| Abstract|| |
The purpose of this study is to determine the mortality among patients on hemodialysis (HD). This observational cohort study was conducted at Dubai Hospital during the period between January 2012 and December 2016. All adults’ patients with end-stage renal disease (ESRD) on HD irrespective of their age, gender, and duration of dialysis were enrolled. Mortality among these patients along with certain information like age at the time of death, gender, cause of ESRD, comorbidities, and serology report, were collected. Out of a total of 411 patients, 112 (27.3%) patients died during the study period, 56% were male and their median age at the time of initiation of dialysis and at the time of death was 59.38 ± 13.5 and 63.8 ± 13.6, respectively. Thirteen patients suffered early mortality; i.e., died within 365 days of initiation of dialysis. Diabetes mellitus (DM) was the most common cause of ESRD (73%) among the deceased populations, whereas hypertension was the most prevalent comorbidity in our study group. Anemia (46%), hypoalbuminemia (54%), and hypoparathyroidism (72%), whereas high ferritin (63%) and abnormal phosphorus (61.6%) were predominant biochemical parameters in the deceased patients. The leading cause of death was cardiovascular in 48 patients (42.85%) followed by infection/sepsis (21 patients, 18.75%), unknown causes/sudden death (including sudden death at home) in 18 patients (16.07%) and cerebrovascular events in seven patients (6.2%). Other causes include gastrointestinal hemorrhage, liver disease, and pulmonary embolism. In general, older age group, DM, prolonged duration on dialysis and cardiac diseases were the common causes of mortality in our study population. We found that the conventional risk factors such as old age, diabetes, cardiovascular disease, duration on dialysis, dialysis adequacy, low hemoglobin and low albumin, abnormal phosphorus, and high ferritin are comparatively prevalent in our study patients. Monitoring and timely intervention of these risk factors can help in reducing mortality in future.
|How to cite this article:|
Ahmed M, Alalawi F, AlNour H, Gulzar K, Alhadari A. Five-Year Mortality Analysis in Hemodialysis Patients in a Single-Center in Dubai. Saudi J Kidney Dis Transpl 2020;31:1062-8
|How to cite this URL:|
Ahmed M, Alalawi F, AlNour H, Gulzar K, Alhadari A. Five-Year Mortality Analysis in Hemodialysis Patients in a Single-Center in Dubai. Saudi J Kidney Dis Transpl [serial online] 2020 [cited 2020 Dec 2];31:1062-8. Available from: https://www.sjkdt.org/text.asp?2020/31/5/1062/301172
| Introduction|| |
In spite of the advancement and general improvement in the treatment of end-stage renal disease (ESRD), its incidence is increasing worldwide.,, Globally, more than two million peoples are on dialysis or underwent renal transplants to stay alive. Moreover, it was estimated that one in five men and one in four women aged in between 65 and 74 are suffering from chronic kidney disease (CKD). According to the estimates given by the World Health Organization, in 2005, out of average 58 million mortality worldwide, 35 million deaths were caused by CKD, also according to Center for Disease Control, CKD is ranked 8th most common cause of mortality in the USA in 2017 (13 deaths per 100,000 population). A study on the basis of data reported by 18 countries revealed that approximately 350.2 per million patients are on dialysis. Furthermore, mortality is an important way to determine the outcome in dialysis patients. This study was conducted with the aim to determine the mortality among patients on hemodialysis (HD). Cardiovascular and cere-brovascular diseases are the two most important causes of morbidity and mortality in ESRD patients, especially in diabetics, and those with lupus erythematosus. Cardiovascular diseases (CVDs) are more common in ESRD patients as compared to the general population.,,, According to the United States Renal Data System (USRDS) 2015, congestive heart failure was present in 40%, coronary heart disease in 42%, and myocardial infarction in 12% of the ESRD patients. CVDs are the leading cause of death in ESRD patients; cardiac arrest accounts for 40% of the total deaths. Among diabetics, CVD-related mortality is higher as compared to nondiabetics., The survival rate is an important outcome measure in dialysis patients. According to the National Kidney Foundation, life expectancy for ESRD patients varies differently, dependent on comorbidities, quality, and compliance to dialysis. Average life expectancy is 5–10 years, however many patients survive quite well on dialysis for 20–30 years., As per USRDS 2015 data, the mortality rate is 40.6 per 100 patients/year in the age-group 65–74 years and increases to 68.9 per 100 patients/ year in patient's ages 75 years and older. The mortality rate depends on age, sex, race, cause of ESRD, the modality of treatment and its complication besides unknown reasons. Elderly, male white American patients, and comorbid illness like diabetes, hypertension, and infections are considered the main factors behind high mortality in dialysis patients.
| Materials and Methods|| |
Medical records of 411 ESRD patients who were on dialysis between January 2012 and December 2016 were reviewed at Dubai Nephrology Department, Dubai Hospital, Dubai. Demographic data (name, age, sex), the etiology of ESRD and duration of renal replacement therapy (RRT) were recorded. Laboratory profile, comorbidities, complications during dialysis, and cause of death were also studied. Comorbid conditions such as diabetes mellitus (DM), CVDs, virology report, neoplasms, vascular diseases, and hypertension were considered. Laboratory parameters like hemoglobin level, calcium level, serum phosphate level, albumin level, parathyroid hormone, urea, creatinine, uric acid estimation, liver function tests, iron saturation, and serum ferritin level were also explored, in addition to the dialysis adequacy and nutritional status. The statistical analyses were performed using IBM SPSS Statistics for Windows version 26.0 (IBM Corp., Armonk, NY, IL, USA). Results were systematically tabulated and statistically analysed. Descriptive statistics were calculated for quantitative variables (mean, SD, and median in the case of skewed distribution) and for qualitative variables, absolute and percentage frequencies. Mann–Whitney U-test was applied to see the difference of these variables with mortality. Chi-square test was applied to see the association of mortality with confounding variables, such as gender, ESRD causes, comorbidities, previous renal transplant status, and serology report. P <0.05 was taken as significant.
| Results|| |
One hundred and twelve (27.2%) fatalities occurred in 411 dialysis patients during the conduct of this retrospective study in the span of five years with an annual death rate/year of 13%–20% (average 16.2%). Mean age among the expired patients at the start of HD was 59.38 ± 13.55, with 31% of patients were 55 years or less, whereas 69% were >60 years of age at the time of death, there were more males as compared to females, i.e., 56% and 44% respectively [Table 1]. Thirteen patients (11.6%) died during the 1st year of dialysis, while 53.7% were dialyzed for >3 years [Table 1]. Eighty-six percent of patients were not suffering from a viral illness (HBV, HCV, and HIV), whereas the rest were suffering from one or more viral infections [Table 1]. Regarding the cause of kidney disease, diabetes and hypertension were the two most common among deceased patients, affecting 89% [73% (82) and 16% (18) respectively] patients, also obstructive uropathy, chronic glomerulonephritis and other miscellaneous disorders affect 11% of patients [Table 1]. Frequency of comorbidities showed that hypertension was found higher (n = 98, 88%) followed by DM (n = 89, 79%), cardiac disease (n = 59, 53%), vascular disease (n = 24, 21%), [Table 2]. Low hemoglobin (46%, n = 50), abnormal phosphorus, low parathyroid hormone (72%, n = 75), low albumin (54%, n = 58), and high ferritin (63%, n = 66) are pre-dominant laboratory parameters in deceased population [Table 3], whereas 35.7% only of deceased patients had received adequate dialysis (URR ≥65%). Cardiac events and infection/sepsis are two most common cause of death in our study population, comprising of 43 and 18.7% [Table 4]. Among sepsis patients, frequent organisms were Enterococcus, Staphylococcus aureus, and Staphylococcus epidermidis.
| Discussion|| |
In maintenance HD patients, mortality rates are higher than the general population. Here death pattern was analyzed in 112 (27.2%) patients from a total of 411 patients using retrospective data in the nephrology department of Dubai hospital. Our results showed that mortality rates are highest among patients aged more than 60 years (69.7%), Al-Wakeel et al observed somewhat similar numbers whereas USRDS and Robinson et al reported 49% and 51.1%, respectively. Diabetes was the most common cause of ESRD in our population, 73% of the deceased was suffering from it, compared to 38.6% reported by Robinson et al and 28.6% of USRDS patients, the difference of sample size probably explains the difference in figures. High prevalence of DM may explain the highest mortality in dialysis patients since on the one hand it affects vascular access maturity and on the other hand, it deteriorates arterial stiffness and vascular calcification, hence diabetes and ESRD synergistically increase cardiovascular mortality., Hypertension and diabetes were the most common comorbidities among our population, followed by cardiac, vascular, and liver disease. Malignancy was not reported in any of our studied patients. Many factors influence the survival in dialysis patients; CVD is associated with the worst survival in dialysis patients. Studies have reported up to 10 to 20 times higher CVD associated mortality in dialysis as compared to the general population. Chang et al observed 3.3 times higher mortality risk in dialysis patients suffering from DM and CVD than dialysis patients without DM or CVD. Leading cause of death in our study group was cardiac (48, 42.8%), and 43% of total patients were suffering from diabetes and CVD both. Similarly, Al Wakeel et al and Tong et al found CVD as the most common reason for fatality (41.1% and 44%, respectively). Foley et al reported left ventricular hypertrophy in 73.9% and systolic dysfunction in 14.8% of patients. High mortality after initiation of dialysis is a recognized fact now, The European Renal Association – European Dialysis and Transplant Association registry (European renal association) suggests 86% survival probability in the 1st year. Low albumin, catheter-related sepsis, dialysis complications, old age are some reasons that might explain this phenomenon. We observed 13 (11.6%) fatalities in the 1st year of dialysis, seven males and six females. Eight were above 60 years of age. Robinson et al observed 25% of patients died in the first 365 days in DOPPS study and Bradbury et al in US HD patients where the mortality risk was elevated during the first 120 days compared with the next 121 to 365 days (27.5 vs. 21.9 deaths/100 person-years; P = 0.002). Noordzil and Jager called this universal phenomenon.
Though our patient sample is small, reflecting a single center data, yet we have an average annual death rate/year of 16.2%, comparable to Europe (15.6%), higher than in Japan (6.6%), but relatively better than in USA (21.7%). The mortality rate is inversely associated with the dose of dialysis; Held et al reported 7 and 11% decrease in mortality rate by increasing 0.1 in Kt/V and 5% in urea reduction ratio. In our study group, 64.3% of deceased patients received inadequate dialysis mostly because of access-related issues and noncompliance to follow dialysis prescription, particularly the elderly. Certain hematological and biochemical parameters may also predispose the dialysis population to high mortality. Anemia is one of the important factors to determine mortality in dialysis patients. Low hemoglobin and hematocrit are associated with higher infection, higher hospitalization rate, reduced quality of life and increases the burden on the heart. Approximately half of our deceased patients (45.4%) at their time of death had a hemoglobin less than 10 g/dL, correspondingly Koilin et al had reported in Taiwan population 62% of fatalities in dialysis patients with hemoglobin less than 10 g/dL. Importance of phosphorus as a prognostic factor of morbidity and mortality in dialysis patients is recognized universally, one plausible explanation could be the involvement of phosphorus in vascular calcification and left ventricular hypertrophy, which contributes to cardiovascular disease and death. Eddington et al observed that high phosphorus can increase all-cause mortality in dialysis patients; we found 37% of our study population had high phosphorus. Albumin and Ferritin levels are of prognostic significance in dialysis patients, Inflammation causes rise in ferritin and decrease in albumin, which in turn increase all-cause of mortality in dialysis patients whereas Park et al proposed that association of high ferritin at the time of initiation of dialysis is independent risk factor of mortality regardless of systemic inflammation and nutrition. We observed high ferritin (more than 500 ng/mL) in 63% and low albumin (<3.5 g/dL) in 55.3% of our deceased dialysis population, de Mustert et al suggest that 1 g/dL decrease in albumin will increase mortality risk of 47% in HD patients, that was partly explained by inflammation, also he implies that low albumin in his study population was not consequence of malnutrition as measured with subjective global assessment and normalized protein nitrogen appearance. We have an average annual death rate/year of 16.2%, our death rate can be still incredibly low, however, since the majority of our population were >60 years of age (70%) and mostly were diabetics, and the two factors on itself are outstanding indicators of high mortality, which had pondered adversely our rate.
| Conclusion|| |
Our study explored a single-center experience of mortality in HD patients. We found that the mortality rate in our study group was comparable to other international data, rather we have reduced death rates as compared to many developed countries, and the conventional risk factors either fixed like old age or relative such as diabetes mellitus, CVD, duration on dialysis, dialysis adequacy, low hemoglobin and albumin, high phosphorus and ferritin levels are comparatively prevalent in our study patients. Monitoring and timely intervention of relative risk factors can help in reducing mortality in the future.
Conflict of interest: None for all authors.
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Department of Nephrology, Dubai Hospital, Dubai Health Authority, Dubai
United Arab Emirates
[Table 1], [Table 2], [Table 3], [Table 4]