Saudi Journal of Kidney Diseases and Transplantation

LETTER TO THE EDITOR
Year
: 2015  |  Volume : 26  |  Issue : 6  |  Page : 1307--1310

Epidemiology of chronic kidney disease in a Pakistani population


Kifayat Ullah, Ghias Butt, Imtiaz Masroor, Kinza Kanwal, Farina Kifayat 
 Department of Nephrology, Pakistan Institute of Medical Sciences, Islamabad, Pakistan

Correspondence Address:
Dr. Kifayat Ullah
Department of Nephrology, Pakistan Institute of Medical Sciences, Islamabad
Pakistan




How to cite this article:
Ullah K, Butt G, Masroor I, Kanwal K, Kifayat F. Epidemiology of chronic kidney disease in a Pakistani population.Saudi J Kidney Dis Transpl 2015;26:1307-1310


How to cite this URL:
Ullah K, Butt G, Masroor I, Kanwal K, Kifayat F. Epidemiology of chronic kidney disease in a Pakistani population. Saudi J Kidney Dis Transpl [serial online] 2015 [cited 2022 Jan 19 ];26:1307-1310
Available from: https://www.sjkdt.org/text.asp?2015/26/6/1307/168694


Full Text

To the Editor,

Chronic kidney disease (CKD) is progressively increasing in south Asian countries like Pakistan, and the reason for this spread is multi-factorial. Most of the people have inadequate health-care provision due to either lack of health education, lack of primary healthcare, inadequate funding on the part of the government and, most importantly, the increasing prevalence of risk factors for CKD such as diabetes and hypertension. [1] In addition, other causes like glomerulonephritis and renal stones are prevalent due to infections and dry weather conditions.

Lack of a central registry makes epidemiological assessment extremely difficult and inadequate in Pakistan. Most of the data regarding disease burden estimates are mostly centerbased. Our nephrology unit, which is part of a large tertiary care hospital, the Pakistan Institute of Medical Sciences, Islamabad caters to a large population in the region. The average population served by this center is large and the catchment area includes a vast area of Punjab, Khyber and Kashmir (the three provinces). We have a separate dedicated CKD clinic.

This study evaluates the etiology of CKD among patients presenting at our center.

This was a cross-sectional study of four months' duration conducted in the Nephrology Department of the Pakistan Institute of Medical Sciences, Islamabad from September till December of 2013.

A case record form was used to record demographic details, stage of renal disease and possible etiology of patients with established CKD. The data was obtained from patient interviews, diagnosis charts and case records, ultrasound scan reports and renal biopsy findings.

We included all patients with a diagnosis of established CKD who visited our outpatient department or were admitted in our ward during the study duration. The possible cause of CKD was evaluated as follows. A diagnosis of diabetic nephropathy was established based on the presence of confirmed diabetes mellitus and one of the following criteria: Longstanding diabetes preceding CKD (minimum of 10 years), normal-sized kidneys on ultrasound or presence of established diabetic retinopathy by fundoscopy. CKD due to hypertension was established based on history of hypertension (minimum of five years) preceding renal dysfunction, evidence of hypertension-related end-organ damage and exclusion of other renal diseases.

A diagnosis of chronic tubulo-interstitial disease was made based on history of polyuria, nocturia with low-specific gravity of urine and low or normal blood pressure associated with small kidneys on ultrasound.

The other etiologies of CKD were determined based on renal biopsy and ultrasound findings. The stage of CKD was established by recording the most recent (within the last three months) eGFR according to the (Modification of Diet in Renal Disease (MDRD) equation. Reports from Pakistan have shown that eGFR measured by the Cockcroft Gault or MDRD formula is a better predictor of reduced GFR than serum creatinine alone in the Pakistani population. [1] CKD staging was performed according to the Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines.

Informed consent was obtained from every individual studied. Ethical approval was obtained from the Ethics Review Committee of the Pakistan Institute of Medical Sciences, Islamabad.

Study data were analyzed using SPSS version 16.

A total of 520 patients were initially included in the study, with a male to female ratio of 1:1 (100:100). A total of 500 patients were considered for final analysis based on data adequacy. The mean age of the population was 46.3 years, with the minimum age being 20 years and the maximum being 83 years. Common causes of CKD identified in these patients included diabetic nephropathy (140, 28%), glomerulonephritis (110, 22%), hypertension (73, 14.6%), tubulo-interstitial disease (67, 13.4%) and renal stone disease (40, 8%). The cause was unknown in a significant percentage of patients (53, 10.6%). Other causes including post-partum renal failure, which constituted 2% of the cases [Table 1].{Table 1}

The majority of patients were in end-stage renal failure at presentation (93%). Stages 3 and 4 constituted a minority (2% and 5%, respectively) [Table 2]. In 20% of the patients, a diagnosis of acute on CKD, mostly due to drugs, was made.{Table 2}

A total of 268 patients were below the age of 50 years. The common etiology of CKD in this age-group included glomerulonephritis (33.2%), diabetic nephropathy (17.9%), tubulo-interstitial disease (10%) and renal stone disease (13.8%). The patients who had CKD of unknown cause comprised 12.31%.

Among the 232 patients who were ≥50 years, the following causes of CKD were identified: diabetic nephropathy (39.6%), hypertension (19.8%), renal stone disease (12.9%), tubulointerstitial disease (5.6%) and adult polycystic kidney disease (3%). Only 8.6% of patients in this age-group had CKD of unknown etiology [Table 3].{Table 3}

CKD is a worldwide public health issue, the incidence and prevalence of which are increasing, resulting in high cost and poor outcomes. [1] In the United States, the prevalence of earlier stages of CKD is approximately 100times greater than the prevalence of kidney failure, affecting almost 11% of adults in the United States. [2],[3] The situation is probably the reverse in developing countries, where late presentation is more common. [4]

CKD is defined as abnormalities of kidney structure or function, present for at least three months, [5] and r epresentative estimates of the burden of CKD in most developing countries are lacking. [3] No data regarding the epidemiological pattern have been reported from our catchment area, and this justifies our study.

It is estimated that the annual incidence of new cases of end-stage renal disease (ESRD) is >100 per million population in Pakistan. [3],[6] In our study, diabetes was the leading cause of CKD, confirming previous results from Pakistan. [4] These results are also consistent with those reported from Western countries. According to the United States Renal Data System (USRDS), diabetes is the leading cause of ESRD (42.9%). [3] The prevalence of diabetes in countries of the Indian subcontinent is higher than that reported in Western countries, and is expected to multiply over the next two decades. [7]

Glomerulonephritis remains the second leading cause of CKD, which probably reflects the high prevalence of infections in our society. Studies from Karachi have reported chronic glomerulonephritis as the leading cause of ESRD in dialysis patients, indicating the high prevalence of infections in the community. [8],[9]

Studies from India have shown that chronic glomerulonephritis (37%) is the most common cause of ESRD in their population, followed by diabetic nephropathy (14%) and chronic tubulo-interstitial disease. [10] Another study from India reported chronic glomerulonephritis as the prime cause of CKD (49.4%), followed by diabetic nephropathy (28.4%). [11]

Hypertension represents the third major cause. In our setup, hypertension largely remains unrecognized and untreated due to the asymptomatic nature of the disease and lack of regular health checkup thus leading to complications like CKD.

Tubulo-interstitial disease remains one of the leading causes (13.4%) in our study, probably reflecting misuse of analgesics and herbal drugs.

In a significant number of patients (10.6%), the cause of renal failure was not known. These patients mostly included those who presented very late or those in whom multiple disorders co-existed and thus the cause could not be ascertained.

 Limitations of the study



Because of the cross-sectional study design, the results cannot be generalized to the whole country. Furthermore, most of the patients presented with advanced stages of CKD and biopsy was not possible. The cause was ascertained from the remaining available data, and this may result in misclassification of etiology in a few patients.

Conflict of interest: None declared.

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