| Abstract|| |
Background: Chronic kidney disease (CKD) is now a public health burden. If simple screening tests like the glomerular filtration rate (GFR) and presence of albuminuria are done in asymptomatic persons, CKD can be diagnosed earlier that will help in halting the disease and not let it progress to end-stage renal disease (ESRD). Aim: This study was conducted to see the proportion of renal function abnormality in the relatives of CKD patients. Settings and Design: This was a cross-sectional comparative study conducted at Chittagong Medical College Hospital (CMCH), Chittagong, Bangladesh, a tertiary hospital in the southern part of Bangladesh. Materials and Methods: We screened the relatives of CKD patients, as a risk population, by urine albumin and estimated GFR (eGFR). Results: We observed a significant difference in urine albumin (29% vs 10% in relatives and nonrelatives, respectively) and abnormal renal function [albuminuria/creatinine clearance (CCr) criteria] (30% vs 11% in relatives and nonrelatives, respectively) between relatives and nonrelatives. Relatives of glomerulonephritis-CKD (GN-CKD) patients had more albuminuria than others. Risk factors like hypertension (HTN), impaired glucose tolerance (IGT)/diabetes mellitus (DM), and family history of DM/HTN/cardiovascular disease (CVD) were significant among relatives and might have some link to familial influence on developing CKD. Conclusion: Relatives of CKD patients should be screened as a risk population to evaluate abnormal renal function.
Keywords: Albuminuria, chronic kidney disease (CKD), estimated GFR (eGFR), relatives
|How to cite this article:|
Dutta PK, Haider M, Kashem A. Impaired renal function in relatives of chronic kidney disease patients. Ann Trop Med Public Health 2015;8:113-6
|How to cite this URL:|
Dutta PK, Haider M, Kashem A. Impaired renal function in relatives of chronic kidney disease patients. Ann Trop Med Public Health [serial online] 2015 [cited 2020 Apr 2];8:113-6. Available from: http://www.atmph.org/text.asp?2015/8/4/113/162366
| Introduction|| |
Chronic kidney disease (CKD) is a major public health issue worldwide.  Cardiovascular morbidity, mortality, and premature death increase as CKD progresses to end-stage renal disease (ESRD). ,,
Earlier studies suggested that relatives of CKD patients have an increased risk of abnormal kidney function, as evidenced by the decreased glomerular filtration rate (GFR) and/or albuminuria. ,,, Different cross-sectional studies showed creatinine clearance (Ccr) >60 mL/min/1.73 m 2 , which was 6.7-14% more in the relatives of CKD than nonrelatives. ,,, Also, there was more prevalence of proteinuria in family members than the age- and sex-matched control group.  About nearly 18 million people have CKD in Bangladesh.  In developing countries like Bangladesh, besides the high rate of illiteracy, malnutrition, poor socioeconomic condition, and lack of health care knowledge, there is a shortage of facilities like dialysis and renal transplantation that are the only treatment options for the terminal stage of CKD. On the other hand, CKD patients are increasing due to increased number of hypertensive and diabetic patients in urban areas with improved health-care services. So, early detection, prevention, and treatment of CKD are essential to decrease the societal and personal burdens of ESRD in Bangladesh. Hence, screening of the high-risk group (relatives of CKD patients) by a common and cost-effective way may help to diagnose and halt further progression to advanced stages. This group of people is easily approachable and oriented as they used to accompany their relatives to hospitals. So, we designed this study to evaluate abnormal kidney functions among the relatives of CKD patients in Chittagong Medical College Hospital (CMCH), a tertiary hospital in the southern part of Bangladesh, using serum creatinine (SCr)-based equation to estimate estimated GFR (eGFR) and urine dipstick for albumin. Though it is a small-sample, cross-sectional comparative study, the findings might be useful for health care policy makers to develop national strategies and to rationally plan health services for the prevention and treatment of CKD and its related complications.
| Materials and Methods|| |
It was a cross-sectional comparative study conducted in the Department of Nephrology, CMCH, from July 2011 to June 2012. Two hundred relatives (first-degree and second-degree relatives) and 200 age-matched nonrelative attendants of CKD patients and hospital staff were taken as a study population. They were divided into the following three groups: Group A: First-degree relatives of CKD patients, Group B: Second-degree relatives of CKD patients, and Group C: Nonrelatives (friends, neighbors, and hospital staff). Pregnant subjects and those who had recent pregnancy, those below 18 years and above 65 years of age, those with acute kidney injury (AKI), known diabetes mellitus (DM), hypertension (HTN) patients, those with chronic illness, chronic nonsteroid anti-inflammatory drugs (NSAIDs) and other drug users, those with acute illness, known CKD, and persons who did not give written consent were excluded. Informed written consent was taken from each participant and ethical approval was obtained from our institution's Ethical Committee. Diabetes, HTN, and cardiovascular disease (CVD) were defined with standard definitions. , The case record form included questionnaires about sociodemographics (age, gender, and education), smoking, personal and family history (DM, CKD, CVD), physical parameters (height, weight, body surface area, and blood pressure) and laboratory variables (SCr, blood sugar, and dipstick urine albumin). SCr level was estimated by the photometric colorimetric method. Random blood sugar (venous) was measured with Accu-Check glucometer strip method. Urinary albumin was checked with strip (Bayer, Germany) on the spot-collected urine. eGFR was calculated using Cockcroft-Gault equation and was standardized for 1.73 m 2 body surface area. 
Statistical analyses of the results were obtained by using the software devised by Statistical Packages for Social Sciences (SPSS-18) (SPSS Inc., Chicago, IL, USA). The continuous data (age and SCr) were expressed as mean ± standard deviation (SD) and were compared via the Student's t-test. The categorical data (sex, occupation, education, smoking, DM, HTN, and proteinuria) were expressed as number and percentage, and were compared via the chi-square test or Fischer's exact test. Two-tailed P < 0.05 was considered significant.
| Results|| |
We screened the renal function abnormalities of the relatives of 66 CKD patients. Their 200 relatives (123 males, 77 females; mean age: 33.41 ± 11.21 years) were compared with their 200 nonrelatives (105 males, 95 females; mean age: 32.61 ± 10.43 years). The participants' sociodemographic and health characteristics are shown in [Table 1]. The table also shows that smoking history and family history of DM, HTN, and CVD of CKD patients' relatives were more prevalent compared with nonrelatives. The prevalence of proteinuria was significantly higher in CKD patients' relatives as compared with nonrelatives [Table 2]. Relatives of glomerulonephritis-CKD (GN-CKD) patients had increased prevalence of proteinuria (39.8%) compared with relatives of DM-CKD (21.9%), HTN-CKD (17.9%), and others (20%) [Table 3]. The prevalence of abnormal renal function (combined proteinuria and CCr) was three times higher among relatives compared with nonrelatives but there was no significant difference in renal function abnormalities between the first-degree and second-degree relatives of CKD patients [Table 4].
|Table 1: Sociodemographics and health characteristics of relatives and nonrelatives∗|
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|Table 3: Distribution of albuminuria among the relatives (n = 200) according to CKD patients' (index cases) etiology|
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| Discussion|| |
CKD is one of the noncommunicable diseases, the incidence of which is gradually increasing globally. Several previous studies suggested that family members of CKD patients have increased risk of abnormal kidney function, as evidenced by decreased CCr (eGFR) and/or albuminuria. ,,,,
In this study, it was observed that the prevalence of proteinuria was significantly higher (P < 0.029) in the relatives than nonrelatives (29% vs 10%) [Table 2]. Gaoda et al.  found 10.6% relatives, Wei et al.  showed 12.9% first-degree relatives, and Claudine Jercovitz et al.  showed 9.9% of relatives with albuminuria. The prevalence rate of albuminuria was much higher in CKD relatives in our study than in previous studies in community screening, which might have been influenced by false positivity due to single time spot detection. So, future studies with multiple urine albumin estimation will probably truly evaluate the prevalence of persistent albuminuria. Relatives of GN-CKD patients showed significantly higher (P = 0.029) albuminuria than relatives of DM-CKD and HTN-CKD [Table 3]. A previous study by Wei et al.  showed findings similar to that of our study, but Daniel et al.  found higher rates of albuminuria in HTN-CKD group. This increased albuminuria in the GN-CKD group might be due to more number of GN-CKD relatives' enrollment in our study, which needs detailed evaluation with a large population survey to have conclusive data.
Overall abnormal renal function in consideration of both CCr and albuminuria was 30% among the CKD-relatives in comparison with 11 % among the nonrelatives [Table 4]. Jarcovitz et al.  and Xin Wel et al.  in their studies showed that 24% and 29.7% of CKD relatives, respectively, were positive for renal abnormalities. In our study, renal abnormalities were mostly reflected by albuminuria that might have been due to early screening before advanced kidney damage occurred among the relatives.
Relatives had a significantly higher rate of smoking. Smoking might have some influence on renal functional abnormalities though this has not been tested widely. Gauda et al.,  and Ejerblad et al.  showed that cigarette smoking increased the risk of CKD.
The number of newly detected HTN patients were more among the relatives (19%) than the nonrelatives (8.5%), which was highly significant (P = 0.002) [Table 1] and consistent with the findings of Gauda et al.  and XinWei et al.  Family history of DM (P = 0.001), HTN (P = 0.000), and CVD (P = 0.000) [Table 1] were also analyzed. Statistically significant results were found among relatives than nonrelatives.
From our study, it has been suggested that relatives of CKD patients have relatively more chance of developing renal functional abnormalities than nonrelatives. Most relatives with normal CCr levels were found to have albuminuria, which is a risk marker and needs to be followed up for persistent findings. No significant difference was noted in renal functional abnormalities between first-degree and second-degree relatives. There were some limitations in this study such as small sample size, spot dipstick albuminuria detection, and lack of prolonged follow-ups. We compared with controls (nonrelatives) to add to the strength of the study findings.
| Conclusion|| |
In this cross-sectional study, it has been observed that relatives of CKD patients are more at risk and prone to developing renal functional abnormalities than nonrelatives. Relatives are associated with a much greater prevalence of unaware HTN and DM/impaired glucose tolerance (IGT). Although our findings suggest that screening these individuals might help identify people with early kidney disease and prevent them from progressing to advanced CKD, further studies are required before promoting such screening programs nationwide.
| Acknowledgment|| |
We acknowledge the cooperation of the Principal, Chittagong Medical College and the Director of CMCH. We also express our gratitude to all the doctors and technical staff of the Nephrolgy and Biochemistry Department of Chittgong Medical College. We would also like to express our gratitude to the patients for their cooperation during the study.
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Pradip Kumar Dutta
Department of Nephrology, Chittagong Medical College, Chittagong - 4203
Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2], [Table 3], [Table 4]