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

Search Article 
  
Advanced search 
 
Saudi Journal of Kidney Diseases and Transplantation
Users online: 1727 Home Bookmark this page Print this page Email this page Small font sizeDefault font size Increase font size 
 

Table of Contents   
LETTER TO THE EDITOR  
Year : 2017  |  Volume : 28  |  Issue : 4  |  Page : 945-946
The importance of calciuria on sodium fractional excretion rate


1 Department of Cardiology, Rajaie Cardiovascular Medical and Research Center, University of Medical Sciences, Tehran, Iran
2 Department of Cardiology, Tabriz University of Medical Sciences, Tabriz, Iran
3 Department of Nephrology, Sevome-e-Shaban Hospital, Tehran, Iran

Click here for correspondence address and email

Date of Web Publication21-Jul-2017
 

How to cite this article:
Moradian M, Ghaffari S, Malaki M. The importance of calciuria on sodium fractional excretion rate. Saudi J Kidney Dis Transpl 2017;28:945-6

How to cite this URL:
Moradian M, Ghaffari S, Malaki M. The importance of calciuria on sodium fractional excretion rate. Saudi J Kidney Dis Transpl [serial online] 2017 [cited 2020 May 29];28:945-6. Available from: http://www.sjkdt.org/text.asp?2017/28/4/945/211360


To the Editor,

Fractional excretion of sodium (FENa) is a well-known laboratory marker that can help to differentiate prerenal azotemia from acute tubular necrosis , an FENa of <1% indicating a prerenal cause and value >3% indicating tubular damage.[1]

Urine sodium excretion can be influenced by a phenomenon: calcium affecting on tubular function inducing natriuresis.[2] Hypercalciuria is observed in nearly half of ill children.[3]

In 40 children aged over two years who were admitted to Intensive Care Unit ward we found that FENa higher in hypercalciuric chidren (urine calcium/creatinine >0.2) than in children with normal calcium excretion (1.9 ± 2.1 vs. 0.8 ± 0.7 (P 0.03) [Table 1]. FENa is prominently higher if hypercalciuria occurs in normal hydration and with normal GFR compared to that seen in dehydrated children or those with reduced GFR (defined as <75 mL/ min/1.73 m2)[4] [Table 1]. There is also a linear correlation between urine calcium excretion and FENa (R2: 0.2, P 0.007) [Figure 1]. Earlier in 1985, FENa as a diagnostic tool has been questioned in especial clinical conditions by Zarich et al[5] after then Adami[2] explained physiologically that calcium excretion can affect sodium excretion rate if calcium sensing receptor on renal tubules are activated to inhibit both calcium and sodium reabsorption. They found that hypercalcemia leads to natriuresis and volume depletion. They also found that severe hypercalcemia and volume contraction can trigger more calcium reabsorbtion aggravating the hypercalcemia. Kovacevic et al[6] found that sodium and phosphate excretion lead to hypercalciuria. Adami[2] and Kovacevic et al[6] show that calcium can induce natriuresis and sodium can also induce hypercalciuria. Our result show these mechanisms can be activated in normal glomerular filtration rate (GFR) situations (GFR >75 mL/min/ 1.73 m2.
Table 1: Sodium fractional excretion of sodium in two groups of normal calcium excretion and hypercalciuria groups in different conditions.

Click here to view
Figure 1: Relation of fractional excretion of sodium and urine calcium (calcium/creatinine randomly).

Click here to view


Hypercalciuria is a common finding in ill immobilized children and has strongly related to FENa , this effect being more prominent in normal GFR; There is also a linear relationship between urine calcium excretion level and FENa. Thus, FENa is not a reliable laboratory test to detect and differentiate renal tubular function in conditions of hypercalciuria.


   Acknowledgement Top


We dedicate this study to our leader Dr. Mohammad Mosadegh, god bless his soul.

Conflict of interest: None declared.



 
   References Top

1.
Espinel CH. The FENa test. Use in the differential diagnosis of acute renal failure. JAMA 1976;236:579-81.  Back to cited text no. 1
[PUBMED]    
2.
Adami S, Parfitt AM. Calcium-induced natriuresis: Physiologic and clinical implications. Calcif Tissue Int 2000;66:425-9.  Back to cited text no. 2
[PUBMED]    
3.
Malaki M. Renal leak; mechanism of hypercalciuria in short-term immobilization. Int J Crit Illn Inj Sci 2015;5:216-7.  Back to cited text no. 3
[PUBMED]  [Full text]  
4.
Pottel H, Hoste L, Delanaye P. Abnormal glomerular filtration rate in children, adolescents and young adults starts below 75 mL/min/1.73 m2. J Int Pediatr Nephrol Assoc 2015;30:821-8.  Back to cited text no. 4
[PUBMED]    
5.
Zarich S, Fang LS, Diamond JR. Fractional excretion of sodium. Exceptions to its diagnostic value. Arch Intern Med 1985;145:108-12.  Back to cited text no. 5
[PUBMED]    
6.
Kovacevic L, Kovacevic S, Smoljanic Z, et al. Renal tubular function in children with hypercalciuria. Srp Arh Celok Lek 1998;126:223-7.  Back to cited text no. 6
    

Top
Correspondence Address:
Majid Malaki
Department of Nephrology, Sevome-e-Shaban Hospital, Tehran
Iran
Login to access the Email id


PMID: 28748905

Rights and Permissions


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1]



 

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


 
   Acknowledgement
    References
    Article Figures
    Article Tables
 

 Article Access Statistics
    Viewed1260    
    Printed7    
    Emailed0    
    PDF Downloaded146    
    Comments [Add]    

Recommend this journal