Novel Kidney Injury Biomarker Detected Subclinical Renal Injury in Severely Obese Adolescents with Normal Kidney Function
Year: 2014
Type: article
Study design: Observational Study
Abstract: Background: Obesity is an independent risk factor for kidney injury.It is associated with albuminuria, hyperfiltration and progression of chronic kidney disease (CKD).Obesity-related kidney damage may occur long before detectable microalbuminuria or obvious change in glomerular filtration rate.Due to limitation of the current kidney function markers, detection of early kidney injury has been delayed in obese children.One sensitive and specific urinary biomarker, neutrophil gelatinase-associated lipocalin (NGAL) has been identified during the last decade for early risk prediction of kidney injury.We hypothesize that urinary NGAL is elevated in severely obese youth, representing existence of consistent kidney injuries.Objective: To investigate subclinical kidney injury in severely obese adolescents, using novel urinary biomarker, NGAL.Design/ Methods: This was a pilot, prospective study of severely obese adolescents who had no microalbuminuria or decreased estimated glomerular filtrating rate (eGFR) at baseline, and after surgical weight loss.Urinary NGAL were measured in the obese cohort at baseline, 6 and 12 months post-operatively and in a local general pediatric population.Regression analysis was conducted to confirm the association between elevated NGAL levels and obesity status.T test and ANOVA was performed for comparison of variables.Results: The severely obese cohort (n=18) had a mean baseline BMI of 47.76 kg/m 2 .The controls (n=161) were younger (median age 5.1 years vs. 16.2 years, p < 0.00001) with more males (52% vs. 28%) in comparison to the obese cohort.Urine NGAL was significantly elevated in obese children compared to controls at baseline.Multivariate analysis showed that only obesity status was significantly associated with elevated urine NGAL levels.At 1 year postoperative follow-up, BMI in the bariatric participates decreased by 32% (p<0.001).The obese cohort had a further increase in urine NGAL at 6 months, followed by decline at 1 year.The overall change in NGAL levels through 1 year after bariatric surgery, however, was not significant.Conclusions: Our preliminary data indicates that severe obesity is associated with increased urinary excretion of NGAL in adolescents with normal kidney function, representing clinically silent but persistent structural and inflammatory kidney injury.Our findings suggest that aggressive weight controls should be considered in severely obese adolescents from kidney protection standpoint even without obvious kidney dysfunction.In addition, close long-term follow up of kidney status is warranted in this population.
Author: Nianzhou Xiao
Institution: University of Cincinnati
Language: English
Subfield: Nephrology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2734910816