Renal tubular function and urinary N-acetyl-β-d-glucosaminidase and kidney injury molecule-1 levels in asthmatic children.
BACKGROUND
Asthma is a chronic inflammatory disorder of the airways which results in chronic hypoxia. Chronic hypoxia and inflammation can affect renal tubular function.


OBJECTIVE
The aim of this study was to investigate renal tubular function and early kidney injury molecules such as urinary N-acetyl-betaglucosaminidase (NAG) and kidney injury molecule-1 (KIM-1) excretion in children with asthma.


METHODS
Enrolled in the study were 73 children diagnosed with asthma and 65 healthy age- and gender-matched control subjects. Urine pH, sodium, phosphorus, potassium, microalbumin, creatinine, NAG, KIM-1, and serum creatinine, sodium, phosphorus were evaluated. The diagnosis of asthma and classification of mild or moderate were done according to the Global Initiative for Asthma guidelines.


RESULTS
Serum sodium, phosphorus, creatinine, and urinary microalbumin were within normal levels in the both groups. Urinary pH, sodium, potassium, phosphorus, microalbumin, and KIM-1 excretions were similar between the control and study groups. Tubular phosphorus reabsorption was within normal limits in two groups. Urine NAG was elevated in the study group (P = 0.001). Urinary KIM-1 and NAG levels were positively correlated (r = 0.837; P = 0.001). When children with mild and moderate asthma were compared, all of the parameters were similar (P >0.05).


CONCLUSIONS
This study showed that chronic asthma can lead to subtle renal impacts. We suggest that in children with asthma, urinary NAG level is a more valuable parameter to show degree of renal tubular injury than markers such as microalbumin and KIM-1. Chronic hypoxy and inflammation probably contributes to these subclinical renal effects.
Bezmialem Vakif University, Faculty of Medicine, Department of Pediatrics, Istanbul, Turkey ayseguldogandemir@gmail.com.
Ayşegül Doğan
AD
Demir
Bezmialem Vakif University, Faculty of Medicine, Department of Pediatric Nephrology, Istanbul, Turkey.
Nilufer
N
Goknar
Bezmialem Vakif University, Faculty of Medicine, Department of Pediatric Nephrology, Istanbul, Turkey.
Faruk
F
Oktem
Bezmialem Vakif University, Faculty of Medicine, Department of Pediatric Allergy, Istanbul, Turkey.
Emin
E
Özkaya
Bezmialem Vakif University, Faculty of Medicine, Department of Pediatric Allergy, Istanbul, Turkey.
Mebrure
M
Yazıcı
Bezmialem Vakif University, Faculty of Medicine, Department of Pediatrics, Istanbul, Turkey.
Emel
E
Torun
Bezmialem Vakif University, Faculty of Medicine, Department of Pediatrics, Istanbul, Turkey.
Aysel
A
Vehapoğlu
Bezmialem Vakif University, Faculty of Medicine, Department of Pediatrics, Istanbul, Turkey.
Mehmet
M
Kucukkoc
D000118:Acetylglucosaminidase / Q000652:urine*; D000418:Albumins / Q000378:metabolism; D001249:Asthma / Q000097:blood / Q000378:metabolism / Q000503:physiopathology* / Q000652:urine*; D015415:Biomarkers / Q000097:blood / Q000378:metabolism / Q000652:urine; D016022:Case-Control Studies; D002648:Child; D003404:Creatinine / Q000097:blood; D005260:Female; D000072596:Hepatitis A Virus Cellular Receptor 1 / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007674:Kidney Diseases / Q000097:blood / Q000378:metabolism / Q000503:physiopathology / Q000652:urine*; D007684:Kidney Tubules / Q000378:metabolism* / Q000503:physiopathology*; D008297:Male; D010758:Phosphorus / Q000097:blood / Q000652:urine; D011188:Potassium / Q000652:urine; D012964:Sodium / Q000097:blood / Q000652:urine
D000418:Albumins; D015415:Biomarkers; C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; D010758:Phosphorus; D012964:Sodium; D003404:Creatinine; D000118:Acetylglucosaminidase; D011188:Potassium
N-acetyl-betaglucosaminidase (NAG); asthma; inflammation; injury; kidney injury molecule-1 (KIM-1); tubulus