Home About us Current issue Ahead of Print Back issues Submission Instructions Advertise Contact Login   

Search Article 
Advanced search 
Saudi Journal of Kidney Diseases and Transplantation
Users online: 1290 Home Bookmark this page Print this page Email this page Small font sizeDefault font size Increase font size 

Table of Contents   
Year : 2016  |  Volume : 27  |  Issue : 3  |  Page : 500-506
Prevalence of asymptomatic urinary abnormalities among adolescents

1 Department of Internal Medicine, Nephrology Division, Zagazig University Hospital, Egypt
2 Department of Clinical Pathology, Zagazig University Hospital, Zagazig, Egypt

Click here for correspondence address and email

Date of Web Publication13-May-2016


To determine the prevalence of asymptomatic urinary abnormalities in adolescents, first morning clean mid-stream urine specimens were obtained from 2500 individuals and examined by dipstick and light microscopy. Adolescents with abnormal screening results were reexamined after two weeks and those who had abnormal results twice were subjected to systemic clinical examination and further clinical and laboratory investigations. Eight hundred and three (32.1%) individuals had urinary abnormalities at the first screening, which significantly decreased to 345 (13.8%) at the second screening, (P <0.001). Hematuria was the most common urinary abnormalities detected in 245 (9.8%) adolescents who had persistent urine abnormalities; 228 (9.1%) individuals had non glomerular hematuria. The hematuria was isolated in 150 (6%) individuals, combined with leukocyturia in 83 (3.3%) individuals, and combined with proteinuria in 12 (0.5%) individuals. Leukocyturia was detected in 150 (6%) of all studied adolescents; it was isolated in 39 (1.6%) individuals and combined with proteinuria in 28 (1.1%) of them. Asymp- tomatic bacteriuria was detected in 23 (0.9%) of all studied adolescents; all the cases were females. Proteinuria was detected in 65 (2.6%) of all the studied adolescents; 45 (1.8%) indivi- duals had <0.5 g/day and twenty (0.8%) individuals had 0.5-3 g/day. Asymptomatic urinary abnormalities were more common in males than females and adolescents from rural than urban areas (P <0.01) and (P <0.001), respectively. The present study found a high prevalence of asymptomatic urinary abnormalities among adolescents in our population.

How to cite this article:
Fouad M, Boraie M. Prevalence of asymptomatic urinary abnormalities among adolescents. Saudi J Kidney Dis Transpl 2016;27:500-6

How to cite this URL:
Fouad M, Boraie M. Prevalence of asymptomatic urinary abnormalities among adolescents. Saudi J Kidney Dis Transpl [serial online] 2016 [cited 2021 Oct 18];27:500-6. Available from: https://www.sjkdt.org/text.asp?2016/27/3/500/182383

   Introduction Top

In 2002, the Kidney Disease Outcomes Quality Initiative of the National Kidney Foun- dation defined and classified chronic kidney diseases (CKD).[1]The definition and classifi- cation of CKD were accepted by the Interna- tional Board of Directors of Kidney Disease: Improving Global Outcomes.[2]CKD was de- fined in five stages based on the appearance of proteinuria and glomerular filtration rate le- vels. Patients with early stage CKD had no symptoms, and the majority of individuals in early stage CKD were undiagnosed, even in developed countries.[3],[4]To reduce the number of patients with both end-stage renal disease (ESRD) and cardiovascular disease,[5],[6]effective screening and treatment methods for CKD should be established.[2],[7],[8]

Most primary chronic glomerulonephritis manifest as asymptomatic proteinuria and/or hematuria.[9],[10],[11],[12]Urinalysis, a simple and inex- pensive test, remains a cornerstone in the eva- luation of the kidney function[13]and it is help- ful in early detection of renal and urinary abnormalities at relatively low cost.[14]Mass urinary screening helps to determine the preva- lence of renal diseases[3]and to improve the outcome in the population.[15]

Microscopic hematuria is common in asymp- tomatic adults;[16]the morphology of the red cells and color of the urine may help to iden- tify the origin of bleeding.[17]Asymptomatic persistent proteinuria may be the first mani- festation of significant renal or systemic disease.[18],[19],[20],[21]

The aim of this study was to estimate such prevalence and to set up screening program for early diagnoses and prevention of CKD.

   Patients and Methods Top

This cross-section study was carried out on adolescent individuals living in Sharkia gover- norate that is located in the East of the Egypt- Delta from December 2012 to October 2014. The initial number of the screened individuals was 3157 adolescent; 657 were excluded from the study, 625 did not deliver urine samples correctly, and 32 were symptomatic. The final included number was 2500 adolescents. The age of the participants in the study ranged from 12 to 15 years (mean age 13.92 ± 0.83). Of the 2500 adolescents (1733 were males and 767 females, ratio 2.25:1), 1750 individuals were from rural and 750 from urban areas (2.3:1). All studied males were circumcised and all the females were sexually inactive, and none of them had any clinical evidence of renal or systemic diseases. The study was approved by the local Institutional Ethics Committee. The aim of the study was explained to the parti- cipants and informed consent was obtained from their parents and school managers.

The participants were instructed how to obtain a clean mid-stream first morning urine specimen to exclude orthostatic proteinuria. The urine containers were brought to the school in the early morning. All specimens were examined by dipstick and light micros- copy.

The dipstick consisted of 10 reagents: ph, specific gravity, protein, blood, glucose, leuko- cytes, nitrites, urobilinogen, bilirubin, and ketones (urine quick test; Combur-10-Test™, Roche, Mannheim, Germany).

Urinalysis was considered abnormal if any the following was detected:

  1. >5 red blood cell/µL; hematuria (green dots on yellow test: intact erythrocytes or uniform green coloration of test: free hemoglobin or hemolyzed erythrocytes)
  2. 1+ or greater proteinuria (trace, 1+, 2+, 3+, and 4+ that correspond to 10 mg/dL, 30 mg/dL, 100 mg/dL, 300 mg/dL, and 1000 mg/dL, respectively)
  3. >5 white blood cell/µL; leukocyturia.
Microscopic analysis was performed by centrifuging 10 mL of well-mixed urine at 1500 g (revolutions per minute) for five mi- nutes in a graduated plastic conical centrifuge tube. Afterward, most of the supernatant was poured off by inversion of the tube, and the sediment was thoroughly resuspended in the remaining supernatant. One drop of this sus- pension was placed on a glass slide, cover- slipped, and examined by subdued bright-field illumination at X[10]and X[40]under a light microscope.

Asymptomatic bacteriuria (ASB) was diag- nosed by the presence of two consecutive clear-voided urine specimens both yielding positive cultures 10[5]colony-forming unit of the same uropathogen.[22]

All adolescents with urinary abnormalities in the first screening were reexamined after two weeks to exclude transient causes of urinary abnormalities, false positive results, and menses in females. Persistently positive individuals were subjected to further analysis; the urine samples of the hematuric group were examined by double phase microscopy to differentiate glomerular (90% of the film dysmorphic) form non glomerular hematuria (90% of the film were isomorphic), while persistently proteinuric individuals were further evaluated by quanti- tative measurements of 24 h proteinuria.

All adolescents with urinary abnormalities in the second screening were subjected to further investigations as indicated: serum creatinine levels, C3 levels, antistreptolysin O titers, and pelvic-abdominal ultrasounds.

   Statistical analysis Top

Data were collected, entered, and analyzed in an Statistical Package for the Social Sciences (SPSS) version 19.0, (SPSS Inc., Chicago, Ill, USA). Data were expressed as a mean ± standard deviation. z-test, and Chi-square (c2 test were used in the analysis of the data. P <0.05 was considered significant.

   Results Top

The prevalence of asymptomatic urinary ab- normalities among the studied individuals was 803 (32.1%) in the first screening. Hematuria, proteinuria, and leukocyturia were detected in 660 (26.4%), 95 (3.8%), and 288 (11.5%), res- pectively. In the second screening, asymp- tomatic urinary abnormalities significantly decreased to 345 (13.8%) P <0.001, similarly hematuria and leukocyturia were significantly decreased to 245 (9.8%) P <0.01 and 150 (6%) P = 0.03, respectively, although proteinuria also decreased to 65 (2.6%) but insignificantly [Figure 1] and [Table 1].
Figure 1. All study analysis

Click here to view
Table 1. The results of the first and second screen and significant difference in between

Click here to view

Asymptomatic urinary abnormalities were more common in adolescent males from rural areas [Table 2].
Table 2. Total urinary abnormalities frequently seen in males gender and rural areas, similarly hematuria more frequent in males and rural areas, proteinuria more frequent only in rural areas lastly leukocyturia more frequent in female gender and rural areas

Click here to view
{Figure 1}

Hematuria was non glomerular and glome- rular in 228 (9.1%) and 17 (0.7%) studied indi- viduals, respectively. Hematuria was isolated, combined with leukocyturia, and combined with proteinuria in 150 (6%), 83 (3.3%), and 12 (0.5%), respectively.

Leukocyturia was detected in 150 (6%), iso- lated in 39 (1.6%) and combined with protei- nuria in 28 (1.1%). ASB was detected in 23 (0.9%) of all adolescents; all cases were females, and Escherichia coli was isolated from all of them.

Proteinuria was <0.5 g/24 h and ranging from 0.5 to 3 g/24 h in 45 (1.8%) and 20 (0.8%) individuals, respectively. Finally, isolated pro- teinuria was presented in 25 (1%) of the studied individuals.

Schistosoma hematobium ova was detected in 208 (8.3%) of all the studied adolescents. Investigations of adolescents with urinary ab- normalities revealed that 12 of them had small renal stones <6 mm, and other six individuals had mild hydronephrosis. There were no cases of poststreptococcal glomerulonephritis and kidney function was within the normal range in all the study individuals.

   Discussion Top

A major problem in nephrology practice in developing countries is how to define stra- tegies that can detect early urinary abnormality who are at risk of developing CKD later in life; a screening program is recommended in this regard.[23]

In the current study, the prevalence of asymp- tomatic urinary abnormalities in adolescents was 32.1% in the first screening, and these abnormalities persisted only in 13.8% in the second screening. Our findings are in contrast to previous study by Bakr et al[24]that found only 1.3% of the samples studied had urinary abnormalities at the first screening, and these abnormalities persisted in 0.72% at the second screening. This wide difference implied the marked increasing of the annual incidence of asymptomatic urinary abnormalities and high- lighting the magnitude of such problem in Egypt. However, our results were comparable to Bolivian study[25]which reported urinary abnormalities in 30.3% at the first screening and persisted in 7.2% at the second screening. Contrary to our results, others studies showed lower prevalence of asymptomatic urinary abnormalities in elementary school children such as 0.62% in Japan,[26]0.3% in Taiwan,[15]1.9% in Malaysia,[27]and 5.25% in Nigeria.[28]All previous screening was in primary school children; all younger than adolescents sharing in the current study that suggest increased prevalence in older age. Accordingly, some countries such as Japan introduced an annual urinalysis screening program for every school child in 1973, for every working adult in 1972, and for every resident older than 40 years of age in 1982.[26],[29],[30]In addition, different ethni- cities and socioeconomic factors may play a role.

Hematuria was the most common abnor- mality found in our study with the prevalence of 9.8% of all adolescents. This was compa- rable to other previous studies in Egypt,[31]Bolivia,[25]and Lebanon,[32]but in contrast with to a Nigerian study[33]where proteinuria was the most common positive finding. The high pre- valence of hematuria particularly non glo- merular (9.1%) in the current study was attributed to schistosomal infestation (8.3%) in the study patients. Hence, long-term follow up for adolescents with microscopic hematuria is advisable.[34]

The prevalence of isolated hematuria and of hematuria combined with proteinuria was comparable to the Finnish study which found that the prevalence of a combination of hema- turia and proteinuria was significantly less common than either isolated proteinuria or hematuria (0.7%).[35]Adolescents with such a combination are more likely to have significant renal disease and require further evaluation.

The prevalence of proteinuria in our study was consistent with another study from Egypt (2.13%),[31]Northern Iran (1.6%),[36]Nigeria (3.5%),[33]and India (2.6%);[37]similar socioeco- nomic factors may explain this agreement with our results. This prevalence is higher than that reported from Tokyo[26]and Lebanon[32](0.08% and 0.1%, respectively).

The levels of proteinuria are one of the strongest predictors for renal function deterio- ration.[38]Asymptomatic proteinuria warrants further work-up to detect and even prevent ESRD.[39]

The prevalence of leukocyturia in our study was comparable to others two studies from Egypt (4.9%)[31]and (7%)[40] and one from Tur- key (4.5 %).[41] Contrary to our results a lower prevalence was reported from Japan (0.29%).[42]The differences in between the previous studies could be explained by the different methods of diagnosis and socio-economic factors.

ASB prevalence in our study was comparable to that in school-age girls (2%).[43]Contrary to our results, a higher prevalence of ASB (5%) was observed in young sexually active women.[44]Hematuria as predominant asymptomatic uri- nary abnormalities was more common in males. This was attributed to males more liable to Schistosoma infestation by swimming in Nile River, especially in rural areas.

Leukocyturia and ASB were more common in females; consistent with other studies from Lebanon,[32]Nigeria,[33]and Vietnam.[45]The female predominance was attributed to the fact that girls have short urethra, which predisposes them to ascending bacterial infection.[46]

In our study, asymptomatic urinary abnor- malities were more prevalent in rural areas than urban, and this may be attributed to poor socioeconomic status, poor health education, and infrequent routine medical visits. Our findings were comparable to those reported from another Egyptian study[31]and Eastern Turkey study.[47]

We conclude that our present study found a high prevalence of asymptomatic urinary ab- normalities in Egyptian adolescents. We pro- pose accordingly a national screening program for early detection of asymptomatic urinary ab- normalities, which may help reducing the ESRD population in Egypt.

Conflict of interest: No conflict of interest has been declared by the authors.

   References Top

K/DOQI clinical practice guidelines for chro- nic kidney disease: Evaluation, classification, and stratification. Part 5. Evaluation of labo- ratory measurements for clinical assessment of kidney. Am J Kidney Dis 2002;39:76-110.   Back to cited text no. 1
Levey AS, Eckardt KU, Tsukamoto Y, et al. Definition and classification of chronic kidney disease: a position statement from kidney disease: Improving global outcomes (KDIGO). Kidney Int 2005;67:2089-100.  Back to cited text no. 2
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. 3
Schieppati A, Remuzzi G. Chronic renal disea- ses as a public health problem: epidemiology, social, and economic implications. Kidney Int Suppl 2005;98:S7-10.  Back to cited text no. 4
Levey AS, Beto JA, Coronado BE, et al. Controlling the epidemic of cardiovascular disease in chronic renal disease: what do we know? What do we need to learn? Where do we go from here? National Kidney Foundation Task Force on Cardiovascular Disease. Am J Kidney Dis 1998;32:853-906.  Back to cited text no. 5
Go AS, Chertow GM, Fan D, McCulloch CE, Hsu CY. Chronic kidney disease and the risks of death, cardiovascular events, and hospita- lization. N Engl J Med 2004;351:1296-305.  Back to cited text no. 6
Eknoyan G, Lameire N, Barsoum R, et al. The burden of kidney disease: improving global outcomes. Kidney Int 2004;66:1310-4.  Back to cited text no. 7
Uhlig K, Macleod A, Craig J, et al. Grading evidence and recommendations for clinical practice guidelines in nephrology. A position statement from kidney disease: Improving global outcomes (KDIGO). Kidney Int 2006; 70:2058-65.  Back to cited text no. 8
Tiebosch AT, Wolters J, Frederik PF, van der Wiel TW, Zeppenfeldt E, van Breda Vriesman PJ. Epidemiology of idiopathic glomerular disease: a prospective study. Kidney Int 1987; 32:112-6.  Back to cited text no. 9
Simon P, Ramée MP, Autuly V, et al. Epide- miology of primary glomerular diseases in a French region. Variations according to period and age. Kidney Int 1994;46:1192-8.  Back to cited text no. 10
Koyama A, Igarashi M, Kobayashi M. Natural history and risk factors for immunoglobulin A nephropathy in Japan. Research Group on Progressive Renal Diseases. Am J Kidney Dis 1997;29:526-32.  Back to cited text no. 11
Cameron JS. Proteinuria and progression in human glomerular diseases. Am J Nephrol 1990;10 Suppl 1:81-7.  Back to cited text no. 12
Fraser CG, Smith BC, Peake MJ. Effectiveness of an outpatient urine screening program. Clin Chem 1977;23:2216-8.  Back to cited text no. 13
Devillé WL, Yzermans JC, van Duijn NP, Bezemer PD, van der Windt DA, Bouter LM. The urine dipstick test useful to rule out infec- tions. A meta-analysis of the accuracy. BMC Urol 2004;4:4.  Back to cited text no. 14
Park YH, Choi JY, Chung HS, et al. Hematuria and proteinuria in a mass school urine scree- ning test. Pediatr Nephrol 2005;20:1126-30.  Back to cited text no. 15
Froom P, Ribak J, Benbassat J. Significance of microhaematuria in young adults. Br Med J (Clin Res Ed) 1984;288:20-2.  Back to cited text no. 16
Chow KM, Kwan BC, Li PK, Szeto CC. Asymptomatic isolated microscopic haema- turia: long-term follow-up. QJM 2004;97:739- 45.  Back to cited text no. 17
Woolhandler S, Pels RJ, Bor DH, Himmelstein DU, Lawrence RS. Dipstick urinalysis scree- ning of asymptomatic adults for urinary tract disorders. I. Hematuria and proteinuria. JAMA 1989;262:1214-9.  Back to cited text no. 18
Jafar TH, Stark PC, Schmid CH, et al. Proteinuria as a modifiable risk factor for the progression of non-diabetic renal disease. Kidney Int 2001;60:1131-40.  Back to cited text no. 19
de Zeeuw D, Parving HH, Henning RH. Microalbuminuria as an early marker for cardiovascular disease. J Am Soc Nephrol 2006;17:2100-5.  Back to cited text no. 20
Zhang Y, Galloway JM, Welty TK, et al. Inci- dence and risk factors for stroke in American Indians: the strong heart study. Circulation 2008;118:1577-84.  Back to cited text no. 21
Kass EH. Asymptomatic infections of the urinary tract. Trans Assoc Am Physicians 1956; 69:56-64.  Back to cited text no. 22
Hogg RJ, Furth S, Lemley KV, et al. National Kidney Foundation's Kidney Disease Outcomes Quality Initiative clinical practice guidelines for chronic kidney disease in children and adolescents: evaluation, classification, and stratification. Pediatrics 2003;111(6 Pt 1): 1416-21.  Back to cited text no. 23
Bakr A, Sarhan A, Hammad A, et al. Asymp- tomatic urinary abnormalities among primary school children in Egypt. World J Pediatr 2007; 3:214-7.  Back to cited text no. 24
Plata R, Silva C, Yahuita J, Perez L, Schieppati A, Remuzzi G. The first clinical and epidemio- logical programme on renal disease in Bolivia: a model for prevention and early diagnosis of renal diseases in the developing countries. Nephrol Dial Transplant 1998;13:3034-6.  Back to cited text no. 25
Murakami M, Yamamoto H, Ueda Y, Murakami K, Yamauchi K. Urinary screening of elemen- tary and junior high-school children over a 13- year period in Tokyo. Pediatr Nephrol 1991; 5:50-3.  Back to cited text no. 26
Zainal D, Baba A, Mustaffa BE. Screening pro- teinuria and hematuria in Malaysian children. Southeast Asian J Trop Med Public Health 1995;26:785-8.  Back to cited text no. 27
Oviasu E, Oviasu SV. Urinary abnormalities in asymptomatic adolescent Nigerians. West Afr J Med 1994;13:152-5.  Back to cited text no. 28
Yanagihara T, Kuroda N, Hayakawa M, et al. Epidemiology of school urinary screening over a 30 year period in Tokyo. Pediatr Int 2007; 49:570-6.  Back to cited text no. 29
Yamagata K, Iseki K, Nitta K, 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. 30
El-Shafie AM, El-Nemr FM, Bahbah MH, Shokry M, Attia A. The role of urine screening (In School Children of Menoufiya Gover- norate) in early detection of renal disorders. J Am Sci 2014;10:143-150.  Back to cited text no. 31
Hajar F, Taleb M, Aoun B, Shatila A. Dipstick urine analysis screening among asymptomatic school children. N Am J Med Sci 2011;3:179- 84.  Back to cited text no. 32
Akor F, Okolo S, Agaba E, Okolo A. Urine examination findings in apparently healthy new school entrants in Jos, Nigeria. S Afr J Child Health 2009;3:60-3.  Back to cited text no. 33
Bergstein J, Leiser J, Andreoli S. The clinical significance of asymptomatic gross and microscopic hematuria in children. Arch Pediatr Adolesc Med 2005;159:353-5.  Back to cited text no. 34
Vehaskari VM, Rapola J, Koskimies O, Savilahti E, Vilska J, Hallman N. Microscopic hematuria in school children: epidemiology and clinicopathologic evaluation. J Pediatr 1979;95(5 Pt 1):676-84.  Back to cited text no. 35
Badeli H, Heidarzadeh A, Ahmadian M. Preva- lence of hematuria and proteinuria in healthy 4 to 6 year old children in daycare centers of Rasht (Northern Iran). Iran J Pediatr 2009; 19:169-72.  Back to cited text no. 36
Sharma AK, Gupta R, Agarwal VS, et al. Prevalence of proteinuria in school children. Indian J Nephrol 1998;8:96-737.  Back to cited text no. 37
Iseki K, Ikemiya Y, Iseki C, Takishita S. Proteinuria and the risk of developing end- stage renal disease. Kidney Int 2003;63:1468- 74.  Back to cited text no. 38
Hanif R, Ally SH, Jalal-ud-Din Khan K. Effec- tiveness of routine urine analysis of patient attending rural health centers in Abbottabad. J Ayub Med Coll Abbottabad 2006;18:63-4.  Back to cited text no. 39
el-Gamal SA, Saleh LH. Asymptomatic bacte- riuria in school children in a rural area, Egypt. J Egypt Public Health Assoc 1991;66:113-21.  Back to cited text no. 40
Nebigil I, Tümer N. Asymptomatic urinary tract infection in childhood. Eur J Pediatr 1992;151:308-9.  Back to cited text no. 41
Iitaka K, Sakai T, Oyama K, Izawa T, Igarashi S. Screening for bacteriuria in Japanese school children. Acta Paediatr Jpn 1990;32:690-5.  Back to cited text no. 42
Nicolle LE. Asymptomatic bacteriuria: when to screen and when to treat. Infect Dis Clin North Am 2003;17:367-94.  Back to cited text no. 43
Hooton TM, Scholes D, Stapleton AE, et al. A prospective study of asymptomatic bacteriuria in sexually active young women. N Engl J Med 2000;343:992-7.  Back to cited text no. 44
Dang le NN, Doan Tle B, Doan NH, et al. Epidemiological urinalysis of children from kindergartens of Can Gio, Ho Chi Minh City - Vietnam. BMC Pediatr 2013;13:183.  Back to cited text no. 45
Travis LB, Brouhard BH. Infection of the urinary tract. In: Rudolph AM, ed. Rudolph's Paediatrics. 12th ed. Stamford: Appelton and Lange; 1996. p. 1388-92.  Back to cited text no. 46
Caksen H, Arslan S, Abuhandan M, Celik A, Bozkurt H, Odabas D. Asymptomatic bacte- riuria in infants in Eastern Turkey. Acta Paediatr Taiwan 2001;42:338-9.  Back to cited text no. 47

Correspondence Address:
Mohamed Fouad
Department of Internal Medicine, Nephrology Division, Zagazig University Hospital, Zagazig
Login to access the Email id

DOI: 10.4103/1319-2442.182383

PMID: 27215241

Rights and Permissions


  [Figure 1]

  [Table 1], [Table 2]


    Similar in PUBMED
    Search Pubmed for
    Search in Google Scholar for
    Email Alert *
    Add to My List *
* Registration required (free)  

   Patients and Methods
   Statistical analysis
    Article Figures
    Article Tables

 Article Access Statistics
    PDF Downloaded375    
    Comments [Add]    

Recommend this journal