CKD-aP. Pakistani patients were recruited from July 2016 to April 2017 from two tertiary hospitals in Peshawar and Rawalpindi. Whilst Malaysian patients were recruited from February to September 2017 from a tertiary hospital and its affiliated dialysis centers in Kuala Lumpur.

A total of 354 Pakistani and 334 Malaysian patients were recruited (response rate=100%). The CKD-aP prevalence was 74% and 61.3% in Pakistan and Malaysia, respectively. Pakistani patients had poorer PSQI and health-related quality of life (HRQOL) scores compared to Malaysian patients. The prevalence of CKD-aP and the PSQI score was slightly higher in Pakistan than in Malaysia. CKD-aP was significantly associated with PSQI score and HRQOL in both populations.

Keywords: Malaysia, Sleep, Hemodialysis, Quality of life, CKD-associated pruritus, Pakistan

A longer duration of CKD and the age of patients were associated with CKD-aP in Pakistani patients [10]. However, no factors were found to be correlated with CKD-aP in Malaysian patients [11]. The pruritus intensity was significantly associated with poorer sleep quality and HRQOL among both population patients [17, 18].

The prevalence of CKD-aP, pruritus score, and severity of pruritus were higher in Pakistan than in Malaysia. PSQI and HRQOL scores were also found to be worse in Pakistan when compared to Malaysia. The severity of pruritus was significantly associated with poorer sleep quality [10, 11] and HRQOL [17, 18] among both population patients. A longer duration of CKD and the age of patients were associated with CKD-aP in Pakistani patients [10]. However, no correlation between any of the factors and CKD-aP in Malaysian patients [11].

The prevalence of CKD-aP was slightly higher in Pakistani patients (74%) when compared to Malaysian patients (63.1%). Our findings are aligned with other studies in Pakistan, which reported rates of 64.0% to 77.7% [12], and in Malaysia, which reported rates of 58.6% to 64.2% [11]. The pruritus median score was also significantly higher in Pakistani 10.0 [8.0-12.0] compared to Malaysian patients 8.0 [6.0-9.0]; p=<0.001. In our study, we discovered that longer CKD duration and the age-associated with CKD-aP in Pakistani patients [10]. However, no correlation between any of the factors and CKD-aP in Malaysian patients [11]. Previous studies reported a significant association between serum levels of parathyroid hormone (PTH) [11], blood urea nitrogen (BUN) [11], CKD duration; hyperphosphatemia [11, 19], serum calcium, and being on dialysis (more than 2 years) [20]; while other studies found no association of CKD-aP with PTH and serum P levels [21], and also the age of patients [19]. The possible reasons for the variation in the prevalence of CKD-associated pruritus between Pakistani and Malaysian data may be because patients in Pakistan receive hemodialysis twice/week, whilst in Malaysia, it is three times/week. Additionally, low to medium flux dialyzers were used in Pakistan, whilst high flux dialyzers (which remove average-sized molecules more effectively – thus reducing the severity of uremic pruritus) were used in Malaysia. CKD-aP is believed to be caused by middle-molecule uremic toxins which are not dialyzed properly when using low flux dialyzer [19]. Worldwide, high-flux hemodialysis is the most commonly-used blood purification method. However, in Pakistan low-flux dialysis is mainly used and hemodialysis centers are also limited in Pakistan as in 2009 there were only 175 hemodialysis centers [22]. Patients have limited access to treatment as out of the available dialysis centers 10-15% are non-functional [22].

Pakistani patients were significantly younger than Malaysian patients, and had a shorter median duration of CKD and being on hemodialysis. This may be due to poorer management of chronic conditions (such as diabetes mellitus or hypertension) which predisposes an individual to renal damage in younger individuals. Additionally, the knowledge about chronic conditions and their complications is lower in Pakistani patients and therefore may not have known to take any preventive measures i.e., control of hypertension and dietary modifications [23]. One study found that Malaysian participants had higher knowledge levels regarding diabetes and hypertension [24, 25], which was, however, quite different for the Pakistani population [26, 27]. Moreover, awareness and attitude also play a decisive role in the actions of patients with diabetes and hypertension. Furthermore, in Pakistan, multiple factors may account for poorer dialysis outcomes; such as anemia, malnutrition, late referral, and lacking qualified nephrologists at the centers for dialysis [28].

In our study, the overall PSQI score was significantly different between Pakistan (8.0) and Malaysia (6.0), which may be because 52.0% of Pakistani patients versus 86.3% of Malaysian patients reported “mild” pruritus. Moreover, hemodialysis patients having moderate to the extreme intensity of CKD-aP suffer from nocturnal awakenings and difficulty falling asleep [29].

The quality of patients’ life and the medical outcomes can be adversely affected by CKD-aP [2, 3]. Pruritus was associated with poorer HRQOL in both Pakistani and Malaysian patients [17, 18]. This was similar to previous studies, which found that 54% of patients on hemodialysis with CKD-aP in the UK had CKD-aP that affected their life quality [30]. Other studies found that social function, emotion, and symptoms were affected by CKD-aP [31]. Moreover, the lack of clinical practice guidelines (CPG) in Pakistan directly translates to a lack of procedures facilitating timely referrals for specialist support. The finding is opposite to that of Malaysia where physicians are equipped with CPG [32] thereby making them comfortable with the cutoff limit for a referral from where take-up of the case by the specialist leads to a well-preserved prognosis. Nevertheless, Malaysia being NIC has definite advantages to build up a system, which is absent in the case of Pakistan.

To the best of our knowledge, there has been no study comparing the prevalence of chronic kidney disease CKD-aP among patients on hemodialysis between Pakistan and Malaysia. However, a limitation of our study was that findings are not generalizable because only two centers from Malaysia and Pakistan provided the data. Future research should focus on pharmacological or non-pharmacological interventions to develop CKD-aP management.

CONCLUSION

The CKD-aP prevalence was slightly higher in Pakistan in comparison with Malaysia. Similarly, the pruritus score and PSQI score were also higher in the Pakistani population. However, the HRQOL for social and mental wellbeing was improved in the Malaysian population as compared to the Pakistani population. Furthermore; a statistically significant association between CKD-aP and PSQI score, as well as CKD-ap and HRQOL life, was observed among both populations.

ACKNOWLEDGMENTS: None

CONFLICT OF INTEREST: The article has not been submitted elsewhere or published previously and the authors have no conflicts of interest. All authors have read the final version of the manuscript; they meet the requirements for authorship and believe that the manuscript represents honest work.

FINANCIAL SUPPORT: None

ETHICS STATEMENT: All procedures performed in studies involving human participants were in accordance with the ethical standards of the national research committee and with the 1964 Helsinki declaration; Monash University Human Research and Ethics Committee (MUHREC Approval No: CF16/1766–2016000890). The Institute of Kidney Diseases (IKD Peshawar) Pakistan ethical committee approved this study (Approval No: 844), ethical committee of the Pakistan Kidney Patient Association (Rawalpindi) Pakistan and University of Malaya Medical Center (MREC ID No: 20161230–4722). This article does not contain any studies with animals performed by any of the authors.

Informed consent was obtained from all individual participants included in the study.