Diabetes mellitus: the leading cause of haemodialysis in Jordan

Le diabète sucré, indication majeure de l'hémodialyse en Jordanie

السكَّري هو السبب الرئيسي لإجراء الديال الدموي (الغسيل الكلوي) في الأردن

S. Abdallah; A.T. Ahmad; A. Batieha; K. Ajlouni

National Centre for Diabetes, Endocrinology and Genetics, Amman, Jordan (Correspondence to K. Ajlouni: ajlouni@ju.edu.jo)

ABSTRACT

This study aimed to define the role of diabetes mellitus as a cause of end-stage renal disease requiring haemodialysis in Jordan, and to compare diabetic and nondiabetic patients. All patients on haemodialysis in Jordan at the time of the survey in 2003 (n = 1711) were personally interviewed and additional data were obtained from medical records. Diabetes mellitus was the most common cause of end-stage renal disease (29.2% of cases). The mean age of patients was higher in diabetics [57.5 years, standard deviation (SD) 12.3] than nondiabetics (45.4 years, SD 17.1). Duration on haemodialysis was significantly shorter in diabetics compared to nondiabetic patients.

RÉSUMÉ

Cette étude menée en Jordanie avait pour double objectif de définir le rôle du diabète sucré dans l’étiologie de l’insuffisance rénale terminale nécessitant une hémodialyse et de comparer les populations diabétiques et non diabétiques. Tous les hémodialysés jordaniens au moment de l’enquête, soit 1711 patients en 2003, ont été soumis à un entretien individuel, les données complémentaires étant extraites des dossiers médicaux. Le diabète sucré est apparu comme la principale cause d’insuffisance rénale terminale (29,2 % des cas). Chez les diabétiques, l’âge moyen s’est avéré supérieur à celui des non-diabétiques (57,5 ans [E.T. : 12,3] contre 45,4 ans [ET : 17,1]). Chez les diabétiques, la durée du traitement par hémodialyse a été significativement plus brève que chez les non-diabétiques.

الخلاصـة

أُجريت هذه الدراسة بُغْيَةَ تحديد دور السكَّري كسبب لتطوُّر مرض الكلى ووصوله إلى مرحلته النهائية التي تستلزم إجراء ديال دموي (غسيل كلوي)، في الأردن، وبُغْيَةَ عقد مقارنة بين السكَّريـِّين وغير السكَّريِّـين من هؤلاء المرضى. وتمت مقابلة من كان يخضع للديال الدموي (الغسيل الكلوي) في الأردن، وقت إجراء هذا المسح عام 2003 وعددهم 1711 مريضاً، وجُمعت معلومات إضافية عن حالاتهم من سجلاتهم الطبية. وقد تبيَّن أن السكَّري هو أكثر الأسباب شيوعاً لتطوُّر المرض ووصوله إلى مرحلته النهائية (29.2% من الحالات). وكان متوسط أعمار المرضى أعلى في مجموعة السكَّريِّـين (57.5 عاماً، بانحراف معياري 12.3) منه في مجموعة غير السكَّريِّـين (45.4 عاماً - بانحراف معياري 17.1)، وكانت الفتـرة التي أُجري على مداها الديال الدموي (الغسيل الكلوي) أقصر بدرجة يُعتدُّ بها إحصائياً لدى السكَّريـِّين منها لدى غير السكَّريِّـين من هؤلاء المرضى.

Introduction

End-stage renal disease (ESRD) is a growing problem worldwide and renal replacement therapy is exerting an increasing pressure on health systems [1]. The situation is particularly serious in developing countries where health resources are limited. ESRD is defined as a glomerular filtration rate < 15 mL/minute/1.73 m². Studies from many countries showed that the incidence of ESRD has increased [2-4]. In Jordan for example, the number of patients on haemodialysis has at least doubled over the past 5 years [5], posing a serious challenge to the already strained health care resources. The increasing trend of diabetes mellitus (DM) is believed to be a major contributing factor for the observed increase in the incidence of ESRD. The prevalence of DM has been increasing on a worldwide scale [6,7]. In Jordan, the reported prevalence of DM is 13.4% for people over 25 years of age [8]. Furthermore, different reports indicate that about half the patients with type 2 DM are undetected [9,10].

Key factors for the observed increase in DM include demographic changes, increase in the size of highly susceptible populations, such as the elderly, and sociocultural developments that breed a more sedentary population and expose the people to added environmental risk factors for this disease. At present, DM is the leading cause of ESRD in many countries [4,11-14]. In the Eastern Mediterranean Region, data from Bahrain [15], Oman [16] and Saudi Arabia [17] showed that DM is the cause of ESRD in 30%, 14.5% and 60% of patients respectively. A study from the Czech Republic showed that diabetic nephropathy affects 4%-8% of diabetic patients attending diabetes clinics [18]. One study from the United States reported that diabetic nephropathy occurs in a high percentage (20%-40%) of all diabetic patients [19]. Another study from the United States showed that the incidence of ESRD attributed to DM has grown at the rate of 9% annually since 1992 [11].

Once a patient has ESRD, renal replacement therapy by dialysis (haemodialysis or peritoneal dialysis) or renal transplantation should be applied. Diabetic patients with ESRD are at higher risk of morbidity and mortality because of the presence of other complications of DM, such as atherosclerotic diseases, neuropathy and increased susceptibility to infections [7,20]. Diabetic nephropathy could be reduced and its progression to ESRD significantly delayed with better overall management of the underlying DM [20,21].

Although data on the prevalence of diabetes mellitus are available in Jordan, little is known about the status of control of the disease and its associated complications, including ESRD. The only available study was conducted in 1992 and reported that diabetes was the cause of ESRD in 10.5% of patients on haemodialysis [22]. The purpose of the present study is to report on the role of diabetes as a cause of ESRD necessitating haemodialysis in Jordan, and to determine some of the significant differences between diabetic and nondiabetic patients on haemodialysis as regards age, sex, duration on haemodialysis, family history of DM, history of renal transplantation and rate of hospital admissions.

Methods

As the government reimburses the costs of all haemodialysis services in Jordan, it was possible to ascertain all the patients on haemodialysis in the country. Approval to conduct this study was obtained from all the concerned health sectors in Jordan, namely, the Ministry of Health, the Royal Medical Services and the private sector. We collected data on all patients (n = 1711) who were on haemodialysis at the time of the survey (1 September to 31 October 2003) in all haemodialysis units in Jordan (56 units).

Epi-Info 2002 software was used for data entry and analysis. The distribution of patients by relevant variables was obtained. Diabetic and nondiabetic patients were compared according to a number of relevant variables. The chi-squared test was used to assess the statistical significance of observed differences in proportions while the independent t-test was used to assess the statistical significance of the differences in continuous variables.

Results

Causes of ESRD

At the time of the survey (1 September 2003 to 31 October 2003), a total of 1711 patients on haemodialysis were identified in Jordan. The leading cause of ESRD was DM (29.2% of cases), followed by hypertension (18.4%) and glomerulonephritis (12.3%); the cause was unknown in 21.4% of patients (Table 1). In patients who were initiated on haemodialysis in 2002 (n = 329), DM was responsible for 33.4% and in patients who were initiated on haemodialysis in 2003 (n = 411), DM was responsible for an even higher proportion (44.0%) (Table 1). Hypertension and glomerulonephritis kept their second and third ranks, respectively, in both years. It is noteworthy that hypertension was an associated condition in 63.0% of diabetic patients, and ischaemic heart disease in 22.4% of this population.

More males were on haemodialysis in Jordan (n = 957) than females (n = 754) resulting in a male to female ratio of 1.3:1 approximately. Comparison between diabetic and nondiabetic patients showed that 61.1% of diabetic patients were males compared with 53.8% of nondiabetics (Table 2). The age of diabetic patients ranged from 11 to 88 years with a mean age of 57.5 years [standard deviation (SD) 12.3], while the age of nondiabetics ranged from 5 to 86 years with a mean age of 45.4 years (SD 17.1). More than half of the diabetic patients were ≥ 60 years of age (51.3%) compared with only 25.8% of nondiabetics.

Duration on dialysis

Duration on haemodialysis was significantly shorter in diabetic patients [mean 25 months (SD 25.3), median 17 months] compared with nondiabetics [mean 50 months, (SD 48.8), median 34 months] (P < 0.001). Among all diabetic patients, 38.3% were on haemodialysis < 1 year compared with 20.9% of nondiabetics (Table 2). Only 1% of the diabetic patients were on haemodialysis for > 10 years compared with 10% of non-diabetics.

Family history of DM

As shown in Table 2, and as expected, a significantly higher proportion of diabetics had a positive family history of DM in first-degree relatives (56.5%) as compared with nondiabetics (28.8%) (P < 0.001).

The frequency of previous renal transplants among diabetics was 1.4% compared to 8.5% among nondiabetics (P < 0.001), indicating that diabetic patients are less likely to undergo renal transplantation.

Hospital admission

Admission to hospital during the year prior to the study was significantly more common in diabetic (57.8%) than in nondiabetic patients (42.3%) (P < 0.001) (Table 4).

Discussion

As shown previously in several countries of the world [10,11,15,16], this study confirms that DM is the leading cause of ESRD among patients on haemodialysis in Jordan. ESRD attributed to DM has increased significantly over the years. In Jordan, DM was the cause of ESRD in 10.5% of patients on haemodialysis in 1992 [22] and was the cause of 29% of such cases in 2003. The observation that DM accounted for an even higher proportion of patients who started haemodialysis in 2002 and 2003 (33% and 44% respectively), could indicate that DM has been increasing as a cause of ESRD requiring haemodialysis. This could be attributed, at least partially, to the fact that diabetic patients have a higher overall mortality and spend less time on haemodialysis before they succumb to any of the several complications of DM. It is true that the prognosis of patients who have diabetes and are on renal replacement therapy has improved, but survival remains worse than that of nondiabetic patients. A study published in 1997 showed that the 5-year survival of diabetic patients on haemodialysis was 30% compared with 60% in nondiabetics [23]. Consistent with these figures, the current study suggests a worse survival for diabetics as reflected by the shorter period on haemodialysis among diabetic patients.

Our data suggest a preferential access of males to haemodialysis services. This is evident by the higher number of males on haemodialysis, for which we have no plausible explanation. The abundance of males in the diabetic group as compared to the nondiabetic group (P < 0.006) could be related to a restricted access of women to haemodialysis services if they also have diabetes or other comorbidities.

In the present study, diabetic patients on haemodialysis were less likely to have had renal transplantation, which may relate to the fact that patients in this group are older, and tend to have comorbid conditions and, therefore, were denied this form of intervention.

The association of DM and a positive family history of DM is not surprising, and has been reported by studies in several countries including Kuwait and Mexico [24-26].

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Received: 11/05/05; accepted: 10/10/05

Guidelines for the prevention, management and care of diabetes mellitus

Diabetes mellitus is one of the most common noncommunicable diseases worldwide. In the WHO Eastern Mediterranean Region there has been a rapid increase in the incidence of the disease, and it is now the fourth leading cause of death. The increasing prevalence, the emergence of complications as a cause of early morbidity and mortality, and the enormous burden on health care systems make diabetes a priority health concern. These guidelines provide up-to-date, reliable and balanced information for the prevention and care of diabetes mellitus in the Region. The information is evidence-based and clearly stated to facilitate the use of the guidelines in daily practice. The guidelines are intended to benefit physicians at primary, secondary and tertiary levels, general practitioners, internists and family medicine specialists, clinical dietitians and nurses as well as policy-makers at ministries of health. They provide the information necessary for decision-making by health care providers and patients themselves about disease management in the most commonly encountered situations. 

Guidelines for the prevention, management and care of diabetes mellitus, EMRO Technical Publication Series, No. 32, available at: http://www.emro.who.int/dsaf/dsa664.pdf