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| ORIGINAL ARTICLE |
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| Year : 2022 | Volume
: 7
| Issue : 1 | Page : 3-5 |
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Urinary calcium and uric acid excretion in children with UTI having vesicoureteral reflux
Sufia Khatun1, Md Habibur Rahman2, Ishrat Jahan3, Rezwana Ashraf4, SK M Nazmul Hasan5, Nayema Afroje6, Abdullah Al Mamun2, Mohammad Maajharul Islam7, Rezaul Karim8
1 Department of Biochemistry, Shaheed Syed Nazrul Islam Medical College, Kishoreganj, Bangladesh
2 Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh
3 Department of Pediatric Nephrology, Dhaka Medical College, Dhaka, Bangladesh
4 National Institute of Kidney Diseases & UrologyDhaka, Dhaka, Bangladesh
5 Department of Hepatology, Shaheed Syed Nazrul Islam Medical College, Kishoreganj, Bangladesh
6 Department of Gynaecology and Obstetrics, Shaheed Syed Nazrul Islam Medical College, Kishoreganj, Bangladesh
7 Department of Pediatric Nephrology, Potokhali Medical College Hospital, Patuakhali, Bangladesh
8 Department of General Pediatrics, Cumilla Diabetic Hospital, Comilla, Bangladesh
| Date of Submission | 23-Oct-2021 |
| Date of Acceptance | 05-Feb-2022 |
| Date of Web Publication | 31-May-2022 |
Correspondence Address:
Dr. Sufia Khatun
Department of Biochemistry, Shaheed Syed Nazrul Islam Medical College, Kishoreganj, Dhaka
Bangladesh
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/pnjb.pnjb_19_21
Introduction: Patients with urinary tract infection (UTI) associated with vesicoureteric reflux (VUR) are prone to develop hypercalciuria and hyperuricosuria compared with UTI patients without VUR, which may lead to the formation of stones due to stasis, infection, and inflamed urinary mucosa. Objective: To assess calcium and uric acid excretion in children with VUR and without VUR having a history of treatment for UTI. Materials and Methods: This cross-sectional and analytical study was conducted in the Department of Paediatric Nephrology and Urology of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka. Sixty-one children of both sex from 2 months to 12 years were treated for UTI 4 weeks prior to enrollment for the study and evaluated by micturating cystourethrogram taking all precautionary measures to detect VUR. Patients were grouped into Group A (30 patients with VUR) and Group B (31 patients without VUR). Fasting urine was analyzed for calcium/creatinine (Ca/Cr) and uric acid/creatinine (UA/Cr) ratios. Urinary calcium and urinary uric acid levels were determined by the colorimetric test, and urinary creatinine was measured by the clinical risk and error analysis method by using the Dimension RxL Max System (SIEMENS) of both groups of patients in the Department of Biochemistry, BSMMU. Results: Median (min–max) of Ca/Cr ratio was 0.207 (0.034–0.646) and 0.150 (0.090–0.500) in Group A and Group B, respectively, and the difference between these two groups was statistically significant (P < 0.050). Median (min–max) of UA/Cr ratio was 0.972 (0.307–1.951) and 0.616 (0.500–1.390) in Group A and Group B, respectively, and the difference between these two groups was also statistically significant (P < 0.050). Hypercalciuria was significantly higher in Group A (20.0%) than in Group B (3.2%; P < 0.050). Similarly, hyperuricosuria was significantly higher in Group A (33.3%) than in Group B (6.5%; P < 0.05). Conclusion: Children with VUR having UTI may have a higher level of hypercalciuria and hyperuricosuria than those without VUR. Keywords: urinary calcium and uric acid, UTI, vesicoureteric reflux
How to cite this article:
Khatun S, Rahman MH, Jahan I, Ashraf R, Hasan SM, Afroje N, Mamun AA, Islam MM, Karim R. Urinary calcium and uric acid excretion in children with UTI having vesicoureteral reflux. Paediatr Nephrol J Bangladesh 2022;7:3-5 |
How to cite this URL:
Khatun S, Rahman MH, Jahan I, Ashraf R, Hasan SM, Afroje N, Mamun AA, Islam MM, Karim R. Urinary calcium and uric acid excretion in children with UTI having vesicoureteral reflux. Paediatr Nephrol J Bangladesh [serial online] 2022 [cited 2023 Oct 4];7:3-5. Available from: http://www.pnjb-online.org/text.asp?2022/7/1/3/346344 |
| Introduction | |  |
Vesicoureteric reflux (VUR) is the backward flow of urine from the bladder into the ureter, with an incidence of 1%–2% during childhood.[1] Children with VUR present with recurrent urinary tract infection (UTI) and urinary stasis, both of which promote urinary crystal formation.[2] Crystal formation is also increased by alterations in urinary pH, which decrease the solubility of certain products (e.g., calcium phosphate, uric acid, cystine), and decreased by concentration of inhibitors of crystal formation that include citrate, magnesium, nephrocalcin, and glycosaminoglycans.[3] The current belief suggests that metabolic causes, such as hypercalciuria and hyperuricosuria, may also play an important role in the formation of renal stone in VUR patients.[4] Although renal calculi are uncommon in children, but their incidence is greatly increased when VUR and UTI exist together rather than UTI alone,[5] because in VUR and UTI, inflammations and stasis prevail together, which are predisposing factors for stone formation including metabolic and structural derangements of urinary tract.[6] It has been observed by many studies that in children with VUR associated with UTI, hypercalciuria, hyperuricosuria, and other metabolic de-arrangements are increased manyfold higher than in control healthy children, which may be the potential cause of stone formation in the urinary tract.[7],[8]
So, this cross-sectional case–control study was designed to assess urinary calcium and uric acid excretion in children hospitalized for surgical correction of VUR after treatment for UTI to find out the susceptible future stone former.
| Materials and Methods | | |
This cross-sectional and analytical study was conducted in the Department of Paediatric Nephrology and in the Department of Urology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, from March 2013 to July 2014. Sixty-one children from 2 months to 12 years were properly treated for UTI according to age and severity of the disease 4 weeks prior to enrollment for the study. Patients were evaluated by ultrasonogram of the kidney, ureter, and bladder region for residual urine by an expert radiologist in the field of pediatrics urological anatomy in the Department of Radiology and Imaging of BSMMU. After taking all precautionary measures needed for micturating cystourethrogram, each patient was evaluated with this procedure to detect VUR, and different grades of VUR were detected in 31 patients. Thirty-one patients with VUR having past history of UTI were regarded as group A (case) and rest of the 30 patients without VUR were regarded as Group B (control). Measurement of serum creatinine and fasting urinary creatinine by CREA method, serum electrolytes, serum calcium and serum uric acid, fasting urine for calcium and uric acid by colorimetric method from blood and urine sample by standard technique SIEMENS (Dimension RxL Max System) of both groups in the department of Biochemistry, BSMMU. Data analysis was done using the software SPSS 12. For all statistical test, P < 0.05 was considered as statistically significant. Categorical data were presented as frequency with percentage and numerical data were presented as mean with standard deviation (SD). The chi-square test and the Mann–Whitney U test were done for analysis of data where and whenever required.
| Results and Observation | | |
Maximum patients were in the age group 13–60 months followed by >60 months and ≤12 months. Median age of Group A patients was lower than that of Group B patients, and the difference was statistically significant (P < 0.050) [Table 1].
Males were predominant than females in both the groups. There was no significant difference between these two groups (P > 0.050). The male to female ratio was 1:0.32 [Table 2].
Median (min–max) of calcium/creatinine (Ca/Cr) ratio was 0.207 (0.034–0.646) and 0.150 (0.090–0.500) in Group A and Group B, respectively, and the difference between these two groups was statistically significant (P < 0.050). Median (min–max) of uric acid/creatinine (UA/Cr) ratio was 0.972 (0.307–1.951) and 0.616 (0.500–1.390) in Group A and Group B, respectively, and the difference between these two groups was also statistically significant (P < 0.050) [Table 3]. | Table 3: Comparison of urinary Ca/Cr and UA/Cr ratio in both groups (N = 61)
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Hypercalciuria was significantly higher in Group A (20.0%) than in Group B (3.2%; P < 0.050). Similarly, hyperuricosuria was significantly higher in Group A (33.3%) than in Group B (6.5%; P < 0.05). Odds ratio of hypercalciuria was 7.50 (95% confidence interval [CI]: 0.84–66.61). Odds ratio of hyperuricosuria was 7.25 (95% CI: 1.43–36.69) [Table 4].
| Discussion | | |
In this study, the maximum patients were in the age group 13–60 months, followed by >60 months and ≤12 months. Median age of the patients in Group A was 12 months (2–132 months) and that in Group B was 42 months (11–132 months). Median age of Group A patients was lower than that of Group B patients, and the difference was statistically significant (P < 0.050). Mahmoodzadeh et al.[9] revealed that mean age was 41.14 ± 22.1 months and 43.98 ± 16.23 months in the VUR group and the control group, respectively. Their study group consisted of 26 (57.8%) girls and 19 (42.2%) boys. However, in this study, males were predominant than females. The male:female ratio was 1:0.32.
Median of Ca/Cr ratio was 0.207 (0.034–0.646) and 0.150 (0.090–0.500) in Group A and Group B, respectively, and the difference between these two groups was statistically significant (P < 0.05). Median (min–max) of UA/Cr ratio was 0.972 (0.307–1.951) and 0.616 (0.500–1.390) in Group A and Group B, respectively, and the difference between these two groups was statistically significant (P < 0.05). This result is consistent with that of Madani et al.[2] In their study, mean (SD) Ca/Cr and UA/Cr ratios were 0.18 ± 0.09 and 0.35 ± 0.14, respectively, in the control group and 0.31 ± 0.22 and 0.51 ± 0.46, respectively, in the VUR group. Fallahzadeh et al.[10] revealed that 31.3% of their study subjects were hypercalciuric. They also reported that urine Ca/Cr ratio was significantly higher in all the subgroups with one or more of the urinary symptoms (P < 0.001). Badeli et al.[11] concluded in their study that urine calcium excretion is elevated in children with reflux.
Metabolic abnormalities are common in pediatric patients with urinary calculi. Calcium and uric acid abnormalities were the most common, and VUR seemed to be the most common urological abnormality, which led to urinary stasis and calculus formation.[4] García-Nieto et al.[12] reported that the prevalence of hypercalciuria was greater in pediatric patients with VUR than that in the general population. In this study, hypercalciuria was significantly higher in the VUR group (20.0%) than that in the non-VUR group (3.2%). Hyperuricosuria was also significantly higher in the VUR group (33.3%) than that in the non-VUR group (6.5%). Hypercalciuria was more frequently diagnosed in the VUR patients than that in the control group (21.3% vs. 3.6%; P = 0.0001).[2] In this study, the frequency of hyperuricosuria was higher in the VUR group than that in the non-VUR group. This result is consistent with that of Madani et al.[2] Mahmoodzadeh et al.[9] reported that hypercalciuria in the study group and the control group was 20.0% and 15.6%, respectively. Naseri et al.[4] revealed that hypercalciuria and hyperuricosuria were 17.6% and 16.1%, respectively. Mortazavi and Mahbubi[13] found that 64% had a metabolic risk factor including normocalcemic hypercalciuria 42% and hyperuricosuria 10.5%. This study result is consistent with that of the above studies.
Hypercalciuria has been reported as the most common metabolic abnormality in pediatric calculus formation.[4],[14] The relationship between urolithiasis and malformation is not yet clear.[12] Urolithiasis in children is known to be related to congenital anatomic deformities of the genitourinary tract.[12] Urolithiasis in patients with VUR had a metabolic origin.[12] The prevalence of VUR in normal population is <1%.[8] Urolithiasis occurs in only 5% of children with hypercalciuria.[6] The prevalence of VUR in patients with renal stones has been estimated to be between 4.1% and 8.3%.[7],[15] In this study, no child was found with urolithiasis; it may be because the sample size was not so large. Children with UTI having VUR are at higher risk of urolithiasis, so monitoring is needed.
| Conclusion | | |
From this study, it may be concluded that urinary calcium and uric acid excretion are higher in patients with VUR with UTI than in those without VUR with UTI.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Chand DH, Rhoades T, Poe SA, Kraus S, Strife CF Incidence and severity of vesicoureteral reflux in children related to age, gender, race and diagnosis. J Urol 2003;170:1548-50.  |
| 2. | Madani A, Kermani N, Ataei N, Esfahani ST, Hajizadeh N, Khazaeipour Z, et al. Urinary calcium and uric acid excretion in children with vesicoureteral reflux. Pediatr Nephrol 2012;27:95-9. |
| 3. | Milliner DS Urolithiasis. In: Anver ED, Hrmon WE, Niaudet P, Yoshikawa N editors. Pediatric Nephrology, 6th ed. New York: Springer; 2009. p. 1405-30. |
| 4. | Naseri M, Varasteh AR, Alamdaran SA Metabolic factors associated with urinary calculi in children. Iran J Kidney Dis 2010;4:32-8. |
| 5. | Richard EB, Jenson HB, Stanton BF Nelson Textbook of Pediatrics, 18th ed. Philadelphia, PA: Saunders.Kliegman; 2007. |
| 6. | Naseri M, Sadeghi R Role of high-dose hydrochlorothiazide in idiopathic hypercalciuric urolithiasis of childhood. Iran J Kidney Dis 2011;5:162-8. |
| 7. | Noe HN, Stapleton FB, Jerkins GR, Roy S 3rd. Clinical experience with pediatric urolithiasis. J Urol 1983;129:1166-8. |
| 8. | Arant BS Jr. Vesicoureteral reflux and renal injury. Am J Kidney Dis 1991;17:491-511. |
| 9. | Mahmoodzadeh H, Nikibakhsh A, Karamyyar M, Gheibi S, Gholizadeh S, Hooshmand H Idiopathic hypercalciuria in children with vesico ureteral reflux and recurrent urinary tract infection. Urol J 2010;7:95-8. |
| 10. | Fallahzadeh MK, Fallahzadeh MH, Mowla A, Derakhshan A Hypercalciuria in children with urinary tract symptoms. Saudi J Kidney Dis Transpl 2010;21:673-7. |
| 11. | Badeli H, Sadeghi M, Shafe O, Khoshnevis T, Heidarzadeh A Determination and comparison of mean random urine calcium between children with vesicoureteral reflux and those with improved vesicoureteral reflux. Saudi J Kidney Dis Transpl 2011;22:79-82. |
| 12. | García-Nieto V, Siverio B, Monge M, Toledo C, Molini N Urinary calcium excretion in children with vesicoureteral reflux. Nephrol Dial Transplant 2003;18:507-11. |
| 13. | Mortazavi F, Mahbubi L Clinical features and risk factors of pediatric urolithiasis. Iran J Pediatr 2007;17:129-33. |
| 14. | Gillespie RS, Stapleton FB Nephrolithiasis in children. Pediatr Rev 2004;25:131-9. |
| 15. | Ghazali S, Barratt TM, Williams DI Childhood urolithiasis in Britain. Arch Dis Child 1973;48:291-5. |
[Table 1], [Table 2], [Table 3], [Table 4]
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