The First Report on the Frequency of Asymptomatic Proteinuria in Iranian School-aged Children

Document Type : Original Article


1 Department of Pediatrics, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran

2 Department of Pediatric Nephrology, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran

3 Department of Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran

4 Medical Students Research Center, Isfahan University of Medical Sciences, Isfahan, Iran


Background: Proteinuria is a well-known indicator of renal dysfunction. In this study, we evaluated the frequency of proteinuria in a sample of healthy Iranian elementary school students using both dipsticks and urine albumin-to-creatinine ratio (UACR) methods. Materials and Methods: This cross-sectional study was performed on 478 school students aged 7–9 years who were selected by multistage random cluster sampling from Isfahan city, Iran. A clean midstream first-morning urine sample was obtained from each subject. Urine samples were examined by dipstick method, and accordingly, they were reported as negative; trace; 1+; 2+; 3+; and 4+. UACR was determined in samples with positive dipstick proteinuria (defined as trace or greater). Results: This study included 478 students (42.8% boys), with mean age of 7.0 ± 0.4 years. Positive dipstick was detected in 124 (25.9%) cases. The frequency of positive dipstick proteinuria was significantly higher in the girls than boys (29.6% vs. 20.9%, respectively; P = 0.04). In cases with a positive dipstick, 10 (2.1%) cases had UACR 30–300 mg/g. The frequency of UACR of 30–300 mg/g was 1.4% and 2.5% in boys and girls, respectively. There was no significant difference in the frequency of UACR 30–300 mg/g in terms of gender (P = 0.4). None of the subjects had UACR above 300 mg/g. Conclusion: While the frequency of asymptomatic proteinuria varies widely across different studies, we found a higher rate of proteinuria in Iranian children. Cost-effectiveness analyses are needed to justify large screening program for detecting asymptomatic proteinuria, as a cardinal manifestation of kidney disease, in Iranian children.


Warady BA, Chadha V. Chronic kidney disease in children: The global perspective. Pediatr Nephrol 2007;22:1999-2009.  Back to cited text no. 1
Coresh J, Astor BC, Greene T, Eknoyan G, Levey AS. Prevalence of chronic kidney disease and decreased kidney function in the adult US population: Third National Health and Nutrition Examination Survey. Am J Kidney Dis 2003;41:1-12.  Back to cited text no. 2
Codreanu I, Perico N, Sharma SK, Schieppati A, Remuzzi G. Prevention programmes of progressive renal disease in developing nations. Nephrology (Carlton) 2006;11:321-8.  Back to cited text no. 3
Yamagata K, Iseki K, Nitta K, Imai H, Iino Y, Matsuo S, et al. Chronic kidney disease perspectives in Japan and the importance of urinalysis screening. Clin Exp Nephrol 2008;12:1-8.  Back to cited text no. 4
Harambat J, van Stralen KJ, Kim JJ, Tizard EJ. Epidemiology of chronic kidney disease in children. Pediatr Nephrol 2012;27:363-73.  Back to cited text no. 5
Gheissari A, Kelishadi R, Roomizadeh P, Abedini A, Haghjooy-Javanmard S, Abtahi SH, et al. Chronic kidney disease stages 3-5 in Iranian children: Need for a school-based screening strategy: The CASPIAN-III Study. Int J Prev Med 2013;4:95-101.  Back to cited text no. 6
Roomizadeh P, Taheri D, Abedini A, Mortazavi M, Larry M, Mehdikhani B, et al. Limited knowledge of chronic kidney disease and its main risk factors among Iranian community: An appeal for promoting national public health education programs. Int J Health Policy Manag 2014;2:161-6.  Back to cited text no. 7
Al-Eisa A, Naseef M, Al-Hamad N, Pinto R, Al-Shimeri N, Tahmaz M. Chronic renal failure in Kuwaiti children: An eight-year experience. Pediatr Nephrol 2005;20:1781-5.  Back to cited text no. 8
Zhai YH, Xu H, Zhu GH, Wei MJ, Hua BC, Shen Q, et al. Efficacy of urine screening at school: Experience in Shanghai, China. Pediatr Nephrol 2007;22:2073-9.  Back to cited text no. 9
Cho BS, Kim SD. School urinalysis screening in Korea. Nephrology (Carlton) 2007;12 Suppl 3:S3-7.  Back to cited text no. 10
Lin CY, Sheng CC, Lin CC, Chen CH, Chou P. Mass urinary screening and follow-up for school children in Taiwan Province. Acta Paediatr Taiwan 2001;42:134-40.  Back to cited text no. 11
Kondo M, Yamagata K, Hoshi SL, Saito C, Asahi K, Moriyama T, et al. Budget impact analysis of chronic kidney disease mass screening test in Japan. Clin Exp Nephrol 2014;18:885-91.  Back to cited text no. 12
White SL, Yu R, Craig JC, Polkinghorne KR, Atkins RC, Chadban SJ. Diagnostic accuracy of urine dipsticks for detection of albuminuria in the general community. Am J Kidney Dis 2011;58:19-28.  Back to cited text no. 13
Newman DJ, Pugia MJ, Lott JA, Wallace JF, Hiar AM. Urinary protein and albumin excretion corrected by creatinine and specific gravity. Clin Chim Acta 2000;294:139-55.  Back to cited text no. 14
Ruggenenti P, Perna A, Mosconi L, Pisoni R, Remuzzi G. Urinary protein excretion rate is the best independent predictor of ESRF in non-diabetic proteinuric chronic nephropathies. “Gruppo Italiano di Studi Epidemiologici in Nefrologia” (GISEN). Kidney Int 1998;53:1209-16.  Back to cited text no. 15
Eknoyan G, Levin NW. K/DOQI clinical practice guidelines for chronic kidney disease: Evaluation, classification, and stratification – Foreword. Am J Kidney Dis 2002;39:S14-266.  Back to cited text no. 16
Crowe E, Halpin D, Stevens P; Guideline Development Group. Early identification and management of chronic kidney disease: Summary of NICE guidance. BMJ 2008;337:a1530.  Back to cited text no. 17
Wen CP, Yang YC, Tsai MK, Wen SF. Urine dipstick to detect trace proteinuria: An underused tool for an underappreciated risk marker. Am J Kidney Dis 2011;58:1-3.  Back to cited text no. 18
Clark WF, Macnab JJ, Sontrop JM, Jain AK, Moist L, Salvadori M, et al. Dipstick proteinuria as a screening strategy to identify rapid renal decline. J Am Soc Nephrol 2011;22:1729-36.  Back to cited text no. 19
Lin CY, Sheng CC, Chen CH, Lin CC, Chou P. The prevalence of heavy proteinuria and progression risk factors in children undergoing urinary screening. Pediatr Nephrol 2000;14:953-9.  Back to cited text no. 20
Pugia MJ, Lott JA, Kajima J, Saambe T, Sasaki M, Kuromoto K, et al. Screening school children for albuminuria, proteinuria and occult blood with dipsticks. Clin Chem Lab Med 1999;37:149-57.  Back to cited text no. 21
Zainal D, Baba A, Mustaffa BE. Screening proteinuria and hematuria in Malaysian children. Southeast Asian J Trop Med Public Health 1995;26:785-8.  Back to cited text no. 22
Jafar TH, Chaturvedi N, Hatcher J, Khan I, Rabbani A, Khan AQ, et al. Proteinuria in South Asian children: Prevalence and determinants. Pediatr Nephrol 2005;20:1458-65.  Back to cited text no. 23
Chronic Kidney Disease Prognosis Consortium, Matsushita K, van der Velde M, Astor BC, Woodward M, Levey AS, et al. Association of estimated glomerular filtration rate and albuminuria with all-cause and cardiovascular mortality in general population cohorts: A collaborative meta-analysis. Lancet 2010;375:2073-81.  Back to cited text no. 24
Wen CP, Cheng TY, Tsai MK, Chang YC, Chan HT, Tsai SP, et al. All-cause mortality attributable to chronic kidney disease: A prospective cohort study based on 462 293 adults in Taiwan. Lancet 2008;371:2173-82.  Back to cited text no. 25
Kondo M, Yamagata K, Hoshi SL, Saito C, Asahi K, Moriyama T, et al. Cost-effectiveness of chronic kidney disease mass screening test in Japan. Clin Exp Nephrol 2012;16:279-91.  Back to cited text no. 26
Tsai TC, Chen YC, Lo CW, Wang WS, Lo SS, Tang GJ, et al. Incidence and renal survival of ESRD in the young Taiwanese population. Clin J Am Soc Nephrol 2014;9:302-9.  Back to cited text no. 27