Water renal management is altered more frequently than albuminuria in children in the G1 stage of the 2012 KDIGO Guideline.

BACKGROUND The G1 stage of chronic kidney disease (CKD) is defined in the 2012 KDIGO Guideline as kidney damage characterized by structural or functional kidney abnormalities without deterioration of glomerular filtration rate. Albuminuria and electrolyte abnormalities due to tubular disorders are considered functional markers of kidney damage. Changes in renal water handling are not explicitly cited in these guidelines. A large sample of children with abnormal dimercaptosuccinic acid (DMSA) scan located in the G1 stage was used in this study. METHODS Ambispective, cross-sectional study to evaluate the clinical histories of 116 pediatric patients. 100 patients were included in the first group (G1 stage) and 16 patients in the G2-G5 stages according to the classification of CKD Guideline KDIGO. All the patients had a renal pathologic DMSA scan. GFR, maximum urine osmolality and albumin/creatinine and NAG/creatinine ratios were determined. RESULTS The patients with normal GFR, in relation to those with reduced GFR, had significantly higher values of maximum urine osmolality and significantly reduced values of urine volume and albumin/creatinine and NAG/creatinine ratios. The most frequently observed alterations in children in the KDIGO G1 stage were those involving the water renal management such as urinary concentrating ability defect (29%) and increased urinary volume (20%). The frequency of children with increased urinary elimination of albumin (12%) and NAG (3%) was more lower. All children in KDIGO G2-G5 stages had alterations in water renal management. CONCLUSIONS The parameters related with the water renal management are affected more frequently than albumin urinary excretion in children who have loss of parenchyma and normal GFR.